Protein Folding in the Eukaryotic Cytosol

描述（由申请人提供）：本研究计划的长期目标是了解新翻译的蛋白质如何在真核细胞中折叠。该研究将集中于多肽合成过程中核糖体的折叠事件，并将研究分子伴侣在其折叠过程中的作用。理解从头蛋白质折叠的概念框架源于我们在上一个资助周期的工作，该工作表明，一个名为CLIPS（与蛋白质合成相关的伴侣蛋白）的伴侣蛋白网络在物理和功能上与翻译机制相关联。我们的工作假设是，CLIPS伴侣蛋白的任务是引导新合成的多肽进入它们的折叠构象。伴侣蛋白介导的折叠途径似乎涉及不同类型的clip的合作，包括在折叠过程早期起作用的伴侣蛋白，如新生链相关复合物（NAC）、Hsp70蛋白和GIM/预折叠蛋白复合物，以及在折叠过程中起作用较晚的机制上不同的伴侣蛋白TRiC/CCT和Hsp90。我们阐明伴侣蛋白如何介导新合成蛋白的折叠的一般策略依赖于体外和体内方法的紧密结合。我们提出的实验旨在获得关于伴侣蛋白在新生折叠中的作用的功能，机制和结构见解。

DESCRIPTION (provided by applicant): The long term goal of this Research Program is to understand how newly translated proteins fold in eukaryotic cells. The proposed research will focus on folding events as they occur at the ribosome during synthesis of a polypeptide and will examine the role of molecular chaperones in their folding process. The conceptual framework for understanding de novo protein folding originates from our work in the previous funding cycle, which showed that a network of chaperones named CLIPS (Chaperones Linked to Protein Synthesis) is physically and functionally linked to the translation machinery. Our working hypothesis is that the CLIPS chaperones are tasked with guiding newly synthesized polypeptides to their folded conformation. Chaperone-mediated folding pathways appear to involve the cooperation of different classes of CLIPS, including chaperones that act early in the folding process, such as the Nascent Chain Associated Complex (NAC), the Hsp70 proteins and the GIM/prefoldin complex, and the mechanistically distinct chaperones TRiC/CCT and Hsp90, which appear to act later in the folding process. Our general strategy to elucidate how chaperones mediate the folding of newly synthesized proteins relies on the close integration of in vitro and in vivo approaches. Our proposed experiments are aimed at obtaining functional, mechanistic and structural insights into the role of chaperones in de novo folding.