HUMAN LENS CONNEXIN GENES IN HEREDITARY CATARACT

描述：遗传性白内障是一种威胁视力的晶状体疾病。 通常表现为一种先天性常染色体显性孟德尔遗传特征 高外显性和相当大的家族间和家族内临床 变种。该项目的主要目标是确定 连接蛋白50(CX50)和连接蛋白46(CX46)基因突变 PI具有的常染色体显性带状粉碎性白内障 分别定位于人类染色体1q和13q。 DNA克隆和测序技术将用于识别突变和 用于野生型和野生型功能表达研究的工程构建 CX50和CX46的突变形式。野生型的电压门控特性 在非洲爪哇卵母细胞中合成的突变形式CX50和Cx46将被 使用定义的双微电极电压钳位技术来确定 PH值条件。野生型和突变型的细胞间通道特性 CX50和Cx46在连接蛋白缺陷HeLa细胞系Will中的表达 用荧光染料转移法测定。转基因小鼠 将使用技术来模拟野生型和野生型的等位基因互作 导致白内障发生的CX50和Cx46突变形式 活体镜头。这些研究的结果将有助于阐明 一种临床上重要的遗传性疾病的发病机制 并为连接蛋白在人类白内障中的作用提供了新的见解 人类晶状体发育。最终，这些数据将有助于设计 为临床管理提供新的预防和治疗策略 白内障的症状。

DESCRIPTION: Inherited cataract is a sight-threatening lens disease that usually presents as a congenital, autosomal dominant Mendelian trait showing high penetrance and considerable inter- and intra-familial clinical variation. The primary objective of this project is to determine whether mutations in the genes for connexin50 (Cx50) and connexin46 (CX46) underlie autosomal dominant forms of zonular pulverulent cataract that the PI has mapped to human chromosomes 1q and 13q, respectively. DNA cloning and sequencing techniques will be used to identify mutations and engineer constructs for functional expression studies on the wild-type and mutant forms of Cx50 and Cx46. The voltage-gating properties of wild-type and mutant forms Cx50 and Cx46 synthesized in Xenopus oocytes will be determined using a two microelectrode voltage clamp technique under defined pH conditions. The intercellular channel properties of wildtype and mutant forms Cx50 and Cx46 expressed in the connexin-deficient HeLa cell-line will be measured by fluorescent dye-transfer methods. Transgenic mouse techniques will be used to model the allelic interactions of wild-type and mutant forms of Cx50 and Cx46 that lead to cataract development in the living lens. Results from these studies will help to elucidate the pathogenetic mechanisms underlying a clinically important form of inherited cataract in humans and provide new insight into the role of connexins in human lens development. Ultimately, such data will contribute to the design of new preventative and therapeutic strategies for the clinical management of cataract.