3 Ontology Annotations
| GO Term | Gene Name |
|---|---|
| GO:0004965 | IPR002457 |
| GO:0007186 | IPR002457 |
| GO:0016021 | IPR002457 |
1 Parent Features
| DB identifier | Type | Name |
|---|---|---|
| IPR002455 | Family | GPCR, family 3, gamma-aminobutyric acid receptor, type B |
| Type: | Family | Name: | GPCR, family 3, gamma-aminobutyric acid receptor, type B2 |
| 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 []. A new subtype of the type B receptor (type B2) has been identified by EST database mining []. Yeast two-hybrid screening has shown that the new subtype forms heterodimers with GABA subtype B1 via an interaction at their intracellular C-terminal tails. On expression with B2 in HEK293Tcells, B1 is terminally glycosylated and expressed at the cell surface. Co-expression of the receptors produces a fully functional type Breceptor at the cell surface; this receptor binds GABA with a high affinity equivalent to that of the endogenous brain receptor []. Such results indicate that, in vivo, functional brain GABA(B) receptors may be heterodimers of the B1 and B2 subtypes. | Short Name: | GPCR_3_GABA_rcpt_B2 |
| GO Term | Gene Name |
|---|---|
| GO:0004965 | IPR002457 |
| GO:0007186 | IPR002457 |
| GO:0016021 | IPR002457 |
| DB identifier | Type | Name |
|---|---|---|
| IPR002455 | Family | GPCR, family 3, gamma-aminobutyric acid receptor, type B |
