Structure, Function, and Expression of Tubulins, Globins, and Microtubule-Dependent Motors from Cold-Adapted Antarctic Fishes

在过去的2500万年里，随着南大洋的冷却，南极沿海水域的鱼类进化出了生化和生理适应，维持了基本的细胞过程，如细胞骨架功能和基因转录。例如，它们的微管在体温（-1.8到+1摄氏度）远低于温带物种的情况下组装和运作。该研究项目的长期目标是在分子水平上确定增强微管组装的适应性，微管蛋白和珠蛋白基因的表达，以及微管马达在这种极端热状态下的活性。具体目标有三个：1)确定导致南极鱼类微管在低温下高效聚合的初级序列变化；2)研究南极岩鳕鱼和温带岩鳕鱼的微管蛋白和珠蛋白基因的结构、组织和启动子驱动表达；3)研究南极鱼类在低温条件下大脑运动蛋白的高效功能所需要的生化适应。总之，这些研究应该揭示南极鱼类在低温下维持有效的细胞骨架组装、机械化学运动功能和基因表达的分子适应性。

9815381DETRICHAs the Southern Ocean cooled during the past 25 million years, the fishes of Antarctic coastal waters evolved biochemical and physiological adaptations that maintain essential cellular processes such as cytoskeletal function and gene transcription. Their microtubules, for example, assemble and function at body temperatures (-1.8 to +1 degree centigrade) well below those of temperate species. The long-range goals of this research project are to determine, at the molecular level, the adaptations that enhance the assembly of microtubules, the expression of tubulin and globin genes, and the activity of microtubule motors in this extreme thermal regime. The specific objects are three in number: 1) to determine the primary sequence changes that contribute to the efficient polymerization of Antarctic fish tubulins at low temperatures; 2) to characterize the structure, organization and promoter-driven expression of tubulin and globin genes from an Antarctic rockcod and a temperate congener; and 3) to examine the biochemical adaptation required for efficient function of the brain kinesin motor of Antarctic fishes at low temperatures. Together, these studies should reveal the molecular adaptation of Antarctic fishes that maintain efficient cytoskeletal assembly, mechanochemical motor function, and gene expression at low temperatures.