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Conserved domains on  [gi|1720426105|ref|XP_030099091|]
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neuronal acetylcholine receptor subunit beta-3 isoform X1 [Mus musculus]

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 ...
1-320 8.09e-91

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: 278.52  E-value: 8.09e-91
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   1 MTKAIVKS--SGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYDGTMVDLILINEN---VDRKDFFDNGEWEIL 75
Cdd:TIGR00860 131 MTNVLVRIhpNGSVLYSPRITLTLACPMDLRNFPFDVQNCSLKFESWGYTTNDIKLEWKEQGavqVDDSLFISLPEFELL 210
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105  76 NAKGMKG-NRREGFYSYPFVTYSFVLRRLPLFYTLFLIIPCLGLSFLTVLVFYLPSD-EGEKLSLSTSVLVSLTVFLLVI 153
Cdd:TIGR00860 211 GVYGTRYcTSETNTGEYPCLTFSFVLRRRPLYYLLQLYIPSILIVILSWVSFWLPADaSGARVSLGITTLLTMTTFSSGV 290
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105 154 EEIIPSSSkVIPLIGEYLLFIMIFVTLSIIVTVFVINVHHRSSSTYHpmapwvKRLFLEKLPRWLCMKDPRDRFSFPD-G 232
Cdd:TIGR00860 291 RESLPAVS-YVKAIDVYFAVCMAFVFLALLETAFVNYVHHKDPAQGK------RHLLLERCAWRLCKQEPGEDYRRPAlD 363
                         250       260       270       280       290       300       310       320
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105 233 TESKGTVRGKfPGKKKQTPTSDGE----------RVLVAFLEKASESIRyISRHVKKEHFISQVVQDWKFVAQVLDRIFL 302
Cdd:TIGR00860 364 HASLSSVEMR-AKDGGRGLESPTErqrllhspppAEGDLDLAGILEEVR-IAHRFRKRDESEEVVRDWKFRAKVIDKLSR 441
                         330
                  ....*....|....*...
gi 1720426105 303 WLFLTASVLGSVLIFIPA 320
Cdd:TIGR00860 442 MAFPLAFLLFNIGYWMSY 459
 
Name Accession Description Interval E-value
LIC TIGR00860
Cation transporter family protein; The Ligand-gated Ion Channel (LIC) Family of ...
1-320 8.09e-91

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: 278.52  E-value: 8.09e-91
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   1 MTKAIVKS--SGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYDGTMVDLILINEN---VDRKDFFDNGEWEIL 75
Cdd:TIGR00860 131 MTNVLVRIhpNGSVLYSPRITLTLACPMDLRNFPFDVQNCSLKFESWGYTTNDIKLEWKEQGavqVDDSLFISLPEFELL 210
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105  76 NAKGMKG-NRREGFYSYPFVTYSFVLRRLPLFYTLFLIIPCLGLSFLTVLVFYLPSD-EGEKLSLSTSVLVSLTVFLLVI 153
Cdd:TIGR00860 211 GVYGTRYcTSETNTGEYPCLTFSFVLRRRPLYYLLQLYIPSILIVILSWVSFWLPADaSGARVSLGITTLLTMTTFSSGV 290
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105 154 EEIIPSSSkVIPLIGEYLLFIMIFVTLSIIVTVFVINVHHRSSSTYHpmapwvKRLFLEKLPRWLCMKDPRDRFSFPD-G 232
Cdd:TIGR00860 291 RESLPAVS-YVKAIDVYFAVCMAFVFLALLETAFVNYVHHKDPAQGK------RHLLLERCAWRLCKQEPGEDYRRPAlD 363
                         250       260       270       280       290       300       310       320
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105 233 TESKGTVRGKfPGKKKQTPTSDGE----------RVLVAFLEKASESIRyISRHVKKEHFISQVVQDWKFVAQVLDRIFL 302
Cdd:TIGR00860 364 HASLSSVEMR-AKDGGRGLESPTErqrllhspppAEGDLDLAGILEEVR-IAHRFRKRDESEEVVRDWKFRAKVIDKLSR 441
                         330
                  ....*....|....*...
gi 1720426105 303 WLFLTASVLGSVLIFIPA 320
Cdd:TIGR00860 442 MAFPLAFLLFNIGYWMSY 459
Neur_chan_memb pfam02932
Neurotransmitter-gated ion-channel transmembrane region; This family includes the four ...
111-317 3.30e-77

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: 236.01  E-value: 3.30e-77
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105 111 LIIPCLGLSFLTVLVFYLPSDE-GEKLSLSTSVLVSLTVFLLVIEEIIPSSSKVIPLIGEYLLFIMIFVTLSIIVTVFVI 189
Cdd:pfam02932   1 LIIPCVLISFLSWLVFWLPADAvGEKVTLGITVLLTMTVFLLLIRESLPKTSYVVPLIGKYLLFCMVFVFLSLVETVFVL 80
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105 190 NVHHRSSSTyHPMAPWVKRLFLEKLPRWLCMKDP---------------RDRFSFPDG-TESKGTVRGKFPGKKKQTPTS 253
Cdd:pfam02932  81 NVHHRSPST-HKMPPWVRKIFLEKLPRLLGMKRPpeappppaspgygskAEEYILRKPrSELPFEKQSERHGLGRETTCS 159
                         170       180       190       200       210       220       230
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1720426105 254 DGE---------RVLVAFLEKASESIRYISRHVKKEHFISQVVQDWKFVAQVLDRIFLWLFLTASVLGSVLIF 317
Cdd:pfam02932 160 YGCslgngssqpRELSPELKKAVEGVNFIAKHLRSQDEYISVKEDWKYVAMVIDRLSRWIFPIAFVLGTLGYF 232
LGIC_ECD_nAChR_B3 cd19026
extracellular domain of nicotinic acetylcholine receptor subunit beta 3 (CHRNB3); This ...
1-103 1.66e-73

extracellular domain of nicotinic acetylcholine receptor subunit beta 3 (CHRNB3); This subfamily contains the extracellular domain of nicotinic acetylcholine receptor subunit beta 3 (beta3), encoded by the CHRNB3 gene. CHRNB3 polymorphisms have been reported to potentially affect nicotine-induced upregulation of nicotinic and to be associated with disorders such as schizophrenia, autism, and cancer. Beta3 subunit is depleted in the striatum of Parkinson's disease patients. Rare variants in CHRNB3 are also implicated in risk for alcohol and cocaine dependence and independently associated with bipolar disorder. Human alpha6beta2beta3* (* indicating possible additional assembly partners) nAChRs on dopaminergic neurons are important targets for drugs to treat nicotine addiction and Parkinson's disease; (alpha6beta2)(alpha4beta2)beta3 nAChR is essential for addiction to nicotine and a target for drug development for smoking cessation.


Pssm-ID: 349827  Cd Length: 179  Bit Score: 224.85  E-value: 1.66e-73
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   1 MTKAIVKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYDGTMVDLILINENVDRKDFFDNGEWEILNAKGM 80
Cdd:cd19026    77 MTKAIVKYNGTVTWTPPASYKSSCTMDVTFFPFDRQNCSMKFGSWTYDGNMVDLILIDENVDRKDFFDNGEWEILNAKGM 156
                          90       100
                  ....*....|....*....|...
gi 1720426105  81 KGNRREGFYSYPFVTYSFVLRRL 103
Cdd:cd19026   157 KGNRKDGLYSYPFITYSFVLRRL 179
 
Name Accession Description Interval E-value
LIC TIGR00860
Cation transporter family protein; The Ligand-gated Ion Channel (LIC) Family of ...
1-320 8.09e-91

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: 278.52  E-value: 8.09e-91
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   1 MTKAIVKS--SGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYDGTMVDLILINEN---VDRKDFFDNGEWEIL 75
Cdd:TIGR00860 131 MTNVLVRIhpNGSVLYSPRITLTLACPMDLRNFPFDVQNCSLKFESWGYTTNDIKLEWKEQGavqVDDSLFISLPEFELL 210
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105  76 NAKGMKG-NRREGFYSYPFVTYSFVLRRLPLFYTLFLIIPCLGLSFLTVLVFYLPSD-EGEKLSLSTSVLVSLTVFLLVI 153
Cdd:TIGR00860 211 GVYGTRYcTSETNTGEYPCLTFSFVLRRRPLYYLLQLYIPSILIVILSWVSFWLPADaSGARVSLGITTLLTMTTFSSGV 290
                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105 154 EEIIPSSSkVIPLIGEYLLFIMIFVTLSIIVTVFVINVHHRSSSTYHpmapwvKRLFLEKLPRWLCMKDPRDRFSFPD-G 232
Cdd:TIGR00860 291 RESLPAVS-YVKAIDVYFAVCMAFVFLALLETAFVNYVHHKDPAQGK------RHLLLERCAWRLCKQEPGEDYRRPAlD 363
                         250       260       270       280       290       300       310       320
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105 233 TESKGTVRGKfPGKKKQTPTSDGE----------RVLVAFLEKASESIRyISRHVKKEHFISQVVQDWKFVAQVLDRIFL 302
Cdd:TIGR00860 364 HASLSSVEMR-AKDGGRGLESPTErqrllhspppAEGDLDLAGILEEVR-IAHRFRKRDESEEVVRDWKFRAKVIDKLSR 441
                         330
                  ....*....|....*...
gi 1720426105 303 WLFLTASVLGSVLIFIPA 320
Cdd:TIGR00860 442 MAFPLAFLLFNIGYWMSY 459
Neur_chan_memb pfam02932
Neurotransmitter-gated ion-channel transmembrane region; This family includes the four ...
111-317 3.30e-77

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: 236.01  E-value: 3.30e-77
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105 111 LIIPCLGLSFLTVLVFYLPSDE-GEKLSLSTSVLVSLTVFLLVIEEIIPSSSKVIPLIGEYLLFIMIFVTLSIIVTVFVI 189
Cdd:pfam02932   1 LIIPCVLISFLSWLVFWLPADAvGEKVTLGITVLLTMTVFLLLIRESLPKTSYVVPLIGKYLLFCMVFVFLSLVETVFVL 80
                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105 190 NVHHRSSSTyHPMAPWVKRLFLEKLPRWLCMKDP---------------RDRFSFPDG-TESKGTVRGKFPGKKKQTPTS 253
Cdd:pfam02932  81 NVHHRSPST-HKMPPWVRKIFLEKLPRLLGMKRPpeappppaspgygskAEEYILRKPrSELPFEKQSERHGLGRETTCS 159
                         170       180       190       200       210       220       230
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1720426105 254 DGE---------RVLVAFLEKASESIRYISRHVKKEHFISQVVQDWKFVAQVLDRIFLWLFLTASVLGSVLIF 317
Cdd:pfam02932 160 YGCslgngssqpRELSPELKKAVEGVNFIAKHLRSQDEYISVKEDWKYVAMVIDRLSRWIFPIAFVLGTLGYF 232
LGIC_ECD_nAChR_B3 cd19026
extracellular domain of nicotinic acetylcholine receptor subunit beta 3 (CHRNB3); This ...
1-103 1.66e-73

extracellular domain of nicotinic acetylcholine receptor subunit beta 3 (CHRNB3); This subfamily contains the extracellular domain of nicotinic acetylcholine receptor subunit beta 3 (beta3), encoded by the CHRNB3 gene. CHRNB3 polymorphisms have been reported to potentially affect nicotine-induced upregulation of nicotinic and to be associated with disorders such as schizophrenia, autism, and cancer. Beta3 subunit is depleted in the striatum of Parkinson's disease patients. Rare variants in CHRNB3 are also implicated in risk for alcohol and cocaine dependence and independently associated with bipolar disorder. Human alpha6beta2beta3* (* indicating possible additional assembly partners) nAChRs on dopaminergic neurons are important targets for drugs to treat nicotine addiction and Parkinson's disease; (alpha6beta2)(alpha4beta2)beta3 nAChR is essential for addiction to nicotine and a target for drug development for smoking cessation.


