Secretin receptor family (class B GPCR subfamily[1]) consists of secretin receptors regulated by peptide hormones from the glucagon hormone family.
These receptors activate adenylyl cyclase and the phosphatidyl-inositol-calcium pathway.
[5] The secretin-receptor family GPCRs exist in many animal species.
Data mining with the Pfam signature has identified members in fungi, although due to their presumed non-hormonal function they are more commonly referred to as Adhesion G protein-coupled receptors, making the Adhesion subfamily the more basal group.
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.