metabotropic glutamate receptor 2 isoform X3 [Homo sapiens]
Protein Classification
G-protein coupled receptor( domain architecture ID 11659922)
G-protein coupled receptor (GPCR) transmits physiological signals from the outside of the cell to the inside by binding to an extracellular agonist, which induces conformational changes that lead to the activation of heterotrimeric G proteins, which then bind to and activate numerous downstream effector proteins
List of domain hits
| Name | Accession | Description | Interval | E-value | |||||||
| 7tm_GPCRs super family | cl28897 | seven-transmembrane G protein-coupled receptor superfamily; This hierarchical evolutionary ... |
384-637 | 2.11e-171 | |||||||
seven-transmembrane G protein-coupled receptor superfamily; This hierarchical evolutionary model represents the seven-transmembrane (7TM) receptors, often referred to as G protein-coupled receptors (GPCRs), which transmit physiological signals from the outside of the cell to the inside via G proteins. GPCRs constitute the largest known superfamily of transmembrane receptors across the three kingdoms of life that respond to a wide variety of extracellular stimuli including peptides, lipids, neurotransmitters, amino acids, hormones, and sensory stimuli such as light, smell and taste. All GPCRs share a common structural architecture comprising of seven-transmembrane (TM) alpha-helices interconnected by three extracellular and three intracellular loops. A general feature of GPCR signaling is agonist-induced conformational changes in the receptors, leading to activation of the heterotrimeric G proteins, which consist of the guanine nucleotide-binding G-alpha subunit and the dimeric G-beta-gamma subunits. The activated G proteins then bind to and activate numerous downstream effector proteins, which generate second messengers that mediate a broad range of cellular and physiological processes. However, some 7TM receptors, such as the type 1 microbial rhodopsins, do not activate G proteins. Based on sequence similarity, GPCRs can be divided into six major classes: class A (the rhodopsin-like family), class B (the Methuselah-like, adhesion and secretin-like receptor family), class C (the metabotropic glutamate receptor family), class D (the fungal mating pheromone receptors), class E (the cAMP receptor family), and class F (the frizzled/smoothened receptor family). Nearly 800 human GPCR genes have been identified and are involved essentially in all major physiological processes. Approximately 40% of clinically marketed drugs mediate their effects through modulation of GPCR function for the treatment of a variety of human diseases including bacterial infections. The actual alignment was detected with superfamily member cd15447: Pssm-ID: 475119 Cd Length: 254 Bit Score: 490.21 E-value: 2.11e-171
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| Periplasmic_Binding_Protein_type1 super family | cl10011 | Type 1 periplasmic binding fold superfamily; Type 1 periplasmic binding fold superfamily. This ... |
26-298 | 6.48e-153 | |||||||
Type 1 periplasmic binding fold superfamily; Type 1 periplasmic binding fold superfamily. This model and hierarchy represent the ligand binding domains of the LacI family of transcriptional regulators, periplasmic binding proteins of the ABC-type transport systems, the family C G-protein couples receptors (GPCRs), membrane bound guanylyl cyclases including the family of natriuretic peptide receptors (NPRs), and the N-terminal leucine-isoleucine-valine binding protein (LIVBP)-like domains of the ionotropic glutamate receptors (iGluRs). In LacI-like transcriptional regulator and the bacterial periplasmic binding proteins, the ligands are monosaccharides, including lactose, ribose, fructose, xylose, arabinose, galactose/glucose and other sugars, with a few exceptions. Periplasmic sugar binding proteins are one of the components of ABC transporters and are involved in the active transport of water-soluble ligands. The LacI family of proteins consists of transcriptional regulators related to the lac repressor. In this case, the sugar binding domain binds a sugar which changes the DNA binding activity of the repressor domain. The periplasmic binding proteins are the primary receptors for chemotaxis and transport of many sugar based solutes. The core structures of periplasmic binding proteins are classified into two types, and they differ in number and order of beta strands: type 1 has six beta strands while type 2 has five beta strands per sub-domain. These two structural folds are thought to be distantly related via a common ancestor. Notably, while the N-terminal LIVBP-like domain of iGluRs belongs to the type 1 periplasmic-binding fold protein superfamily, the glutamate-binding domain of the iGluR is structurally similar to the type 2 periplasmic-binding fold. The actual alignment was detected with superfamily member cd06375: Pssm-ID: 471960 [Multi-domain] Cd Length: 462 Bit Score: 450.81 E-value: 6.48e-153
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| NCD3G | pfam07562 | Nine Cysteines Domain of family 3 GPCR; This conserved sequence contains several ... |
314-364 | 1.39e-14 | |||||||
Nine Cysteines Domain of family 3 GPCR; This conserved sequence contains several highly-conserved Cys residues that are predicted to form disulphide bridges. It is predicted to lie outside the cell membrane, tethered to the pfam00003 in several receptor proteins. : Pssm-ID: 462210 Cd Length: 53 Bit Score: 68.43 E-value: 1.39e-14
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| Name | Accession | Description | Interval | E-value | |||||||
| 7tmC_mGluR2 | cd15447 | metabotropic glutamate receptor 2 in group 2, member of the class C family of ... |
384-637 | 2.11e-171 | |||||||
metabotropic glutamate receptor 2 in group 2, member of the class C family of seven-transmembrane G protein-coupled receptors; The metabotropic glutamate receptors (mGluRs) in group 2 include mGluR 2 and 3. They are homodimeric class C G-protein coupled receptors which are activated by glutamate, the major excitatory neurotransmitter of the CNS. mGluRs are involved in regulating neuronal excitability and synaptic transmission via intracellular activation of second messenger signaling pathways. While the ionotropic glutamate receptor subtypes (AMPA, NMDA, and kainite) mediate fast excitatory postsynaptic transmission, mGluRs are known to mediate slower excitatory postsynaptic responses and to be involved in synaptic plasticity in the mammalian brain. In addition to seven-transmembrane helices, the class C GPCRs are characterized by a large N-terminal extracellular Venus flytrap-like domain, which is composed of two adjacent lobes separated by a cleft which binds an endogenous ligand. Moreover, they exist as either homo- or heterodimers, which are essential for their function. For instance, mGluRs form homodimers via interactions between the N-terminal Venus flytrap domains and the intermolecular disulphide bonds between cysteine residues located in the cysteine-rich domain (CRD). At least eight different subtypes of metabotropic receptors (mGluR1-8) have been identified and further classified into three groups based on their sequence homology, pharmacological properties, and signaling pathways. Group 1 (mGluR1 and mGluR5) receptors are predominantly located postsynaptically on neurons and are involved in long-term synaptic plasticity in the brain, including long-term potentiation (LTP) in the hippocampus and long-term depression (LTD) in the cerebellum. They are coupled to G(q/11) proteins, thereby activating phospholipase C to generate inositol-1,4,5-triphosphate (IP3) and diacyglycerol (DAG), which in turn lead to Ca2+ release and protein kinase C activation, respectively. Group 1 mGluR expression is shown to be strongly upregulated in animal models of epilepsy, brain injury, inflammatory, and neuropathic pain, as well as in patients with amyotrophic lateral sclerosis or multiple sclerosis. Group 2 (mGluR2 and mGluR3) and 3 (mGluR4, mGluR6, mGluR7, and mGluR8) receptors are predominantly localized presynaptically in the active region of neurotransmitter release. They are coupled to G(i/o) proteins, which leads to inhibition of adenylate cyclase activity and cAMP formation, and consequently to a decrease in protein kinase A (PKA) activity. Ultimately, activation of these receptors leads to inhibition of neurotransmitter release such as glutamate and GABA via inhibition of Ca2+ channels and activation of K+ channels. Furthermore, while activation of Group 1 mGluRs increases NMDA (N-methyl-D-aspartate) receptor activity and risk of neurotoxicity, Group 2 and 3 mGluRs decrease NMDA receptor activity and prevent neurotoxicity. Pssm-ID: 320563 Cd Length: 254 Bit Score: 490.21 E-value: 2.11e-171
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| PBP1_mGluR_groupII | cd06375 | ligand binding domain of the group II metabotropic glutamate receptor; Ligand binding domain ... |
26-298 | 6.48e-153 | |||||||
ligand binding domain of the group II metabotropic glutamate receptor; Ligand binding domain of the group II metabotropic glutamate receptor, a family that contains mGlu2R and mGlu3R, all of which inhibit adenylyl cyclase. The metabotropic glutamate receptor is a member of the family C of G-protein-coupled receptors that transduce extracellular signals into G-protein activation and ultimately into intracellular responses. The mGluRs are classified into three groups which comprise eight subtypes Pssm-ID: 380598 [Multi-domain] Cd Length: 462 Bit Score: 450.81 E-value: 6.48e-153
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| 7tm_3 | pfam00003 | 7 transmembrane sweet-taste receptor of 3 GCPR; This is a domain of seven transmembrane ... |
379-631 | 1.15e-71 | |||||||
7 transmembrane sweet-taste receptor of 3 GCPR; This is a domain of seven transmembrane regions that forms the C-terminus of some subclass 3 G-coupled-protein receptors. It is often associated with a downstream cysteine-rich linker domain, NCD3G pfam07562, which is the human sweet-taste receptor, and the N-terminal domain, ANF_receptor pfam01094. The seven TM regions assemble in such a way as to produce a docking pocket into which such molecules as cyclamate and lactisole have been found to bind and consequently confer the taste of sweetness. Pssm-ID: 459626 [Multi-domain] Cd Length: 247 Bit Score: 232.94 E-value: 1.15e-71
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| NCD3G | pfam07562 | Nine Cysteines Domain of family 3 GPCR; This conserved sequence contains several ... |
314-364 | 1.39e-14 | |||||||
Nine Cysteines Domain of family 3 GPCR; This conserved sequence contains several highly-conserved Cys residues that are predicted to form disulphide bridges. It is predicted to lie outside the cell membrane, tethered to the pfam00003 in several receptor proteins. Pssm-ID: 462210 Cd Length: 53 Bit Score: 68.43 E-value: 1.39e-14
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| ANF_receptor | pfam01094 | Receptor family ligand binding region; This family includes extracellular ligand binding ... |
60-276 | 3.37e-14 | |||||||
Receptor family ligand binding region; This family includes extracellular ligand binding domains of a wide range of receptors. This family also includes the bacterial amino acid binding proteins of known structure. Pssm-ID: 460062 [Multi-domain] Cd Length: 347 Bit Score: 74.34 E-value: 3.37e-14
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| Name | Accession | Description | Interval | E-value | ||||||||
| 7tmC_mGluR2 | cd15447 | metabotropic glutamate receptor 2 in group 2, member of the class C family of ... |
384-637 | 2.11e-171 | ||||||||
metabotropic glutamate receptor 2 in group 2, member of the class C family of seven-transmembrane G protein-coupled receptors; The metabotropic glutamate receptors (mGluRs) in group 2 include mGluR 2 and 3. They are homodimeric class C G-protein coupled receptors which are activated by glutamate, the major excitatory neurotransmitter of the CNS. mGluRs are involved in regulating neuronal excitability and synaptic transmission via intracellular activation of second messenger signaling pathways. While the ionotropic glutamate receptor subtypes (AMPA, NMDA, and kainite) mediate fast excitatory postsynaptic transmission, mGluRs are known to mediate slower excitatory postsynaptic responses and to be involved in synaptic plasticity in the mammalian brain. In addition to seven-transmembrane helices, the class C GPCRs are characterized by a large N-terminal extracellular Venus flytrap-like domain, which is composed of two adjacent lobes separated by a cleft which binds an endogenous ligand. Moreover, they exist as either homo- or heterodimers, which are essential for their function. For instance, mGluRs form homodimers via interactions between the N-terminal Venus flytrap domains and the intermolecular disulphide bonds between cysteine residues located in the cysteine-rich domain (CRD). At least eight different subtypes of metabotropic receptors (mGluR1-8) have been identified and further classified into three groups based on their sequence homology, pharmacological properties, and signaling pathways. Group 1 (mGluR1 and mGluR5) receptors are predominantly located postsynaptically on neurons and are involved in long-term synaptic plasticity in the brain, including long-term potentiation (LTP) in the hippocampus and long-term depression (LTD) in the cerebellum. They are coupled to G(q/11) proteins, thereby activating phospholipase C to generate inositol-1,4,5-triphosphate (IP3) and diacyglycerol (DAG), which in turn lead to Ca2+ release and protein kinase C activation, respectively. Group 1 mGluR expression is shown to be strongly upregulated in animal models of epilepsy, brain injury, inflammatory, and neuropathic pain, as well as in patients with amyotrophic lateral sclerosis or multiple sclerosis. Group 2 (mGluR2 and mGluR3) and 3 (mGluR4, mGluR6, mGluR7, and mGluR8) receptors are predominantly localized presynaptically in the active region of neurotransmitter release. They are coupled to G(i/o) proteins, which leads to inhibition of adenylate cyclase activity and cAMP formation, and consequently to a decrease in protein kinase A (PKA) activity. Ultimately, activation of these receptors leads to inhibition of neurotransmitter release such as glutamate and GABA via inhibition of Ca2+ channels and activation of K+ channels. Furthermore, while activation of Group 1 mGluRs increases NMDA (N-methyl-D-aspartate) receptor activity and risk of neurotoxicity, Group 2 and 3 mGluRs decrease NMDA receptor activity and prevent neurotoxicity. Pssm-ID: 320563 Cd Length: 254 Bit Score: 490.21 E-value: 2.11e-171
