The endogenous ligand for the G-protein-coupled receptor APJ. The peptide (77 aa) is cleaved into various active fragments (apelins-13, -28, -31, and -36). It will inhibit HIV-1 entry in cells coexpressing CD4 and APJ. It is expressed in the brain and secreted by the mammary gland into colostrum and milk.
Subjects: Medicine and Health.