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Conserved domains on  [gi|1958798078|ref|XP_038938124|]
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5-hydroxytryptamine receptor 3A isoform X5 [Rattus norvegicus]

Protein Classification

ligand-gated ion channel( domain architecture ID 1903566)

ligand-gated ion channel (LIC or LGIC) is a member of a family of neurotransmitter receptors vital for communication throughout the nervous system

CATH:  2.70.170.10
Gene Ontology:  GO:0022834|GO:0004888
PubMed:  23357172|7754520
TCDB:  1.A.9

Graphical summary

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List of domain hits

Name Accession Description Interval E-value
LIC super family cl42365
Cation transporter family protein; The Ligand-gated Ion Channel (LIC) Family of ...
23-317 9.80e-111

Cation transporter family protein; The Ligand-gated Ion Channel (LIC) Family of Neurotransmitter Receptors TC 1.A.9)Members of the LIC family of ionotropic neurotransmitter receptors are found only in vertebrate and invertebrate animals. They exhibit receptor specificity for (1)acetylcholine, (2) serotonin, (3) glycine, (4) glutamate and (5) g-aminobutyric acid (GABA). All of these receptor channels are probably hetero- orhomopentameric. The best characterized are the nicotinic acetyl-choline receptors which are pentameric channels of a2bgd subunit composition. All subunits arehomologous. The three dimensional structures of the protein complex in both the open and closed configurations have been solved at 0.9 nm resolution.The channel protein complexes of the LIC family preferentially transport cations or anions depending on the channel (e.g., the acetylcholine receptors are cationselective while glycine receptors are anion selective). [Transport and binding proteins, Cations and iron carrying compounds]


The actual alignment was detected with superfamily member TIGR00860:

Pssm-ID: 455710 [Multi-domain]  Cd Length: 459  Bit Score: 329.37  E-value: 9.80e-111
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958798078  23 QDINISLWRTpEEVRSDKSIFINQGEWELLGVFTKFQEFSIETSNSYAEMKFYVVIRRRPLFYAVSLLLPSIFLMVVDIV 102
Cdd:TIGR00860 182 NDIKLEWKEQ-GAVQVDDSLFISLPEFELLGVYGTRYCTSETNTGEYPCLTFSFVLRRRPLYYLLQLYIPSILIVILSWV 260
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958798078 103 GFCLPPD-SGERVSFKITLLLGYSVFLIIVSDTLPATAiGTPLIGVYFVVCMALLVISLAETIFIVQLVHKQDLQRPvpd 181
Cdd:TIGR00860 261 SFWLPADaSGARVSLGITTLLTMTTFSSGVRESLPAVS-YVKAIDVYFAVCMAFVFLALLETAFVNYVHHKDPAQGK--- 336
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958798078 182 wlRHLVLDRIAWLLCLGEQPMAHRPPATFQANktddcsgslLPAMGNHCSHvgSPQDLEK-TSRSRDSPLPPPREASLAV 260
Cdd:TIGR00860 337 --RHLLLERCAWRLCKQEPGEDYRRPALDHAS---------LSSVEMRAKD--GGRGLESpTERQRLLHSPPPAEGDLDL 403
                         250       260       270       280       290
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1958798078 261 RGLLQELsSIRHSLEKRDEMREVARDWLRVGYVLDRLLFRIYLLAVLAYSITLVTLW 317
Cdd:TIGR00860 404 AGILEEV-RIAHRFRKRDESEEVVRDWKFRAKVIDKLSRMAFPLAFLLFNIGYWMSY 459
 
Name Accession Description Interval E-value
LIC TIGR00860
Cation transporter family protein; The Ligand-gated Ion Channel (LIC) Family of ...
23-317 9.80e-111

Cation transporter family protein; The Ligand-gated Ion Channel (LIC) Family of Neurotransmitter Receptors TC 1.A.9)Members of the LIC family of ionotropic neurotransmitter receptors are found only in vertebrate and invertebrate animals. They exhibit receptor specificity for (1)acetylcholine, (2) serotonin, (3) glycine, (4) glutamate and (5) g-aminobutyric acid (GABA). All of these receptor channels are probably hetero- orhomopentameric. The best characterized are the nicotinic acetyl-choline receptors which are pentameric channels of a2bgd subunit composition. All subunits arehomologous. The three dimensional structures of the protein complex in both the open and closed configurations have been solved at 0.9 nm resolution.The channel protein complexes of the LIC family preferentially transport cations or anions depending on the channel (e.g., the acetylcholine receptors are cationselective while glycine receptors are anion selective). [Transport and binding proteins, Cations and iron carrying compounds]