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| 7tmC_mGluR_group2 | cd15284 | metabotropic glutamate receptors in group 2, member of the class C family of ... |
384-637 | 1.93e-165 | ||||||||
metabotropic glutamate receptors in group 2, member of the class C family of seven-transmembrane G protein-coupled receptors; The metabotropic glutamate receptors (mGluRs) in group 2 include mGluR 2 and 3. They are homodimeric class C G-protein coupled receptors which are activated by glutamate, the major excitatory neurotransmitter of the CNS. mGluRs are involved in regulating neuronal excitability and synaptic transmission via intracellular activation of second messenger signaling pathways. While the ionotropic glutamate receptor subtypes (AMPA, NMDA, and kainite) mediate fast excitatory postsynaptic transmission, mGluRs are known to mediate slower excitatory postsynaptic responses and to be involved in synaptic plasticity in the mammalian brain. In addition to seven-transmembrane helices, the class C GPCRs are characterized by a large N-terminal extracellular Venus flytrap-like domain, which is composed of two adjacent lobes separated by a cleft which binds an endogenous ligand. Moreover, they exist as either homo- or heterodimers, which are essential for their function. For instance, mGluRs form homodimers via interactions between the N-terminal Venus flytrap domains and the intermolecular disulphide bonds between cysteine residues located in the cysteine-rich domain (CRD). At least eight different subtypes of metabotropic receptors (mGluR1-8) have been identified and further classified into three groups based on their sequence homology, pharmacological properties, and signaling pathways. Group 1 (mGluR1 and mGluR5) receptors are predominantly located postsynaptically on neurons and are involved in long-term synaptic plasticity in the brain, including long-term potentiation (LTP) in the hippocampus and long-term depression (LTD) in the cerebellum. They are coupled to G(q/11) proteins, thereby activating phospholipase C to generate inositol-1,4,5-triphosphate (IP3) and diacyglycerol (DAG), which in turn lead to Ca2+ release and protein kinase C activation, respectively. Group 1 mGluR expression is shown to be strongly upregulated in animal models of epilepsy, brain injury, inflammatory, and neuropathic pain, as well as in patients with amyotrophic lateral sclerosis or multiple sclerosis. Group 2 (mGluR2 and mGluR3) and 3 (mGluR4, mGluR6, mGluR7, and mGluR8) receptors are predominantly localized presynaptically in the active region of neurotransmitter release. They are coupled to G(i/o) proteins, which leads to inhibition of adenylate cyclase activity and cAMP formation, and consequently to a decrease in protein kinase A (PKA) activity. Ultimately, activation of these receptors leads to inhibition of neurotransmitter release such as glutamate and GABA via inhibition of Ca2+ channels and activation of K+ channels. Furthermore, while activation of Group 1 mGluRs increases NMDA (N-methyl-D-aspartate) receptor activity and risk of neurotoxicity, Group 2 and 3 mGluRs decrease NMDA receptor activity and prevent neurotoxicity. Pssm-ID: 320411 Cd Length: 254 Bit Score: 474.72 E-value: 1.93e-165
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| PBP1_mGluR_groupII | cd06375 | ligand binding domain of the group II metabotropic glutamate receptor; Ligand binding domain ... |
26-298 | 6.48e-153 | ||||||||
ligand binding domain of the group II metabotropic glutamate receptor; Ligand binding domain of the group II metabotropic glutamate receptor, a family that contains mGlu2R and mGlu3R, all of which inhibit adenylyl cyclase. The metabotropic glutamate receptor is a member of the family C of G-protein-coupled receptors that transduce extracellular signals into G-protein activation and ultimately into intracellular responses. The mGluRs are classified into three groups which comprise eight subtypes Pssm-ID: 380598 [Multi-domain] Cd Length: 462 Bit Score: 450.81 E-value: 6.48e-153
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| 7tmC_mGluRs_group2_3 | cd15934 | metabotropic glutamate receptors in group 2 and 3, member of the class C family of ... |
384-637 | 2.43e-152 | ||||||||
metabotropic glutamate receptors in group 2 and 3, member of the class C family of seven-transmembrane G protein-coupled receptors; The metabotropic glutamate receptors (mGluRs) are homodimeric class C G-protein coupled receptors which are activated by glutamate, the major excitatory neurotransmitter of the CNS. The mGluRs are involved in regulating neuronal excitability and synaptic transmission via intracellular activation of second messenger signaling pathways. While the ionotropic glutamate receptor subtypes (AMPA, NMDA, and kainite) mediate fast excitatory postsynaptic transmission, mGluRs are known to mediate slower excitatory postsynaptic responses and to be involved in synaptic plasticity in the mammalian brain. In addition to seven-transmembrane helices, the class C GPCRs are characterized by a large N-terminal extracellular Venus flytrap-like domain, which is composed of two adjacent lobes separated by a cleft which binds an endogenous ligand. Moreover, they exist as either homo- or heterodimers, which are essential for their function. For instance, mGluRs form homodimers via interactions between the N-terminal Venus flytrap domains and the intermolecular disulphide bonds between cysteine residues located in the cysteine-rich domain (CRD). At least eight different subtypes of metabotropic receptors (mGluR1-8) have been identified and further classified into three groups based on their sequence homology, pharmacological properties, and signaling pathways. Group 1 (mGluR1 and mGluR5) receptors are predominantly located postsynaptically on neurons and are involved in long-term synaptic plasticity in the brain, including long-term potentiation (LTP) in the hippocampus and long-term depression (LTD) in the cerebellum. They are coupled to G(q/11) proteins, thereby activating phospholipase C to generate inositol-1,4,5-triphosphate (IP3) and diacyglycerol (DAG), which in turn lead to Ca2+ release and protein kinase C activation, respectively. Group I mGluR expression is shown to be strongly upregulated in animal models of epilepsy, brain injury, inflammatory, and neuropathic pain, as well as in patients with amyotrophic lateral sclerosis or multiple sclerosis. Group 2 (mGluR2 and mGluR3) and 3 (mGluR4, mGluR6, mGluR7, and mGluR8) receptors are predominantly localized presynaptically in the active region of neurotransmitter release. They are coupled to (Gi/o) proteins, which leads to inhibition of adenylate cyclase activity and cAMP formation, and consequently to a decrease in protein kinase A (PKA) activity. Ultimately, activation of these receptors leads to inhibition of neurotransmitter release such as glutamate and GABA via inhibition of Ca2+ channels and activation of K+ channels. Furthermore, while activation of Group 1 mGluRs increases NMDA (N-methyl-D-aspartate) receptor activity and risk of neurotoxicity, Group 2 and 3 mGluRs decrease NMDA receptor activity and prevent neurotoxicity. Pssm-ID: 320600 Cd Length: 252 Bit Score: 441.28 E-value: 2.43e-152
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| 7tmC_mGluR3 | cd15448 | metabotropic glutamate receptor 3 in group 2, member of the class C family of ... |
384-637 | 4.54e-142 | ||||||||
metabotropic glutamate receptor 3 in group 2, member of the class C family of seven-transmembrane G protein-coupled receptors; The metabotropic glutamate receptors (mGluRs) in group 2 include mGluR 2 and 3. They are homodimeric class C G-protein coupled receptors which are activated by glutamate, the major excitatory neurotransmitter of the CNS. mGluRs are involved in regulating neuronal excitability and synaptic transmission via intracellular activation of second messenger signaling pathways. While the ionotropic glutamate receptor subtypes (AMPA, NMDA, and kainite) mediate fast excitatory postsynaptic transmission, mGluRs are known to mediate slower excitatory postsynaptic responses and to be involved in synaptic plasticity in the mammalian brain. In addition to seven-transmembrane helices, the class C GPCRs are characterized by a large N-terminal extracellular Venus flytrap-like domain, which is composed of two adjacent lobes separated by a cleft which binds an endogenous ligand. Moreover, they exist as either homo- or heterodimers, which are essential for their function. For instance, mGluRs form homodimers via interactions between the N-terminal Venus flytrap domains and the intermolecular disulphide bonds between cysteine residues located in the cysteine-rich domain (CRD). At least eight different subtypes of metabotropic receptors (mGluR1-8) have been identified and further classified into three groups based on their sequence homology, pharmacological properties, and signaling pathways. Group 1 (mGluR1 and mGluR5) receptors are predominantly located postsynaptically on neurons and are involved in long-term synaptic plasticity in the brain, including long-term potentiation (LTP) in the hippocampus and long-term depression (LTD) in the cerebellum. They are coupled to G(q/11) proteins, thereby activating phospholipase C to generate inositol-1,4,5-triphosphate (IP3) and diacyglycerol (DAG), which in turn lead to Ca2+ release and protein kinase C activation, respectively. Group 1 mGluR expression is shown to be strongly upregulated in animal models of epilepsy, brain injury, inflammatory, and neuropathic pain, as well as in patients with amyotrophic lateral sclerosis or multiple sclerosis. Group 2 (mGluR2 and mGluR3) and 3 (mGluR4, mGluR6, mGluR7, and mGluR8) receptors are predominantly localized presynaptically in the active region of neurotransmitter release. They are coupled to G(i/o) proteins, which leads to inhibition of adenylate cyclase activity and cAMP formation, and consequently to a decrease in protein kinase A (PKA) activity. Ultimately, activation of these receptors leads to inhibition of neurotransmitter release such as glutamate and GABA via inhibition of Ca2+ channels and activation of K+ channels. Furthermore, while activation of Group 1 mGluRs increases NMDA (N-methyl-D-aspartate) receptor activity and risk of neurotoxicity, Group 2 and 3 mGluRs decrease NMDA receptor activity and prevent neurotoxicity. Pssm-ID: 320564 Cd Length: 254 Bit Score: 415.12 E-value: 4.54e-142
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| 7tmC_mGluRs | cd15045 | metabotropic glutamate receptors, member of the class C family of seven-transmembrane G ... |
384-637 | 4.55e-126 | ||||||||
metabotropic glutamate receptors, member of the class C family of seven-transmembrane G protein-coupled receptors; The metabotropic glutamate receptors (mGluRs) are homodimeric class C G-protein coupled receptors which are activated by glutamate, the major excitatory neurotransmitter of the CNS. mGluRs are involved in regulating neuronal excitability and synaptic transmission via intracellular activation of second messenger signaling pathways. While the ionotropic glutamate receptor subtypes (AMPA, NMDA, and kainite) mediate fast excitatory postsynaptic transmission, mGluRs are known to mediate slower excitatory postsynaptic responses and to be involved in synaptic plasticity in the mammalian brain. In addition to seven-transmembrane helices, the class C GPCRs are characterized by a large N-terminal extracellular Venus flytrap-like domain, which is composed of two adjacent lobes separated by a cleft which binds an endogenous ligand. Moreover, they exist as either homo- or heterodimers, which are essential for their function. For instance, mGluRs form homodimers via interactions between the N-terminal Venus flytrap domains and the intermolecular disulphide bonds between cysteine residues located in the cysteine-rich domain (CRD). At least eight different subtypes of metabotropic receptors (mGluR1-8) have been identified and further classified into three groups based on their sequence homology, pharmacological properties, and signaling pathways. Group 1 (mGluR1 and mGluR5) receptors are predominantly located postsynaptically on neurons and are involved in long-term synaptic plasticity in the brain, including long-term potentiation (LTP) in the hippocampus and long-term depression (LTD) in the cerebellum. They are coupled to G(q/11) proteins, thereby activating phospholipase C to generate inositol-1,4,5-triphosphate (IP3) and diacyglycerol (DAG), which in turn lead to Ca2+ release and protein kinase C activation, respectively. Group I mGluR expression is shown to be strongly upregulated in animal models of epilepsy, brain injury, inflammatory, and neuropathic pain, as well as in patients with amyotrophic lateral sclerosis or multiple sclerosis. Group 2 (mGluR2 and mGluR3) and 3 (mGluR4, mGluR6, mGluR7, and mGluR8) receptors are predominantly localized presynaptically in the active region of neurotransmitter release. They are coupled to (Gi/o) proteins, which leads to inhibition of adenylate cyclase activity and cAMP formation, and consequently to a decrease in protein kinase A (PKA) activity. Ultimately, activation of these receptors leads to inhibition of neurotransmitter release such as glutamate and GABA via inhibition of Ca2+ channels and activation of K+ channels. Furthermore, while activation of Group 1 mGluRs increases NMDA (N-methyl-D-aspartate) receptor activity and risk of neurotoxicity, Group 2 and 3 mGluRs decrease NMDA receptor activity and prevent neurotoxicity. Pssm-ID: 320173 [Multi-domain] Cd Length: 253 Bit Score: 373.89 E-value: 4.55e-126
