Secretin family of 7 transmembrane receptors | |||||||||
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Structure of a 31 amino acid fragment of the extracellular N-terminus of the human parathyroid hormone receptor.
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Identifiers | |||||||||
Symbol | 7tm_2 | ||||||||
Pfam | PF00002 | ||||||||
InterPro | IPR000832 | ||||||||
PROSITE | PDOC00559 | ||||||||
TCDB | 9.A.14 | ||||||||
OPM superfamily | 6 | ||||||||
OPM protein | 4k5y | ||||||||
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Available protein structures: | |
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Pfam | structures |
PDB | RCSB PDB; PDBe; PDBj |
PDBsum | structure summary |
Secretin family of 7 transmembrane receptors is a family of evolutionarily related proteins.
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.
Subfamily B1 contains classical hormone receptors, such as receptors for secretin and glucagon, that are all involved in cAMP-mediated signalling pathways.
Subfamily B2 contains receptors with long extracellular N-termini, such as the leukocyte cell-surface antigen CD97; calcium-independent receptors for latrotoxin and brain-specific angiogenesis inhibitor receptors amongst others.