Pssm-ID: 273305 [Multi-domain]  Cd Length: 459  Bit Score: 329.37  E-value: 9.80e-111
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958798078  23 QDINISLWRTpEEVRSDKSIFINQGEWELLGVFTKFQEFSIETSNSYAEMKFYVVIRRRPLFYAVSLLLPSIFLMVVDIV 102
Cdd:TIGR00860 182 NDIKLEWKEQ-GAVQVDDSLFISLPEFELLGVYGTRYCTSETNTGEYPCLTFSFVLRRRPLYYLLQLYIPSILIVILSWV 260
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958798078 103 GFCLPPD-SGERVSFKITLLLGYSVFLIIVSDTLPATAiGTPLIGVYFVVCMALLVISLAETIFIVQLVHKQDLQRPvpd 181
Cdd:TIGR00860 261 SFWLPADaSGARVSLGITTLLTMTTFSSGVRESLPAVS-YVKAIDVYFAVCMAFVFLALLETAFVNYVHHKDPAQGK--- 336
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958798078 182 wlRHLVLDRIAWLLCLGEQPMAHRPPATFQANktddcsgslLPAMGNHCSHvgSPQDLEK-TSRSRDSPLPPPREASLAV 260
Cdd:TIGR00860 337 --RHLLLERCAWRLCKQEPGEDYRRPALDHAS---------LSSVEMRAKD--GGRGLESpTERQRLLHSPPPAEGDLDL 403
                         250       260       270       280       290
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1958798078 261 RGLLQELsSIRHSLEKRDEMREVARDWLRVGYVLDRLLFRIYLLAVLAYSITLVTLW 317
Cdd:TIGR00860 404 AGILEEV-RIAHRFRKRDESEEVVRDWKFRAKVIDKLSRMAFPLAFLLFNIGYWMSY 459
Neur_chan_memb pfam02932
Neurotransmitter-gated ion-channel transmembrane region; This family includes the four ...
89-313 2.90e-62

Neurotransmitter-gated ion-channel transmembrane region; This family includes the four transmembrane helices that form the ion channel.


Pssm-ID: 460753 [Multi-domain]  Cd Length: 232  Bit Score: 197.49  E-value: 2.90e-62
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958798078  89 LLLPSIFLMVVDIVGFCLPPDS-GERVSFKITLLLGYSVFLIIVSDTLPATAIGTPLIGVYFVVCMALLVISLAETIFIV 167
Cdd:pfam02932   1 LIIPCVLISFLSWLVFWLPADAvGEKVTLGITVLLTMTVFLLLIRESLPKTSYVVPLIGKYLLFCMVFVFLSLVETVFVL 80
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958798078 168 QLVHKQDLQRPVPDWLRHLVLDRIAWLLCLGEQPMAHRPPA----TFQANKTDDCSG-SLLPAMGNHCSHVGSPQDLEKT 242
Cdd:pfam02932  81 NVHHRSPSTHKMPPWVRKIFLEKLPRLLGMKRPPEAPPPPAspgyGSKAEEYILRKPrSELPFEKQSERHGLGRETTCSY 160
                         170       180       190       200       210       220       230
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 1958798078 243 SRSRDSPLPPPREASLAVRGLLQELSSIRHSLEKRDEMREVARDWLRVGYVLDRLLFRIYLLAVLAYSITL 313
Cdd:pfam02932 161 GCSLGNGSSQPRELSPELKKAVEGVNFIAKHLRSQDEYISVKEDWKYVAMVIDRLSRWIFPIAFVLGTLGY 231
LGIC_TM_5-HT3 cd19063
transmembrane domain of 5-hydroxytryptamine 3 (5-HT3) receptor; This family contains ...
83-197 1.69e-45

transmembrane domain of 5-hydroxytryptamine 3 (5-HT3) receptor; This family contains transmembrane (TM) domain of the serotonin 5-HT3 receptors. The transmembrane region consists of four transmembrane-spanning alpha-helical segments (M1-M4) that are linked by loops. The intracellular loop that links M1 and M2 determines the ion selectivity of the channel. The 5-HT3 channel is cation-selective and mediates neuronal depolarization and excitation within the central and peripheral nervous systems. Like other ligand gated ion channels, the 5-HT3 receptor consists of five subunits arranged around a central ion conducting pore, which is permeable to Na+, K+, and Ca2+ ions. Binding of the neurotransmitter 5-hydroxytryptamine (serotonin) to the 5-HT3 receptor opens the channel, which then leads to an excitatory response in neurons, and the rapidly activating, desensitizing, inward current is predominantly carried by Na+ and K+ ions. This receptor is most closely related by homology to the nicotinic acetylcholine receptor (nAChR). Five subunits have been identified for this family: 5-HT3A, 5-HT3B, 5-HT3C, 5-HT3D, and 5-HT3E, encoded by HTR3A-E genes. Only 5-HT3A subunits are able to form functional homomeric receptors, whereas the 5-HT3B, C, D, and E subunits form heteromeric receptors with 5-HT3A. Different receptor subtypes are important mediators of nausea and vomiting during chemotherapy, pregnancy, and following surgery, while some contribute to neuro-gastroenterologic disorders such irritable bowel syndrome (IBS) and eating disorders as well as co-morbid psychiatric conditions. 5-HT3 receptor antagonists are established treatments for emesis and IBS, and are beneficial in the treatment of psychiatric diseases.


