Cerdà J, Conrad M, Markl J, Brand M, Herrmann H
Division of Cell Biology, German Cancer Research Center, Heidelberg.
Eur J Cell Biol. 1998 Nov;77(3):175-87. doi: 10.1016/S0171-9335(98)80105-2.
To provide a basis for the investigation of the intermediate filament (IF) protein vimentin in one of the most promising experimental vertebrate systems, the zebrafish (Danio rerio), we have isolated a cDNA clone of high sequence identity to and with the characteristic features of human vimentin. Using this clone we produced recombinant zebrafish vimentin and studied its assembly behaviour. Unlike other vimentins, zebrafish vimentin formed unusually thick filaments when assembled at temperatures below 21 degrees C. At 37 degrees C few filaments were observed, which often also terminated in aggregated masses, indicating that its assembly was severely disturbed at this temperature. Between 21 and 34 degrees C apparently normal IFs were generated. By viscometry, the temperature optimum of assembly was determined to be around 28 degrees C. At this temperature, zebrafish vimentin partially rescued, in mixing experiments, the temperature-dependent assembly defect of trout vimentin. Therefore it is apparently able to "instruct" the misorganized trout vimentin such that it can enter normal IFs. This feature, that assembly is best at the normal body temperature of various species, puts more weight on the assumption that vimentin is vital for some aspects of generating functional adult tissues. Remarkably, like in most other vertebrates, zebrafish vimentin appears to be an abundant factor in the lens and the retina as well as transiently, during development, in various parts of the central and peripheral nervous system. Therefore, promising cell biological investigations may now be performed with cells involved in the generation of the vertebrate eye and brain, and, in particular, the retina. Moreover, the power of genetics of the zebrafish system may be employed to investigate functional properties of vimentin in vivo.
为了在最具潜力的实验性脊椎动物系统之一斑马鱼（Danio rerio）中研究中间丝（IF）蛋白波形蛋白提供基础，我们分离出了一个与人类波形蛋白具有高度序列同一性及特征的cDNA克隆。利用该克隆，我们制备了重组斑马鱼波形蛋白并研究了其组装行为。与其他波形蛋白不同，斑马鱼波形蛋白在低于21摄氏度的温度下组装时形成异常粗大的丝。在37摄氏度时，观察到的丝很少，且这些丝常常也终止于聚集物中，这表明其组装在该温度下受到严重干扰。在21至34摄氏度之间能产生明显正常的中间丝。通过粘度测定法，确定组装的最适温度约为28摄氏度。在此温度下，在混合实验中，斑马鱼波形蛋白部分挽救了鳟鱼波形蛋白依赖温度的组装缺陷。因此，它显然能够“指导”紊乱的鳟鱼波形蛋白，使其能够进入正常的中间丝。这种在各种物种的正常体温下组装最佳的特征，进一步支持了波形蛋白对于生成功能性成体组织的某些方面至关重要这一假设。值得注意的是，与大多数其他脊椎动物一样，斑马鱼波形蛋白似乎在晶状体和视网膜中含量丰富，并且在发育过程中在中枢和外周神经系统的各个部位短暂存在。因此，现在可以对参与脊椎动物眼睛和大脑，特别是视网膜生成的细胞进行有前景的细胞生物学研究。此外，斑马鱼系统的遗传学优势可用于研究波形蛋白在体内的功能特性。
