Model to account for responsiveness to cAMP level in activation but not inactivation of eumelanin synthesis

Model to account for responsiveness to cAMP level in activation but not inactivation of eumelanin synthesis. See Discussion for main explanation. (A-YY) ASIP-YY, (Mc) melanocyte, (Mb) melanoblast, (Ub) ubiquitinylation. Melanocortin-1 receptor (MC1R) is shown with some basal activity (left, lost in e mutant), to explain why POMC null, a/a mice are black, and related data (see text). (This might alternatively be due to BD103 or some unknown signal). Agouti signaling protein (ASIP) would not be required for pheomelanogenesis unless Y has been switched on by the MC1R/cAMP pathway, hence inactive MC1R would give a yellow color even with deficient MGRN1, as seen in e/e, md/md mice.

Publication

Agouti protein, mahogunin, and attractin in pheomelanogenesis and melanoblast-like alteration of melanocytes: a cAMP-independent pathway. (2009) Tokimasa Hida, et al. Pigment Cell Melanoma Res. 2009 Oct;22(5):623-634. Figure: F7. Homo sapiens

Disease mentions