Pssm-ID: 349865  Cd Length: 121  Bit Score: 150.47  E-value: 1.69e-45
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958798078  83 LFYAVSLLLPSIFLMVVDIVGFCLPPDSGERVSFKITLLLGYSVFLIIVSDTLPATAIGTPLIGVYFVVCMALLVISLAE 162
Cdd:cd19063     1 LLYVVNLLIPSIFLMLVDLASFYLPPNSGERLGFKVTLLLGYSVFLLILNDLLPATAIGTPLIGVYFVVCLALMVLSLLE 80
                          90       100       110
                  ....*....|....*....|....*....|....*.
gi 1958798078 163 TIFIVQLVHkqdlqrpvpdWLR-HLVLDRIAWLLCL 197
Cdd:cd19063    81 TILIVKLLH----------WLRvAYVLDRLLFRLYL 106
 
Name Accession Description Interval E-value
LIC TIGR00860
Cation transporter family protein; The Ligand-gated Ion Channel (LIC) Family of ...
23-317 9.80e-111

Cation transporter family protein; The Ligand-gated Ion Channel (LIC) Family of Neurotransmitter Receptors TC 1.A.9)Members of the LIC family of ionotropic neurotransmitter receptors are found only in vertebrate and invertebrate animals. They exhibit receptor specificity for (1)acetylcholine, (2) serotonin, (3) glycine, (4) glutamate and (5) g-aminobutyric acid (GABA). All of these receptor channels are probably hetero- orhomopentameric. The best characterized are the nicotinic acetyl-choline receptors which are pentameric channels of a2bgd subunit composition. All subunits arehomologous. The three dimensional structures of the protein complex in both the open and closed configurations have been solved at 0.9 nm resolution.The channel protein complexes of the LIC family preferentially transport cations or anions depending on the channel (e.g., the acetylcholine receptors are cationselective while glycine receptors are anion selective). [Transport and binding proteins, Cations and iron carrying compounds]


Pssm-ID: 273305 [Multi-domain]  Cd Length: 459  Bit Score: 329.37  E-value: 9.80e-111
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958798078  23 QDINISLWRTpEEVRSDKSIFINQGEWELLGVFTKFQEFSIETSNSYAEMKFYVVIRRRPLFYAVSLLLPSIFLMVVDIV 102
Cdd:TIGR00860 182 NDIKLEWKEQ-GAVQVDDSLFISLPEFELLGVYGTRYCTSETNTGEYPCLTFSFVLRRRPLYYLLQLYIPSILIVILSWV 260
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958798078 103 GFCLPPD-SGERVSFKITLLLGYSVFLIIVSDTLPATAiGTPLIGVYFVVCMALLVISLAETIFIVQLVHKQDLQRPvpd 181
Cdd:TIGR00860 261 SFWLPADaSGARVSLGITTLLTMTTFSSGVRESLPAVS-YVKAIDVYFAVCMAFVFLALLETAFVNYVHHKDPAQGK--- 336
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958798078 182 wlRHLVLDRIAWLLCLGEQPMAHRPPATFQANktddcsgslLPAMGNHCSHvgSPQDLEK-TSRSRDSPLPPPREASLAV 260
Cdd:TIGR00860 337 --RHLLLERCAWRLCKQEPGEDYRRPALDHAS---------LSSVEMRAKD--GGRGLESpTERQRLLHSPPPAEGDLDL 403
                         250       260       270       280       290
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1958798078 261 RGLLQELsSIRHSLEKRDEMREVARDWLRVGYVLDRLLFRIYLLAVLAYSITLVTLW 317
Cdd:TIGR00860 404 AGILEEV-RIAHRFRKRDESEEVVRDWKFRAKVIDKLSRMAFPLAFLLFNIGYWMSY 459
Neur_chan_memb pfam02932
Neurotransmitter-gated ion-channel transmembrane region; This family includes the four ...
89-313 2.90e-62

Neurotransmitter-gated ion-channel transmembrane region; This family includes the four transmembrane helices that form the ion channel.