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| 7tmC_mGluR_group1 | cd15285 | metabotropic glutamate receptors in group 1, member of the class C family of ... |
384-637 | 1.85e-105 | ||||||||
metabotropic glutamate receptors in group 1, member of the class C family of seven-transmembrane G protein-coupled receptors; Group 1 mGluRs includes mGluR1 and mGluR5, as well as their closely related invertebrate receptors. They are homodimeric class C G-protein coupled receptors which are activated by glutamate, the major excitatory neurotransmitter of the CNS. mGluRs are involved in regulating neuronal excitability and synaptic transmission via intracellular activation of second messenger signaling pathways. While the ionotropic glutamate receptor subtypes (AMPA, NMDA, and kainite) mediate fast excitatory postsynaptic transmission, mGluRs are known to mediate slower excitatory postsynaptic responses and to be involved in synaptic plasticity in the mammalian brain. In addition to seven-transmembrane helices, the class C GPCRs are characterized by a large N-terminal extracellular Venus flytrap-like domain, which is composed of two adjacent lobes separated by a cleft which binds an endogenous ligand. Moreover, they exist as either homo- or heterodimers, which are essential for their function. For instance, mGluRs form homodimers via interactions between the N-terminal Venus flytrap domains and the intermolecular disulphide bonds between cysteine residues located in the cysteine-rich domain (CRD). At least eight different subtypes of metabotropic receptors (mGluR1-8) have been identified and further classified into three groups based on their sequence homology, pharmacological properties, and signaling pathways. Group 1 (mGluR1 and mGluR5) receptors are predominantly located postsynaptically on neurons and are involved in long-term synaptic plasticity in the brain, including long-term potentiation (LTP) in the hippocampus and long-term depression (LTD) in the cerebellum. They are coupled to G(q/11) proteins, thereby activating phospholipase C to generate inositol-1,4,5-triphosphate (IP3) and diacyglycerol (DAG), which in turn lead to Ca2+ release and protein kinase C activation, respectively. Group 1 mGluR expression is shown to be strongly upregulated in animal models of epilepsy, brain injury, inflammatory, and neuropathic pain, as well as in patients with amyotrophic lateral sclerosis or multiple sclerosis. Group 2 (mGluR2 and mGluR3) and 3 (mGluR4, mGluR6, mGluR7, and mGluR8) receptors are predominantly localized presynaptically in the active region of neurotransmitter release. They are coupled to G(i/o) proteins, which leads to inhibition of adenylate cyclase activity and cAMP formation, and consequently to a decrease in protein kinase A (PKA) activity. Ultimately, activation of these receptors leads to inhibition of neurotransmitter release such as glutamate and GABA via inhibition of Ca2+ channels and activation of K+ channels. Furthermore, while activation of Group 1 mGluRs increases NMDA (N-methyl-D-aspartate) receptor activity and risk of neurotoxicity, Group 2 and 3 mGluRs decrease NMDA receptor activity and prevent neurotoxicity. Pssm-ID: 320412 Cd Length: 250 Bit Score: 320.74 E-value: 1.85e-105
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| 7tmC_mGluR_group3 | cd15286 | metabotropic glutamate receptors in group 3, member of the class C family of ... |
384-644 | 1.53e-96 | ||||||||
metabotropic glutamate receptors in group 3, member of the class C family of seven-transmembrane G protein-coupled receptors; The metabotropic glutamate receptors (mGluRs) in group 3 include mGluRs 4, 6, 7, and 8. They are homodimeric class C G-protein coupled receptors which are activated by glutamate, the major excitatory neurotransmitter of the CNS. mGluRs are involved in regulating neuronal excitability and synaptic transmission via intracellular activation of second messenger signaling pathways. While the ionotropic glutamate receptor subtypes (AMPA, NMDA, and kainite) mediate fast excitatory postsynaptic transmission, mGluRs are known to mediate slower excitatory postsynaptic responses and to be involved in synaptic plasticity in the mammalian brain. In addition to seven-transmembrane helices, the class C GPCRs are characterized by a large N-terminal extracellular Venus flytrap-like domain, which is composed of two adjacent lobes separated by a cleft which binds an endogenous ligand. Moreover, they exist as either homo- or heterodimers, which are essential for their function. For instance, mGluRs form homodimers via interactions between the N-terminal Venus flytrap domains and the intermolecular disulphide bonds between cysteine residues located in the cysteine-rich domain (CRD). At least eight different subtypes of metabotropic receptors (mGluR1-8) have been identified and further classified into three groups based on their sequence homology, pharmacological properties, and signaling pathways. Group 1 (mGluR1 and mGluR5) receptors are predominantly located postsynaptically on neurons and are involved in long-term synaptic plasticity in the brain, including long-term potentiation (LTP) in the hippocampus and long-term depression (LTD) in the cerebellum. They are coupled to G(q/11) proteins, thereby activating phospholipase C to generate inositol-1,4,5-triphosphate (IP3) and diacyglycerol (DAG), which in turn lead to Ca2+ release and protein kinase C activation, respectively. Group 1 mGluR expression is shown to be strongly upregulated in animal models of epilepsy, brain injury, inflammatory, and neuropathic pain, as well as in patients with amyotrophic lateral sclerosis or multiple sclerosis. Group 2 (mGluR2 and mGluR3) and 3 (mGluR4, mGluR6, mGluR7, and mGluR8) receptors are predominantly localized presynaptically in the active region of neurotransmitter release. They are coupled to G(i/o) proteins, which leads to inhibition of adenylate cyclase activity and cAMP formation, and consequently to a decrease in protein kinase A (PKA) activity. Ultimately, activation of these receptors leads to inhibition of neurotransmitter release such as glutamate and GABA via inhibition of Ca2+ channels and activation of K+ channels. Furthermore, while activation of Group 1 mGluRs increases NMDA (N-methyl-D-aspartate) receptor activity and risk of neurotoxicity, Group 2 and 3 mGluRs decrease NMDA receptor activity and prevent neurotoxicity. Pssm-ID: 320413 Cd Length: 271 Bit Score: 298.64 E-value: 1.53e-96
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| 7tmC_mGluR4 | cd15452 | metabotropic glutamate receptor 4 in group 3, member of the class C family of ... |
385-643 | 3.60e-91 | ||||||||
metabotropic glutamate receptor 4 in group 3, member of the class C family of seven-transmembrane G protein-coupled receptors; The receptors in group 3 include mGluRs 4, 6, 7, and 8. They are homodimeric class C G-protein coupled receptors which are activated by glutamate, the major excitatory neurotransmitter of the CNS. mGluRs are involved in regulating neuronal excitability and synaptic transmission via intracellular activation of second messenger signaling pathways. While the ionotropic glutamate receptor subtypes (AMPA, NMDA, and kainite) mediate fast excitatory postsynaptic transmission, mGluRs are known to mediate slower excitatory postsynaptic responses and to be involved in synaptic plasticity in the mammalian brain. In addition to seven-transmembrane helices, the class C GPCRs are characterized by a large N-terminal extracellular Venus flytrap-like domain, which is composed of two adjacent lobes separated by a cleft which binds an endogenous ligand. Moreover, they exist as either homo- or heterodimers, which are essential for their function. For instance, mGluRs form homodimers via interactions between the N-terminal Venus flytrap domains and the intermolecular disulphide bonds between cysteine residues located in the cysteine-rich domain (CRD). At least eight different subtypes of metabotropic receptors (mGluR1-8) have been identified and further classified into three groups based on their sequence homology, pharmacological properties, and signaling pathways. Group 1 (mGluR1 and mGluR5) receptors are predominantly located postsynaptically on neurons and are involved in long-term synaptic plasticity in the brain, including long-term potentiation (LTP) in the hippocampus and long-term depression (LTD) in the cerebellum. They are coupled to G(q/11) proteins, thereby activating phospholipase C to generate inositol-1,4,5-triphosphate (IP3) and diacyglycerol (DAG), which in turn lead to Ca2+ release and protein kinase C activation, respectively. Group 1 mGluR expression is shown to be strongly upregulated in animal models of epilepsy, brain injury, inflammatory, and neuropathic pain, as well as in patients with amyotrophic lateral sclerosis or multiple sclerosis. Group 2 (mGluR2 and mGluR3) and 3 (mGluR4, mGluR6, mGluR7, and mGluR8) receptors are predominantly localized presynaptically in the active region of neurotransmitter release. They are coupled to G(i/o) proteins, which leads to inhibition of adenylate cyclase activity and cAMP formation, and consequently to a decrease in protein kinase A (PKA) activity. Ultimately, activation of these receptors leads to inhibition of neurotransmitter release such as glutamate and GABA via inhibition of Ca2+ channels and activation of K+ channels. Furthermore, while activation of Group 1 mGluRs increases NMDA (N-methyl-D-aspartate) receptor activity and risk of neurotoxicity, Group 2 and 3 mGluRs decrease NMDA receptor activity and prevent neurotoxicity. Pssm-ID: 320568 [Multi-domain] Cd Length: 327 Bit Score: 286.88 E-value: 3.60e-91
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| 7tmC_mGluR6 | cd15453 | metabotropic glutamate receptor 6 in group 3, member of the class C family of ... |
385-643 | 5.87e-86 | ||||||||
metabotropic glutamate receptor 6 in group 3, member of the class C family of seven-transmembrane G protein-coupled receptors; The receptors in group 3 include mGluRs 4, 6, 7, and 8. They are homodimeric class C G-protein coupled receptors which are activated by glutamate, the major excitatory neurotransmitter of the CNS. mGluRs are involved in regulating neuronal excitability and synaptic transmission via intracellular activation of second messenger signaling pathways. While the ionotropic glutamate receptor subtypes (AMPA, NMDA, and kainite) mediate fast excitatory postsynaptic transmission, mGluRs are known to mediate slower excitatory postsynaptic responses and to be involved in synaptic plasticity in the mammalian brain. In addition to seven-transmembrane helices, the class C GPCRs are characterized by a large N-terminal extracellular Venus flytrap-like domain, which is composed of two adjacent lobes separated by a cleft which binds an endogenous ligand. Moreover, they exist as either homo- or heterodimers, which are essential for their function. For instance, mGluRs form homodimers via interactions between the N-terminal Venus flytrap domains and the intermolecular disulphide bonds between cysteine residues located in the cysteine-rich domain (CRD). At least eight different subtypes of metabotropic receptors (mGluR1-8) have been identified and further classified into three groups based on their sequence homology, pharmacological properties, and signaling pathways. Group 1 (mGluR1 and mGluR5) receptors are predominantly located postsynaptically on neurons and are involved in long-term synaptic plasticity in the brain, including long-term potentiation (LTP) in the hippocampus and long-term depression (LTD) in the cerebellum. They are coupled to G(q/11) proteins, thereby activating phospholipase C to generate inositol-1,4,5-triphosphate (IP3) and diacyglycerol (DAG), which in turn lead to Ca2+ release and protein kinase C activation, respectively. Group 1 mGluR expression is shown to be strongly upregulated in animal models of epilepsy, brain injury, inflammatory, and neuropathic pain, as well as in patients with amyotrophic lateral sclerosis or multiple sclerosis. Group 2 (mGluR2 and mGluR3) and 3 (mGluR4, mGluR6, mGluR7, and mGluR8) receptors are predominantly localized presynaptically in the active region of neurotransmitter release. They are coupled to G(i/o) proteins, which leads to inhibition of adenylate cyclase activity and cAMP formation, and consequently to a decrease in protein kinase A (PKA) activity. Ultimately, activation of these receptors leads to inhibition of neurotransmitter release such as glutamate and GABA via inhibition of Ca2+ channels and activation of K+ channels. Furthermore, while activation of Group 1 mGluRs increases NMDA (N-methyl-D-aspartate) receptor activity and risk of neurotoxicity, Group 2 and 3 mGluRs decrease NMDA receptor activity and prevent neurotoxicity. Pssm-ID: 320569 [Multi-domain] Cd Length: 273 Bit Score: 271.13 E-value: 5.87e-86
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| 7tmC_mGluR8 | cd15454 | metabotropic glutamate receptor 8 in group 3, member of the class C family of ... |
384-643 | 9.97e-86 | ||||||||