Pssm-ID: 349827  Cd Length: 179  Bit Score: 224.85  E-value: 1.66e-73
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   1 MTKAIVKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYDGTMVDLILINENVDRKDFFDNGEWEILNAKGM 80
Cdd:cd19026    77 MTKAIVKYNGTVTWTPPASYKSSCTMDVTFFPFDRQNCSMKFGSWTYDGNMVDLILIDENVDRKDFFDNGEWEILNAKGM 156
                          90       100
                  ....*....|....*....|...
gi 1720426105  81 KGNRREGFYSYPFVTYSFVLRRL 103
Cdd:cd19026   157 KGNRKDGLYSYPFITYSFVLRRL 179
LGIC_ECD_nAChR_A5 cd19018
extracellular domain of nicotinic acetylcholine receptor subunit alpha 5 (CHRNA5); This ...
2-105 2.78e-59

extracellular domain of nicotinic acetylcholine receptor subunit alpha 5 (CHRNA5); This subfamily contains the extracellular domain of nicotinic acetylcholine receptor subunit alpha 5 (alpha5), encoded by the CHRNA5 gene, which is part of the CHRNA5/A3/B4 gene cluster. Polymorphisms in this gene cluster have been identified as risk factors for nicotine dependence, lung cancer, chronic obstructive pulmonary disease, alcoholism, and peripheral arterial disease. A loss-of-function polymorphism in CHRNA5 is strongly linked to nicotine abuse and schizophrenia; the alpha5 nAChR subunit is strategically situated in the prefrontal cortex (PFC), where a loss-of-function in this subunit may contribute to cognitive disruptions in both disorders. Alpha5 forms heteropentamers with alpha3beta2 or alpha3beta4 nAChRs which increases the calcium permeability of the resulting receptors possibly playing significant roles in the initiation of ACh-induced signaling cascades under normal and pathological condition. Acetylcholine (ACh) release and signaling via alpha4/beta2 nAChR subunits plays a central role in the control of attention, but a subset of these oligomers also contains alpha5 subunit. A strong association is seen between a CHRNA5 polymorphism and the risk of lung cancer, especially in smokers.


Pssm-ID: 349819 [Multi-domain]  Cd Length: 207  Bit Score: 189.40  E-value: 2.78e-59
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   2 TKAIVKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYDGTMVDLILINENVDRKDFFDNGEWEILNAKGMK 81
Cdd:cd19018   104 TKTVVRYDGTITWTPPANYKSSCTIDVTFFPFDLQNCSMKFGSWTYDGSQVDIILEDYDVDKRDFFDNGEWEIVSATGSK 183
                          90       100
                  ....*....|....*....|....
gi 1720426105  82 GNRREGFYSYPFVTYSFVLRRLPL 105
Cdd:cd19018   184 GNRTDGCCWYPFITYSFIIRRLPL 207
LGIC_ECD_nAChR cd18997
extracellular domain of nicotinic acetylcholine receptor; This family contains the ...
1-102 2.72e-47

extracellular domain of nicotinic acetylcholine receptor; This family contains the extracellular domain of nicotinic acetylcholine receptor (nAChR), a member of the pentameric "Cys-loop" superfamily of transmitter-gated ion channels. 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: 349798  Cd Length: 181  Bit Score: 157.65  E-value: 2.72e-47
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   1 MTKAIVKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYDGTMVDLILINENVDRKDFFDNGEWEILNAKGM 80
Cdd:cd18997    77 KTNVIVYSDGTVTWLPPAIFKSSCKIDVTYFPFDEQNCTLKFGSWTYDGSELDLQLKSDTVDLSDYIENGEWDLLGAPAK 156
                          90       100
                  ....*....|....*....|....*..
gi 1720426105  81 kgnRREGFYS-----YPFVTYSFVLRR 102
Cdd:cd18997   157 ---RNVVKYSccpepYPDVTFTIHIRR 180
LGIC_TM_nAChR cd19064
transmembrane domain of nicotinic acetylcholine receptor (nAChR); This family contains ...
105-194 2.16e-46

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: 152.67  E-value: 2.16e-46
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105 105 LFYTLFLIIPCLGLSFLTVLVFYLPSDEGEKLSLSTSVLVSLTVFLLVIEEIIPSSSKVIPLIGEYLLFIMIFVTLSIIV 184
Cdd:cd19064     1 LFYTVNLIIPCVLISFLTVLVFYLPADSGEKITLSISVLLALTVFLLLIAEIIPPTSLVVPLIGKYLLFTMILVTLSIIV 80
                          90
                  ....*....|
gi 1720426105 185 TVFVINVHHR 194
Cdd:cd19064    81 TVIVLNVHHR 90
LGIC_ECD_nAChR_A2 cd19015
extracellular domain of nicotinic acetylcholine receptor subunit alpha 2 (CHRNA2); This ...
1-104 8.74e-43

extracellular domain of nicotinic acetylcholine receptor subunit alpha 2 (CHRNA2); This subfamily contains the extracellular domain of nicotinic acetylcholine receptor subunit alpha 2 (alpha2), encoded by the CHRNA2 gene. It is specifically expressed in medial subpallium-derived amygdalar nuclei from early developmental stages to adult. This subunit is incorporated in heteropentameric neuronal nAChRs mainly with beta2 or beta4 subunits and, along with the alpha4 and alpha7, is one of the main nAChR subunits expressed in primate brain. In Xenopus laevis oocytes, when alpha2 is co-expressed with the beta2 subunit, two subtypes of alpha2beta2 nAChR are formed with either low or high ACh sensitivity. Mouse mutation studies show that alpha2 subunits in the nAChRs influence hippocampus-dependent learning and memory as well as CA1 synaptic plasticity in adolescent mice.


Pssm-ID: 349816 [Multi-domain]  Cd Length: 207  Bit Score: 146.73  E-value: 8.74e-43
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   1 MTKAIVKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYDGTMVDLILINENVDRKDFFDNGEWEILNAKGM 80
Cdd:cd19015   102 MTKAHLFSTGKVKWVPPAIYKSSCSIDVTFFPFDQQNCKMKFGSWTYDKAKIDLEQMEQTVDLKDYWESGEWAIVNATGT 181
                          90       100
                  ....*....|....*....|....*.
gi 1720426105  81 KGNRREGFYS--YPFVTYSFVLRRLP 104
Cdd:cd19015   182 YNSKKYDCCTeiYPDITYYFVIRRLP 207
LGIC_ECD_nAChR_proto_alpha-like cd19031
extracellular domain of nicotinic acetylcholine receptor subunit alpha-like found in ...
1-106 2.97e-41

extracellular domain of nicotinic acetylcholine receptor subunit alpha-like found in protostomia; This subfamily contains the extracellular domain of nicotinic acetylcholine receptor subunit alpha-like in organisms that include arthropods, mollusks, annelid worms, and flat worms, and have their cholinergic system limited to the central nervous system. C. elegans genome encodes 29 acetylcholine receptor subunits, of which the levamisole-sensitive receptor (L-AChR) alpha-subunits, UNC-38, UNC-63, and LEV-8, included in this subfamily, form heteromers with the two non-alpha (also known as beta-like) subunits, UNC-29 and LEV-1. This receptor functions as the main excitatory postsynaptic receptor at neuromuscular junctions, indicating that many are expressed in neurons. Also included is the nicotinic alpha subunit MARA1 (Manduca ACh Receptor Alpha 1) which is expressed in Ca2+ responding neurons and contributes to the nicotinic responses in the neurons. In insects, the receptors supply fast synaptic excitatory transmission and represent a major target for several insecticides. In Drosophila, ten exclusively neuronal nAChRs have been identified, Dalpha1-Dalpha7 and Dbeta1-Dbeta3, and various combinations of these subunits and mutations are key to nAChR function. Alpha5 subunit is involved in alpha-bungarotoxin sensitivity while the alpha6 subunit is essential for the insecticidal effect of spinosad. nAChR agonists acetylcholine, nicotine, and neonicotinoids stimulate dopamine release in Drosophila larval ventral nerve cord and mutations in nAChR subunits affect how insecticides stimulate dopamine release.