Pssm-ID: 460753 [Multi-domain]  Cd Length: 232  Bit Score: 197.49  E-value: 2.90e-62
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958798078  89 LLLPSIFLMVVDIVGFCLPPDS-GERVSFKITLLLGYSVFLIIVSDTLPATAIGTPLIGVYFVVCMALLVISLAETIFIV 167
Cdd:pfam02932   1 LIIPCVLISFLSWLVFWLPADAvGEKVTLGITVLLTMTVFLLLIRESLPKTSYVVPLIGKYLLFCMVFVFLSLVETVFVL 80
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958798078 168 QLVHKQDLQRPVPDWLRHLVLDRIAWLLCLGEQPMAHRPPA----TFQANKTDDCSG-SLLPAMGNHCSHVGSPQDLEKT 242
Cdd:pfam02932  81 NVHHRSPSTHKMPPWVRKIFLEKLPRLLGMKRPPEAPPPPAspgyGSKAEEYILRKPrSELPFEKQSERHGLGRETTCSY 160
                         170       180       190       200       210       220       230
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 1958798078 243 SRSRDSPLPPPREASLAVRGLLQELSSIRHSLEKRDEMREVARDWLRVGYVLDRLLFRIYLLAVLAYSITL 313
Cdd:pfam02932 161 GCSLGNGSSQPRELSPELKKAVEGVNFIAKHLRSQDEYISVKEDWKYVAMVIDRLSRWIFPIAFVLGTLGY 231
LGIC_TM_5-HT3 cd19063
transmembrane domain of 5-hydroxytryptamine 3 (5-HT3) receptor; This family contains ...
83-197 1.69e-45

transmembrane domain of 5-hydroxytryptamine 3 (5-HT3) receptor; This family contains transmembrane (TM) domain of the serotonin 5-HT3 receptors. The transmembrane region consists of four transmembrane-spanning alpha-helical segments (M1-M4) that are linked by loops. The intracellular loop that links M1 and M2 determines the ion selectivity of the channel. The 5-HT3 channel is cation-selective and mediates neuronal depolarization and excitation within the central and peripheral nervous systems. Like other ligand gated ion channels, the 5-HT3 receptor consists of five subunits arranged around a central ion conducting pore, which is permeable to Na+, K+, and Ca2+ ions. Binding of the neurotransmitter 5-hydroxytryptamine (serotonin) to the 5-HT3 receptor opens the channel, which then leads to an excitatory response in neurons, and the rapidly activating, desensitizing, inward current is predominantly carried by Na+ and K+ ions. This receptor is most closely related by homology to the nicotinic acetylcholine receptor (nAChR). Five subunits have been identified for this family: 5-HT3A, 5-HT3B, 5-HT3C, 5-HT3D, and 5-HT3E, encoded by HTR3A-E genes. Only 5-HT3A subunits are able to form functional homomeric receptors, whereas the 5-HT3B, C, D, and E subunits form heteromeric receptors with 5-HT3A. Different receptor subtypes are important mediators of nausea and vomiting during chemotherapy, pregnancy, and following surgery, while some contribute to neuro-gastroenterologic disorders such irritable bowel syndrome (IBS) and eating disorders as well as co-morbid psychiatric conditions. 5-HT3 receptor antagonists are established treatments for emesis and IBS, and are beneficial in the treatment of psychiatric diseases.


Pssm-ID: 349865  Cd Length: 121  Bit Score: 150.47  E-value: 1.69e-45
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958798078  83 LFYAVSLLLPSIFLMVVDIVGFCLPPDSGERVSFKITLLLGYSVFLIIVSDTLPATAIGTPLIGVYFVVCMALLVISLAE 162
Cdd:cd19063     1 LLYVVNLLIPSIFLMLVDLASFYLPPNSGERLGFKVTLLLGYSVFLLILNDLLPATAIGTPLIGVYFVVCLALMVLSLLE 80
                          90       100       110
                  ....*....|....*....|....*....|....*.
gi 1958798078 163 TIFIVQLVHkqdlqrpvpdWLR-HLVLDRIAWLLCL 197
Cdd:cd19063    81 TILIVKLLH----------WLRvAYVLDRLLFRLYL 106
LGIC_TM cd03559
transmembrane domain of Cys-loop neurotransmitter-gated ion channels; This superfamily ...
84-174 2.66e-34

transmembrane domain of Cys-loop neurotransmitter-gated ion channels; This superfamily contains the transmembrane domain of Cys-loop neurotransmitter-gated ion channels, which include nicotinic acetylcholine receptor (nAChR), serotonin 5-hydroxytryptamine receptor (5-HT3), type-A gamma-aminobutyric acid receptor (GABAAR), and glycine receptor (GlyR). These ligand-gated ion channels (LGICs) are found across metazoans and have close homologs in bacteria. They are vital for communication throughout the nervous system where the sign of synaptic connections (excitatory or inhibitory) is determined by the charge of the ions that flow through these channels. In general, channels that conduct positive ions are excitatory, whereas channels that conduct negative ions are inhibitory. The transmembrane region consists of four transmembrane-spanning alpha-helical segments (M1-M4) that are linked by loops. The intracellular loop that links M1 and M2 determines the ion selectivity of the channel. GABAAR and GlyR are anionic channels, both mediating fast inhibitory synaptic transmission. Cl- ions are selectively conducted through the GABAAR receptor pore, resulting in hyperpolarization of the neuron. nAChR is a non-selective cation channel that is permeable to Na+ and K+, and some subunit combinations are also permeable to Ca2+. Na+ enters and K+ exits to allow net flow of positively charged ions inward. 5-HT3, a cation-selective channel, binds serotonin and is permeable to Na+, K+, and Ca2+. It mediates neuronal depolarization and excitation within the central and peripheral nervous systems. These ligand-gated chloride channels are critical not only for maintaining appropriate neuronal activity, but have long been important therapeutic targets: benzodiazepines, barbiturates, some intravenous and volatile anaesthetics, alcohol, strychnine, picrotoxin, and ivermectin all derive their biological activity from acting on the inhibitory half of the Cys-loop receptor family.