metabotropic glutamate receptor 8 in group 3, member of the class C family of seven-transmembrane G protein-coupled receptors; The receptors in group 3 include mGluRs 4, 6, 7, and 8. They are homodimeric class C G-protein coupled receptors which are activated by glutamate, the major excitatory neurotransmitter of the CNS. mGluRs are involved in regulating neuronal excitability and synaptic transmission via intracellular activation of second messenger signaling pathways. While the ionotropic glutamate receptor subtypes (AMPA, NMDA, and kainite) mediate fast excitatory postsynaptic transmission, mGluRs are known to mediate slower excitatory postsynaptic responses and to be involved in synaptic plasticity in the mammalian brain. In addition to seven-transmembrane helices, the class C GPCRs are characterized by a large N-terminal extracellular Venus flytrap-like domain, which is composed of two adjacent lobes separated by a cleft which binds an endogenous ligand. Moreover, they exist as either homo- or heterodimers, which are essential for their function. For instance, mGluRs form homodimers via interactions between the N-terminal Venus flytrap domains and the intermolecular disulphide bonds between cysteine residues located in the cysteine-rich domain (CRD). At least eight different subtypes of metabotropic receptors (mGluR1-8) have been identified and further classified into three groups based on their sequence homology, pharmacological properties, and signaling pathways. Group 1 (mGluR1 and mGluR5) receptors are predominantly located postsynaptically on neurons and are involved in long-term synaptic plasticity in the brain, including long-term potentiation (LTP) in the hippocampus and long-term depression (LTD) in the cerebellum. They are coupled to G(q/11) proteins, thereby activating phospholipase C to generate inositol-1,4,5-triphosphate (IP3) and diacyglycerol (DAG), which in turn lead to Ca2+ release and protein kinase C activation, respectively. Group 1 mGluR expression is shown to be strongly upregulated in animal models of epilepsy, brain injury, inflammatory, and neuropathic pain, as well as in patients with amyotrophic lateral sclerosis or multiple sclerosis. Group 2 (mGluR2 and mGluR3) and 3 (mGluR4, mGluR6, mGluR7, and mGluR8) receptors are predominantly localized presynaptically in the active region of neurotransmitter release. They are coupled to G(i/o) proteins, which leads to inhibition of adenylate cyclase activity and cAMP formation, and consequently to a decrease in protein kinase A (PKA) activity. Ultimately, activation of these receptors leads to inhibition of neurotransmitter release such as glutamate and GABA via inhibition of Ca2+ channels and activation of K+ channels. Furthermore, while activation of Group 1 mGluRs increases NMDA (N-methyl-D-aspartate) receptor activity and risk of neurotoxicity, Group 2 and 3 mGluRs decrease NMDA receptor activity and prevent neurotoxicity. Pssm-ID: 320570 [Multi-domain] Cd Length: 311 Bit Score: 272.28 E-value: 9.97e-86
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| 7tm_classC_mGluR-like | cd13953 | metabotropic glutamate receptor-like class C family of seven-transmembrane G protein-coupled ... |
384-637 | 7.71e-84 | ||||||||
metabotropic glutamate receptor-like class C family of seven-transmembrane G protein-coupled receptors superfamily; The class C GPCRs consist of glutamate receptors (mGluR1-8), the extracellular calcium-sensing receptors (caSR), the gamma-amino-butyric acid type B receptors (GABA-B), the vomeronasal type-2 pheromone receptors (V2R), the type 1 taste receptors (TAS1R), and the promiscuous L-alpha-amino acid receptor (GPRC6A), as well as several orphan receptors. Structurally, these receptors are typically composed of a large extracellular domain containing a Venus flytrap module which possesses the orthosteric agonist-binding site, a cysteine-rich domain (CRD) with the exception of GABA-B receptors, and the seven-transmembrane domains responsible for G protein activation. Moreover, the Venus flytrap module shows high structural homology with bacterial periplasmic amino acid-binding proteins, which serve as primary receptors in transport of a variety of soluble substrates such as amino acids and polysaccharides, among many others. The class C GPCRs exist as either homo- or heterodimers, which are essential for their function. The GABA-B1 and GABA-B2 receptors form a heterodimer via interactions between the N-terminal Venus flytrap modules and the C-terminal coiled-coiled domains. On the other hand, heterodimeric CaSRs and Tas1Rs and homodimeric mGluRs utilize Venus flytrap interactions and intermolecular disulphide bonds between cysteine residues located in the cysteine-rich domain (CRD), which can also acts as a molecular link to mediate the signal between the Venus flytrap and the 7TMs. Furthermore, members of the class C GPCRs bind a variety of endogenous ligands, ranging from amino acids, ions, to pheromones and sugar molecules, and play important roles in many physiological processes such as synaptic transmission, calcium homeostasis, and the sensation of sweet and umami tastes. Pssm-ID: 320091 [Multi-domain] Cd Length: 251 Bit Score: 264.87 E-value: 7.71e-84
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| 7tmC_mGluR7 | cd15451 | metabotropic glutamate receptor 7 in group 3, member of the class C family of ... |
385-643 | 2.18e-82 | ||||||||
metabotropic glutamate receptor 7 in group 3, member of the class C family of seven-transmembrane G protein-coupled receptors; The receptors in group 3 include mGluRs 4, 6, 7, and 8. They are homodimeric class C G-protein coupled receptors which are activated by glutamate, the major excitatory neurotransmitter of the CNS. mGluRs are involved in regulating neuronal excitability and synaptic transmission via intracellular activation of second messenger signaling pathways. While the ionotropic glutamate receptor subtypes (AMPA, NMDA, and kainite) mediate fast excitatory postsynaptic transmission, mGluRs are known to mediate slower excitatory postsynaptic responses and to be involved in synaptic plasticity in the mammalian brain. In addition to seven-transmembrane helices, the class C GPCRs are characterized by a large N-terminal extracellular Venus flytrap-like domain, which is composed of two adjacent lobes separated by a cleft which binds an endogenous ligand. Moreover, they exist as either homo- or heterodimers, which are essential for their function. For instance, mGluRs form homodimers via interactions between the N-terminal Venus flytrap domains and the intermolecular disulphide bonds between cysteine residues located in the cysteine-rich domain (CRD). At least eight different subtypes of metabotropic receptors (mGluR1-8) have been identified and further classified into three groups based on their sequence homology, pharmacological properties, and signaling pathways. Group 1 (mGluR1 and mGluR5) receptors are predominantly located postsynaptically on neurons and are involved in long-term synaptic plasticity in the brain, including long-term potentiation (LTP) in the hippocampus and long-term depression (LTD) in the cerebellum. They are coupled to G(q/11) proteins, thereby activating phospholipase C to generate inositol-1,4,5-triphosphate (IP3) and diacyglycerol (DAG), which in turn lead to Ca2+ release and protein kinase C activation, respectively. Group 1 mGluR expression is shown to be strongly upregulated in animal models of epilepsy, brain injury, inflammatory, and neuropathic pain, as well as in patients with amyotrophic lateral sclerosis or multiple sclerosis. Group 2 (mGluR2 and mGluR3) and 3 (mGluR4, mGluR6, mGluR7, and mGluR8) receptors are predominantly localized presynaptically in the active region of neurotransmitter release. They are coupled to G(i/o) proteins, which leads to inhibition of adenylate cyclase activity and cAMP formation, and consequently to a decrease in protein kinase A (PKA) activity. Ultimately, activation of these receptors leads to inhibition of neurotransmitter release such as glutamate and GABA via inhibition of Ca2+ channels and activation of K+ channels. Furthermore, while activation of Group 1 mGluRs increases NMDA (N-methyl-D-aspartate) receptor activity and risk of neurotoxicity, Group 2 and 3 mGluRs decrease NMDA receptor activity and prevent neurotoxicity. Pssm-ID: 320567 Cd Length: 307 Bit Score: 263.04 E-value: 2.18e-82
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| PBP1_mGluR | cd06362 | ligand binding domain of metabotropic glutamate receptors (mGluR); Ligand binding domain of ... |
30-300 | 4.32e-81 | ||||||||
ligand binding domain of metabotropic glutamate receptors (mGluR); Ligand binding domain of the metabotropic glutamate receptors (mGluR), which are members of the family C of G-protein-coupled receptors that transduce extracellular signals into G-protein activation and ultimately into cellular responses. mGluRs bind to glutamate and function as an excitatory neurotransmitter; they are involved in learning, memory, anxiety, and the perception of pain. Eight subtypes of mGluRs have been cloned so far, and are classified into three groups according to their sequence similarities, transduction mechanisms, and pharmacological profiles. Group I is composed of mGlu1R and mGlu5R that both stimulate PLC hydrolysis. Group II includes mGlu2R and mGlu3R, which inhibit adenylyl cyclase, as do mGlu4R, mGlu6R, mGlu7R, and mGlu8R, which form group III. Pssm-ID: 380585 [Multi-domain] Cd Length: 460 Bit Score: 264.93 E-value: 4.32e-81
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| PBP1_mGluR_groupIII | cd06376 | ligand-binding domain of the group III metabotropic glutamate receptor; Ligand-binding domain ... |
28-305 | 1.16e-75 | ||||||||
ligand-binding domain of the group III metabotropic glutamate receptor; Ligand-binding domain of the group III metabotropic glutamate receptor, a family which contains mGlu4R, mGluR6R, mGluR7, and mGluR8; all of which inhibit adenylyl cyclase. The metabotropic glutamate receptor is a member of the family C of G-protein-coupled receptors that transduce extracellular signals into G-protein activation and ultimately into intracellular responses. The mGluRs are classified into three groups which comprise eight subtypes. Pssm-ID: 380599 [Multi-domain] Cd Length: 467 Bit Score: 250.88 E-value: 1.16e-75
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| 7tm_3 | pfam00003 | 7 transmembrane sweet-taste receptor of 3 GCPR; This is a domain of seven transmembrane ... |
379-631 | 1.15e-71 | ||||||||
7 transmembrane sweet-taste receptor of 3 GCPR; This is a domain of seven transmembrane regions that forms the C-terminus of some subclass 3 G-coupled-protein receptors. It is often associated with a downstream cysteine-rich linker domain, NCD3G pfam07562, which is the human sweet-taste receptor, and the N-terminal domain, ANF_receptor pfam01094. The seven TM regions assemble in such a way as to produce a docking pocket into which such molecules as cyclamate and lactisole have been found to bind and consequently confer the taste of sweetness. Pssm-ID: 459626 [Multi-domain] Cd Length: 247 Bit Score: 232.94 E-value: 1.15e-71
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| 7tmC_mGluR5 | cd15450 | metabotropic glutamate receptor 5 in group 1, member of the class C family of ... |
387-636 | 2.19e-66 | ||||||||
metabotropic glutamate receptor 5 in group 1, member of the class C family of seven-transmembrane G protein-coupled receptors; Group 1 mGluRs includes mGluR1 and mGluR5, as well as their closely related invertebrate receptors. They are homodimeric class C G-protein coupled receptors which are activated by glutamate, the major excitatory neurotransmitter of the CNS. mGluRs are involved in regulating neuronal excitability and synaptic transmission via intracellular activation of second messenger signaling pathways. While the ionotropic glutamate receptor subtypes (AMPA, NMDA, and kainite) mediate fast excitatory postsynaptic transmission, mGluRs are known to mediate slower excitatory postsynaptic responses and to be involved in synaptic plasticity in the mammalian brain. In addition to seven-transmembrane helices, the class C GPCRs are characterized by a large N-terminal extracellular Venus flytrap-like domain, which is composed of two adjacent lobes separated by a cleft which binds an endogenous ligand. Moreover, they exist as either homo- or heterodimers, which are essential for their function. For instance, mGluRs form homodimers via interactions between the N-terminal Venus flytrap domains and the intermolecular disulphide bonds between cysteine residues located in the cysteine-rich domain (CRD). At least eight different subtypes of metabotropic receptors (mGluR1-8) have been identified and further classified into three groups based on their sequence homology, pharmacological properties, and signaling pathways. Group 1 (mGluR1 and mGluR5) receptors are predominantly located postsynaptically on neurons and are involved in long-term synaptic plasticity in the brain, including long-term potentiation (LTP) in the hippocampus and long-term depression (LTD) in the cerebellum. They are coupled to G(q/11) proteins, thereby activating phospholipase C to generate inositol-1,4,5-triphosphate (IP3) and diacyglycerol (DAG), which in turn lead to Ca2+ release and protein kinase C activation, respectively. Group 1 mGluR expression is shown to be strongly upregulated in animal models of epilepsy, brain injury, inflammatory, and neuropathic pain, as well as in patients with amyotrophic lateral sclerosis or multiple sclerosis. Group 2 (mGluR2 and mGluR3) and 3 (mGluR4, mGluR6, mGluR7, and mGluR8) receptors are predominantly localized presynaptically in the active region of neurotransmitter release. They are coupled to G(i/o) proteins, which leads to inhibition of adenylate cyclase activity and cAMP formation, and consequently to a decrease in protein kinase A (PKA) activity. Ultimately, activation of these receptors leads to inhibition of neurotransmitter release such as glutamate and GABA via inhibition of Ca2+ channels and activation of K+ channels. Furthermore, while activation of Group 1 mGluRs increases NMDA (N-methyl-D-aspartate) receptor activity and risk of neurotoxicity, Group 2 and 3 mGluRs decrease NMDA receptor activity and prevent neurotoxicity. Pssm-ID: 320566 Cd Length: 250 Bit Score: 219.09 E-value: 2.19e-66
