Assembly mechanism of cochaperone-kinase complexes

派：Gelis，Ioannis 项目摘要 HSP90与其他称为辅伴侣的蛋白质一起，形成了一种分子机制，控制着 一系列不同底物或客户的构象成熟。热休克蛋白90介导的伴侣循环 发生在蛋白质折叠的后期，以增加客户的稳定性和/或引起细微的结构变化， 促进“合作伙伴”绑定和/或导致客户端激活。它始于招聘人员对客户的认可 辅助人和随后的客户转移到HSP90。然后释放辅助伴侣，并重塑客户 Hsp90的释放伴随着Hsp90的构象变化。这两者之间的进展 序列步骤受到其他辅伴侣的存在的精细调节，即核苷酸的同一性 绑定到Hsp90和翻译后修改。在分子水平上，Hsp90与其相互作用 辅伴酮及其与其ATPase循环相关的构象变化已在 原子分辨率。尽管这些研究对我们全面了解 伴侣的功能，底物参与伴侣的分子机制 人们对周期仍然知之甚少。在Hsp90介导的激酶伴侣的第一步中，CDC37是 与Hsp90相关的无处不在的底物募集分子辅伴蛋白可以赋予激酶的特异性。尽管它的 在蛋白激酶伴侣中的核心作用，对CDC37识别的分子机制知之甚少 蛋白激酶，将依赖于Hsp90的蛋白从不依赖于Hsp90的蛋白激酶中分离出来，并将它们传递给Hsp90。我们会 使用多学科方法，其中来自核磁共振的高分辨率结构和动态信息 光谱学，将与热力学和动力学相结合，以及与活体 功能分析，阐明CDC37控制激酶进入细胞内的分子机制 HSP90分子伴侣周期。具体目标旨在解决以下问题(1)什么是 Cdc37的结构和动力学性质；(2)cdc37如何识别蛋白质的催化结构域 以及(3)CDC37如何区分依赖于Hsp90和非依赖于Hsp90的激酶？

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?