The melanocortin-1 receptor and human pigmentation

摘要: alpha-Melanocyte stimulating hormone (alpha-MSH) is known to be the main physiologic regulator for integumental pigmentation of various vertebrate species. However, role alpha-MSH and related melanocortins in regulation human cutaneous only beginning understood. Cloning melanocortin-1 receptor (MC1R), feasibility establishing normal epidermal melanocyte cultures have made it possible demonstrate direct specific biological effects on these cells. It now recognized that both ACTH similar mitogenic melanogenic melanocytes. These are mediated by binding hormones MC1R recognizes them with affinity. Human homologous its mouse counterpart activation leads stimulation eumelanin synthesis. also site agouti signaling protein (ASP), product locus. melanocytes respond purified recombinant or ASP, a reduction basal tyrosinase activity, complete abrogation alpha-MSH. results suggest ASP induces pheomelanin synthesis competing MC1R. This seems subject variety paracrine and/or autocrine factors synthesized response exposure skin ultraviolet radiation (UVR). Activation pivotal UV-induced melanogenesis, since cAMP pathway plays key The UVR might influenced presence allelic variants gene. Allelic been identified shown associated red hair, poor tanning ability, possibly melanoma. influence function needs investigated, order understand physiological consequence mutations. Also, interaction other affect better understood define this acquired hyper- hypopigmentation.