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| 7tmC_mGluR1 | cd15449 | metabotropic glutamate receptor 1 in group 1, member of the class C family of ... |
390-636 | 3.06e-65 | ||||||||
metabotropic glutamate receptor 1 in group 1, member of the class C family of seven-transmembrane G protein-coupled receptors; Group 1 mGluRs includes mGluR1 and mGluR5, as well as their closely related invertebrate receptors. They are homodimeric class C G-protein coupled receptors which are activated by glutamate, the major excitatory neurotransmitter of the CNS. mGluRs are involved in regulating neuronal excitability and synaptic transmission via intracellular activation of second messenger signaling pathways. While the ionotropic glutamate receptor subtypes (AMPA, NMDA, and kainite) mediate fast excitatory postsynaptic transmission, mGluRs are known to mediate slower excitatory postsynaptic responses and to be involved in synaptic plasticity in the mammalian brain. In addition to seven-transmembrane helices, the class C GPCRs are characterized by a large N-terminal extracellular Venus flytrap-like domain, which is composed of two adjacent lobes separated by a cleft which binds an endogenous ligand. Moreover, they exist as either homo- or heterodimers, which are essential for their function. For instance, mGluRs form homodimers via interactions between the N-terminal Venus flytrap domains and the intermolecular disulphide bonds between cysteine residues located in the cysteine-rich domain (CRD). At least eight different subtypes of metabotropic receptors (mGluR1-8) have been identified and further classified into three groups based on their sequence homology, pharmacological properties, and signaling pathways. Group 1 (mGluR1 and mGluR5) receptors are predominantly located postsynaptically on neurons and are involved in long-term synaptic plasticity in the brain, including long-term potentiation (LTP) in the hippocampus and long-term depression (LTD) in the cerebellum. They are coupled to G(q/11) proteins, thereby activating phospholipase C to generate inositol-1,4,5-triphosphate (IP3) and diacyglycerol (DAG), which in turn lead to Ca2+ release and protein kinase C activation, respectively. Group 1 mGluR expression is shown to be strongly upregulated in animal models of epilepsy, brain injury, inflammatory, and neuropathic pain, as well as in patients with amyotrophic lateral sclerosis or multiple sclerosis. Group 2 (mGluR2 and mGluR3) and 3 (mGluR4, mGluR6, mGluR7, and mGluR8) receptors are predominantly localized presynaptically in the active region of neurotransmitter release. They are coupled to G(i/o) proteins, which leads to inhibition of adenylate cyclase activity and cAMP formation, and consequently to a decrease in protein kinase A (PKA) activity. Ultimately, activation of these receptors leads to inhibition of neurotransmitter release such as glutamate and GABA via inhibition of Ca2+ channels and activation of K+ channels. Furthermore, while activation of Group 1 mGluRs increases NMDA (N-methyl-D-aspartate) receptor activity and risk of neurotoxicity, Group 2 and 3 mGluRs decrease NMDA receptor activity and prevent neurotoxicity. Pssm-ID: 320565 Cd Length: 250 Bit Score: 216.03 E-value: 3.06e-65
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| PBP1_mGluR_groupI | cd06374 | ligand binding domain of the group I metabotropic glutamate receptor; Ligand binding domain of ... |
23-296 | 2.49e-61 | ||||||||
ligand binding domain of the group I metabotropic glutamate receptor; Ligand binding domain of the group I metabotropic glutamate receptor, a family containing mGlu1R and mGlu5R, all of which stimulate phospholipase C (PLC) hydrolysis. The metabotropic glutamate receptor is a member of the family C of G-protein-coupled receptors that transduce extracellular signals into G-protein activation and ultimately into intracellular responses. The mGluRs are classified into three groups which comprise eight subtypes. Pssm-ID: 380597 [Multi-domain] Cd Length: 474 Bit Score: 212.59 E-value: 2.49e-61
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| 7tmC_V2R_AA_sensing_receptor-like | cd15044 | vomeronasal type-2 pheromone receptors, amino acid-sensing receptors and closely related ... |
390-637 | 1.41e-46 | ||||||||
vomeronasal type-2 pheromone receptors, amino acid-sensing receptors and closely related proteins; member of the class C family of seven-transmembrane G protein-coupled receptors; This group is composed of vomeronasal type-2 pheromone receptors (V2Rs), a subgroup of broad-spectrum amino-acid sensing receptors including calcium-sensing receptor (CaSR) and GPRC6A, as well as their closely related proteins. Members of the V2R family of vomeronasal GPCRs are involved in detecting protein pheromones for social and sexual cues between the same species. V2Rs and G-alpha(o) protein are co-expressed in the basal layer of the vomeronasal organ (VNO), which is the sensory organ of the accessory olfactory system present in amphibians, reptiles, and non-primate mammals such as mice and rodents, but it is non-functional or absent in humans, apes, and monkeys. On the other hand, members of the V1R receptor family and G-alpha(i2) protein are co-expressed in the apical neurons of the VNO. Activation of V1R or V2R causes activation of phospholipase pathway, producing the second messengers diacylglycerol (DAG) and IP3. However, in contrast to V1Rs, V2Rs contain the long N-terminal extracellular domain, which is believed to bind pheromones. CaSR is a widely expressed GPCR that is involved in sensing small changes in extracellular levels of calcium ion to maintain a constant level of the extracellular calcium via modulating the synthesis and secretion of calcium regulating hormones, such as parathyroid hormone (PTH), in order to regulate Ca(2+)transport into or out of the extracellular fluid via kidney, intestine, and/or bone. For instance, when Ca2+ is high, CaSR downregulates PTH synthesis and secretion, leading to an increase in renal Ca2+ excretion, a decrease in intestinal Ca2+ absorption, and a reduction in release of skeletal Ca2+. GRPC6A (GPCR, class C, group 6, subtype A) is a widely expressed amino acid-sensing GPCR that is most closely related to CaSR. GPRC6A is most potently activated by the basic amino acids L-arginine, L-lysine, and L-ornithine and less potently by small aliphatic amino acids. Moreover, the receptor can be either activated or modulated by divalent cations such as Ca2+. GPRC6A is expressed in the testis, but not the ovary and specifically also binds to the osteoblast-derived hormone osteocalcin (OCN), which regulates testosterone production by the testis and male fertility independently of the hypothalamic-pituitary axis. Furthermore, GPRC6A knockout studies suggest that GRPC6A is involved in regulation of bone metabolism, male reproduction, energy homeostasis, glucose metabolism, and in activation of inflammation response, as well as prostate cancer growth and progression, among others. Pssm-ID: 320172 [Multi-domain] Cd Length: 251 Bit Score: 165.72 E-value: 1.41e-46
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| 7tmC_V2R_pheromone | cd15283 | vomeronasal type-2 pheromone receptors, member of the class C family of seven-transmembrane G ... |
390-637 | 1.46e-42 | ||||||||
vomeronasal type-2 pheromone receptors, member of the class C family of seven-transmembrane G protein-coupled receptors; This group represents vomeronasal type-2 pheromone receptors (V2Rs). Members of the V2R family of vomeronasal GPCRs are involved in detecting protein pheromones for social and sexual cues between the same species. V2Rs and G-alpha(o) protein are coexpressed in the basal layer of the vomeronasal organ (VNO), which is the sensory organ of the accessory olfactory system present in amphibians, reptiles, and non-primate mammals such as mice and rodents, but it is non-functional or absent in humans, apes, and monkeys. On the other hand, members of the V1R receptor family and G-alpha(i2) protein are coexpressed in the apical neurons of the VNO. Activation of V1R or V2R causes activation of phospholipase pathway, producing the second messengers diacylglycerol (DAG) and IP3. However, in contrast to V1Rs, V2Rs contain the long N-terminal extracellular domain, which is believed to bind pheromones. Pssm-ID: 320410 [Multi-domain] Cd Length: 252 Bit Score: 154.36 E-value: 1.46e-42
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| 7tmC_CaSR | cd15282 | calcium-sensing receptor, member of the class C of seven-transmembrane G protein-coupled ... |
393-637 | 1.33e-40 | ||||||||
calcium-sensing receptor, member of the class C of seven-transmembrane G protein-coupled receptors; CaSR is a widely expressed GPCR that is involved in sensing small changes in extracellular levels of calcium ion to maintain a constant level of the extracellular calcium via modulating the synthesis and secretion of calcium regulating hormones, such as parathyroid hormone (PTH), in order to regulate Ca(2+)transport into or out of the extracellular fluid via kidney, intestine, and/or bone. For instance, when Ca2+ is high, CaSR downregulates PTH synthesis and secretion, leading to an increase in renal Ca2+ excretion, a decrease in intestinal Ca2+ absorption, and a reduction in release of skeletal Ca2+. CaSR is coupled to both G(q/11)-dependent activation of phospholipase and, subsequently, intracellular calcium mobilization and protein kinase C activation as well as G(i/o)-dependent inhibition of adenylate cyclase leading to inhibition of cAMP formation. CaSR is closely related to GRPC6A (GPCR, class C, group 6, subtype A), which is an amino acid-sensing GPCR that is most potently activated by the basic amino acids L-arginine, L-lysine, and L-ornithine. These receptors contain a large extracellular Venus flytrap-like domain in the N-terminus, cysteine-rich domain (CRD), and seven-transmembrane (7TM) domain, which are characteristics of the class C GPCRs. The Venus flytrap-like domain shares strong sequence homology to bacterial periplasmic binding proteins and possess the orthosteric amino acid and calcium binding sites for members of the class C, including CaSR, GABA-B1, GPRC6A, mGlu, and TASR1 receptors. Pssm-ID: 320409 [Multi-domain] Cd Length: 252 Bit Score: 148.94 E-value: 1.33e-40
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| 7tmC_V2R-like | cd15280 | vomeronasal type-2 receptor-like proteins, member of the class C family of seven-transmembrane ... |
390-639 | 9.38e-37 | ||||||||
vomeronasal type-2 receptor-like proteins, member of the class C family of seven-transmembrane G protein-coupled receptors; This group represents vomeronasal type-2 receptor-like proteins that are closely related to the V2R family of vomeronasal GPCRs. Members of the V2R family of vomeronasal GPCRs are involved in detecting protein pheromones for social and sexual cues between the same species. V2Rs and G-alpha(o) protein are coexpressed in the basal layer of the vomeronasal organ (VNO), which is the sensory organ of the accessory olfactory system present in amphibians, reptiles, and non-primate mammals such as mice and rodents, but it is non-functional or absent in humans, apes, and monkeys. On the other hand, members of the V1R receptor family and G-alpha(i2) protein are co-expressed in the apical neurons of the VNO. Activation of V1R or V2R causes activation of phospholipase pathway, generating the secondary messengers diacylglycerol (DAG) and IP3. However, in contrast to V1Rs, V2Rs contain the long N-terminal extracellular domain, which is believed to bind pheromones. Human V2R1-like protein, also known as putative calcium-sensing receptor-like 1 (CASRL1), is not included here because it is a nonfunctional pseudogene. Pssm-ID: 320407 [Multi-domain] Cd Length: 253 Bit Score: 138.38 E-value: 9.38e-37
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| 7tmC_GPRC6A | cd15281 | class C of seven-transmembrane G protein-coupled receptors, subtype 6A; GRPC6A (GPCR, class C, ... |
392-637 | 4.09e-31 | ||||||||
class C of seven-transmembrane G protein-coupled receptors, subtype 6A; GRPC6A (GPCR, class C, group 6, subtype A) is a widely expressed amino acid-sensing GPCR that is most closely related to CaSR. GPRC6A is most potently activated by the basic amino acids L-arginine, L-lysine, and L-ornithine and less potently by small aliphatic amino acids. Moreover, the receptor can be either activated or modulated by divalent cations such as Ca2+ and Mg2+. GPRC6A is expressed in the testis, but not the ovary and specifically also binds to the osteoblast-derived hormone osteocalcin (OCN), which regulates testosterone production by the testis and male fertility independently of the hypothalamic-pituitary axis. Furthermore, GPRC6A knockout studies suggest that GRPC6A is involved in regulation of bone metabolism, male reproduction, energy homeostasis, glucose metabolism, and in activation of inflammation response, as well as prostate cancer growth and progression, among others. GPRC6A has been suggested to couple to the Gq subtype of G proteins, leading to IP3 production and intracellular calcium mobilization. GPRC6A contains a large extracellular Venus flytrap-like domain in the N-terminus, cysteine-rich domain (CRD), and seven-transmembrane (7TM) domain, which are characteristics of the class C GPCRs. The Venus flytrap-like domain shares strong sequence homology to bacterial periplasmic binding proteins and possess the orthosteric amino acid and calcium binding sites for members of the class C, including CaSR, GABA-B, GPRC6A, mGlu, and TAS1R receptors. Pssm-ID: 320408 Cd Length: 249 Bit Score: 122.19 E-value: 4.09e-31