Pssm-ID: 349850  Cd Length: 116  Bit Score: 121.48  E-value: 2.66e-34
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958798078  84 FYAVSLLLPSIFLMVVDIVGFCLPPDSGERVSFKITLLLGYSVFLIIVSDTLPATAiGTPLIGVYFVVCMALLVISLAET 163
Cdd:cd03559     1 YYAVSLLLPSILIMVVSWVGFWLPPDSGERVSFKITLLLTYSVFLIIVSDTLPATP-YTPLIDVYFVVCMALLFIALLET 79
                          90
                  ....*....|.
gi 1958798078 164 IFIVQLVHKQD 174
Cdd:cd03559    80 IFIVRLVHKQD 90
LGIC_TM_cation cd19051
transmembrane domain of Cys-loop neurotransmitter-gated ion channels, includes 5HT3, nAChR, ...
83-197 1.86e-32

transmembrane domain of Cys-loop neurotransmitter-gated ion channels, includes 5HT3, nAChR, and ZAC; This superfamily contains the transmembrane (TM) domain of cationic Cys-loop neurotransmitter-gated ion channels, which include nicotinic acetylcholine receptor (nAChR), serotonin 5-hydroxytryptamine receptor (5-HT3), and zinc-activated ligand-gated ion channel (ZAC) receptor. The transmembrane region consists of four transmembrane-spanning alpha-helical segments (M1-M4) that are linked by loops. The intracellular loop that links M1 and M2 determines the ion selectivity of the channel. The ligand-gated ion channels (LGICs) in this family are found across metazoans and have close homologs in bacteria. They are vital for communication throughout the nervous system. nAChR is a non-selective cation channel that is permeable to Na+ and K+, and some subunit combinations are also permeable to Ca2+. Na+ enters and K+ exits to allow net flow of positively charged ions inward. 5-HT3, a cation-selective channel, binds serotonin and is permeable to Na+, K+, and Ca2+. It mediates neuronal depolarization and excitation within the central and peripheral nervous systems. ZAC forms an ion channel gated by Zn2+, Cu2+, and H+ and is non-selectively permeable to monovalent cations. However, the role of ZAC in Zn2+, Cu2+, and H+ signaling require is as yet unknown.


Pssm-ID: 349853 [Multi-domain]  Cd Length: 112  Bit Score: 116.31  E-value: 1.86e-32
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958798078  83 LFYAVSLLLPSIFLMVVDIVGFCLPPDSGERVSFKITLLLGYSVFLIIVSDTLPATAIGTPLIGVYFVVCMALLVISLAE 162
Cdd:cd19051     1 LFYVFNLILPCVLLSVLALLVFLLPPDSGEKVSLGITVLLSLTVFLLLVSESLPPTSDSVPLIGIYLLATMVLSALSTVL 80
                          90       100       110
                  ....*....|....*....|....*....|....*
gi 1958798078 163 TIFIVQLvhkqdlqrpvpdwlrHLVLDRIAWLLCL 197
Cdd:cd19051    81 TVIVLNL---------------HHVLDRLFFWLFL 100
LGIC_ECD_5-HT3A cd19011
extracellular domain of serotonin 5-hydroxytryptamine receptor (5-HT3) receptor subunit A ...
23-81 2.92e-31

extracellular domain of serotonin 5-hydroxytryptamine receptor (5-HT3) receptor subunit A (5HT3A); This subfamily contains extracellular domain of subunit A of serotonin 5-HT3 receptor (5-HT3AR), encoded by the HTR3A gene. 5-HT3A subunit forms a homopentameric complex or a heterologous combination with other subunits (B-E). Heteromeric combination of A and B subunits provides the full functional features of this receptor, since either subunit alone results in receptors with very low conductance and response amplitude. 5-HT3A receptors are located in the dorsal vagal complex of the brainstem and in the gastrointestinal (GI) tract, and form a channel circuit that controls gut motility, secretion, visceral perception, and the emesis reflex. These receptors are implicated in several GI and psychiatric disorder conditions including anxiety, depression, bipolar disorder, and irritable bowel syndrome (IBS). Several 5-HT3AR antagonists, such as the isoquinoline Palonosetron, are in clinical use to control emetic reflexes associated with gastrointestinal pathologies and cancer therapies. SNPs in the 5-HT3A serotonin receptor gene are associated with psychiatric disorders.