Pssm-ID: 349832  Cd Length: 222  Bit Score: 143.19  E-value: 2.97e-41
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   1 MTKAIVKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYDGTMVDL-----------ILINENVDRKDFFDN 69
Cdd:cd19031   104 MTKATLHYNGTVRWEPPAIYKSSCEIDVEYFPFDEQTCFMKFGSWTYDGFEVDLrhvdqkygsedEVIDVGIDLSEFYPS 183
                          90       100       110       120
                  ....*....|....*....|....*....|....*....|..
gi 1720426105  70 GEWEILNAKGMkgnRREGFYS-----YPFVTYSFVLRRLPLF 106
Cdd:cd19031   184 VEWDLLEVPAR---RNEKYYPccdepYPDITFNITLRRKTLF 222
Neur_chan_LBD pfam02931
Neurotransmitter-gated ion-channel ligand binding domain; This family is the extracellular ...
1-104 3.74e-41

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: 142.79  E-value: 3.74e-41
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   1 MTKAIVKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYDGTMVDLILINEN-------VDRKDFFDNGEWE 73
Cdd:pfam02931 103 NTNVRVYYDGTVLWSPPAIYKSSCSIDVTYFPFDEQNCSLKFGSWTYNGEEVDLRWDDDPpvveleeIDLSDFWLNGEWD 182
                          90       100       110
                  ....*....|....*....|....*....|...
gi 1720426105  74 ILNAKGMKGNRREGFYS--YPFVTYSFVLRRLP 104
Cdd:pfam02931 183 IVDVPAKRREYPYGCYSelTGDVTFYFTLRRKP 215
LGIC_ECD_nAChR_A3 cd19016
extracellular domain of nicotinic acetylcholine receptor subunit alpha 3 (CHRNA3); This ...
2-104 1.99e-39

extracellular domain of nicotinic acetylcholine receptor subunit alpha 3 (CHRNA3); This subfamily contains the extracellular domain of nicotinic acetylcholine receptor subunit alpha 3 (alpha3), encoded by the CHRNA3 gene, and likely plays a role in neurotransmission. The alpha3 subunit is expressed in the aorta and macrophages, and may play a regulatory role in the process of vascular inflammation. One of the most broadly expressed subtype is the alpha3beta4 nAChR, also known as the ganglion-type nicotinic receptor, located in the autonomic ganglia and adrenal medulla, where activation yields post- and/or presynaptic excitation, mainly by increased Na+ and K+ permeability. The exact pentameric stochiometry of alpha3beta4 receptor is not known and functional assemblies with varying subunit stoichiometries are possible. Alpha4 plays a pivotal role in regulating the inflammatory responses in endothelial cells and macrophages, via mechanisms involving the modulations of multiple cell signaling pathways. Polymorphisms in this gene (CHRNA3) have been associated with an increased risk of smoking initiation and an increased susceptibility to lung cancer.


Pssm-ID: 349817 [Multi-domain]  Cd Length: 207  Bit Score: 138.15  E-value: 1.99e-39
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   2 TKAIVKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYDGTMVDLILINENVDRKDFFDNGEWEILNAKGMK 81
Cdd:cd19016   103 TKALLKYTGEVTWIPPAIFKSSCKIDVTYFPFDYQNCTMKFGSWSYDKAKIDLVLIGSSMNLKDYWESGEWAIIKAPGYK 182
                          90       100
                  ....*....|....*....|....*...
gi 1720426105  82 GNRRegfYS-----YPFVTYSFVLRRLP 104
Cdd:cd19016   183 HDIK---YNcceeiYPDITYSLYIRRLP 207
LGIC_ECD_nAChR_A6 cd19019
extracellular domain of nicotinic acetylcholine receptor subunit alpha 6 (CHRNA6); This ...
2-103 1.43e-37

extracellular domain of nicotinic acetylcholine receptor subunit alpha 6 (CHRNA6); This subfamily contains the extracellular domain of nicotinic acetylcholine receptor subunit alpha 6 (alpha6), encoded by the CHRNA6 gene. Human (alpha6beta2)(alpha4beta2)3 nicotinic acetylcholine receptors (AChRs) are essential for addiction to nicotine and a target for drug development for smoking cessation. In xenopus oocytes, data show efficient expression of (alpha6beta2)2beta3 AChR subunits with only small changes in alpha6 subunits, while not altering AChR pharmacology or channel structure. Alternatively spliced transcript variants have been observed for this gene. Single nucleotide polymorphisms in this gene have been associated with both nicotine and alcohol dependence. CHRNA6 has a cellular expression signature for retinal ganglion cells with high correlation to Thy1, a known marker, and is preferentially expressed by retinal ganglion cells (RGCs) in the young and adult mouse retina and expression is reduced in glaucoma. A genetic variant in CHRNB3#CHRNA6 cluster is associated with esophageal adenocarcinoma.


Pssm-ID: 349820 [Multi-domain]  Cd Length: 181  Bit Score: 132.46  E-value: 1.43e-37
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   2 TKAIVKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYDGTMVDLILINENVDRKDFFDNGEWEILNAKGMK 81
Cdd:cd19019    78 TKALLKYNGMITWTPPAIFKSSCPMDITFFPFDHQNCSLKFGSWTYDKAKIDLLIIGSKVDMNDFWENSEWEIVDASGYK 157
                          90       100
                  ....*....|....*....|....
gi 1720426105  82 GNRREGFYS--YPFVTYSFVLRRL 103
Cdd:cd19019   158 HDIKYNCCEeiYTDITYSFYIRRL 181
LGIC_ECD_cation cd18989
extracellular domain (LBD) of cationic Cys-loop neurotransmitter-gated ion channels; This ...
2-102 2.13e-34

extracellular domain (LBD) of cationic Cys-loop neurotransmitter-gated ion channels; This superfamily contains the extracellular domain (ECD) 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. 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. 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: 349790 [Multi-domain]  Cd Length: 180  Bit Score: 124.01  E-value: 2.13e-34
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   2 TKAIVKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYDGTMVDLILINENVDRKDFFDNGEWEILNAKGMK 81
Cdd:cd18989    79 TLVRVSSDGTVTWVPPGVLTTSCDIDVTYFPFDTQTCSLRFGSWSYTTDEINLTPSSNGVDLEDYEENGEWELLSTSVSR 158
                          90       100
                  ....*....|....*....|.
gi 1720426105  82 GNRREGFYSYPFVTYSFVLRR 102
Cdd:cd18989   159 EEDKYCNETYSELTFTITLKR 179
LGIC_ECD_nAChR_A4 cd19017
extracellular domain of neuronal acetylcholine receptor subunit alpha 4 (CHRNA4); This ...
1-103 5.75e-34

extracellular domain of neuronal acetylcholine receptor subunit alpha 4 (CHRNA4); This subfamily contains the extracellular domain of nicotinic acetylcholine receptor subunit alpha 4 (alpha4), encoded by the CHRNA4 gene. Alpha4 forms a functional nAChR by interacting with either nAChR beta2 or beta4 subunits. Alpha4beta2, the major heteropentameric nAChR in the brain, exists in two isoforms, (alpha4)3(beta2)2 and (alpha4)2(beta2)3, with the latter believed to constitute the majority of alpha4beta2 nAChR in the cortex. Both isoforms contain two canonical alpha4:beta2 ACh-binding sites with either low or high ACh sensitivity. This protein is an integral membrane receptor subunit that can interact with either nAChR beta-2 or nAChR beta-4 to form a functional receptor. Mutations in this gene (CHRNA4) cause nocturnal frontal lobe epilepsy type 1. Polymorphisms in this gene may provide protection against nicotine addiction.


Pssm-ID: 349818  Cd Length: 181  Bit Score: 122.85  E-value: 5.75e-34
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   1 MTKAIVKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYDGTMVDLILINENVDRKDFFDNGEWEILNAKGM 80
Cdd:cd19017    77 LTKAHLFHDGRVQWTPPAIYKSSCSIDVTFFPFDQQNCTMKFGSWTYDKAKIDLVSMHSRVDQLDFWESGEWVIVDAVGT 156
                          90       100
                  ....*....|....*....|....*
gi 1720426105  81 KGNRREGFYS--YPFVTYSFVLRRL 103
Cdd:cd19017   157 YNTRKYECCAeiYPDITYAFIIRRL 181
LGIC_TM_cation cd19051
transmembrane domain of Cys-loop neurotransmitter-gated ion channels, includes 5HT3, nAChR, ...
105-194 2.38e-33

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: 119.00  E-value: 2.38e-33
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105 105 LFYTLFLIIPCLGLSFLTVLVFYLPSDEGEKLSLSTSVLVSLTVFLLVIEEIIPSSSKVIPLIGEYLLFIMIFVTLSIIV 184
Cdd:cd19051     1 LFYVFNLILPCVLLSVLALLVFLLPPDSGEKVSLGITVLLSLTVFLLLVSESLPPTSDSVPLIGIYLLATMVLSALSTVL 80
                          90
                  ....*....|
gi 1720426105 185 TVFVINVHHR 194
Cdd:cd19051    81 TVIVLNLHHV 90
LGIC_ECD_nAChR_B2 cd19025
extracellular domain of nicotinic acetylcholine receptor subunit beta 2 (CHRNB2); This ...
2-104 5.06e-31

extracellular domain of nicotinic acetylcholine receptor subunit beta 2 (CHRNB2); This subfamily contains the extracellular domain of nicotinic acetylcholine receptor subunit beta 2 (beta2), encoded by the CHRNB2 gene. The most abundant nicotinic subtype in the human brain is alpha4beta2 receptor which is known to assemble in two functional subunit stoichiometries, (alpha4)3(beta2)2 and (alpha4)2(beta2)3, the latter having a much higher affinity for both acetylcholine and nicotine. This subtype is implicated in the pathophysiology of neurodevelopmental disorders such as schizophrenia and autism, and neurodegenerative disorders such as Parkinson's disease and Alzheimer's disease. Thus, pharmacological ligands targeting this subtype have been researched and developed as a treatment approach implicated in these diseases. They include agonists such as varenicline and cytisine used as smoking cessation aids, as well as positive allosteric modulators (PAMs) such as desformylflustrabromine (dFBr), which are ligands that bind to nicotinic receptors at sites other than the orthosteric site where acetylcholine binds, and are not able to act as agonists on nAChR.


Pssm-ID: 349826  Cd Length: 204  Bit Score: 115.86  E-value: 5.06e-31
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   2 TKAIVKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYDGTMVDLILINENVDRKDFFDNGEWEILNAKGMK 81
Cdd:cd19025   103 SNAVVSYDGSIFWLPPAIYKSACKIEVKHFPFDQQNCTLKFRSWTYDRTEIDLVLRSDVASLDDFTPSGEWDIVALPGRR 182
                          90       100
                  ....*....|....*....|...
gi 1720426105  82 gNRREGFYSYPFVTYSFVLRRLP 104
Cdd:cd19025   183 -NENPNDSTYVDITYDFIIRRKP 204
LGIC_ECD_nAChR_proto-like cd19033
nicotinic acetylcholine receptor (nAChR) subunit extracellular domain in molluscs and annelids; ...
4-102 5.83e-31

nicotinic acetylcholine receptor (nAChR) subunit extracellular domain in molluscs and annelids; This subfamily contains the extracellular domain of nicotinic acetylcholine receptor subunit found in molluscs, including several Lymnaea nAChRs, and annelids that are mostly uncharacterized. To date, 12 Lymnaea nAChRs have been identified which can be subdivided in two subtypes according to the residues that may be contributing to the selectivity of ion conductance. Phylogenetic analysis of the nAChR gene sequences suggests that anionic nAChRs in molluscs probably evolved from cationic ancestors through amino acid substitutions in the ion channel pore which is a mechanism different from acetylcholine-gated channels in other invertebrates.


