哺乳动物毛囊黑素细胞中色素合成的研究进展

Progress in Research on Melanin Synthesis in Mammalian Hair Follicle Melanocytes

哺乳动物毛色的多样性及其环境适应性具有重要的生物学意义。毛发中不同色素的类型和含量决定了毛发的颜色及深浅,真黑素含量较高的毛发呈黑色或深棕色,含量较低的毛发则呈浅褐色、棕褐色或灰色;褐色素含量高的产生其他颜色的毛发,如棕色、红色和黄色。毛发中的色素由多巴胺分子产生。多巴胺通过一系列的反应最终转化为真黑素和褐色素,赋予毛发不同的颜色。毛囊色素在黑素细胞内黑素小体中合成,黑素小体的结构和功能由一组驻留及跨膜蛋白决定,其中许多仅在色素细胞中表达,并特异性定位于黑素小体。编码黑素小体的特异性蛋白质或运输进出黑素小体所需的蛋白基因变异或缺陷,会导致各种形式的毛色变异以及人体眼部或皮肤的白化病。黑素小体的主要成分包括催化酪氨酸前体合成黑色素的酶TYR、TYRP1和TYRP2(DCT),使这些酶发挥作用需要多种转运蛋白,黑素小体维持形状和黑色素沉积的结构蛋白。通过对哺乳动物毛色色素合成调控的总结,以期为哺乳动物色素研究提供参考。

The diversity of mammalian coat colors is of important significance for their environmental adaptability.The type and content of different pigments in hair determine its color and depth.Hair with higher content of eumelanin appears black or dark brown,while hair with lower content of eumelanin appears light brown,brown,or gray.Those with high level of pheomelanin produce other colors,such as brown,red,and yellow.The pigments in hair are produced by a molecule called dopamine.Dopamine is ultimately converted into eumelanin and pheomelanin through a series of reactions,giving hair different colors.Hair melanin is synthesized in melanosomes of melanocyte.The structure and function of melanosomes are determined by a set of resident and transmembrane proteins,many of which are only expressed in melanocytes and specifically localized to melanosomes.It is the genetic variations and defects in the genes encoding melanosome-specific proteins or encoding components required for transport in or out of the melanosomes that lead to various forms of coat color variation and ocular or skin albinism in people.The main components of melanosomes include the enzymes TYR,TYRP1,and TYRP2(DCT),which catalyze the synthesis of melanin by tyrosine precursors,as well as many structural proteins and transporters for maintaining the melanosome shape,melanin deposition and transportation.In the paper,we summarized the regulation of mammalian coat pigment synthesis,in order to provide reference for understanding the mechanism of mammalian pigments formation.