Biogenesis of the Yeast Mitochondrial ATPase Complex

描述（由申请人提供）：需氧细胞的能量需求主要通过F1 F0 ATP合酶的作用得到满足，该酶在氧化磷酸化过程中催化ATP合成。酶（F1）的催化单位是亚基组成为α 3 β 3 γ-δ-γ的多聚体蛋白。 我们实验室的工作，采用酵母酿酒酵母作为模型系统的线粒体功能的研究，提供了证据表明，装配的F1寡聚体在线粒体中需要两个分子伴侣蛋白Atp 11 p和Atp 12 p。如果没有这些蛋白质，F1的α和β亚基在细胞器内聚集成聚集的蛋白质。先前的研究表明，Atp 11 p结合F1 β亚基，Atp 12 p结合F1 α亚基。目标1（F1组装途径中间体的表征）下的一组研究旨在确定F1亚基从伴侣蛋白释放后发生了什么。 Atp 11 p和Atp 12 p的结构/功能关系将通过化学修饰和诱变来探测。目标1下的其他研究集中于Atp 11 p和Atp 12 p与线粒体的Hsp 60/Hsp 10折叠机制的关系。在目标2（F1组装过程中蛋白质相互作用的鉴定）下，我们将研究Atp 11 p、Atp 12 p以及F1 α和β亚基在F1组装过程中作为蛋白质-蛋白质相互作用的介质的作用。 我们还将表征导致组装缺陷表型的α和β亚基基因突变，并筛选线粒体中可能与Atp 11 p和Atp 12 p协同作用的其他蛋白质。目标3（Atp 11 p和Atp 12 p的结构研究工程）下的工作是我们小组和两个结构生物学实验室之间的合作，通过X射线晶体学和核磁共振确定Atp 11 p和Atp 12 p的三维结构。

DESCRIPTION (provided by applicant): The energy needs of aerobic cells are met principally through the action of the F1F0 ATP synthase, which catalyzes ATP synthesis during oxidative phosphorylation. The catalytic unit of the enzyme (F1) is a multimeric protein of subunit composition alpha3beta3gamma-delta-epsilon. Work in our laboratory, which employs the yeast Saccharomyces cerevisiae as a model system for studies of mitochondrial function, has provided evidence that assembly of the F1 oligomer in mitochondria requires two molecular chaperone proteins called Atp11p and Atp12p. Without these proteins, the alpha and beta subunits of the F1 accumulate as aggregated proteins inside the organelle. Previous studies have shown that Atp11p binds the F1 beta subunit and Atp12p binds the F1 alpha subunit. A subset of studies under Aim 1 (Characterization of intermediates in the F1 assembly pathway) are designed to determine what happens to the F1 subunits following their release from the chaperone proteins. Structure/function relationships in Atp11p and Atp12p will be probed by chemical modification and mutagenesis. Other studies under Aim 1 focus on the relationship of Atp11p and Atp12p with the Hsp60/Hsp10 folding machinery of mitochondria. In work under Aim 2 (Identification of protein protein interactions durinq F1 assembly) we will examine Atp11p, Atp12p, and the F1 alpha and Beta subunits for actions as mediators of protein-protein interactions during the process of F1 assembly. We will also characterize mutations in the genes for the alpha and beta subunits that cause an assembly defective phenotype and screen for additional proteins in mitochondria that may act in concert with Atp11p and Atp12p. Work under Aim 3 (Engineerinq of Atp11p and Atp12p for structural studies) is a collaboration between our group and two laboratories of structural biology to determine the three dimensional structure for Atp11p and for Atp12p by means of X-ray crystallography and nuclear magnetic resonance.