Secretin receptor family
|Secretin family of 7 transmembrane receptors|
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.
- Pituitary adenylate cyclase-activating polypeptide type 1 receptor InterPro: IPR002285
- Calcitonin receptor InterPro: IPR003287
- Corticotropin-releasing hormone receptor InterPro: IPR003051
- Glucose-dependent insulinotropic polypeptide receptor/Gastric inhibitory polypeptide receptor InterPro: IPR001749
- Glucagon receptor InterPro: IPR003291
- Glucagon receptor-related InterPro: IPR003290
- Growth hormone releasing hormone receptor InterPro: IPR003288
- Parathyroid hormone receptor InterPro: IPR002170
- Secretin receptor InterPro: IPR002144
- Vasoactive intestinal peptide receptor InterPro: IPR001571
Subfamily B2 contains receptors with long extracellular N-termini, such as the leukocyte cell-surface antigen CD97; calcium-independent receptors for latrotoxin (such as , and brain-specific angiogenesis inhibitor receptors (such as ) amongst others.
- Brain-specific angiogenesis inhibitor InterPro: IPR008077
- CD97 antigen InterPro: IPR003056
- EMR hormone receptor InterPro: IPR001740
- GPR56 orphan receptor InterPro: IPR003910
- Latrophilin receptor InterPro: IPR003924
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.
- doi:10.1021/bi981265h. PMID 9737850.; Pellegrini M; Bisello A; Rosenblatt M; Chorev M; Mierke DF (September 1998). "Binding domain of human parathyroid hormone receptor: from conformation to function". Biochemistry 37 (37): 12737–43.
- Harmar AJ (2001). "Family-B G-protein-coupled receptors". Genome Biol. 2 (12): REVIEWS3013. doi:10.1186/gb-2001-2-12-reviews3013. PMC 138994. PMID 11790261.
- "Structure of the human glucagon class B G-protein-coupled receptor". Nature 499 (7459): 444–449. doi:10.1038/nature12393. PMC 3820480. PMID 23863937.; Siu FY; He M; de Graaf C; Han GW; Yang D; Zhang Z; Zhou C; Xu Q; Wacker D; Joseph JS; Liu W; Lau J; Cherezov V; Katritch V; Wang M-W; Stevens RC (July 2013).
- Hollenstein K; de Graaf C; Bortolato A; Wang MW; Marshall FH; Stevens RC (2014). "Insights into the structure of class B GPCRs". Trends Pharmacol Sci 35 (1): 12–22. doi:10.1016/j.tips.2013.11.001. PMID 24359917.