Les protéines de régulation de la mélanogenèse. Génétique moléculaire des albinismes cutanés

Abstract

Pigmentation - or melanogenesis - results from interactions between several genes and their products, to produce melanins. These specific pigments are synthesized by melanocytes, within specialized organelles, the melanosomes. Melanogenesis is regulated at many different levels, developmental, cellular as well as molecular. However, one enzyme, tyrosinase, is mainly responsible for the control of melanin biosynthesis. Previous work using mice genetics had shown linkage between the tyrosinase gene and the mouse albino locus. The structure of this protein has now been elucidated, its gene cloned, and several mutations have been characterized in human and mice. These mutations are responsible for the different forms of albinism. More recently, other melanocyte-specific genes have been cloned and characterized. The structure of these genes and their products is related to that of tyrosinase, and therefore defines a family of molecules which interactions are essential for the cellular events of melanogenesis.