Pssm-ID: 349834  Cd Length: 183  Bit Score: 115.08  E-value: 5.83e-31
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   4 AIVKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYDGTMVDLILIN--ENVDRKDFFDNGEWEILNAKGMk 81
Cdd:cd19033    80 VVVYSTGTVLWMPQAIYKSTCEIDIKYFPFDTQTCYLKFGSWTYDGTRLDITFYDneEEIDLTDYIESNEWEILAYPAV- 158
                          90       100
                  ....*....|....*....|....*.
gi 1720426105  82 gnRREGFYS-----YPFVTYSFVLRR 102
Cdd:cd19033   159 --KNVKYYPccpepYPDLTFFLVIKR 182
LGIC_ECD_nAChR_B4 cd19027
extracellular domain of nicotinic acetylcholine receptor subunit beta 4 (CHRNB4); This ...
2-102 1.92e-29

extracellular domain of nicotinic acetylcholine receptor subunit beta 4 (CHRNB4); This subfamily contains the extracellular domain of nicotinic acetylcholine receptor subunit beta 4 (beta4), encoded by the CHRNB4 gene and ubiquitously expressed on lung epithelial cells. The cluster of human neuronal nicotinic receptor gene CHRNA5-CHRNA3-CHRNB4 is related to drug-related behaviors and the development of lung cancer. One of the most broadly expressed subtype is the alpha-3 beta-4 nAChR, also known as the ganglion-type nicotinic receptor, located in the autonomic ganglia and adrenal medulla, where activation yields post- and/or pre-synaptic excitation, mainly by increased Na+ and K+ permeability. Beta4 forms heteromeric nAchRs to modulate receptor affinity for nicotine, but the exact pentameric stochiometry of alpha3beta4 receptor is not known; functional assemblies with varying subunit stoichiometries are possible.


Pssm-ID: 349828  Cd Length: 178  Bit Score: 110.86  E-value: 1.92e-29
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   2 TKAIVKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYDGTMVDLILINENVDRKDFFDNGEWEILnakGMK 81
Cdd:cd19027    78 TNAIVQNNGSVAWLPPAIYKSACKIEVKHFPFDQQNCTLKFRSWTYDHTEIDMVLKTPTASMDDFTPSGEWDIV---ALP 154
                          90       100
                  ....*....|....*....|...
gi 1720426105  82 GNRREGFY--SYPFVTYSFVLRR 102
Cdd:cd19027   155 GRRTVNPLdpTYVDVTYDFIIKR 177
LGIC_ECD_nAChR_proto_beta-like cd19032
extracellular domain of nicotinic acetylcholine receptor subunit beta-like found in ...
1-102 8.71e-29

extracellular domain of nicotinic acetylcholine receptor subunit beta-like found in protostomia; This subfamily contains the extracellular domain of nicotinic acetylcholine receptor subunit beta-like in organisms that include arthropods, mollusks, annelid worms, and flat worms, and have their cholinergic system limited to the central nervous system. C. elegans genome encodes 29 acetylcholine receptor subunits, of which the levamisole-sensitive receptor alpha-subunits (L-AChR), UNC-38, UNC-63, and LEV-8, form heteromers with the two non-alpha (also known as beta-like) subunits, UNC-29 and LEV-1 found in this subfamily. This receptor functions as the main excitatory postsynaptic receptor at neuromuscular junctions, indicating that many are expressed in neurons. In insects, the receptors supply fast synaptic excitatory transmission and represent a major target for several insecticides. In Drosophila, ten exclusively neuronal nAChR subunits have been identified, Dalpha1-Dalpha7 and Dbeta1-Dbeta3, and various combinations of these subunits and mutations are key to nAChR function. Dbeta1 subunits in dopaminergic neurons play a role in acute locomotor hyperactivity caused by nicotine in male Drosophila. Mutations of Dbeta2 or Dalpha1 nAChR subunits in Drosophila strains have significantly lower neonicotinoid-stimulated release, but no changes in nicotine-stimulated release; they are highly resistant to the neonicotinoids nitenpyram and imidacloprid. This family also includes a novel nAChR found in Aplysia bag cell neurons (neuroendocrine cells that control reproduction) which is a cholinergic ionotropic receptor that is both, nicotine insensitive and acetylcholine sensitive.


Pssm-ID: 349833 [Multi-domain]  Cd Length: 208  Bit Score: 110.11  E-value: 8.71e-29
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   1 MTKAIVKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYDGTMVDLILINEN--VDRKDFFDNGEWEILNAK 78
Cdd:cd19032   103 KSNVLIYSTGEVLWVPPAIYKSSCTIDVEYFPFDQQECEMKFGSWTFNGDEVSLDLYNNKkfVDLSDYWKSGTWDIIDVP 182
                          90       100
                  ....*....|....*....|....
gi 1720426105  79 GMKGNRREGFYSYPFVTYSFVLRR 102
Cdd:cd19032   183 GQLVNKDDAGPTETDIIFKIKIRR 206
LGIC_ECD cd03558
extracellular domain (ECD) of Cys-loop neurotransmitter-gated ion channels (also known as ...
1-103 2.12e-28

extracellular domain (ECD) of Cys-loop neurotransmitter-gated ion channels (also known as ligand-gated ion channel (LGIC)); This superfamily contains the extracellular domain (ECD) 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. 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. The ECD contains the ligand binding sites for these receptors.


Pssm-ID: 349787  Cd Length: 179  Bit Score: 108.28  E-value: 2.12e-28
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   1 MTKAIVKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYDGTMVDLILINENVDRKDFFDNGEWEILNAKGM 80
Cdd:cd03558    77 NVLIRLSPDGTVLYSPRAILKSACPMDLKRFPFDQQNCTMKLESWTYDTTDIELVWDSERPDQADFLELPEWDIVEKRGR 156
                          90       100
                  ....*....|....*....|...
gi 1720426105  81 KGNRREGFYSYPFVTYSFVLRRL 103
Cdd:cd03558   157 YCTVVYNTGIYSDITYRFRLKRQ 179
LGIC_ECD_nAChR_A10 cd19023
extracellular domain of neuronal acetylcholine receptor subunit alpha 10 (CHRNA10); This ...
2-102 1.09e-27

extracellular domain of neuronal acetylcholine receptor subunit alpha 10 (CHRNA10); This subfamily contains the extracellular domain of nicotinic acetylcholine receptor subunit alpha 10 (alpha10), encoded by the CHRNA10 gene. This protein is involved in cochlea hair cell development and is also expressed in the outer hair cells (OHCs) of the adult cochlea as well as in keratinocytes, the pituitary gland, B-cells, and T-cells. Unlike alpha9 nAChR subunits, alpha10 subunits do not generate functional channels when expressed heterologously, suggesting that alpha10 might serve as a structural subunit, much like a beta subunit of heteromeric receptors, providing only complementary components to the agonist binding site. Mammalian alpha10 subunits can form functional heteromeric alpha9alpha10 receptors, an atypical heteromeric receptor since it is composed only of alpha subunits compared to nAChRs typically assembled from alpha and beta subunits. A stoichiometry of (alpha9)2(alpha10)3 has been determined for the rat recombinant receptor. The alpha9alpha10 nAChR is an important therapeutic target for pain; selective block of alpha9alpha10 nicotinic acetylcholine receptors by the conotoxin RgIA has been shown to be analgesic in an animal model of nerve injury pain, and accelerates recovery of nerve function after injury, possibly through immune/inflammatory-mediated mechanisms.


Pssm-ID: 349824  Cd Length: 181  Bit Score: 106.61  E-value: 1.09e-27
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   2 TKAIVKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYDGTMVDLILINENVDRKDFFDNGEWEILnakGMK 81
Cdd:cd19023    78 TNVVIRSDGQIMWDSPAITKSSCKVDVSFFPFDGQQCRLTFGSWTYNGNQIDILNLLDTGDLTDFVENVEWEVL---GMP 154
                          90       100
                  ....*....|....*....|....*.
gi 1720426105  82 GNRREGFYS-----YPFVTYSFVLRR 102
Cdd:cd19023   155 AKRNVITYGccsepYPDVTYTLLLKR 180
LGIC_ECD_nAChR_A1 cd19014
extracellular domain of nicotinic acetylcholine receptor subunit alpha 1 (CHRNA1); This ...
1-104 8.13e-27

extracellular domain of nicotinic acetylcholine receptor subunit alpha 1 (CHRNA1); This subfamily contains the extracellular domain of nicotinic acetylcholine receptor subunit alpha 1 (alpha1), encoded by the CHRNA1 gene. These muscle type nicotinic subunits form heteropentamers with other nAChR subunits, most broadly expressed as combination of two alpha1, beta1, delta, and epsilon subunits in mature muscles, and of two alpha1, beta1, delta, and gamma in embryonic cells. The alpha1 subunit in human nAChR is the primary target of Myasthenia gravis antibodies that disrupt communication between the nervous system and the muscle, causing chronic muscle weakness.


Pssm-ID: 349815  Cd Length: 210  Bit Score: 104.94  E-value: 8.13e-27
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   1 MTKAIVKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYDGTMVdliLINENVDRKD---FFDNGEWEILNA 77
Cdd:cd19014   104 ETKVLLEYTGKITWTPPAIFKSYCEIIVTHFPFDQQNCSMKLGTWTYDGTLV---VINPESDRPDlsnFMESGEWVMKDY 180
                          90       100       110
                  ....*....|....*....|....*....|...
gi 1720426105  78 KGMKgnrREGFYS------YPFVTYSFVLRRLP 104
Cdd:cd19014   181 RGWK---HWVYYTccpdtpYLDITYHFLLQRLP 210
LGIC_ECD_nAChR_A9 cd19022
extracellular domain of neuronal acetylcholine receptor subunit alpha 9 (CHRNA9); This ...
2-102 9.94e-26

extracellular domain of neuronal acetylcholine receptor subunit alpha 9 (CHRNA9); This subfamily contains the extracellular domain of nicotinic acetylcholine receptor subunit alpha 9 (alpha9), encoded by the CHRNA9 gene. This protein is involved in cochlea hair cell development and is also expressed in the outer hair cells (OHCs) of the adult cochlea as well as in keratinocytes, the pituitary gland, B-cells, and T-cells. Mammalian alpha9 subunits can form functional homomeric alpha9 receptors as well as the heteromeric alpha9alpha10 receptors, the latter being atypical since the heteromeric alpha9alpha10 receptor is composed only of alpha subunits compared to nAChRs typically assembled from alpha and beta subunits. A stoichiometry of (alpha9)2(alpha10)3 has been determined for the rat recombinant receptor. The alpha9alpha10 nAChR is an important therapeutic target for pain; selective block of alpha9alpha10 nicotinic acetylcholine receptors by the conotoxin RgIA has been shown to be analgesic in an animal model of nerve injury pain, and accelerates recovery of nerve function after injury, possibly through immune/inflammatory-mediated mechanisms. CHRNA9 polymorphisms are associated with non-small cell lung cancer, and effect of a particular SNP (rs73229797) and passive smoking exposure on risk of breast malignancy has been observed.