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| PBP1_GPCR_family_C-like | cd06350 | ligand-binding domain of membrane-bound glutamate receptors that mediate excitatory ... |
33-150 | 1.25e-30 | ||||||||
ligand-binding domain of membrane-bound glutamate receptors that mediate excitatory transmission on the cellular surface through initial binding of glutamate; categorized into ionotropic glutamate receptors (iGluRs) and metabotropic glutamate receptors (m; Ligand-binding domain of membrane-bound glutamate receptors that mediate excitatory transmission on the cellular surface through initial binding of glutamate and are categorized into ionotropic glutamate receptors (iGluRs) and metabotropic glutamate receptors (mGluRs). The metabotropic glutamate receptors (mGluR) are key receptors in the modulation of excitatory synaptic transmission in the central nervous system. The mGluRs are coupled to G proteins and are thus distinct from the iGluRs which internally contain ligand-gated ion channels. The mGluR structure is divided into three regions: the extracellular region, the seven-spanning transmembrane region and the cytoplasmic region. The extracellular region is further divided into the ligand-binding domain (LBD) and the cysteine-rich domain. The LBD has sequence similarity to the LIVBP, which is a bacterial periplasmic protein (PBP), as well as to the extracellular region of both iGluR and the gamma-aminobutyric acid (GABA)b receptor. iGluRs are divided into three main subtypes based on pharmacological profile: NMDA, AMPA, and kainate receptors. All family C GPCRs have a large extracellular N terminus that contain a domain with homology to bacterial periplasmic amino acid-binding proteins. Pssm-ID: 380573 Cd Length: 350 Bit Score: 123.56 E-value: 1.25e-30
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| PBP1_ABC_transporter_GPCR_C-like | cd04509 | Family C of G-protein coupled receptors and their close homologs, the type 1 ... |
33-153 | 2.24e-28 | ||||||||
Family C of G-protein coupled receptors and their close homologs, the type 1 periplasmic-binding proteins of ATP-binding cassette transporter-like systems; This CD includes members of the family C of G-protein coupled receptors and their close homologs, the type 1 periplasmic-binding proteins of ATP-binding cassette transporter-like systems. The family C GPCR includes glutamate/glycine-gated ion channels such as the NMDA receptor, G-protein-coupled receptors, metabotropic glutamate, GABA-B, calcium sensing, pheromone receptors, and atrial natriuretic peptide-guanylate cyclase receptors. The glutamate receptors that form cation-selective ion channels, iGluR, can be classified into three different subgroups according to their binding-affinity for the agonists NMDA (N-methyl-D-asparate), AMPA (alpha-amino-3-dihydro-5-methyl-3-oxo-4-isoxazolepropionic acid), and kainate. L-glutamate is a major neurotransmitter in the brain of vertebrates and acts through either mGluRs or iGluRs. mGluRs subunits possess seven transmembrane segments and a large N-terminal extracellular domain. ABC-type leucine-isoleucine-valine binding protein (LIVBP) is a bacterial periplasmic binding protein that has homology with the amino-terminal domain of the glutamate-receptor ion channels (iGluRs). The extracellular regions of iGluRs are made of two PBP-like domains in tandem, a LIVBP-like domain that constitutes the N terminus (included in this model) followed by a domain related to lysine-arginine-ornithine-binding protein (LAOBP) that belongs to the type 2 periplasmic binding fold protein superfamily. The uncharacterized periplasmic components of various ABC-type transport systems are also included in this family. Pssm-ID: 380490 Cd Length: 306 Bit Score: 115.87 E-value: 2.24e-28
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| 7tmC_GABA-B-like | cd15047 | gamma-aminobutyric acid type B receptor and related proteins, member of the class C family of ... |
390-635 | 1.18e-27 | ||||||||
gamma-aminobutyric acid type B receptor and related proteins, member of the class C family of seven-transmembrane G protein-coupled receptors; The type B receptor for gamma-aminobutyric acid, GABA-B, is activated by its endogenous ligand GABA, the principal inhibitory neurotransmitter. The functional GABA-B receptor is an obligatory heterodimer composed of two related subunits, GABA-B1, which is primarily involved in GABA ligand binding, and GABA-B2, which is responsible for both G-protein coupling and trafficking of the heterodimer to the plasma membrane. Activation of GABA-B couples to G(i/o)-type G proteins, which in turn modulate three major downstream effectors: adenylate cyclase, voltage-sensitive Ca2+ channels, and inwardly-rectifying K+ channels. Consequently, GABA-B receptor produces slow and sustained inhibitory responses by decreased neurotransmitter release via inhibition of Ca2+ channels and by postsynaptic hyperpolarization via the activation of K+ channels through the G-protein beta-gamma dimer. The GABA-B is expressed in both pre- and postsynaptic sites of glutamatergic and GABAergic neurons in the brain where it regulates synaptic activity. Thus, the GABA-B receptor agonist, baclofen, is used to treat muscle tightness and cramping caused by spasticity in multiple sclerosis patients. Moreover, GABA-B antagonists improves cognitive performance in mammals, while GABA-B agonists suppress cognitive behavior. In most of the class C family members, the extracellular Venus-flytrap domain in the N-terminus is connected to the seven-transmembrane (7TM) via a cysteine-rich domain (CRD). However, in the GABA-B receptor, the CRD is absent in both subunits and the Venus-flytrap ligand-binding domain is directly connected to the 7TM via a 10-15 amino acids linker, suggesting that GABA-B receptor may utilize a different activation mechanism. Also included in this group are orphan receptors, GPR156 and GPR158, which are closely related to the GABA-B receptor family. Pssm-ID: 320175 Cd Length: 263 Bit Score: 112.65 E-value: 1.18e-27
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| 7tmC_TAS1R | cd15046 | type 1 taste receptors, member of the class C of seven-transmembrane G protein-coupled ... |
386-637 | 3.44e-23 | ||||||||
type 1 taste receptors, member of the class C of seven-transmembrane G protein-coupled receptors; This subfamily represents the type I taste receptors (TAS1Rs) that belongs to the class C family of G protein-coupled receptors. The functional TAS1Rs are obligatory heterodimers built from three known members, TAS1R1-3. TAS1R1 combines with TAS1R3 to form an umami taste receptor, which is responsible for the perception of savory taste, such as the food additive mono-sodium glutamate (MSG); whereas the combination of TAS1R2-TAS1R3 forms a sweet-taste receptor for sugars and D-amino acids. On the other hand, the type II taste receptors (TAS2Rs), which belong to the class A family of GPCRs, recognize bitter tasting compounds. In the case of sweet, for example, the TAS1R2-TAS1R3 heterodimer activates phospholipase C (PLC) via alpha-gustducin, a heterodimeric G protein that is involved in perception of sweet and bitter tastes. This activation leads to generation of inositol (1, 4, 5)-trisphosphate (IP3) and diacylglycerol (DAG), and consequently increases intracellular Ca2+ mobilization and activates a cation channel, TRPM5. In contrast to the TAS1R2-TAS1R3 heterodimer, TAS1R3 alone could activate adenylate cyclase leading to cAMP formation in the absence of alpha-gustducin. Each TAS1R contains a large extracellular Venus flytrap-like domain in the N-terminus, cysteine-rich domain (CRD) and seven-transmembrane (7TM) domain, which are characteristics of the class C GPCRs. The Venus flytrap-like domain shares strong sequence homology to bacterial periplasmic binding proteins and possess the orthosteric amino acid and calcium binding sites for members of the class C, including CaSR, GABA-B1, GPRC6A, mGlu, and TAS1R receptors. Pssm-ID: 320174 [Multi-domain] Cd Length: 253 Bit Score: 99.52 E-value: 3.44e-23
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| 7tmC_TAS1R1 | cd15289 | type 1 taste receptor subtype 1, member of the class C of seven-transmembrane G ... |
389-637 | 4.26e-21 | ||||||||
type 1 taste receptor subtype 1, member of the class C of seven-transmembrane G protein-coupled receptors; This group represents TAS1R1, which is a member of the type I taste receptor (TAS1R) family that belongs to the class C of G protein-coupled receptors. The functional TAS1Rs are obligatory heterodimers built from three known members, TAS1R1-3. TAS1R1 combines with TAS1R3 to form an umami taste receptor, which is responsible for the perception of savory taste, such as the food additive mono-sodium glutamate (MSG); whereas the combination of TAS1R2-TAS1R3 forms a sweet-taste receptor for sugars and D-amino acids. On the other hand, the type II taste receptors (TAS2Rs), which belong to the class A family of GPCRs, recognize bitter tasting compounds. In the case of sweet, for example, the TAS1R2-TAS1R3 heterodimer activates phospholipase C (PLC) via alpha-gustducin, a heterodimeric G protein that is involved in perception of sweet and bitter tastes. This activation leads to generation of inositol (1, 4, 5)-trisphosphate (IP3) and diacylglycerol (DAG), and consequently increases intracellular Ca2+ mobilization and activates a cation channel, TRPM5. In contrast to the TAS1R2-TAS1R3 heterodimer, TAS1R3 alone could activate adenylate cyclase leading to cAMP formation in the absence of alpha-gustducin. Each TAS1R contains a large extracellular Venus flytrap-like domain in the N-terminus, cysteine-rich domain (CRD) and seven-transmembrane (7TM) domain, which are characteristics of the class C GPCRs. The Venus flytrap-like domain shares strong sequence homology to bacterial periplasmic binding proteins and possess the orthosteric amino acid and calcium binding sites for members of the class C, including CaSR, GABA-B1, GPRC6A, mGlu, and TAS1R receptors. Pssm-ID: 320416 Cd Length: 253 Bit Score: 93.25 E-value: 4.26e-21
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| 7tmC_TAS1R2 | cd15288 | type 1 taste receptor subtype 2, member of the class C of seven-transmembrane G ... |
390-637 | 7.39e-20 | ||||||||
type 1 taste receptor subtype 2, member of the class C of seven-transmembrane G protein-coupled receptors; This group represents TAS1R2, which is a member of the type I taste receptor (TAS1R) family that belongs to the class C of G protein-coupled receptors. The functional TAS1Rs are obligatory heterodimers built from three known members, TAS1R1-3. TAS1R1 combines with TAS1R3 to form an umami taste receptor, which is responsible for the perception of savory taste, such as the food additive mono-sodium glutamate (MSG); whereas the combination of TAS1R2-TAS1R3 forms a sweet-taste receptor for sugars and D-amino acids. On the other hand, the type II taste receptors (TAS2Rs), which belong to the class A family of GPCRs, recognize bitter tasting compounds. In the case of sweet, for example, the TAS1R2-TAS1R3 heterodimer activates phospholipase C (PLC) via alpha-gustducin, a heterodimeric G protein that is involved in perception of sweet and bitter tastes. This activation leads to generation of inositol (1, 4, 5)-trisphosphate (IP3) and diacylglycerol (DAG), and consequently increases intracellular Ca2+ mobilization and activates a cation channel, TRPM5. In contrast to the TAS1R2-TAS1R3 heterodimer, TAS1R3 alone could activate adenylate cyclase leading to cAMP formation in the absence of alpha-gustducin. Each TAS1R contains a large extracellular Venus flytrap-like domain in the N-terminus, cysteine-rich domain (CRD) and seven-transmembrane (7TM) domain, which are characteristics of the class C GPCRs. The Venus flytrap-like domain shares strong sequence homology to bacterial periplasmic binding proteins and possess the orthosteric amino acid and calcium binding sites for members of the class C, including CaSR, GABA-B1, GPRC6A, mGlu, and TAS1R receptors. Pssm-ID: 320415 Cd Length: 254 Bit Score: 89.46 E-value: 7.39e-20
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| 7tmC_GPR158-like | cd15293 | orphan GPR158 and similar proteins, member of the class C family of seven-transmembrane G ... |
389-603 | 9.03e-17 | ||||||||
orphan GPR158 and similar proteins, member of the class C family of seven-transmembrane G protein-coupled receptors; This group includes orphan receptors GPR158, GPR158-like (also called GPR179) and similar proteins. These orphan receptors are closely related to the type B receptor for gamma-aminobutyric acid (GABA-B), which is activated by its endogenous ligand GABA, the principal inhibitory neurotransmitter. The functional GABA-B receptor is an obligatory heterodimer composed of two related subunits, GABA-B1, which is primarily involved in GABA ligand binding, and GABA-B2, which is responsible for both G-protein coupling and trafficking of the heterodimer to the plasma membrane. Activation of GABA-B couples to G(i/o)-type G proteins, which in turn modulate three major downstream effectors: adenylate cyclase, voltage-sensitive Ca2+ channels, and inwardly-rectifying K+ channels. Consequently, GABA-B receptor produces slow and sustained inhibitory responses by decreased neurotransmitter release via inhibition of Ca2+ channels and by postsynaptic hyperpolarization via the activation of K+ channels through the G-protein beta-gamma dimer. The GABA-B is expressed in both pre- and postsynaptic sites of glutamatergic and GABAergic neurons in the brain where it regulates synaptic activity. Thus, the GABA-B receptor agonist, baclofen, is used to treat muscle tightness and cramping caused by spasticity in multiple sclerosis patients. Moreover, GABA-B antagonists improves cognitive performance in mammals, while GABA-B agonists suppress cognitive behavior. In most of the class C family members, the extracellular Venus-flytrap domain in the N-terminus is connected to the seven-transmembrane (7TM) via a cysteine-rich domain (CRD). However, in the GABA-B receptor, the CRD is absent in both subunits and the Venus-flytrap ligand-binding domain is directly connected to the 7TM via a 10-15 amino acids linker, suggesting that GABA-B receptor may utilize a different activation mechanism. Pssm-ID: 320420 Cd Length: 252 Bit Score: 80.34 E-value: 9.03e-17
