Protein Domain : IPR002456

Type:  Family Name:  GPCR, family 3, gamma-aminobutyric acid receptor, type B1
Description:  GPCR family 3 receptors (also known as family C) are structurally similar to other GPCRs, but do not show any significant sequence similarity and thus represent a distinct group. Structurally they are composed of four elements; an N-terminal signal sequence; a large hydrophilic extracellular agonist-binding region containing several conserved cysteine residues which could be involved in disulphide bonds; a shorter region containing seven transmembrane domains; and a C-terminal cytoplasmic domain of variable length []. Family 3 members include the metabotropic glutamate receptors, the extracellular calcium-sensing receptors, the gamma-amino-butyric acid (GABA) type B receptors, and the vomeronasal type-2 receptors [, , , ]. As these receptors regulate many important physiological processes they are potentially promising targets for drug development.GABA is the principal inhibitory neurotransmitter in the brain, and signals through ionotropic (type A and type C) andmetabotropic (type B) receptor systems. The type B receptors have been cloned, and photoaffinity labelling experiments suggest that theycorrespond to two highly conserved receptor forms in the vertebrate nervous system []. These receptors are involved in the fine tuning of inhibitory synaptic transmission []. Presynaptic receptors inhibit neurotransmitter release by down-regulating high-voltage activated calcium channels, while postsynaptic receptors decrease neuronal excitability by activating a prominent inwardly rectifying potassium (Kir) conductance that underlies the late inhibitory postsynaptic potentials []. The type B receptors negatively couple to adenylylcyclase and show sequence similarity to the metabotropic receptors for the excitatory neurotransmitter L-glutamate. The physiological form of the B receptor may be a heterodimer of the B1 and B2 subtypes []. Neurophysiological and pharmacological studies point to a major role of the GABA type B receptor in the epileptogenesis of absence seizures []. Using in situ hybridisation, the gene encoding the human GABA type B1 receptor has been mapped to chromosome 6p21.3, in the vicinity of a susceptibility locus (EJM1) for idiopathic generalised epilepsies, identifying a candidate gene for inherited forms of epilepsy [, ]. Short Name:  GPCR_3_GABA_rcpt_B1

0 Child Features

1 Contains

DB identifier Type Name
IPR017978 Domain GPCR, family 3, C-terminal

1 Cross References

Identifier
PR01177

0 Found In

3 GO Annotations

GO Term Gene Name
GO:0004965 IPR002456
GO:0007186 IPR002456
GO:0016021 IPR002456

3 Ontology Annotations

GO Term Gene Name
GO:0004965 IPR002456
GO:0007186 IPR002456
GO:0016021 IPR002456

1 Parent Features

DB identifier Type Name
IPR002455 Family GPCR, family 3, gamma-aminobutyric acid receptor, type B

0 Proteins

9 Publications

First Author Title Year Journal Volume Pages PubMed ID
            8255296
            10773016
            1309649
            9292726
            17266540
            9069281
            9844003
            9872316
            9933300