Pssm-ID: 349823  Cd Length: 207  Bit Score: 102.04  E-value: 9.94e-26
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   2 TKAIVKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYDGTMVDLILINENVDRKDFFDNGEWEIlnaKGMK 81
Cdd:cd19022   103 TNVVLRYDGKITWDAPAITKSSCVVDVSYFPFDNQQCNLTFGSWTYNGNQVDIINALDSGDLSDFVEDVEWEV---HGMP 179
                          90       100
                  ....*....|....*....|....*.
gi 1720426105  82 GNRREGFYS-----YPFVTYSFVLRR 102
Cdd:cd19022   180 AVKNVITYGccsepYPDVTFTLILKR 205
LGIC_ECD_nAChR_B1 cd19024
extracellular domain of nicotinic acetylcholine receptor subunit beta 1 (CHRNB1); This ...
5-104 3.05e-25

extracellular domain of nicotinic acetylcholine receptor subunit beta 1 (CHRNB1); This subfamily contains the extracellular domain of nicotinic acetylcholine receptor subunit beta 1 (beta1), encoded by the CHRNB1 gene. It is a muscle type subunit found predominantly in the neuromuscular junction (NMJ), but also in other tissues and cell lines such as adrenal glands, carcinomas, brain, and lung. Simultaneous mRNA and protein expression of beta1 nAChR subunit is present in human placenta and skeletal muscle. The beta1 nAChR subunit forms a heteropentamer with either (alpha1)2, gamma and delta subunits in embryonic type or (alpha1)2, epsilon and delta subunits in adult type receptors. nAChRs containing beta1 subunits have been attributed to efficient clustering and anchoring of the receptors to the cytoskeleton which is important for formation of synapses in the NMJ. Mutations in the transmembrane domain region of this gene are associated with slow-channel congenital myasthenic syndrome (CMS).


Pssm-ID: 349825  Cd Length: 213  Bit Score: 100.67  E-value: 3.05e-25
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   5 IVKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYDGTMVDL-------------ILINENVdrkdFFDNGE 71
Cdd:cd19024   106 LVSSDGSVRWHPPAIYRSSCSIEVTYFPFDWQNCSMVFRSYTYDSSEVSLqhgldpdgkelqeIVIHENT----FIENGQ 181
                          90       100       110
                  ....*....|....*....|....*....|...
gi 1720426105  72 WEILNaKGMKGNRREGFYSYPFVTYSFVLRRLP 104
Cdd:cd19024   182 WSIEH-KPSRKNQLPGDPLYEDITFYLIIRRKP 213
LGIC_ECD_nAChR_A7 cd19020
extracellular domain of neuronal acetylcholine receptor subunit alpha 7 (CHRNA7); This ...
2-102 4.88e-25

extracellular domain of neuronal acetylcholine receptor subunit alpha 7 (CHRNA7); This subfamily contains the extracellular domain of nicotinic acetylcholine receptor subunit alpha 7 (alpha7), encoded by the CHRNA7 gene. Alpha7 subunits form a homo-pentameric channel, displays marked permeability to calcium ions and is a major component of brain nicotinic receptors that are blocked by, and highly sensitive to, alpha-bungarotoxin. This protein is ubiquitously expressed in both the central nervous system and in the periphery, in several tissues, including adrenal, small intestine, testis, and stomach. CHRNA7 is located in a region identified as a major susceptibility locus for juvenile myoclonic epilepsy and a chromosomal location involved in the genetic transmission of schizophrenia. It is also genetically linked to other disorders with cognitive deficits, including bipolar disorder, ADHD, Alzheimer's disease, and Rett syndrome. An evolutionarily recent partial duplication of CHRNA7 on chromosome 15 forms a new gene, CHRFAM7A or FAM7A, which encodes the protein dup-alpha7. This protein assembles with alpha7 subunits, results in fewer binding sites and is a dominant negative regulator of alpha7 nAChR function.


Pssm-ID: 349821 [Multi-domain]  Cd Length: 180  Bit Score: 99.30  E-value: 4.88e-25
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   2 TKAIVKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYDGTMVDLILINENVdrKDFFDNGEWEILnakGMK 81
Cdd:cd19020    79 TNVLVNSSGHCQYLPPGIFKSSCYIDVRWFPFDVQKCNLKFGSWTYGGWSLDLQMQEADI--SGYISNGEWDLV---GVP 153
                          90       100
                  ....*....|....*....|....*.
gi 1720426105  82 GNRREGFYS-----YPFVTYSFVLRR 102
Cdd:cd19020   154 GKRNEKFYEcckepYPDVTFTVTMRR 179
LGIC_ECD_nAChR_A7L cd19021
extracellular domain of neuronal acetylcholine receptor subunit alpha-7-like; This family ...
2-102 1.92e-21

extracellular domain of neuronal acetylcholine receptor subunit alpha-7-like; This family contains the extracellular domain of nicotinic acetylcholine receptor (nAChR), a member of the pentameric "Cys-loop" superfamily of transmitter-gated ion channels. 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.


Pssm-ID: 349822 [Multi-domain]  Cd Length: 179  Bit Score: 89.71  E-value: 1.92e-21
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   2 TKAIVKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYDGTMVDLILINENVdrKDFFDNGEWEILnakGMK 81
Cdd:cd19021    78 TNVLVNYSGSCQYIPPGILKSTCYIDVRWFPFDVQKCDLKFGSWTHSGWLIDLQMLEADI--SNYISNGEWDLV---GVP 152
                          90       100
                  ....*....|....*....|....*.
gi 1720426105  82 GNRREGFYS-----YPFVTYSFVLRR 102
Cdd:cd19021   153 GKRNELYYEcckepYPDVTYTITMRR 178
LGIC_ECD_nAChR_E cd19030
extracellular domain of nicotinic acetylcholine receptor subunit epsilon (CHRNE); This ...
5-102 2.83e-19

extracellular domain of nicotinic acetylcholine receptor subunit epsilon (CHRNE); This subfamily contains the extracellular domain of nicotinic acetylcholine receptor subunit epsilon (epsilon), encoded by the CHRNE gene and found in adult skeletal muscle. Epsilon subunit forms a heteropentamer with (alpha1)2, beta and delta after birth, replacing the gamma subunit seen in embryonic receptors. The adult-type epsilon-AChR has a higher conductance and a shorter open time compared to embryonic gamma-AChR and the open channel is non-selectively cation permeable. Mutations of the CHRNE gene are the most common causes of congenital myasthenic syndrome (CMS), most of which are autosomal recessive loss-of-function mutations, resulting in endplate AChR deficiency. A highly fatal fast-channel syndrome is caused by AChR epsilon subunit mutation (Trp to Arg; changing environment from anionic to cationic) at the agonist binding site at the alpha/epsilon interface of the receptor, thus disrupting agonist binding affinity and gating efficiency.


Pssm-ID: 349831  Cd Length: 191  Bit Score: 84.29  E-value: 2.83e-19
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   5 IVKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYDGTMVDLIL--------INE-NVDRKDFFDNGEWEIL 75
Cdd:cd19030    81 LVYEGGSVSWLPPAIYRSTCAVEVTYFPFDWQNCSLIFRSQTYNAEEVEFTFavdddgktINKiDIDTEAYTENGEWAID 160
                          90       100       110
                  ....*....|....*....|....*....|
gi 1720426105  76 NAKGMKGNRREGFYSYPFVT---YSFVLRR 102
Cdd:cd19030   161 FCPGVIRRHHGGSTDGPGETdviYSLIIRR 190
LGIC_ECD_nAChR_G cd19029
extracellular domain of nicotinic acetylcholine receptor subunit gamma (CHRNG); This subfamily ...
2-74 8.50e-19

extracellular domain of nicotinic acetylcholine receptor subunit gamma (CHRNG); This subfamily contains the extracellular domain of nicotinic acetylcholine receptor subunit gamma (gamma), encoded by the CHRNG gene expressed during early fetal development, and replaced by the epsilon subunit in the adult. The gamma subunit forms a heteropentamer with (alpha1)2, beta, and delta and plays a role in neuromuscular organogenesis and ligand binding. Disruption of gamma subunit expression prevents the correct localization of the receptor in cell membranes. Mutations in CHRNG may cause the non-lethal Escobar variant (EVMPS) and lethal form (LMPS) of multiple pterygium syndrome (MPS), a condition characterized by prenatal growth failure with pterygium and akinesia leading to muscle weakness and severe congenital contractures, as well as scoliosis. Muscle-type acetylcholine receptor is the major antigen in the autoimmune disease myasthenia gravis.


Pssm-ID: 349830  Cd Length: 193  Bit Score: 82.90  E-value: 8.50e-19
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   2 TKAIVKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYDGTMVDLILINEN--------VDRKDFFDNGEWE 73
Cdd:cd19029    80 ANVLVYPDGSMYWLPPAIYRSTCPIEVTYFPFDWQNCSLVFQSQTYSANEINLQLSVEEgttiewidIDPEAFTENGEWA 159

                  .
gi 1720426105  74 I 74
Cdd:cd19029   160 I 160
LGIC_ECD_nAChR_D cd19028
extracellular domain of nicotinic acetylcholine receptor subunit delta (CHRND); This subfamily ...
5-104 4.10e-18

extracellular domain of nicotinic acetylcholine receptor subunit delta (CHRND); This subfamily contains the extracellular domain of nicotinic acetylcholine receptor subunit delta (delta), encoded by the CHRND gene and found in the muscle. Delta nAChR subunit forms a heteropentamer with either (alpha1)2, beta and gamma subunits in embryonic type or (alpha1)2, beta and epsilon subunits in adult type receptors. Defects in this gene are a cause of multiple pterygium syndrome lethal type (MUPSL), congenital myasthenic syndrome slow-channel type (SCCMS), and congenital myasthenic syndrome fast-channel type (FCCMS). The slow-channel congenital myasthenic syndromes (SCCMS) are caused by prolonged opening episodes of AChR due to dominant gain-of-function mutations in the transmembrane regions of the heteropentamer. These mutations produce an increase in the channel opening rate, a decrease in the channel closing rate, or an increase in the affinity of ACh for the AChR, resulting in the stabilization of the open state or the destabilization of the closed state of the AChR.


