Assembly and Stability of Microtubules from Antarctic Fish at Low Temperatures

拟议研究的长期目标是确定， 在分子水平上， 南极鱼类的微管蛋白在下半身 温度（-2至+2摄氏度）所经历的这些冷适应 脊椎动物，并检查鱼类的动态 微管 该项目的具体目标有五个 在数量上：1）比较大脑的组装能量学 微管蛋白从南极和温带南极鱼类; 2）， 克隆和测序cDNA（与信使互补的DNA 编码南极和温带地区脑微管蛋白的RNA 3）确定微管蛋白的结构 来自南极鱼的基因，也可能来自温带鱼类， 4）确定负责任的结构特征 脑微管蛋白和卵微管蛋白之间的功能差异 南极鱼;和5）描述动力学行为 南极鱼微管在低温下的变化 分子- 将对微管蛋白cDNA进行生物学实验， 来自南极鳕鱼核酸的基因， Notothenia coriiceps neglecta及其温带同类， 新西兰黑鳕（N. angustata。 此外，动态 南极鱼类微管在低温下的变化 通过视频增强的光学显微镜方法检查。 比较 的一级序列和翻译后修饰 南极鱼类微管蛋白与 相关的温带鱼类和温血脊椎动物应该 揭示了分子间的相互作用和结构特征 在低温下微管组装所必需的。 这 这项工作将提供有关该结构的宝贵信息 微管蛋白基因的基因组。

The long-range goals of the proposed research are to determine, at the molecular level, the structural adaptations that enable the tubulins of Antarctic fishes to polymerize at the low body temperatures (-2 to +2 C) experienced by these cold-adapted vertebrates, and to examine the dynamics of the fish microtubules. The specific objectives of this project are five in number: 1) to compare the assembly energetics of brain tubulins from Antarctic and temperate nototheniid fishes; 2) to clone and to sequence cDNAs (DNAs complementary to messenger RNAs) that encode the brain tubulins of Antarctic and temperate nototheniid fishes; 3) to determine the structures of tubulin genes from an Antarctic fish, and possibly from a temperate nototheniid; 4) to determine the structural features responsible for the functional differences between brain and egg tubulins of an Antarctic fish; and 5) to characterize the dynamic behaviors of Antarctic fish microtubules at low temperatures. Molecular- biological experiments will be performed on tubulin cDNAs and genes derived from the nucleic acids of the Antarctic cod, Notothenia coriiceps neglecta, and of its temperate congener, the New Zealand black cod, N. angustata. Additionally, the dynamics of Antarctic fish microtubules at low temperatures will be examined by video-enhanced light-microscopic methods. Comparison of the primary sequences and posttranslational modifications of tubulins from Antarctic fishes with those of tubulins from related temperate fishes and warm-blooded vertebrates should reveal the molecular interactions and structural features necessary for microtubule assembly at low temperatures. This work will provide valuable information concerning the structure of tubulin genes from an extreme Antarctic poikilotherm.