The Hsp90 molecular chaperone system

描述（由申请人提供）：我们的长期目标是了解Hsp 90分子伴侣系统的细胞宽度和影响。为了剖析这个大而多样的伴侣网络，我们利用高通量的方法来识别酵母p23辅伴侣Sba 1的遗传和物理相互作用物，Sba 1是酵母HSP 90（HSP 82）伴侣系统的一个分支。出乎意料的是，生物信息学分析表明，Sba 1子网既与所识别的Hsp 82网络重叠，又对所识别的Hsp 82网络具有主权。值得注意的是，很大一部分Sba 1命中在DNA处或附近起作用。因此，Sba 1似乎将Hsp 82系统的作用扩展到各种核事件，包括转录、染色质、端粒和DNA修复途径。我们将专注于端粒和DNA修复途径，以更好地了解热休克蛋白90系统的组件TS如何影响核事件。为了研究Sba 1分子伴侣的影响，我们将遵循三管齐下的策略，其中a）将利用体内测定来建立Sba 1对DNA相关活性的生理效应; B）将利用遗传表型来鉴定功能性Sba 1等位基因; c）将利用体外测定来描绘分子伴侣对客户蛋白的调节的分子机制。我们的研究将有助于理解Hsp 90分子伴侣网络如何维持细胞蛋白质稳态，以及如何通过靶向cochaperones来解剖这个广泛的分子伴侣系统，以开发针对Hsp 90机制的更具选择性的治疗策略。 公共卫生相关性：更好地了解热休克蛋白90分子伴侣系统的基本细胞功能和药物的方法有重要的意义，如大量的进展中的临床试验证明。考虑到Hsp 90蛋白客户端的广谱性和绝对数量，开发更直接的破坏Hsp 90分子伴侣系统的方法将是有用的，并且辅分子伴侣是更选择性地干扰Hsp 90网络的一种有希望的途径。我们提出的工作将提供深入了解的Sba 1 cochaperone网络的功能能力，可能有助于实现细胞蛋白质稳态，并将作为一种资源，开发更有选择性的治疗试剂，解剖的HSP 90分子伴侣系统。

DESCRIPTION (provided by applicant): Our long-term objective is to understand the cellular breadth and impact of the Hsp90 molecular chaperone system. To dissect this large and diverse chaperone network we have exploited high-throughput approaches to identify genetic and physical interactors of the yeast p23 cochaperone Sba1, which serves one branch of the yeast Hsp90 (Hsp82) chaperone system. Unexpectedly, bioinformatic analysis indicates that the Sba1 subnet both overlaps with and is sovereign to the identified Hsp82 network. Notably, a significant share of the Sba1 hits function at or near DNA. Thus, Sba1 appears to extend the role of the Hsp82 system to a variety of nuclear events including transcription, chromatin, telomere and DNA repair pathways. We will focus on telomere and DNA repair paths to better understand how component ts of the Hsp90 system affect nuclear events. To investigate the influence of the Sba1 chaperone we will follow a three-pronged strategy in which a) in vivo assays will be utilized to establish the physiological effect of Sba1 on DNA-related activities; b) genetic phenotypes will be employed to identify functional sba1 alleles; c) the molecular mechanisms of chaperone-regulation on client proteins will be delineated using in vitro assays. Our studies will contribute to the comprehension of how the Hsp90 chaperone network maintains cellular proteostasis and how this broad chaperone system might be dissected by targeting cochaperones to develop more selective therapeutic strategies that are directed at the Hsp90 machinery. PUBLIC HEALTH RELEVANCE: A better understanding of the Hsp90 chaperone system has important implications for both basic cell functions and medicinal approaches, as demonstrated by the large number of progressing clinical trials. Given the broad spectrum and sheer number of Hsp90 protein clients, it would be useful to develop more directed means of disrupting the Hsp90 chaperone system and cochaperones are one promising avenue to more selectively interfere with the Hsp90 network. Our proposed work will provide insights into the functional capacity of the Sba1 cochaperone network that likely helps achieve cellular proteostasis and will serve as a resource for developing more selective therapeutic reagents to dissect the Hsp90 chaperone system.