Assembly mechanism of cochaperone-kinase complexes

PI：Gelis，Ioannis 项目摘要 热休克蛋白90与其他称为辅伴侣蛋白的蛋白质一起，形成了一种控制细胞凋亡的分子机制。 构象成熟的各种各样的底物或客户。热休克蛋白90介导的分子伴侣循环 发生在蛋白质折叠的后期，以增加客户端稳定性和/或引起精细的结构变化， 促进“伙伴”绑定和/或导致客户端激活。它始于招聘人员对客户的认可 共伴侣蛋白和随后的客户端转移到Hsp 90。然后释放共同伴侣， 并且从Hsp 90释放伴随着Hsp 90的大的构象变化。这些之间的进展 顺序步骤被其他辅伴侣的存在精细地调节，核苷酸的身份 结合到Hsp 90和翻译后修饰。在分子水平上，热休克蛋白90与其 cochaperones和与其ATP酶循环相关的构象变化的特点是， 原子分辨率尽管这些研究对我们全面了解 分子伴侣的功能，底物与分子伴侣结合的分子机制 周期仍然知之甚少。在热休克蛋白90介导的激酶陪伴的第一步，Cdc 37是 与Hsp 90相关的普遍存在的底物募集分子辅伴侣赋予激酶特异性。尽管 虽然Cdc 37在激酶伴侣中起着重要作用，但人们对Cdc 37识别 蛋白激酶，将Hsp 90依赖性激酶与Hsp 90非依赖性激酶分类并将它们递送至Hsp 90。我们将 使用多学科方法，其中来自NMR的高分辨率结构和动态信息 光谱学，将结合热力学和动力学的协会，以及，在体内 功能测定，以阐明允许Cdc 37控制激酶进入细胞的分子机制。 Hsp 90分子伴侣循环。具体目标旨在解决以下问题：（1） Cdc 37的结构和动力学性质;（2）Cdc 37如何识别蛋白质的催化结构域 Cdc 37如何区分Hsp 90依赖性激酶和Hsp 90非依赖性激酶？

PI: Gelis, Ioannis Project Summary Hsp90 in cohort with other proteins termed cochaperones, forms a molecular machinery that controls the conformational maturation of a diverse array of substrates or clients. The Hsp90-mediated chaperone cycle occurs at a late stage of protein folding to increase client stability and/or to elicit fine structural changes which facilitate “partner” binding and/or result in client activation. It begins with client recognition by a recruiter cochaperone and subsequent client transfer to Hsp90. The cochaperone is then released and client remodeling and release from Hsp90 is accompanied by large conformational changes of Hsp90. Progression between these sequential steps is finely modulated by the presence of other cochaperones, the identity of the nucleotide bound to Hsp90 and post-tranlational modifications. At a molecular level, the interaction of Hsp90 with its cochaperones and the conformational changes associated with its ATPase cycle have been characterized at atomic resolution. Although these studies have contributed significantly to our overall understanding of the function of the chaperone, the molecular mechanism by which substrates become engaged into the chaperone cycle remains poorly understood. During the first step of Hsp90-mediated kinase chaperoning, Cdc37 is the ubiquitous substrate recruiter cochaperone associated with Hsp90 to confer kinase specificity. Despite its central role in kinase chaperoning, little is known about the molecular mechanism by which Cdc37 recognizes protein kinases, sorts Hsp90-dependent from Hsp90-independent kinases and delivers them to Hsp90. We will use a multidisciplinary approach, where high resolution structural and dynamic information from NMR spectroscopy, will be combined with thermodynamics and kinetics of association, as well as, with in vivo functional assays, to elucidate the molecular mechanism that allows Cdc37 to control kinase entry into the Hsp90 chaperone cycle. The specific aims are designed to address the following questions (1) what are the structural and dynamic properties of Cdc37; (2) how does Cdc37 recognizes the catalytic domain of protein kinases; and (3) how Cdc37 differentiates between Hsp90-dependent and Hsp90-independent kinases?