磷酸二酯酶6b基因异常表达对视网膜色素变性的作用

The role of abnormal expression of the PDE6b gene in retinitis pigmentosa

磷酸二酯酶(phosphodiesterase,PDE)是一个大家族,包括11个亚家族,即PDE1~PDE11。而PDE6是PDEs亚家族中的一种,由PDE6基因编码的PDE蛋白,水解cGMP,cGMP是视杆细胞外节膜盘离子通道的特异性受体,同时cGMP也是脊椎动物中感光细胞将光信号转化为电信号的重要分子。PDE6b基因的缺失使感光细胞内cGMP增多,引起感光细胞的阳离子增多,细胞中毒而坏死,视网膜的感光细胞不断破坏,从而间接影响到视网膜接受光信号转换为电信号。PDE6b基因异常是常染色体隐性遗传视网膜色素变性最主要的原因之一,因此对于PDE6b基因表达异常在动物模型及家族遗传逐渐成为近年来研究的热点。该文将重点阐述PDE6b基因的结构、功能和突变类型对视网膜色素变性相对应结构及其功能的影响。

Phosphodiesterases （PDEs） are a large family of proteins divided into 11 subfamilies, namely PDE1-PDE11.PDE6 is a PDEs subfamily, the PDE protein encoded by the PDE6 gene, which hydrolyses cGMP, the specific receptor of rod outer segment membrane disc ion channels and also an important molecule in the vertebrate photoreceptor cells that converts light signals into electrical signals.The deletion of pde6b gene results in a nonfunctional PDE and an accumulation of cGMP in the photoreceptor cells, causing the increase of cationic photoreceptor cells, cell poisoning and cell death.The photoreceptor cells in the retina constantly deteriorate, indirectly affecting the retina converting the light signals into electrical signals.The abnormal expression of pde6b gene is one of the most important causes of autosomal recessive retinitis pigmentosa.Therefore, the abnormal expression of pde6b gene in animal models and familial inheritance has gradually become the focus of research in recent years.This paper focuses on the structure, function, and mutation types of pde6b gene, and their influence on the corresponding structure and function of retinitis pigmentosa.