Tracing the Origins of the Chaperonin (CCT) Complex in Eukaryotes

追踪真核生物中伴侣蛋白 (CCT) 复合物的起源

• 批准号: 1819046
• 负责人: Frank Robb
• 金额: $ 10万
• 依托单位: University of Maryland at Baltimore
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-01 至 2019-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1819046&HistoricalAwards=false
• 关键词: Tracing; Origins; Chaperonin; CCT; Complex

Through recent metagenomic analysis, it has become clear that the root of eukaryotes lies among microbes in the kingdom archaea. This project will explore the origins of an ancient protein family that assists with protein folding and stability, the chaperones (CPNs), to track their evolution into the eukaryotes. Recent identification of CPN encoding genes within the genomes of the so-called Asgard archaea will be utilized in order to gain structural insights into the biochemical function of these proteins, which have previously not been available due to the unculturability of the organisms. The project will utilize gene synthesis and expression of protein from metagenomic assembled genomes (MAGs). The main scientific benefit will be through the application of synthetic biology to gain insights into their ancestral protein folding functions and the development of eukaryotes from their prokaryotic ancestors. Proper protein folding is essential to all life processes and has implications in health and disease. Broader impacts will be through the training of a staff scientist and and undergraduates, as well as through outreach activities. The main goal of the project is the discovery of quantitative biochemical insights into the functions of proteins in the newly discovered deepest branch of the CPN60 phylogenetic tree. Rapidly accumulating genome sequences and Single Amplified Genomes (SAGS) from the deepest branches of the archaea reveal lineages with increases in genome complexity and gene duplication. The investigators have identified divergent CPN60 genes in the ASGARD archaea which appear to be ancestral to the CCT subunits of the proteins found in extant eukarya. CPN60 from both the archaea and eukaryotes show cooperative allosteric effects in response to an obligate folding substrate such as tubulin. To explore the functional progression towards the eukaryotic CCT complex, this work will assess the function of these ancient CPN genes and the complex chaperones in terms of their ATP binding and ATPase activity and protein folding ability. Because there are also tubulin homologs in the Asgard Archaea Single Amplified Genomes, the project will address the exciting hypothesis that archaeal proteostasis was the ancestral proving ground for the detailed chaperone/client protein interaction networks found in eukaryotes, and will trace the functional advances of the chaperone complex from a putative ancestor with rudimentary biochemical features to the highly specialized and differentiated eukaryotic CCT complex shared by modern eukaryotes.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

通过最近的宏基因组分析，已经清楚地表明，真核生物的根源在于古细菌王国中的微生物。这个项目将探索一个古老的蛋白质家族的起源，帮助蛋白质折叠和稳定，伴侣蛋白（CPNs），以跟踪它们进化到真核生物。最近的识别CPN编码基因的基因组内的所谓的Asgard古菌将被利用，以获得这些蛋白质的生化功能的结构见解，这是以前没有提供由于不可培养的生物体。该项目将利用宏基因组组装基因组（MAG）的基因合成和蛋白质表达。主要的科学效益将是通过应用合成生物学来深入了解它们的祖先蛋白质折叠功能以及从原核生物祖先发展到真核生物。 正确的蛋白质折叠对所有生命过程至关重要，并对健康和疾病有影响。 更广泛的影响将通过培训科学家和本科生以及通过外展活动来实现。该项目的主要目标是在CPN 60系统发育树的最深分支中发现蛋白质功能的定量生化见解。 来自古细菌最深分支的快速积累的基因组序列和单扩增基因组（SAGS）揭示了基因组复杂性和基因复制增加的谱系。研究人员已经在ASGARD古菌中鉴定出不同的CPN 60基因，这些基因似乎是现存真核生物中发现的蛋白质CCT亚基的祖先。来自古细菌和真核生物的CPN 60均显示出响应于专性折叠底物如微管蛋白的协同变构效应。为了探索真核CCT复合物的功能进展，这项工作将评估这些古老的CPN基因和复合分子伴侣的ATP结合和ATP酶活性以及蛋白质折叠能力的功能。由于在Asgard古细菌单扩增基因组中也有微管蛋白同源物，该项目将解决一个令人兴奋的假设，即古细菌蛋白质稳态是真核生物中发现的详细伴侣/客户蛋白相互作用网络的祖先试验场，并将追踪伴侣复合物从具有基本生化特征的假定祖先到高度特化和分化的真核CCT复合物的功能进展该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。