The intermediate filament cytoskeleton of the lens: an ever changing network through development and differentiation. A minireview.
The intermediate filament cytoskeleton of the lens: an ever changing network through development and differentiation. A minireview.
复制标题
晶状体的中间丝细胞骨架：通过发育和分化不断变化的网络。
作者：
A. Prescott;A. Sandilands;A. M. Hutcheson;J. M. Carter;R. Quinlan
在眼睛晶状体中，中间纤维蛋白形成两种形态不同的聚合物，10纳米的中等纤维和珠状纤维。巧合的是，珠状细丝聚合物和蛋白质细丝蛋白和CP49是晶状体纤维细胞所特有的，因此是纤维细胞分化的极佳标记。在成人晶状体中，细丝蛋白和CP49在晶状体纤维细胞分化的所有阶段都保持不变，而波形蛋白显然在特定阶段从更深的皮质纤维中丢失。CP49和细丝蛋白的表达与珠状细丝的存在相吻合，表明这些蛋白是细丝成分。在体外，CP49和细丝蛋白与α-晶状体蛋白结合形成珠状细丝。在纤维细胞分化过程中，微丝蛋白和CP49被翻译后修饰。在丝蛋白的情况下，蛋白质分解产生两个功能不同的片段集，一个来自丝蛋白的α-螺旋杆状结构域，另一个来自纤维蛋白的C末端尾部结构域。有人认为，丝蛋白和CP49在组织纤维细胞的细胞质和质膜结构域方面都起着至关重要的作用，因此对晶体的光学性质是必不可少的。
In the eye lens, intermediate filament proteins form two morphologically distinct polymers, 10-nm intermediate-sized filaments and beaded filaments. Coincidently, the beaded filament polymer and the proteins filensin and CP49 are specific to lens fibre cells and are therefore excellent markers for fibre cell differentiation. In the adult lens, filensin and CP49 are maintained throughout all stages of lens fibre cell differentiation whilst vimentin is apparently lost at a specific stage from the deeper cortical fibres. The expression of CP49 and filensin is coincident with the presence of beaded filaments suggesting these proteins are filament components. In association with alpha-crystallin, CP49 and filensin form beaded filaments in vitro. During fibre cell differentiation, filensin and CP49 are post-translationally modified. In the case of filensin, proteolysis results in two functionally distinct fragment sets, one derived from the alpha-helical rod domain and the other from the C-terminal tail domain of filensin. It is proposed that both filensin and CP49 are critically involved in organising the cytoplasmic and plasma membrane domains of the fibre cell and therefore essential to the optical properties of the lens.