Pssm-ID: 349829  Cd Length: 221  Bit Score: 81.77  E-value: 4.10e-18
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   5 IVKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYDGTMVDLILINENVDRKD------------FFDNGEW 72
Cdd:cd19028   107 LVYSDGFVYWLPPAIFRSSCPINVNYFPFDWQNCSLKFSSLNYNAKEINLDLKTDTDDGKTypvewiiidpegFTENGEW 186
                          90       100       110
                  ....*....|....*....|....*....|....*
gi 1720426105  73 EILN---AKGMKGNRREGFYSYPFVTYSFVLRRLP 104
Cdd:cd19028   187 EIVHkpaKKNIDPSKPPESTKYQDITFYLIIKRKP 221
LGIC_AChBP cd18995
acetylcholine binding protein (AChBP); This family contains acetylcholine binding protein ...
2-102 2.59e-17

acetylcholine binding protein (AChBP); This family contains acetylcholine binding protein (AChBP) which is a soluble extracellular domain homolog secreted by protostomia, and has been widely recognized as a surrogate for the ligand binding domain of nicotinic acetylcholine receptors (nAChRs). AChBP forms a pentameric structure where the interfaces between the subunits provide an acetylcholine (ACh) binding pocket homologous to the binding pocket of nAChRs. Thus far, AChBPs have been characterized only in aquatic mollusks, which have shown low sensitivity to neonicotinoids, the insecticides targeting insect nAChRs. Lymnaea stagnalis acetylcholine binding protein (Ls-AChBP) which has been found in glial cells as a water-soluble protein modulating synaptic ACh concentration has its the binding pocket show better resemblance as it contains all the five aromatic residues fully conserved in nAChR. Five AChBP subunits have been characterized in Pardosa pseudoannulata, a predator enemy against rice insect pests, and share higher sequence similarities with nAChR subunits of both insects and mammals compared with mollusk AChBP subunits.


Pssm-ID: 349796  Cd Length: 180  Bit Score: 78.56  E-value: 2.59e-17
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   2 TKAIVKSSGTVSWTPPASYKSSCTMDVTFfPFDKQNCSMKFGSWTYDGTMVDLILINENVDRKDFFDNGEWEILNAKGMK 81
Cdd:cd18995    78 QLVLVSSDGTVLWVPPIRIRFSCDLDNVD-PEDGATCRLKIGSWTYSGREIDLNTGTDVDLDSYYNQSSKWELLSATQKR 156
                          90       100
                  ....*....|....*....|....*.
gi 1720426105  82 GNRRegfYS-----YPFVTYSFVLRR 102
Cdd:cd18995   157 EVKT---YSccpepYPDIEFVFTFKK 179
LGIC_TM_5-HT3 cd19063
transmembrane domain of 5-hydroxytryptamine 3 (5-HT3) receptor; This family contains ...
105-193 1.14e-13

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: 66.49  E-value: 1.14e-13
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105 105 LFYTLFLIIPCLGLSFLTVLVFYLPSDEGEKLSLSTSVLVSLTVFLLVIEEIIPSSSKVIPLIGEYLLFIMIFVTLSIIV 184
Cdd:cd19063     1 LLYVVNLLIPSIFLMLVDLASFYLPPNSGERLGFKVTLLLGYSVFLLILNDLLPATAIGTPLIGVYFVVCLALMVLSLLE 80

                  ....*....
gi 1720426105 185 TVFVINVHH 193
Cdd:cd19063    81 TILIVKLLH 89
LGIC_ECD_5-HT3 cd18996
extracellular domain of serotonin 5-HT3 receptor; This family contains extracellular domain of ...
6-102 1.83e-12

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: 65.48  E-value: 1.83e-12
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   6 VKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYdgTMVDLILI----NENV---DRKDFFDNGEWEILNAK 78
Cdd:cd18996   113 VSNNGTVRNYKPLQVVSTCSLDIYKFPFDTQNCNLTFSSFLH--TVNDIILNpgsnSEEItseSKEIFQTQGEWELLNIK 190
                          90       100
                  ....*....|....*....|....
gi 1720426105  79 GMKGNRREGFYSYPFVTYSFVLRR 102
Cdd:cd18996   191 VSDEKLSLLGNSFDQIVYQITIKR 214
LGIC_ECD_5-HT3B cd19012
extracellular domain of serotonin 5-hydroxytryptamine receptor (5-HT3) receptor subunit B ...
6-102 6.40e-11

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: 61.08  E-value: 6.40e-11
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   6 VKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYDGTMVDLILIN--ENV--DRKDFFDNGEWEILNAKGMK 81
Cdd:cd19012   109 VNSSGTIKNYKPIQVVSACDLETYAFPFDRQNCSLTFRSWLHTVGDVDLALWRspEEIanDKREFLNDGEWELLSVPSRY 188
                          90       100
                  ....*....|....*....|.
gi 1720426105  82 GNRREGFYSYPFVTYSFVLRR 102
Cdd:cd19012   189 RILHMEDQDFAQIQFNVVIRR 209
LGIC_ECD_5-HT3C_E cd19013
extracellular domain of serotonin 5-hydroxytryptamine receptor (5-HT3) receptor subunit E ...
4-102 3.16e-10

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: 58.95  E-value: 3.16e-10
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   4 AIVKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYdgtMVDLILINENVDRKDFFDN--------GEWEIL 75
Cdd:cd19013   111 VYVSHTGRVRDDKPVRVVSSCNLDIFTFPFDIQNCTLTFGSYLH---TVDDIKLFLLLSVEEILKNsrkvlttqGEWELV 187
                          90       100
                  ....*....|....*....|....*..
gi 1720426105  76 NAKGMKGNRREGFYSYPFVTYSFVLRR 102
Cdd:cd19013   188 DIKAAKAKLSFGEELYDEITFYVIIRR 214
LGIC_TM cd03559
transmembrane domain of Cys-loop neurotransmitter-gated ion channels; This superfamily ...
106-211 1.12e-08

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: 52.53  E-value: 1.12e-08
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105 106 FYTLFLIIPCLGLSFLTVLVFYLPSDEGEKLSLSTSVLVSLTVFLLVIEEIIPSSSKViPLIGEYLLFIMIFVTLSIIVT 185
Cdd:cd03559     1 YYAVSLLLPSILIMVVSWVGFWLPPDSGERVSFKITLLLTYSVFLIIVSDTLPATPYT-PLIDVYFVVCMALLFIALLET 79
                          90       100
                  ....*....|....*....|....*.
gi 1720426105 186 VFVINVHHRSSSTYHPMAPWVKRLFL 211
Cdd:cd03559    80 IFIVRLVHKQDRVGYVIDRLLRRIFP 105
LGIC_ECD_5-HT3A cd19011
extracellular domain of serotonin 5-hydroxytryptamine receptor (5-HT3) receptor subunit A ...
6-102 1.86e-08

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: 53.69  E-value: 1.86e-08
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   6 VKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSW--TYDGTMVDLILINENV--DRKDFFDNGEWEILNA-KGM 80
Cdd:cd19011   106 VNHEGEVQNYKPIQVVTACSLDIYNFPFDVQNCSLTFTSWlhTIQDINISLWRSPEEVksDKSVFMNQGEWELLGVlPQY 185
                          90       100
                  ....*....|....*....|..
gi 1720426105  81 KGNRREGFYSYPFVTYSFVLRR 102
Cdd:cd19011   186 REFSIDISDSYAEMKFYVVIRR 207
LGIC_ECD_GluCl cd18993
glutamate-gated chloride channel (GluCl) extracellular domain; This subfamily contains ...
6-57 1.47e-07

glutamate-gated chloride channel (GluCl) extracellular domain; This subfamily contains extracellular domain of glutamate-gated chloride channel (GluCl) found only in protostomia, but are closely related to mammalian glycine receptors. They have several roles in these invertebrates, including controlling locomotion and feeding, and mediating sensory inputs into behavior. Comparison of the GluCl gene families between organisms shows that insect gene family is relatively simple, while that found in nematodes tends to be larger and more diverse. Glutamate is an inhibitory neurotransmitter that shapes the responses of projection neurons to olfactory stimuli in the Drosophila. GluCls are targeted by the macrocyclic lactone family of anthelmintics and pesticides in arthropods and nematodes, thus making the GluCls of considerable medical and economic importance. In Drosophila melanogaster, GluCl mediates sensitivity to the antiparasitic agents ivermectin and nodulisporic acid, suggesting that their drug target is the same throughout the Ecdysozoa.


Pssm-ID: 349794  Cd Length: 183  Bit Score: 50.67  E-value: 1.47e-07
                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1720426105   6 VKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYdgTMVDLILI 57
Cdd:cd18993    85 IYPDGKVLYSVRISLTLSCPMDLQYYPFDKQTCSIDLASYGY--TTDDIVYL 134
LGIC_ECD_anion cd18987
extracellular domain (ECD) of anionic Cys-loop neurotransmitter-gated ion channels; This ...
6-56 1.58e-06

extracellular domain (ECD) of anionic Cys-loop neurotransmitter-gated ion channels; This family contains the extracellular domain (ECD) of anionic Cys-loop neurotransmitter-gated ion channels which include type-A gamma-aminobutyric acid receptor (GABAAR), glycine receptor (GlyR), invertebrate glutamate-gated chloride channel (GluCl), and histimine-gated chloride channel (HisCl). These neurotransmitter receptors directly mediate chloride permeability and constitute one half of the Cys-loop receptor family. Receptors in this family are composed of five either identical or homologous subunits, which generate diversity in functional profiles and pharmacological preferences. GABAAR and GlyR, both mediate fast inhibitory synaptic transmission. Cl- ions are selectively conducted through the GABAAR receptor pore, resulting in hyperpolarization of the neuron. GluCl channels are found only in protostomia, but are closely related to mammalian glycine receptors (GlyRs). They have several roles in these invertebrates, including controlling locomotion and feeding, and mediating sensory inputs into behavior. 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 this inhibitory half of the Cys-loop receptor family. Many of the therapeutically useful compounds acting at Cys-loop receptors target an allosteric site. The sites in Cys-loop receptors at which these allosteric ligands bind and their structure-based mechanisms of action are largely unresolved.


