Agouti-signaling protein (ASIP)

Involved in the regulation of melanogenesis.

The binding of ASP to MC1R precludes alpha-MSH initiated signaling and so blocks generation of cAMP, resulting in a down-regulation of eumelanogenesis (brown/black pigment) and thus increasing synthesis of pheomelanin (yellow/red pigment).

In higher primates, agouti may affect the quality of baldness rather than its own pattern of deposition. Could well play a role in neuroendocrine aspects of melanocortin action.