APLN/Apelin Protein, Human (HEK293, Fc)

APLN Protein emerges as the endogenous ligand for the apelin receptor (APLNR), actively participating in the internalization of the receptor. Notably, APLN exhibits differential dissociation characteristics, with apelin-36 dissociating more robustly than (pyroglu)apelin-13 from APLNR. Beyond its role as a ligand, APLN serves diverse physiological functions, influencing cardiac precursor cell movements during gastrulation and heart morphogenesis. Additionally, it has an inhibitory effect on cytokine production in response to T-cell receptor/CD3 cross-linking, suggesting a potential role in modulating immune responses, particularly in neonates through oral intake in colostrum and milk. APLN also contributes to early coronary blood vessel formation and mediates myocardial contractility in an ERK1/2-dependent manner. Furthermore, it may play a role in the central control of body fluid homeostasis by influencing vasopressin release and drinking behavior. In the context of microbial infection, APLN acts as an endogenous ligand for APLNR, serving as an alternative coreceptor with CD4 for HIV-1 infection and exhibiting inhibitory activity on HIV entry in cells coexpressing CD4 and APLNR, with apelin-36 demonstrating greater inhibitory efficacy than other synthetic apelin derivatives.