title: P-locus is a target for the melanogenic effects of MC-1R signaling: a possible control point for facultative pigmentation.
abstract: Melanocortin receptor type 1 (MC-1R) is an important control point for ultraviolet ray (UVR)-induced tanning response in the skin. In this study, we show that p-locus is a downstream target for MC-1R signaling. The expression of p-locus was up-regulated by alpha-MSH as well as db-cAMP, a synthetic analogue of cAMP that mimics activation of MC-1R. Furthermore, p-locus transcript abundance was significantly increased in epidermal melanocytes of white skin with facultative (UVR-induced) pigmentation. Because p-locus product is essential for pigmentation and also has been shown to be highly polymorphic in human population, we propose that the pigmentary response to the melanocortin peptides/UVR would be affected not only by MC-1R mutations but also by the functionality of p-locus product. These factors together could account for the many different levels of tanning ability seen in the white population.
authors.affiliation: Department of Biomedical Sciences, University of Bradford, Bradford, United Kingdom. j.ancans@lycos.co.uk
authors.forename: Janis
authors.initials: J
authors.lastname: Ancans
authors.forename: Niamh
authors.initials: N
authors.lastname: Flanagan
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Hoogduijn
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Thody
mesh_terms: D003994:Bucladesine / Q000378:metabolism; D005786:Gene Expression Regulation; D006801:Humans; D018043:Receptors, Corticotropin / Q000235:genetics / Q000378:metabolism*; D044101:Receptors, Melanocortin; D015398:Signal Transduction / Q000502:physiology*; D012867:Skin / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects; D012880:Skin Pigmentation / Q000502:physiology*; D014466:Ultraviolet Rays; D000521:alpha-MSH / Q000378:metabolism*
chemical_list: D018043:Receptors, Corticotropin; D044101:Receptors, Melanocortin; D000521:alpha-MSH; D003994:Bucladesine