Pssm-ID: 349788 [Multi-domain]  Cd Length: 185  Bit Score: 47.67  E-value: 1.58e-06
                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1720426105   6 VKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYdgTMVDLIL 56
Cdd:cd18987    85 IFPNGTVLYSQRLTLTLSCPMNLQKFPFDTQVCTLRLESYGY--TTDQVVL 133
LGIC_ECD_GABAAR cd18990
gamma-aminobutyric acid receptor extracellular domain; This family contains extracellular ...
21-102 1.72e-06

gamma-aminobutyric acid receptor extracellular domain; This family contains extracellular domain (ECD) of type-A gamma-aminobutyric acid receptor (GABAAR), a member of the pentameric "Cys-loop" superfamily of transmitter-gated ion channels. This family includes 19 isoforms in human; six alpha, 3 beta, 3 gamma, one of delta, epsilon, pi, and theta, known to form heteropentameric GABAARs, and 3 rho subunits that only form homopentameric channels (also known as GABAA rho or GABAC receptor) or pseudoheteromeric if consisting of different rho subunits. The majority of GABAA receptor pentamers contain two alpha subunits, two beta subunits, and a gamma subunit, with different isoforms affecting potency of the neurotransmitter. GABAAR is an anionic channel, mediating fast inhibitory synaptic transmission. Upon gamma-aminobutyric acid (GABA) binding to its site on the ECD, 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. Benzodiazepine and barbiturates each bind to their own distinct sites on the ECD. The channels have to contain the gamma subunit and alpha subunits in order to respond to benzodiazepines. Specific combinations of alpha, beta, and gamma subunits exhibit ethanol sensitivity. All these major classes of drugs favor channel-opening. A decline in GABAAR signaling triggers hyperactive neurological disorders such as insomnia, anxiety, and epilepsy.


Pssm-ID: 349791 [Multi-domain]  Cd Length: 184  Bit Score: 47.55  E-value: 1.72e-06
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105  21 KSSCTMDVTFFPFDKQNCSMKFGSWTYDGTMVDL--------ILINENVDRKDFfdngeweilNAKGMKGNRREGFYS-- 90
Cdd:cd18990   100 TAPCSMDLRKFPMDTQTCSLVFESYGYTTDDVVYkwkegdtpVTILEKIELPQF---------DLTGVTTSEKTEVYPag 170
                          90
                  ....*....|...
gi 1720426105  91 -YPFVTYSFVLRR 102
Cdd:cd18990   171 nYSRLTVTFTFKR 183
LGIC_ECD_GABAAR_pi cd19004
extracellular domain of gamma-aminobutyric acid receptor subunit pi (GABRP); This family ...
8-102 1.15e-05

extracellular domain of gamma-aminobutyric acid receptor subunit pi (GABRP); This family contains extracellular domain of pi subunit of type-A gamma-aminobutyric acid receptor (GABAAR). GABAAR is an anionic channel, mediating fast inhibitory synaptic transmission. Upon gamma-aminobutyric acid (GABA) binding to the ligand binding site on ECD, 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. GABRP is expressed mainly in non-neuronal tissues such as the mammary gland, prostate gland, lung, thymus, and uterus. It is also highly expressed in certain types of cancer such as basal-like breast cancer and pancreatic ductal adenocarcinoma. GABRP is involved in inhibitory synaptic transmission in the central nervous system. Its assembly with other GABAAR subunits alters the sensitivity of recombinant receptors to modulatory agents such as pregnanolone. Studies suggest that polymorphisms in the GABRP gene may be associated with the susceptibility to systematic lupus erythematosus (SLE).


Pssm-ID: 349805  Cd Length: 182  Bit Score: 45.36  E-value: 1.15e-05
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   8 SSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYDGTMVDLILI--NENVDRKDFFDNGEWEILNAKGMKGNRR 85
Cdd:cd19004    85 PNGTVLYALRITTTVACSMDLTKYPMDKQTCTLQLESWGYNINDVMFYWTrgNDSVRGLDHLRLAQYTVEDYFTSVSEAV 164
                          90
                  ....*....|....*..
gi 1720426105  86 EGFYSYPFVTYSFVLRR 102
Cdd:cd19004   165 YETGNYPKLVFHFELKR 181
LGIC_ECD_GlyR cd18991
extracellular domain of glycine receptor (GlyR); This subfamily contains extracellular domain ...
23-56 4.94e-05

extracellular domain of glycine receptor (GlyR); This subfamily contains extracellular domain of glycine receptor (GlyR or GLR) of the amino acid neurotransmitter glycine. GlyR has four known isoforms of the alpha-subunit (alpha1-4, encoded by GLRA1, GLRA2, GLRA3, GLRA4) that are essential to bind ligands and a single beta-subunit (encoded by GLRB), all of which have been described to have a regionally and temporally controlled expression during development and maturation of the central nervous system (CNS). Functional chloride-permeable GlyR ion channels are formed by 5 alpha subunit homopentamers or by alpha and beta subunit heteropentamers, which form complexes with either a 2alpha-3beta or 3alpha-2beta stoichiometry. The receptor can be activated by glycine as well as beta-alanine and taurine, and can be selectively blocked by the high-affinity competitive antagonist strychnine. Caffeine is also a competitive antagonist of GlyR. In human, glycine receptor alpha1 and beta subunits are the major targets of mutations that cause disruption of GlyR surface expression or reduced ability of expressed GlyRs to conduct chloride ions, leading to hyperekplexia, a rare neurological disorder characterized by neonatal hypertonia and exaggerated startle responses to unexpected stimuli. Mutations in GlyR alpha2 are known to cause cortical neuronal migration/autism spectrum disorder and in GlyR alpha3 to cause inflammatory pain sensitization/rhythmic breathing.


Pssm-ID: 349792  Cd Length: 185  Bit Score: 43.35  E-value: 4.94e-05
                          10        20        30
                  ....*....|....*....|....*....|....
gi 1720426105  23 SCTMDVTFFPFDKQNCSMKFGSWTYdgTMVDLIL 56
Cdd:cd18991   103 SCPMDLHKYPLDTQTCPIQIESFGY--TTENLIF 134
LGIC_TM_bact cd19050
transmembrane domain of prokaryotic pentameric ligand-gated ion channels (pLGIC); This family ...
106-195 8.25e-04

transmembrane domain of prokaryotic pentameric ligand-gated ion channels (pLGIC); This family contains transmembrane (TM) domain of bacterial pentameric ligand-gated ion channels (pLGICs) including ones from Gloeobacter violaceus (GLIC) and Erwinia chrysanthemi (ELIC). The transmembrane region consists of four transmembrane-spanning alpha-helical segments (M1-M4) that are linked by loops. Studies show that GLIC activation is inhibited by most general anaesthetics at clinical concentrations, including xenon which has been used in clinical practice as a potent gaseous anesthetic for decades. Xenon binding sites have been identified in three distinct regions of the TMD: in a large intra-subunit cavity, in the pore, and at the interface between adjacent subunits. Propofol, the drug used for induction and maintenance of general anesthesia, and desflurane, a negative allosteric modulator of GLIC bind at the entrance in the intra-subunit cavity. Alzheimer's drug memantine, which blocks ion conduction at vertebrate pLGICs by plugging the channel pore, has been shown to have similar potency in ELIC.


Pssm-ID: 349852  Cd Length: 119  Bit Score: 38.73  E-value: 8.25e-04
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105 106 FYTLFLIIPCLGLSFLTVLVFYL-PSDEGEKLSLSTSVLVSLTVFLLVIEEIIPSSSkVIPLIGEYLLFIMIFVTLSIIV 184
Cdd:cd19050     1 YYIWKVILPLLLIVAMSWSVFWIdPESFGPQIGISVTSMLTLIAFNFLISNSLPRLP-YLTFMDAFILASYLLVFLALIE 79
                          90
                  ....*....|.
gi 1720426105 185 TVFVINVHHRS 195
Cdd:cd19050    80 VIVTHYLARNG 90
LGIC_ECD_GABAAR_A2 cd19035
extracellular domain of gamma-aminobutyric acid receptor subunit alpha-2 (GABAAR-A2 or GABRA2); ...
6-55 2.56e-03

extracellular domain of gamma-aminobutyric acid receptor subunit alpha-2 (GABAAR-A2 or GABRA2); This family contains extracellular domain of gamma-aminobutyric acid receptor subunit alpha-2 (GABAAR-A2), a protein that is encoded by the GABRA2 gene in humans. GABAAR is an anionic channel, mediating fast inhibitory synaptic transmission. Upon gamma-aminobutyric acid (GABA) binding to the ligand binding site on the ECD, 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. The alpha-2 subunit forms heteropentamers with other GABAAR subunits, most broadly expressed as combination of alpha2beta3gamma2. The alpha-2 (GABRA2) subunit is found primarily in the forebrain and hippocampus, and is more confined to areas of the brain compared to other alpha subunits. GABRA2 increases the risk of anxiety, making it a target for treating behavioral disorders including alcohol dependence, and drug use. GABRA2 is a binding site for benzodiazepines (psychoactive drugs known to reduce anxiety), causing chloride channels to open, leading to the hyper-polarization of the membrane. Other anxiolytic drugs such as Diazepam bind this subunit to induce inhibitory effects. GABRA2 is associated with reward behavior when it activates the insula, the part of the cerebral cortex responsible for emotions. GABA alpha2 and/or alpha3 receptor subtypes are also involved in GABAergic modulation of prolactin secretion.


Pssm-ID: 349836 [Multi-domain]  Cd Length: 203  Bit Score: 38.48  E-value: 2.56e-03
                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 1720426105   6 VKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYDGTMVDLI 55
Cdd:cd19035   102 IQDDGTLLYTMRLTVQAECPMHLEDFPMDAHSCPLKFGSYAYTTSEVTYI 151
LGIC_ECD_GABAR_GRD-like cd19007
gamma-aminobutyric acid receptor subunit alpha-like extracellular domain in protostomia, such ...
21-47 4.28e-03

gamma-aminobutyric acid receptor subunit alpha-like extracellular domain in protostomia, such as GRD (GABA/glycine-like receptor of Drosophila); This family contains extracellular domain of alpha-like subunits of type-A gamma-aminobutyric acid receptor (GABAAR) found in protostomia, similar to Drosophila melanogaster GABA/ glycine-like receptor of Drosophila (GRD) subunits. Drosophila melanogaster expresses three GABA-receptor subunit orthologs: (RDL, resistant to dieldrin; GRD, GABA/glycine-like receptor of Drosophila; LCCH3, ligand-gated chloride channel homolog 3), and may possibly form homo- and/or heteropentameric associations. LCCH3 has been shown to combine with subunit GRD to form cation-selective GABA-gated ion channels when co-expressed in Xenopus laevis oocytes. GABAARs are known to be the molecular targets of a class of insecticides. The resulting pentameric receptors in this family have been shown to be activated by insect GABA-receptor agonists muscimol and CACA, and blocked by antagonists fipronil, dieldrin, and picrotoxin, but not bicuculline. GABAARs are abundant in the CNS, where their physiological role is to mediate fast inhibitory neurotransmission. In insects, this inhibitory transmission plays a crucial role in olfactory information processing.