Pssm-ID: 349812  Cd Length: 208  Bit Score: 116.48  E-value: 2.92e-31
                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1958798078  23 QDINISLWRTPEEVRSDKSIFINQGEWELLGVFTKFQEFSIETSNSYAEMKFYVVIRRR 81
Cdd:cd19011   150 QDINISLWRSPEEVKSDKSVFMNQGEWELLGVLPQYREFSIDISDSYAEMKFYVVIRRR 208
LGIC_TM_nAChR cd19064
transmembrane domain of nicotinic acetylcholine receptor (nAChR); This family contains ...
83-191 2.71e-18

transmembrane domain of nicotinic acetylcholine receptor (nAChR); This family contains transmembrane (TM) domain of the nicotinic acetylcholine receptor (nAChR). The transmembrane region consists of four transmembrane-spanning alpha-helical segments (M1-M4) that are linked by loops. The intracellular loop that links M1 and M2 determines the ion selectivity of the channel. nAChR is found in high concentrations at the nerve-muscle synapse, where it mediates fast chemical transmission of electrical signals in response to the endogenous neurotransmitter acetylcholine (ACh) released from the nerve terminal into the synaptic cleft. Thus far, seventeen nAChR subunits have been identified, including ten alpha subunits, four beta subunits and one gamma, delta, and epsilon subunit each, all found on the cell membrane that non-selectively conducts cations (Na+, K+, Ca++). These nAChR subunits combine in several different ways to form functional nAChR subtypes which are broadly categorized as either muscle subtype located at the neuromuscular junction or neuronal subtype that are found on neurons and on other cell types throughout the body. The muscle type of nAChRs are formed by the alpha1, beta1, gamma, delta, and epsilon subunits while the neuronal type are composed of nine alpha subunits and three beta subunits, which combine in various permutations and combinations to form functional receptors. Among various subtypes of neuronal nAChRs, the homomeric alpha7 and the heteromeric alpha4beta2 receptors are the main subtypes widely distributed in the brain and implicated in the pathophysiology of neurodevelopmental disorders such as schizophrenia and autism and neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease. Among subtypes of muscle nAChRs, the heteromeric subunits (alpha1)2, beta, gamma, and delta in fetal muscle, and the gamma subunit replaced by epsilon in adult muscle have been implicated in congenital myasthenic syndromes and multiple pterygium syndromes due to various mutations. This family also includes alpha- and beta-like nAChRs found in protostomia.


Pssm-ID: 349866 [Multi-domain]  Cd Length: 113  Bit Score: 79.09  E-value: 2.71e-18
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958798078  83 LFYAVSLLLPSIFLMVVDIVGFCLPPDSGERVSFKITLLLGYSVFLIIVSDTLPATAIGTPLIGVYFVVCMALLVISLAE 162
Cdd:cd19064     1 LFYTVNLIIPCVLISFLTVLVFYLPADSGEKITLSISVLLALTVFLLLIAEIIPPTSLVVPLIGKYLLFTMILVTLSIIV 80
                          90       100
                  ....*....|....*....|....*....
gi 1958798078 163 TIFIVQlvhkqdlqrpvpdwLRHLVLDRI 191
Cdd:cd19064    81 TVIVLN--------------VHHRVIDRL 95
LGIC_ECD_5-HT3 cd18996
extracellular domain of serotonin 5-HT3 receptor; This family contains extracellular domain of ...
23-81 2.08e-14

extracellular domain of serotonin 5-HT3 receptor; This family contains extracellular domain of serotonin 5-HT3 receptor which belongs to the Cys-loop superfamily of ligand-gated ion channels (LGICs). This ion channel is cation-selective and mediates neuronal depolarization and excitation within the central and peripheral nervous systems. Like other ligand gated ion channels, the 5-HT3 receptor consists of five subunits arranged around a central ion conducting pore, which is permeable to Na+, K+, and Ca2+ ions. Binding of the neurotransmitter 5-hydroxytryptamine (serotonin) to the 5-HT3 receptor opens the channel, which then leads to an excitatory response in neurons, and the rapidly activating, desensitizing, inward current is predominantly carried by Na+ and K+ ions. This receptor is most closely related by homology to the nicotinic acetylcholine receptor (nAChR). Five subunits have been identified for this family: 5-HT3A, 5-HT3B, 5-HT3C, 5-HT3D, and 5-HT3E, encoded by HTR3A-E genes. Only 5-HT3A subunits are able to form functional homomeric receptors, whereas the 5-HT3B, C, D, and E subunits form heteromeric receptors with 5-HT3A. Different receptor subtypes are important mediators of nausea and vomiting during chemotherapy, pregnancy, and following surgery, while some contribute to neuro-gastroenterologic disorders such irritable bowel syndrome (IBS) and eating disorders as well as co-morbid psychiatric conditions. 5-HT3 receptor antagonists are established treatments for emesis and IBS, and are beneficial in the treatment of psychiatric diseases.


