Nanoscale mechanisms of Hsp90 and its co-chaperones

描述（由申请人提供）：许多癌症是由正常蛋白的突变版本的异常活动引起的，这些突变版本严重依赖于“分子伴侣”Hsp90进行折叠。Hsp90不是单独作用，而是在多蛋白组合中与Hsp90、Hsp70、HOP和CHIP蛋白结合。这些关联是由称为tpr的基序介导的。本提案的目标是开发一种基于原子力显微镜（AFM）成像的分析方法，以便对这些纳米级复合物的组装进行详细研究。利用生物素化的HOP和链亲和素表面，研究Hsp90-HOP-Hsp70组装体，并对其形成进行原位和实时监测。此外，使用相同的基于afm的分析，CHIP的作用及其与Hsp90-HOP-Hsp70组装相互作用的性质将被阐明。最后，该实验将用于了解更紧密结合的tpr和小分子的影响，它们能够抑制Hsp90- HOP-Hsp70的形成。这些新颖的研究将使人们对这些纳米级工艺和组件的理解达到一个新的水平。它们与癌症有直接关系，因为抑制Hsp90活性是一种被证实的抗癌治疗方法。

DESCRIPTION (provided by applicant): Many cancers are caused by the aberrant activity of mutant versions of normal proteins, which are critically dependent on the 'molecular chaperone' Hsp90 for folding. Hsp90 does not act alone, but associates with the proteins Hsp90, Hsp70, HOP and CHIP in multi-protein assemblies. These associations are mediated by motifs called TPRs. The goal of this proposal is to develop an atomic force microscope (AFM) imaging-based assay that will allow a detailed study of the assembly of these nano-scale complexes. Using biotinylated HOP and streptavidin surfaces, Hsp90-HOP-Hsp70 assemblies will be studied and their formation monitored in situ and in real time. In addition, using the same AFM-based assay, the role of CHIP and the nature of its interaction with the Hsp90-HOP-Hsp70 assembly will be elucidated. Finally, this assay will be used to understand the effects of tighter binding TPRs and small molecules, which are capable of inhibiting Hsp90- HOP-Hsp70 formation. These novel studies will allow a new level of understanding of these nano-scale processes and assemblies. They have direct relevance to cancer, because inhibition of Hsp90 activity is a proven route to anti-cancer therapeutics.