Pssm-ID: 349808  Cd Length: 183  Bit Score: 37.61  E-value: 4.28e-03
                          10        20
                  ....*....|....*....|....*..
gi 1720426105  21 KSSCTMDVTFFPFDKQNCSMKFGSWTY 47
Cdd:cd19007   100 KASCPMNLEKFPMDTQSCPLIIGSYGY 126
LGIC_ECD_GABAAR_A5 cd19038
extracellular domain of gamma-aminobutyric acid receptor subunit alpha-5 (GABAAR-A5 or GABRA5); ...
6-47 4.50e-03

extracellular domain of gamma-aminobutyric acid receptor subunit alpha-5 (GABAAR-A5 or GABRA5); This family contains extracellular domain of gamma-aminobutyric acid receptor subunit alpha-5 (GABAAR-A5), a protein that is encoded by the GABRA5 gene in humans, with biased expression in the brain and heart. GABAAR is an anionic channel, mediating fast inhibitory synaptic transmission. Upon gamma-aminobutyric acid (GABA) binding to the ligand binding site on the ECD, 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. The alpha-5 subunit forms heteropentamers with other GABAAR subunits, most broadly expressed as alpha5-beta-gamma2, and probably alpha5-beta3-gamma2, predominantly expressed in the hippocampus and localized extrasynaptically. These receptors have been demonstrated to play an important modulatory role in learning and memory processes, thus making them suitable targets for pharmacological intervention. Studies show that alpha5-containing GABAARs play an important part in tonic inhibition in hippocampal pyramidal neurons, and that these can also contribute to synaptic inhibition. Studies strongly suggest that amnesia is primarily mediated by alpha5-beta-gamma2. Polymorphisms in GABRA5 (and GABRA3) are linked to the susceptibility to panic disorder. A genetic association also exists between GABRA5 and bipolar affective disorder.


Pssm-ID: 349839  Cd Length: 199  Bit Score: 37.72  E-value: 4.50e-03
                          10        20        30        40
                  ....*....|....*....|....*....|....*....|..
gi 1720426105   6 VKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTY 47
Cdd:cd19038    98 LEDDGTLLYTMRLTISAECPMQLEDFPMDAHACPLKFGSYAY 139
LGIC_ECD_GABAAR_A6 cd19039
extracellular domain of gamma-aminobutyric acid receptor subunit alpha-6 (GABAAR-A6 or GABRA6); ...
6-47 4.97e-03

extracellular domain of gamma-aminobutyric acid receptor subunit alpha-6 (GABAAR-A6 or GABRA6); This family contains extracellular domain of gamma-aminobutyric acid receptor subunit alpha-6 (GABAAR-A6), a protein that is encoded by the GABRA6 gene in humans. GABAAR is an anionic channel, mediating fast inhibitory synaptic transmission. Upon gamma-aminobutyric acid (GABA) binding to the ligand binding site on the ECD, 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. The alpha-6 subunit forms heteropentamers with other GABAAR subunits, most broadly expressed as alpha6-beta-gamma2 found extrasynaptically, alpha6-beta2/3-delta in the cerebellar granule cells and likely also forms alpha1-alpha6-beta-gamma/alpha1-alpha6-beta-delta. A GABRA6 mutation from Arg to Trp, has been identified as a susceptibility gene that may contribute to the pathogenesis of childhood absence epilepsy and cause neuronal disinhibition and increase in seizures via a reduction of alphabetagamma and alphabetadelta receptor function and expression. Polymorphism in the GABRA6 gene is associated with specific personality characteristics as well as a marked attenuation in hormonal and blood pressure responses to psychological stress. Alpha6-containing receptors lack high sensitivity to diazepam.


Pssm-ID: 349840  Cd Length: 198  Bit Score: 37.70  E-value: 4.97e-03
                          10        20        30        40
                  ....*....|....*....|....*....|....*....|..
gi 1720426105   6 VKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTY 47
Cdd:cd19039    97 IMQNGTILYTMRLTINAECPMRLVNFPMDGHACPLKFGSYAY 138
LGIC_ECD_GABAAR_B cd18999
extracellular domain of gamma-aminobutyric acid receptor subunit beta (GABAAR-B or GABRB); ...
10-102 5.54e-03

extracellular domain of gamma-aminobutyric acid receptor subunit beta (GABAAR-B or GABRB); This family contains extracellular domain (ECD) of beta subunits of type-A gamma-aminobutyric acid receptor (GABAAR), which include beta1-beta4 in vertebrates. GABAAR is an anionic channel, mediating fast inhibitory synaptic transmission. Upon gamma-aminobutyric acid (GABA) binding to the ECD, 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. Benzodiazepine and barbiturates each bind to their own distinct sites on the LBD. The channels must contain the gamma subunit and alpha subunits in order to respond to benzodiazepines. Specific combinations of alpha, beta, and gamma subunits exhibit ethanol sensitivity. All these major classes of drugs favor channel-opening. A decline in GABAAR signaling triggers hyperactive neurological disorders such as insomnia, anxiety, and epilepsy. Mutations or genetic variations of the genes encoding the GABRB2 and GABRB3 have been associated with human epilepsy, both with and without febrile seizures. Mutations in GABRB2, and GABRB3 have been associated with infantile spasms and Lennox-Gastaut syndrome. A de novo missense mutation of GABRB2 causes early myoclonic encephalopathy, a disease with a devastating prognosis, characterized by neonatal onset of seizures. Another de novo heterozygous missense variant in exon 4 of GABRB2 is associated with intellectual disability and epilepsy. Mutations in the GABRB1 gene promote alcohol consumption through increased tonic inhibition.


Pssm-ID: 349800  Cd Length: 182  Bit Score: 37.25  E-value: 5.54e-03
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105  10 GTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYdgTMVDLILI---NEN-VDRKDFFDNGEWEILNAKGMKGNRR 85
Cdd:cd18999    87 GTVLYGLRITTTAACMMDLRRYPLDEQNCTLEIESYGY--TTDDIEFYwqgGDNaVTGVEKIELPQFSIVEYRLVSREVV 164
                          90
                  ....*....|....*..
gi 1720426105  86 EGFYSYPFVTYSFVLRR 102
Cdd:cd18999   165 FTTGSYPRLSLSFRLKR 181
LGIC_ECD_GABAAR_A3 cd19036
extracellular domain of gamma-aminobutyric acid receptor subunit alpha-3 (GABAAR-A3 or GABRA3); ...
9-52 6.94e-03

extracellular domain of gamma-aminobutyric acid receptor subunit alpha-3 (GABAAR-A3 or GABRA3); This family contains extracellular domain of gamma-aminobutyric acid receptor subunit alpha-3 (GABAAR-A3), a protein that is encoded by the GABRA3 gene in humans. GABAAR is an anionic channel, mediating fast inhibitory synaptic transmission. Upon gamma-aminobutyric acid (GABA) binding to the ligand binding site on the ECD, 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. The alpha-3 subunit forms heteropentamers with other GABAAR subunits, most broadly expressed as combination of alpha3betagamma2, typically found post-synaptically. Rare loss-of-function variants in GABRA3 have been shown to increase the risk for a varying combination of epilepsy, intellectual disability/developmental delay, and dysmorphic features. GABRA3, normally exclusively expressed in adult brain, is also expressed in breast cancer, with high expression being inversely correlated with breast cancer survival. It activates the AKT pathway to promote breast cancer cell migration, invasion, and metastasis. GABRA3 promotes lymphatic metastasis in lung adenocarcinoma by mediating upregulation of matrix metalloproteinases, MMP-2 and MMP-9, through activation of the JNK/AP-1 signaling pathway. GABRA3 is overexpressed in human hepatocellular carcinoma growth and, with GABA, promotes the proliferation of cancer cells.


Pssm-ID: 349837  Cd Length: 200  Bit Score: 37.31  E-value: 6.94e-03
                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....
gi 1720426105   9 SGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYDGTMV 52
Cdd:cd19036   102 NGTLLYTMRLTIHAECPMHLEDFPMDVHACPLKFGSYAYTKTEV 145
LGIC_ECD_GABAAR_rho cd19005
extracellular domain of gamma-aminobutyric acid receptor subunit rho; This family contains ...
6-102 7.83e-03

extracellular domain of gamma-aminobutyric acid receptor subunit rho; This family contains extracellular domain of rho subunits (rho1, rho2, and rho3, encoded by GABRR1, GABRR2, and GABRR3, respectively) of type-A gamma-aminobutyric acid receptor (GABAAR). These subunits homo-oligomerize to form GABAA-rho receptors (formerly classified as GABA-rho or GABAC receptor), but do not co-assemble with any of the classical GABAA subunits. They are especially high expression in the retina and their distinctive pharmacological properties are unique; they are not modulated by many GABAA receptor modulators such as barbiturates, benzodiazepines, and neuroactive steroids. In humans, mutations in the GABRR1 and GABRR2 genes may be responsible for some cases of autosomal recessive retinitis pigmentosa. Variation in GABRR1 is also associated with susceptibility to bipolar schizoaffective disorder while a SNP in GABRR2 has been reported to show association with autism.


Pssm-ID: 349806  Cd Length: 186  Bit Score: 36.91  E-value: 7.83e-03
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1720426105   6 VKSSGTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYdgTMVDLILI----NENVDRKDFFDNGEWEIlnaKGMK 81
Cdd:cd19005    85 VFPDGHVLYSLRITVTAMCNMDFSRFPLDTQTCSLELESYAY--TEDDLMLYwkngNESLKTDEKISLSQFLI---QKFH 159
                          90       100
                  ....*....|....*....|....*
gi 1720426105  82 GNRREGFYS----YPFVTYSFVLRR 102
Cdd:cd19005   160 TTSRLAFYSstgwYNRLYINFTLRR 184
LGIC_ECD_GABAAR_theta cd19003
extracellular domain of gamma-aminobutyric acid receptor subunit theta (GABRQ); This family ...
10-56 9.09e-03

extracellular domain of gamma-aminobutyric acid receptor subunit theta (GABRQ); This family contains extracellular domain (ECD) of the theta subunit of type-A gamma-aminobutyric acid receptor (GABAAR), and encoded by the GABRQ gene, which is mapped to chromosome Xq28 in a cluster of genes that also that encode the alpha 3 and epsilon subunits. 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. GABA stimulates human hepatocellular carcinoma growth through overexpressed GABAAR theta subunit. Also, two autism spectrum disorder (ASD)-associated protein truncation variants have been identified in alpha 3 (GABRA3) and theta (GABRQ) genes.


Pssm-ID: 349804  Cd Length: 183  Bit Score: 36.50  E-value: 9.09e-03
                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 1720426105  10 GTVSWTPPASYKSSCTMDVTFFPFDKQNCSMKFGSWTYdgTMVDLIL 56
Cdd:cd19003    88 GTVRYGIRLTTTAACSLDLHKFPMDKQACKLEVESYGY--TVEDIIL 132
 
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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