Independent regulation of hair and skin color by two G protein-coupled pathways.
Hair color and skin color are frequently coordinated in mammalian species. To explore this, we have studied mutations in two different G protein coupled pathways, each of which affects the darkness of both hair and skin color. In each mouse mutant (Gnaq(Dsk1), Gna11(Dsk7), and Mc1r(e)), we analyzed the melanocyte density and the concentrations of eumelanin (black pigment) and pheomelanin (yellow pigment) in the hair or skin to determine the mechanisms regulating pigmentation. Surprisingly, we discovered that each mutation affects hair and skin color differently. Furthermore, we have found that in the epidermis, the melanocortin signaling pathway does not couple the synthesis of eumelanin with pheomelanin, as it does in hair follicles. Even by shared signaling pathways, hair and skin melanocytes are regulated quite independently.
Van Raamsdonk
Catherine D
CD
Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada. cvr@interchange.ubc.ca
Barsh
Gregory S
GS
Wakamatsu
Kazumasa
K
Ito
Shosuke
S
D000818:Animals; D016232:Endothelins / Q000378:metabolism; D005260:Female; D043802:GTP-Binding Protein alpha Subunits, Gq-G11 / Q000235:genetics / Q000378:metabolism*; D006200:Hair Color / Q000502:physiology*; D006801:Humans; D008297:Male; D008543:Melanins / Q000378:metabolism; D008544:Melanocytes / Q000166:cytology / Q000378:metabolism; D051379:Mice; D051739:Microphthalmia-Associated Transcription Factor / Q000378:metabolism; D010858:Pigmentation / Q000502:physiology*; D044102:Receptor, Melanocortin, Type 1 / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology*; D012880:Skin Pigmentation / Q000502:physiology*
D016232:Endothelins; D008543:Melanins; D051739:Microphthalmia-Associated Transcription Factor; C497235:Mitf protein, mouse; D044102:Receptor, Melanocortin, Type 1; C018362:pheomelanin; C041877:eumelanin; D043802:GTP-Binding Protein alpha Subunits, Gq-G11