Pssm-ID: 349797  Cd Length: 215  Bit Score: 70.87  E-value: 2.08e-14
                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958798078  23 QDINISLWRTPEEVRS-DKSIFINQGEWELLGVFTKFQEFSiETSNSYAEMKFYVVIRRR 81
Cdd:cd18996   157 NDIILNPGSNSEEITSeSKEIFQTQGEWELLNIKVSDEKLS-LLGNSFDQIVYQITIKRR 215
LGIC_ECD_5-HT3B cd19012
extracellular domain of serotonin 5-hydroxytryptamine receptor (5-HT3) receptor subunit B ...
23-81 2.32e-13

extracellular domain of serotonin 5-hydroxytryptamine receptor (5-HT3) receptor subunit B (5HT3B); This subfamily contains extracellular domain of subunit B of serotonin 5-HT3 receptor (5-HT3BR), encoded by the HTR3B gene. 5-HT3B is not functional as a homopentameric complex and is co-expression with the 5-HT3A subunit, resulting in heteromeric 5-HT3AB receptors that are functionally distinct from homomeric 5-HT3A receptors. This receptor causes fast, depolarizing responses in neurons after activation, with affinities of competitive ligands at the two receptor subtypes extracellular domains mostly similar. HTR3B gene variants may contribute to variability in severity of and response to anti-emetic therapy for nausea and vomiting in pregnancy, as well as efficacy of ondansetron in cancer chemotherapy, radiation therapy, or surgery. 5-HT3B subunit affects high-potency inhibition of 5-HT3 receptors by morphine by reducing its affinity at its high-affinity, non-competitive site.


Pssm-ID: 349813  Cd Length: 210  Bit Score: 68.01  E-value: 2.32e-13
                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1958798078  23 QDINISLWRTPEEVRSDKSIFINQGEWELLGVFTKFQEFSIETSNsYAEMKFYVVIRRR 81
Cdd:cd19012   153 GDVDLALWRSPEEIANDKREFLNDGEWELLSVPSRYRILHMEDQD-FAQIQFNVVIRRR 210
LGIC_TM_ZAC cd19065
transmembrane domain of zinc-activated ligand-gated ion channel; This family contains ...
87-180 7.73e-13

transmembrane domain of zinc-activated ligand-gated ion channel; This family contains transmembrane (TM) domain of zinc-activated ligand-gated ion channel (ZAC). The transmembrane region consists of four transmembrane-spanning alpha-helical segments (M1-M4) that are linked by loops. The intracellular loop that links M1 and M2 determines the ion selectivity of the channel. ZAC displays low sequence similarity to other members in the superfamily, with closest matches to the human serotonin 5-HT3 receptor (5-HT3R) subunits 5-HT3A and 5-HT3B, and nAChR alpha7 subunits that exhibit approximately 15% amino acid sequence identity to ZAC. Expression of ZAC has been detected in human fetal whole brain, spinal cord, pancreas, placenta, prostate, thyroid, trachea, and stomach, as well as in adult hippocampus, striatum, amygdala, and thalamus. ZAC forms an ion channel gated by Zn2+, Cu2+, and H+, and is non-selectively permeable to monovalent cations. However, the role of ZAC in Zn2+, Cu2+, and H+ signaling is as yet unknown.


Pssm-ID: 349867  Cd Length: 176  Bit Score: 65.77  E-value: 7.73e-13
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958798078  87 VSLLLPSIFLMVVDIVGFCLPPDSGERVSFKITLLLGYSVFLIIVSDTLPATAIGTPLIGVYFVVCMALLVISLAETIFI 166
Cdd:cd19065     5 IALLVPGEALLLADVCGGLLPLRATERIAYKVTLLLSYLVFHSSLVQALPSSSSCNPLLIYYFTVLLLLLFLSTIETVLL 84
                          90
                  ....*....|....*..
gi 1958798078 167 VQLVHKQDLQ---RPVP 180
Cdd:cd19065    85 AGLLARGNLGaksSPSP 101
LGIC_ECD_5-HT3C_E cd19013
extracellular domain of serotonin 5-hydroxytryptamine receptor (5-HT3) receptor subunit E ...
23-81 3.09e-05

extracellular domain of serotonin 5-hydroxytryptamine receptor (5-HT3) receptor subunit E (5HT3E); may include subunits C and D (5-HT3C,D); This subfamily contains extracellular domain of subunit E of serotonin 5-HT3 receptor (5-HT3ER), encoded by the HTR3E gene, and may also contain subunits C and D, all three encoding genes forming a cluster on chromosome 3. Data show that 5-HT3C, 5-HT3D, and 5-HT3E subunits are co-expressed with 5-HT3A in cell bodies of myenteric neurons, and that 5-HT3A and 5-HT3D are expressed in submucosal plexus of the human large intestine while HTR3E is restricted to the colon, intestine, and stomach. None of these subunits can form functional homopentamers, but, upon co-expression with the 5-HT3A subunit, they give rise to functional receptors that differ in maximal responses to 5-HT, and thus modulate 5-HT3 receptor's pharmacological profile. HTR3A and HTR3E polymorphisms have been shown to remarkably up-regulate the expression of 5-HT3 receptors, which have been proved to cause the gastric functional disorders including emesis, eating disorders and IBS-D.


