OCA2基因的研究进展

Research Progress of the OCA2 Gene

摘要

OCA2基因为哺乳动物重要的色素基因, 参与黑色素合成反应, 同时也是人眼睛颜色的主要调控基因。其编码一个110 kD大小的跨膜蛋白, 该蛋白质定位于黑素体膜。研究表明, OCA2主要通过影响黑素体成熟、调节黑素体pH值以及参与黑色素合成途径第一步这3个方面影响黑色素合成。相邻基因HERC2的rs12913832增强子位点通过影响OCA2表达水平, 实现对人眼睛颜色的调控。同时, OCA2基因是Ⅱ型眼皮肤白化病(oculocutaneous albinism type Ⅱ, OCA2)的致病基因, 与普拉德-威利综合征(Prader-Willi syndrome, PWS)、天使综合征(Angelman syndrome, AS)和黑色素瘤之间也存在间接关联, 这些患者通常表现出皮肤或头发低色素沉着。本文从分子生物学、细胞生物学和遗传学的角度对OCA2基因进行概述, 以期为进一步探究OCA2的分子机制以及相关疾病的诊疗提供思路和见解。

Abstract

The OCA2 gene is an important mammalian pigment gene that is involved in the melanin synthe-sis reaction, and is also a main regulator of human eye color. It encodes a 110 kD-sized transmembrane protein, which is located at the melanosome vesicle membrane. Studies have shown that OCA2 affects the melanin synthesis through regulating maturation and pH value of melanosomes, and participating in the first step of the melanin synthesis pathway. The rs12913832 enhancer of the adjacent gene HERC2 modulates the expression level of OCA2 to ultimately control human eye color. In addition, OCA2 is also the causative gene for oculocutaneous albinism typeⅡ(OCA2) and has indirect effects on diseases including Prader-Willi syndrome (PWS), Angelman syndrome (AS) and melanoma, with which patients usually show hypopigmenta-tion of skin or hair. Herein, the research progress of the OCA2 gene from the perspectives of molecular bio-logy, cell biology and genetics is reviewed, so as to provide novel ideas for further exploring the molecular mechanisms of OCA2 and the diagnosis and treatment of the related diseases.

关键词

OCA2基因 / 白化病 / 黑素体 / 黑色素细胞 / pH值 / 眼睛颜色

Key words

OCA2 gene / albinism / melanosome / melanocyte / pH value / eye color