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| PBP1_taste_receptor | cd06363 | ligand-binding domain of the T1R taste receptor; Ligand-binding domain of the T1R taste ... |
26-141 | 3.87e-15 | ||||||||
ligand-binding domain of the T1R taste receptor; Ligand-binding domain of the T1R taste receptor. The T1R is a member of the family C receptors within the G-protein coupled receptor superfamily, which also includes the metabotropic glutamate receptors, GABAb receptors, the calcium-sensing receptor (CaSR), the V2R pheromone receptors, and a small group of uncharacterized orphan receptors. Pssm-ID: 380586 [Multi-domain] Cd Length: 418 Bit Score: 78.12 E-value: 3.87e-15
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| PBP1_CaSR | cd06364 | ligand-binding domain of the CaSR calcium-sensing receptor, a member of the family C receptors ... |
33-305 | 1.06e-14 | ||||||||
ligand-binding domain of the CaSR calcium-sensing receptor, a member of the family C receptors within the G-protein coupled receptor superfamily; Ligand-binding domain of the CaSR calcium-sensing receptor, which is a member of the family C receptors within the G-protein coupled receptor superfamily. CaSR provides feedback control of extracellular calcium homeostasis by responding sensitively to acute fluctuations in extracellular ionized Ca2+ concentration. This ligand-binding domain has homology to the bacterial leucine-isoleucine-valine binding protein (LIVBP) and a leucine binding protein (LBP). CaSR is widely expressed in mammalian tissues and is active in tissues that are not directly involved in extracellular calcium homeostasis. Moreover, CaSR responds to aromatic, aliphatic, and polar amino acids, but not to positively charged or branched chain amino acids, which suggests that changes in plasma amino acid levels are likely to modulate whole body calcium metabolism. Additionally, the family C GPCRs includes at least two receptors with broad-spectrum amino acid-sensing properties: GPRC6A which recognizes basic and various aliphatic amino acids, its gold-fish homolog the 5.24 chemoreceptor, and a specific taste receptor (T1R) which responds to aliphatic, polar, charged, and branched amino acids, but not to aromatic amino acids. Pssm-ID: 380587 [Multi-domain] Cd Length: 473 Bit Score: 76.91 E-value: 1.06e-14
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| NCD3G | pfam07562 | Nine Cysteines Domain of family 3 GPCR; This conserved sequence contains several ... |
314-364 | 1.39e-14 | ||||||||
Nine Cysteines Domain of family 3 GPCR; This conserved sequence contains several highly-conserved Cys residues that are predicted to form disulphide bridges. It is predicted to lie outside the cell membrane, tethered to the pfam00003 in several receptor proteins. Pssm-ID: 462210 Cd Length: 53 Bit Score: 68.43 E-value: 1.39e-14
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| ANF_receptor | pfam01094 | Receptor family ligand binding region; This family includes extracellular ligand binding ... |
60-276 | 3.37e-14 | ||||||||
Receptor family ligand binding region; This family includes extracellular ligand binding domains of a wide range of receptors. This family also includes the bacterial amino acid binding proteins of known structure. Pssm-ID: 460062 [Multi-domain] Cd Length: 347 Bit Score: 74.34 E-value: 3.37e-14
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| 7tmC_TAS1R3 | cd15290 | type 1 taste receptor subtype 3, member of the class C of seven-transmembrane G ... |
400-598 | 1.61e-13 | ||||||||
type 1 taste receptor subtype 3, member of the class C of seven-transmembrane G protein-coupled receptors; This group represents TAS1R3, which is a member of the type I taste receptor (TAS1R) family that belongs to the class C of G protein-coupled receptors. The functional TAS1Rs are obligatory heterodimers built from three known members, TAS1R1-3. TAS1R1 combines with TAS1R3 to form an umami taste receptor, which is responsible for the perception of savory taste, such as the food additive mono-sodium glutamate (MSG); whereas the combination of TAS1R2-TAS1R3 forms a sweet-taste receptor for sugars and D-amino acids. On the other hand, the type II taste receptors (TAS2Rs), which belong to the class A family of GPCRs, recognize bitter tasting compounds. In the case of sweet, for example, the TAS1R2-TAS1R3 heterodimer activates phospholipase C (PLC) via alpha-gustducin, a heterodimeric G protein that is involved in perception of sweet and bitter tastes. This activation leads to generation of inositol (1, 4, 5)-trisphosphate (IP3) and diacylglycerol (DAG), and consequently increases intracellular Ca2+ mobilization and activates a cation channel, TRPM5. In contrast to the TAS1R2-TAS1R3 heterodimer, TAS1R3 alone could activate adenylate cyclase leading to cAMP formation in the absence of alpha-gustducin. Each TAS1R contains a large extracellular Venus flytrap-like domain in the N-terminus, cysteine-rich domain (CRD) and seven-transmembrane (7TM) domain, which are characteristics of the class C GPCRs. The Venus flytrap-like domain shares strong sequence homology to bacterial periplasmic binding proteins and possess the orthosteric amino acid and calcium binding sites for members of the class C, including CaSR, GABA-B1, GPRC6A, mGlu, and TAS1R receptors. Pssm-ID: 320417 [Multi-domain] Cd Length: 253 Bit Score: 70.86 E-value: 1.61e-13
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| 7tmC_TAS1R2a-like | cd15287 | type 1 taste receptor subtype 2a and similar proteins, member of the class C of ... |
390-603 | 1.31e-12 | ||||||||
type 1 taste receptor subtype 2a and similar proteins, member of the class C of seven-transmembrane G protein-coupled receptors; This group includes TAS1R2a and its similar proteins found in fish. They are members of the type I taste receptor (TAS1R) family that belongs to the class C of G protein-coupled receptors. The functional TAS1Rs are obligatory heterodimers built from three known members, TAS1R1-3. TAS1R1 combines with TAS1R3 to form an umami taste receptor, which is responsible for the perception of savory taste, such as the food additive mono-sodium glutamate (MSG); whereas the combination of TAS1R2-TAS1R3 forms a sweet-taste receptor for sugars and D-amino acids. On the other hand, the type II taste receptors (TAS2Rs), which belong to the class A family of GPCRs, recognize bitter tasting compounds. In the case of sweet, for example, the TAS1R2-TAS1R3 heterodimer activates phospholipase C (PLC) via alpha-gustducin, a heterodimeric G protein that is involved in perception of sweet and bitter tastes. This activation leads to generation of inositol (1, 4, 5)-trisphosphate (IP3) and diacylglycerol (DAG), and consequently increases intracellular Ca2+ mobilization and activates a cation channel, TRPM5. In contrast to the TAS1R2-TAS1R3 heterodimer, TAS1R3 alone could activate adenylate cyclase leading to cAMP formation in the absence of alpha-gustducin. Each TAS1R contains a large extracellular Venus flytrap-like domain in the N-terminus, cysteine-rich domain (CRD) and seven-transmembrane (7TM) domain, which are characteristics of the class C GPCRs. The Venus flytrap-like domain shares strong sequence homology to bacterial periplasmic binding proteins and possess the orthosteric amino acid and calcium binding sites for members of the class C, including CaSR, GABA-B1, GPRC6A, mGlu, and TAS1R receptors. Pssm-ID: 320414 Cd Length: 252 Bit Score: 68.17 E-value: 1.31e-12
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| PBP1_pheromone_receptor | cd06365 | Ligand-binding domain of the V2R pheromone receptor, a member of the family C receptors within ... |
33-150 | 3.26e-12 | ||||||||
Ligand-binding domain of the V2R pheromone receptor, a member of the family C receptors within the G-protein coupled receptor superfamily; Ligand-binding domain of the V2R pheromone receptor, a member of the family C receptors within the G-protein coupled receptor superfamily, which also includes the metabotropic glutamate receptor, the GABAb receptor, the calcium-sensing receptor (CaSR), the T1R taste receptor, and a small group of uncharacterized orphan receptors. Pssm-ID: 380588 [Multi-domain] Cd Length: 464 Bit Score: 69.21 E-value: 3.26e-12
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| PBP1_glutamate_receptors-like | cd06269 | ligand-binding domain of family C G-protein couples receptors (GPCRs), membrane bound guanylyl ... |
34-109 | 5.66e-12 | ||||||||
ligand-binding domain of family C G-protein couples receptors (GPCRs), membrane bound guanylyl cyclases such as natriuretic peptide receptors (NPRs), and N-terminal leucine/isoleucine/valine-binding protein (LIVBP)-like domain of ionotropic glutamate rece; This CD represents the ligand-binding domain of the family C G-protein couples receptors (GPCRs), membrane bound guanylyl cyclases such as the family of natriuretic peptide receptors (NPRs), and the N-terminal leucine-isoleucine-valine binding protein (LIVBP)-like domain of the ionotropic glutamate receptors, all of which are structurally similar and related to the periplasmic-binding fold type 1 family. The family C GPCRs consists of metabotropic glutamate receptor (mGluR), a calcium-sensing receptor (CaSR), gamma-aminobutyric acid receptor (GABAbR), the promiscuous L-alpha-amino acid receptor GPR6A, families of taste and pheromone receptors, and orphan receptors. Truncated splicing variants of the orphan receptors are not included in this CD. The family C GPCRs are activated by endogenous agonists such as amino acids, ions, and sugar based molecules. Their amino terminal ligand-binding region is homologous to the bacterial leucine-isoleucine-valine binding protein (LIVBP) and a leucine binding protein (LBP). The ionotropic glutamate receptors (iGluRs) have an integral ion channel and are subdivided into three major groups based on their pharmacology and structural similarities: NMDA receptors, AMPA receptors, and kainate receptors. The family of membrane bound guanylyl cyclases is further divided into three subfamilies: the ANP receptor (GC-A)/C-type natriuretic peptide receptor (GC-B), the heat-stable enterotoxin receptor (GC-C)/sensory organ specific membrane GCs such as retinal receptors (GC-E, GC-F), and olfactory receptors (GC-D and GC-G). Pssm-ID: 380493 [Multi-domain] Cd Length: 332 Bit Score: 67.44 E-value: 5.66e-12
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| PBP1_pheromone_receptor | cd06365 | Ligand-binding domain of the V2R pheromone receptor, a member of the family C receptors within ... |
149-305 | 5.92e-12 | ||||||||
Ligand-binding domain of the V2R pheromone receptor, a member of the family C receptors within the G-protein coupled receptor superfamily; Ligand-binding domain of the V2R pheromone receptor, a member of the family C receptors within the G-protein coupled receptor superfamily, which also includes the metabotropic glutamate receptor, the GABAb receptor, the calcium-sensing receptor (CaSR), the T1R taste receptor, and a small group of uncharacterized orphan receptors. Pssm-ID: 380588 [Multi-domain] Cd Length: 464 Bit Score: 68.44 E-value: 5.92e-12
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| PBP1_GPC6A-like | cd06361 | ligand-binding domain of the promiscuous L-alpha-amino acid receptor GPRC6A which is a ... |
33-149 | 3.11e-11 | ||||||||
ligand-binding domain of the promiscuous L-alpha-amino acid receptor GPRC6A which is a broad-spectrum amino acid-sensing receptor; This family includes the ligand-binding domain of the promiscuous L-alpha-amino acid receptor GPRC6A which is a broad-spectrum amino acid-sensing receptor, and its fish homolog, the 5.24 chemoreceptor. GPRC6A is a member of the family C of G-protein-coupled receptors that transduce extracellular signals into G-protein activation and ultimately into cellular responses. Pssm-ID: 380584 [Multi-domain] Cd Length: 401 Bit Score: 65.86 E-value: 3.11e-11
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| 7tm_GPCRs | cd14964 | seven-transmembrane G protein-coupled receptor superfamily; This hierarchical evolutionary ... |
392-608 | 5.79e-10 | ||||||||
