Secretin receptor family
| Secretin family of 7 transmembrane receptors | |||||
|---|---|---|---|---|---|
| 220px | |||||
| Structure of a 31 amino acid fragment of the extracellular N-terminus of the human parathyroid hormone receptor.[1] | |||||
| Identifiers | |||||
| Symbol | 7tm_2 | ||||
| Pfam | PF00002 | ||||
| InterPro | IPR000832 | ||||
| PROSITE | PDOC00559 | ||||
| SCOP | 1bl1 | ||||
| OPM family | 6 | ||||
| OPM protein | 1fjr | ||||
| |||||
Secretin family of 7 transmembrane receptors is a family of evolutionarily related proteins.[2]
This family is known as Family B, the secretin-receptor family or family 2 of the G-protein-coupled receptors (GPCR). Many secretin receptors are regulated by peptide hormones from the glucagon hormone family.
The secretin-receptor family GPCRs include vasoactive intestinal peptide receptors and receptors for secretin, calcitonin and parathyroid hormone/parathyroid hormone-related peptides. These receptors activate adenylyl cyclase and the phosphatidyl-inositol-calcium pathway. The receptors in this family have 7 transmembrane helices, like rhodopsin-like GPCRs. However, there is no significant sequence identity between these two GPCR families and the secretin-receptor family has its own characteristic 7TM signature.
The secretin-receptor family GPCRs exist in many animal species, but have not been found in plants, fungi or prokaryotes. Three distinct sub-families (B1-B3) are recognized.
Contents
Subfamily B1
Subfamily B1 contains classical hormone receptors, such as receptors for secretin and glucagon, that are all involved in cAMP-mediated signalling pathways.
- Pituitary adenylate cyclase-activating polypeptide type 1 receptor IPR002285
- Calcitonin receptor IPR003287
- Corticotropin-releasing hormone receptor IPR003051
- Glucose-dependent insulinotropic polypeptide receptor/Gastric inhibitory polypeptide receptor IPR001749
- Glucagon receptor-related IPR003290
- Growth hormone releasing hormone receptor IPR003288
- Parathyroid hormone receptor IPR002170
- Secretin receptor IPR002144
- Vasoactive intestinal peptide receptor IPR001571
Subfamily B2
Subfamily B2 contains receptors with long extracellular N-termini, such as the leukocyte cell-surface antigen CD97; calcium-independent receptors for latrotoxin (such as UniProt O94910, and brain-specific angiogenesis inhibitor receptors (such as UniProt O14514) amongst others.
- Brain-specific angiogenesis inhibitor IPR008077
- CD97 antigen IPR003056
- EMR hormone receptor IPR001740
- GPR56 orphan receptor IPR003910
- Latrophilin receptor IPR003924
Subfamily B3
Subfamily B3 includes Methuselah and other Drosophila proteins. Other than the typical seven-transmembrane region, characteristic structural features include an amino-terminal extracellular domain involved in ligand binding, and an intracellular loop (IC3) required for specific G-protein coupling.
Unclassified subfamilies
Unclassified members
HCTR-5; HCTR-6; KPG_006; KPG_008
References
Cite error: Invalid <references> tag;
parameter "group" is allowed only.
<references />, or <references group="..." />- ↑ PDB 1BL1; Lua error in package.lua at line 80: module 'Module:Citation/CS1/Suggestions' not found.
- ↑ Harmar AJ (2001). "Family-B G-protein-coupled receptors". Genome Biol. 2 (12): REVIEWS3013. doi:10.1186/gb-2001-2-12-reviews3013. PMC 138994 Freely accessible. PMID 11790261.
