EphA2基因与先天性白内障

EphA2 gene and congenital cataract

先天性白内障多因与晶状体发育相关基因突变造成，其中EphA2基因位于人类染色体1p36，其编码的EphA2酪氨酸激酶受体是一种存在于哺乳动物细胞中的特异性激酶受体，在人类许多组织细胞中都有表达。EphA2酪氨酸激酶受体与晶状体细胞间交流、细胞内蛋白质结构稳定性等多方面相关，其内的SAM结构域可调控晶状体纤维细胞内蛋白募集过程有序。同时，ephrin 配体-EphA2受体复合物正常结合是晶状体纤维细胞纵向排列的先决条件。只有晶状体纤维细胞内蛋白质稳定，相互间规则排列，晶状体才能维持透明性；反之先天性白内障形成。

Congenital cataracts are mainly caused by gene mutations affecting lens development. The EphA2 gene is located in the human chromosome lp36. It encods EphA2 tyrosine kinase receptor, which is a specific kinase receptor in mammalian cells and expressed in many human tissue cells. The EphA2 tyro-sine kinase receptor is related to numerous biological processes of the lens, such as intercellular communica- tion between lens cells and the stability of the protein structure in the lens cells. The EphA2 SAM domain is responsible for orderly recruiting proteins in lens fiber cells, which is essential for regulation of cell migration. Furthermore, the normal assembling of EphA2/ephrin signaling complexes is prerequisite for the longi- tudinal alignment of lens fiber cells. The lens remains transparent only if the fiber cells are stable arid ar- ranged regularly, otherwise, congenital cataract is formed.