seven-transmembrane G protein-coupled receptor superfamily; This hierarchical evolutionary model represents the seven-transmembrane (7TM) receptors, often referred to as G protein-coupled receptors (GPCRs), which transmit physiological signals from the outside of the cell to the inside via G proteins. GPCRs constitute the largest known superfamily of transmembrane receptors across the three kingdoms of life that respond to a wide variety of extracellular stimuli including peptides, lipids, neurotransmitters, amino acids, hormones, and sensory stimuli such as light, smell and taste. All GPCRs share a common structural architecture comprising of seven-transmembrane (TM) alpha-helices interconnected by three extracellular and three intracellular loops. A general feature of GPCR signaling is agonist-induced conformational changes in the receptors, leading to activation of the heterotrimeric G proteins, which consist of the guanine nucleotide-binding G-alpha subunit and the dimeric G-beta-gamma subunits. The activated G proteins then bind to and activate numerous downstream effector proteins, which generate second messengers that mediate a broad range of cellular and physiological processes. However, some 7TM receptors, such as the type 1 microbial rhodopsins, do not activate G proteins. Based on sequence similarity, GPCRs can be divided into six major classes: class A (the rhodopsin-like family), class B (the Methuselah-like, adhesion and secretin-like receptor family), class C (the metabotropic glutamate receptor family), class D (the fungal mating pheromone receptors), class E (the cAMP receptor family), and class F (the frizzled/smoothened receptor family). Nearly 800 human GPCR genes have been identified and are involved essentially in all major physiological processes. Approximately 40% of clinically marketed drugs mediate their effects through modulation of GPCR function for the treatment of a variety of human diseases including bacterial infections. Pssm-ID: 410628 [Multi-domain] Cd Length: 267 Bit Score: 60.52 E-value: 5.79e-10
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| 7tmC_RAIG_GPRC5 | cd15043 | retinoic acid-inducible orphan G-protein-coupled receptors; class C family of ... |
384-598 | 5.38e-09 | ||||||||
retinoic acid-inducible orphan G-protein-coupled receptors; class C family of seven-transmembrane G protein-coupled receptors, group 5; Retinoic acid-inducible G-protein-coupled receptors (RAIGs), also referred to as GPCR class C group 5, are a group consisting of four orphan receptors RAIG1 (GPRC5A), RAIG2 (GPRC5B), RAIG3 (GPRC5C), and RAIG4 (GPRC5D). Unlike other members of the class C GPCRs which contain a large N-terminal extracellular domain, RAIGs have a shorter N-terminus. Thus, it is unlikely that RAIGs bind an agonist at its N-terminus domain. Instead, agonists may bind to the seven-transmembrane domain of these receptors. In addition, RAIG2 and RAIG3 contain a cleavable signal peptide whereas RAIG1 and RAIG4 do not. Although their expression is induced by retinoic acid (vitamin A analog), their biological function is not clearly understood. To date, no ligand is known for the members of RAIG family. Three receptor types (RAIG1-3) are found in vertebrates, while RAIG4 is only present in mammals. They show distinct tissue distribution with RAIG1 being primarily expressed in the lung, RAIG2 in the brain and placenta, RAIG3 in the brain, kidney and liver, and RAIG4 in the skin. RAIG1 is evolutionarily conserved from mammals to fish. RAIG1 has been to shown to act as a tumor suppressor in non-small cell lung carcinoma as well as oral squamous cell carcinoma, but it could also act as an oncogene in breast cancer, colorectal cancer, and pancreatic cancer. Studies have shown that overexpression of RAIG1 decreases intracellular cAMP levels. Moreover, knocking out RAIG1 induces the activation of the NF-kB and STAT3 signaling pathways leading to cell proliferation and resistance to apoptosis. RAIG2 (GPRC5B), a mammalian Boss (Bride of sevenless) homolog, activates obesity-associated inflammatory signaling in adipocytes, and GPRC5B knockout mice show resistance to high-fat diet-induced obesity and insulin resistance. The specific functions of RAIG3 and RAIG4 are unknown; however, they may play roles in mediating the effects of retinoic acid on embryogenesis, differentiation, and tumorigenesis through interactions with G-protein signaling pathways. Pssm-ID: 320171 Cd Length: 248 Bit Score: 57.58 E-value: 5.38e-09
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| 7tmC_RAIG2_GPRC5B | cd15278 | retinoic acid-inducible orphan G-protein-coupled receptor 2; class C family of ... |
385-598 | 8.81e-09 | ||||||||
retinoic acid-inducible orphan G-protein-coupled receptor 2; class C family of seven-transmembrane G protein-coupled receptors, group 5, member B; Retinoic acid-inducible G-protein-coupled receptors (RAIGs), also referred to as GPCR class C group 5, are a group consisting of four orphan receptors RAIG1 (GPRC5A), RAIG2 (GPRC5B), RAIG3 (GPRC5C), and RAIG4 (GPRC5D). Unlike other members of the class C GPCRs which contain a large N-terminal extracellular domain, RAIGs have a shorter N-terminus. Thus, it is unlikely that RAIGs bind an agonist at its N-terminus domain. Instead, the agonists may bind to the seven-transmembrane domain of these receptors. In addition, RAIG2 and RAIG3 contain a cleavable signal peptide whereas RAIG1 and RAIG4 do not. Although their expression is induced by retinoic acid (vitamin A analog), their biological function is not clearly understood. To date, no ligand is known for the members of RAIG family. Three receptor types (RAIG1-3) are found in vertebrates, while RAIG4 is only present in mammals. They show distinct tissue distribution with RAIG1 being primarily expressed in the lung, RAIG2 in the brain and placenta, RAIG3 in the brain, kidney and liver, and RAIG4 in the skin. RAIG2 (GPRC5B), a mammalian Boss (Bride of sevenless) homolog, has been shown to activate obesity-associated inflammatory signaling in adipocytes, and that the GPRC5B knockout mice have been shown to be resistance to high-fat diet-induced obesity and insulin resistance. Pssm-ID: 320405 Cd Length: 244 Bit Score: 56.75 E-value: 8.81e-09
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| 7tmC_RAIG3_GPRC5C | cd15277 | retinoic acid-inducible orphan G-protein-coupled receptor 3; class C family of ... |
384-595 | 3.27e-08 | ||||||||
retinoic acid-inducible orphan G-protein-coupled receptor 3; class C family of seven-transmembrane G protein-coupled receptors, group 5, member C; Retinoic acid-inducible G-protein-coupled receptors (RAIGs), also referred to as GPCR class C group 5, are a group consisting of four orphan receptors RAIG1 (GPRC5A), RAIG2 (GPRC5B), RAIG3 (GPRC5C), and RAIG4 (GPRC5D). Unlike other members of the class C GPCRs which contain a large N-terminal extracellular domain, RAIGs have a shorter N-terminus. Thus, it is unlikely that RAIGs bind an agonist at its N-terminus domain. Instead, the agonists may bind to the seven-transmembrane domain of these receptors. In addition, RAIG2 and RAIG3 contain a cleavable signal peptide whereas RAIG1 and RAIG4 do not. Although their expression is induced by retinoic acid (vitamin A analog), their biological function is not clearly understood. To date, no ligand is known for the members of RAIG family. Three receptor types (RAIG1-3) are found in vertebrates, while RAIG4 is only present in mammals. They show distinct tissue distribution with RAIG1 being primarily expressed in the lung, RAIG2 in the brain and placenta, RAIG3 in the brain, kidney and liver, and RAIG4 in the skin. The specific function of RAIG3 is unknown; however, this protein may play a role in mediating the effects of retinoic acid on embryogenesis, differentiation, and tumorigenesis through interaction with a G-protein signaling cascade. Pssm-ID: 320404 Cd Length: 250 Bit Score: 55.13 E-value: 3.27e-08
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| 7tmC_GABA-B-R1 | cd15291 | gamma-aminobutyric acid type B receptor subunit 1, member of the class C family of ... |
391-603 | 1.80e-06 | ||||||||
gamma-aminobutyric acid type B receptor subunit 1, member of the class C family of seven-transmembrane G protein-coupled receptors; The type B receptor for gamma-aminobutyric acid, GABA-B, is activated by its endogenous ligand GABA, the principal inhibitory neurotransmitter. The functional GABA-B receptor is an obligatory heterodimer composed of two related subunits, GABA-B1, which is primarily involved in GABA ligand binding, and GABA-B2, which is responsible for both G-protein coupling and trafficking of the heterodimer to the plasma membrane. Activation of GABA-B couples to G(i/o)-type G proteins, which in turn modulate three major downstream effectors: adenylate cyclase, voltage-sensitive Ca2+ channels, and inwardly-rectifying K+ channels. Consequently, GABA-B receptor produces slow and sustained inhibitory responses by decreased neurotransmitter release via inhibition of Ca2+ channels and by postsynaptic hyperpolarization via the activation of K+ channels through the G-protein beta-gamma dimer. The GABA-B is expressed in both pre- and postsynaptic sites of glutamatergic and GABAergic neurons in the brain where it regulates synaptic activity. Thus, the GABA-B receptor agonist, baclofen, is used to treat muscle tightness and cramping caused by spasticity in multiple sclerosis patients. Moreover, GABA-B antagonists improves cognitive performance in mammals, while GABA-B agonists suppress cognitive behavior. In most of the class C family members, the extracellular Venus-flytrap domain in the N-terminus is connected to the seven-transmembrane (7TM) via a cysteine-rich domain (CRD). However, in the GABA-B receptor, the CRD is absent in both subunits and the Venus-flytrap ligand-binding domain is directly connected to the 7TM via a 10-15 amino acids linker, suggesting that GABA-B receptor may utilize a different activation mechanism. Pssm-ID: 320418 Cd Length: 274 Bit Score: 50.03 E-value: 1.80e-06
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| 7tmC_RAIG1_4_GPRC5A_D | cd15279 | retinoic acid-inducible orphan G-protein-coupled receptors 1 and 4; class C family of ... |
384-595 | 9.59e-04 | ||||||||
retinoic acid-inducible orphan G-protein-coupled receptors 1 and 4; class C family of seven-transmembrane G protein-coupled receptors, group 5, member A and D; Retinoic acid-inducible G-protein-coupled receptors (RAIGs), also referred to as GPCR class C group 5, are a group consisting of four orphan receptors RAIG1 (GPRC5A), RAIG2 (GPRC5B), RAIG3 (GPRC5C), and RAIG4 (GPRC5D). Unlike other members of the class C GPCRs which contain a large N-terminal extracellular domain, RAIGs have a shorter N-terminus. Thus, it is unlikely that RAIGs bind an agonist at its N-terminus domain. Instead, the agonists may bind to the seven-transmembrane domain of these receptors. In addition, RAIG2 and RAIG3 contain a cleavable signal peptide whereas RAIG1 and RAIG4 do not. Although their expression is induced by retinoic acid (vitamin A analog), their biological function is not clearly understood. To date, no ligand is known for the members of RAIG family. Three receptor types (RAIG1-3) are found in vertebrates, while RAIG4 is only present in mammals. They show distinct tissue distribution with RAIG1 being primarily expressed in the lung, RAIG2 in the brain and placenta, RAIG3 in the brain, kidney and liver, and RAIG4 in the skin. RAIG1 is evolutionarily conserved from mammals to fish. RAIG1 has been to shown to act as a tumor suppressor in non-small cell lung carcinoma as well as oral squamous cell carcinoma, but it could also act as an oncogene in breast cancer, colorectal cancer, and pancreatic cancer. Studies have shown that overexpression of RAIG1 decreases intracellular cAMP levels. Moreover, knocking out RAIG1 induces the activation of the NF-kB and STAT3 signaling pathways leading to cell proliferation and resistance to apoptosis. The specific function of RAIG4 is unknown; however, this protein may play a role in mediating the effects of retinoic acid on embryogenesis, differentiation, and tumorigenesis through interaction with a G-protein signaling cascade. Pssm-ID: 320406 Cd Length: 248 Bit Score: 41.29 E-value: 9.59e-04
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| 7tmC_GABA-B-R2 | cd15294 | gamma-aminobutyric acid type B receptor subunit 2, member of the class C family of ... |
391-602 | 8.73e-03 | ||||||||
gamma-aminobutyric acid type B receptor subunit 2, member of the class C family of seven-transmembrane G protein-coupled receptors; The type B receptor for gamma-aminobutyric acid, GABA-B, is activated by its endogenous ligand GABA, the principal inhibitory neurotransmitter. The functional GABA-B receptor is an obligatory heterodimer composed of two related subunits, GABA-B1, which is primarily involved in GABA ligand binding, and GABA-B2, which is responsible for both G-protein coupling and trafficking of the heterodimer to the plasma membrane. Activation of GABA-B couples to G(i/o)-type G proteins, which in turn modulate three major downstream effectors: adenylate cyclase, voltage-sensitive Ca2+ channels, and inwardly-rectifying K+ channels. Consequently, GABA-B receptor produces slow and sustained inhibitory responses by decreased neurotransmitter release via inhibition of Ca2+ channels and by postsynaptic hyperpolarization via the activation of K+ channels through the G-protein beta-gamma dimer. The GABA-B is expressed in both pre- and postsynaptic sites of glutamatergic and GABAergic neurons in the brain where it regulates synaptic activity. Thus, the GABA-B receptor agonist, baclofen, is used to treat muscle tightness and cramping caused by spasticity in multiple sclerosis patients. Moreover, GABA-B antagonists improves cognitive performance in mammals, while GABA-B agonists suppress cognitive behavior. In most of the class C family members, the extracellular Venus-flytrap domain in the N-terminus is connected to the seven-transmembrane (7TM) via a cysteine-rich domain (CRD). However, in the GABA-B receptor, the CRD is absent in both subunits and the Venus-flytrap ligand-binding domain is directly connected to the 7TM via a 10-15 amino acids linker, suggesting that GABA-B receptor may utilize a different activation mechanism. Pssm-ID: 320421 Cd Length: 270 Bit Score: 38.56 E-value: 8.73e-03
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