Protein Folding and Function at Cold Temperature: Co-Evolution of the Chaperonin CCT and Tubulins from Antarctic Fishes

低温下的蛋白质折叠和功能：南极鱼类伴侣蛋白 CCT 和微管蛋白的共同进化

• 批准号: 0635470
• 负责人: Harry Detrich
• 金额: $ 52.5万
• 依托单位: Northeastern University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2010-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0635470&HistoricalAwards=false
• 关键词: Protein; Folding; Function; Cold; Temperature

AbstractSince the advent of Antarctic continental glaciation, the opening of the Drake Passage between South America and the Antarctic Peninsula, and the onset of cooling of the Southern Ocean ~38-25 million years ago, evolution of the Antarctic marine biota has been driven by the development of extreme cold temperatures. Because they live at very low and stable temperatures, Antarctic fishes of the suborder Nototheniodei are particularly attractive as models for understanding the mechanisms of biomolecular cold adaptation, or the compensatory restructuring of biochemical and physiological systems to preserve biological function in cold thermal regimes. Two interrelated and potentially co-evolved systems, the tubulins that form microtubules and the chaperonin-containing TCP1 (t-complex protein-1) complex (CCT) that assists the folding of tubulins, provide an unparalleled opportunity to elucidate these mechanisms. This research will yield new and important knowledge regarding: 1) cold adaptation of microtubule assembly and of chaperonin function; and 2) the co-evolutionary origin of tubulin-binding specificity by CCT. The first objective of this proposal is to determine the contributions of five novel amino acid substitutions found in Antarctic fish beta-tubulins to microtubule assembly at cold temperature. The second objective is to establish a chaperonin folding system in vitro using CCT purified from testis tissue of Antarctic fishes and to evaluate its thermal properties and mechanism. The third objective is to evaluate, through phylogenetically controlled contrasts, the hypothesis that CCT and its tubulin substrates from Antarctic fishes have co-evolved to function at cold temperatures. The broader impacts of this proposal include introduction of graduate and REU undergraduate students of Northeastern University to state-of-the-art biochemical, cellular, and molecular-biological research relevant to ecological and environmental issues of the Antarctic marine ecosystem. Because much of the research on the biogenesis and function of cold-adapted proteins will be performed in the field at Palmer Station, these students will gain invaluable experience in the practical considerations of expeditionary biological science. The research also will increase knowledge about molecular cold adaptation in one of the Earth's extreme environments, and hence is relevant to the formulation of refined hypotheses regarding potential extraterrestrial life on Mars or Europa. The cold-functioning chaperonin protein folding system will be of great value to the biopharmaceutical and biotechnological industries for use in folding insoluble proteins.

自3800 - 2500万年前南极大陆冰川作用、南美洲与南极半岛之间德雷克海峡的开通以及南大洋开始变冷以来，南极海洋生物群的演化一直受到极端寒冷温度发展的驱动。因为它们生活在非常低和稳定的温度下，南极鱼类的亚目Nototheniodei是特别有吸引力的模式，了解生物分子冷适应的机制，或补偿性重组的生化和生理系统，以保持生物功能的冷热制度。两个相互关联的和潜在的共同进化的系统，形成微管的微管蛋白和含有伴侣蛋白的TCP 1（t-复合蛋白-1）复合物（CCT），协助微管蛋白的折叠，提供了一个无与伦比的机会来阐明这些机制。 这项研究将产生新的和重要的知识：1）微管组装和伴侣蛋白功能的冷适应;和2）通过CCT的微管结合特异性的共同进化起源。本提案的第一个目标是确定在南极鱼β-微管蛋白中发现的五种新的氨基酸取代对低温下微管组装的贡献。第二个目的是利用从南极鱼类睾丸组织中纯化的CCT建立伴侣蛋白的体外折叠系统，并对其热性质和机制进行评价。第三个目标是评估，通过遗传学控制的对比，假设CCT和微管蛋白底物从南极鱼类共同进化，在寒冷的温度下发挥作用。该提案的更广泛影响包括向东北大学的研究生和REU本科生介绍与南极海洋生态系统的生态和环境问题相关的最先进的生物化学，细胞和分子生物学研究。由于大部分关于冷适应蛋白质的生物起源和功能的研究将在帕尔默站的实地进行，这些学生将在远征生物科学的实际考虑方面获得宝贵的经验。 该研究还将增加有关地球极端环境中分子冷适应的知识，因此与制定有关火星或欧罗巴上潜在外星生命的精确假设有关。冷功能伴侣蛋白质折叠系统对于用于折叠不溶性蛋白质的生物制药和生物技术工业将具有巨大价值。