Pssm-ID: 349814  Cd Length: 215  Bit Score: 44.31  E-value: 3.09e-05
                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958798078  23 QDINISLWRTPEEV-RSDKSIFINQGEWELLGVFTKFQEFSIEtSNSYAEMKFYVVIRRR 81
Cdd:cd19013   157 DDIKLFLLLSVEEIlKNSRKVLTTQGEWELVDIKAAKAKLSFG-EELYDEITFYVIIRRR 215
LGIC_TM_anion cd19049
transmembrane domain of anionic Cys-loop neurotransmitter-gated ion channels, includes GABAAR, ...
84-166 2.76e-03

transmembrane domain of anionic Cys-loop neurotransmitter-gated ion channels, includes GABAAR, GlyR and GluCl; This family contains transmembrane domain of type-A gamma-aminobutyric acid receptor (GABAAR) as well as glycine receptor (GlyR) subunits. Thus far, there are 18 vertebrate receptor subunits categorized in 7 families: alpha1-6, beta1-4, gamma1-4, delta, epsilon, theta, rho, and pi. The transmembrane region consists of four transmembrane-spanning alpha-helical segments (M1-M4) that are linked by loops. The intracellular loop that links M1 and M2 determines the ion selectivity of the channel. GABAAR is an anionic channel, mediating fast inhibitory synaptic transmission. Cl- ions are selectively conducted through the GABAAR pore, resulting in hyperpolarization of the neuron. GABAAR is the principal mediator of rapid inhibitory synaptic transmission in the human brain. A decline in GABAAR signaling triggers hyperactive neurological disorders such as insomnia, anxiety, and epilepsy. GlyR, with a similar structure as GABAAR, is concentrated in the brain stem and spinal cord in the CNS and can be activated by glycine, beta-alanine, or taurine. It is selectively blocked by the high-affinity competitive antagonist strychnine, which causes death by asphyxiation. An autosomal dominant R271Q mutation in GLRA1 causes hyperekplexia (Startle disease or Stiff Baby Syndrome) by decreasing glycine sensitivity.


Pssm-ID: 349851  Cd Length: 111  Bit Score: 37.05  E-value: 2.76e-03
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958798078  84 FYAVSLLLPSIFLMVVDIVGFCLPPDS-GERVSFKITLLLGYSVFLIIVSDTLP----ATAigtplIGVYFVVCMALLVI 158
Cdd:cd19049     1 YYLIQTYIPSILIVILSWVSFWIDPEAvPARVSLGITTVLTMTTQSSGVRSSLPkvsyVKA-----IDVWLGVCFVFVFA 75

                  ....*...
gi 1958798078 159 SLAETIFI 166
Cdd:cd19049    76 ALLEYAVV 83
Neur_chan_LBD pfam02931
Neurotransmitter-gated ion-channel ligand binding domain; This family is the extracellular ...
23-82 3.01e-03

Neurotransmitter-gated ion-channel ligand binding domain; This family is the extracellular ligand binding domain of these ion channels. This domain forms a pentameric arrangement in the known structure.


Pssm-ID: 460752 [Multi-domain]  Cd Length: 215  Bit Score: 38.40  E-value: 3.01e-03
                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 1958798078  23 QDINISLWRTP---EEVRSDKSIFINQGEWELLGV-FTKFQEFSIETSNSYAEMKFYVVIRRRP 82
Cdd:pfam02931 152 EEVDLRWDDDPpvvELEEIDLSDFWLNGEWDIVDVpAKRREYPYGCYSELTGDVTFYFTLRRKP 215
 
Blast search parameters
Data Source: Precalculated data, version = cdd.v.3.21
Preset Options:Database: CDSEARCH/cdd   Low complexity filter: no  Composition Based Adjustment: yes   E-value threshold: 0.01

References:

  • Wang J et al. (2023), "The conserved domain database in 2023", Nucleic Acids Res.51(D)384-8.
  • Lu S et al. (2020), "The conserved domain database in 2020", Nucleic Acids Res.48(D)265-8.
  • Marchler-Bauer A et al. (2017), "CDD/SPARCLE: functional classification of proteins via subfamily domain architectures.", Nucleic Acids Res.45(D)200-3.
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