This intronless gene encodes the receptor protein for
melanocyte-stimulating hormone (MSH). The encoded protein, a seven
pass transmembrane G protein coupled receptor, controls
melanogenesis. Two types of melanin exist: red pheomelanin and
black eumelanin. Gene mutations that lead to a loss in function are
associated with increased pheomelanin production, which leads to
lighter skin and hair color. Eumelanin is photoprotective but
pheomelanin may contribute to UV-induced skin damage by generating
free radicals upon UV radiation. Binding of MSH to its receptor
activates the receptor and stimulates eumelanin synthesis. This
receptor is a major determining factor in sun sensitivity and is a
genetic risk factor for melanoma and non-melanoma skin cancer. Over
30 variant alleles have been identified which correlate with skin
and hair color, providing evidence that this gene is an important
component in determining normal human pigment variation. [provided
by RefSeq].
