Kinetics of macromolecular complex assembly and regulation

 描述（由申请人提供）：尽管蛋白质和核蛋白复合物的错误组装与许多调节性疾病有关，但我们对这些复合物在体内组装的机制的了解非常有限。由于许多蛋白质必须结合成高阶组装体才能发挥其生物学功能，因此预测这些复合物的自组装对于理解蛋白质组的组织和调控至关重要。这些复合物的组装的实验研究是复杂的事实，许多基本的复合物，包括核糖体和蛋白酶体，含有几十个亚基，组装在一个高度合作的方式。此外，现在已知体内组装与在稀释条件下进行的重构实验显著不同，特别是由于存在充当组装辅因子的分子伴侣。因此，需要新的理论方法来科普这种复杂性，并确定在蛋白质组水平上控制强大的自组装和调节的物理原理。 建立在一个强大的自组装理论，我最近开发的描述DNA为基础的纳米结构，我将建立一个新的理论方法来预测蛋白质和核蛋白复合物的组装途径。这种方法将提供一个比单独从实验中获得的更完整的组装机制的图片，并且比传统的模拟效率高出几个数量级。利用这种效率来执行以前难以实现的计算筛选，我将测试核蛋白复合物已经进化到优化组装速率的假设。我也将调查的敏感性，自组装的亚基化学计量的变化，我将应用该理论来研究的作用，伴侣在促进准确的组装。这些理论预测将通过两个特定模型系统的案例研究进行测试。 这项工作将导致在蛋白质组水平上的调节的理解。物理上严格的理论将建立大分子复合物自组装的一般原理。了解分子伴侣辅助自组装的机制也将使仿生分子伴侣的合理工程，这对改变体内复合物的产生具有巨大的潜力，从而指导广泛的蛋白质错误组装疾病的治疗策略的发展。

 DESCRIPTION (provided by applicant): Although the misassembly of protein and nucleoprotein complexes is implicated in many regulatory disorders, we have extremely limited knowledge of the mechanisms by which these complexes assemble in vivo. Because many proteins must associate into higher-order assemblies in order to carry out their biological functions, predicting the self-assembly of these complexes is crucial for understanding the organization and regulation of the proteome. Experimental investigations of the assembly of these complexes are complicated by the fact that many essential complexes, including the ribosome and the proteasome, contain dozens of subunits that assemble in a highly cooperative manner. Furthermore, it is now known that assembly in vivo differs significantly from reconstitution experiments conducted under dilute conditions, particularly due to the presence of molecular chaperones that act as assembly co-factors. New theoretical approaches are thus needed to cope with this complexity and to identify the physical principles governing robust self-assembly and regulation at the proteomic level. Building on a powerful theory of self-assembly that I have recently developed to describe DNA-based nanostructures, I shall establish a novel theoretical approach for predicting the assembly pathways of protein and nucleoprotein complexes. This approach will provide a considerably more complete picture of the mechanism of assembly than can be obtained from experiments alone and is orders of magnitude more efficient than conventional simulations. Leveraging this efficiency to perform computational screens that were previously intractible, I shall test the hypothesis that nucleoprotein complexes have evolved to optimize the rate of assembly. I shall also investigate the sensitivity of self-assembly to variations in subunit stoichiometries, and I shall apply the theory to examine the role of chaperones in promoting accurate assembly. These theoretical predictions will be tested with two case studies of specific model systems. This work will lead to an improved understanding of regulation at the proteomic level. A physically rigorous theory will establish general principles of the self-assembly of macromolecular complexes. Understanding the mechanisms of chaperone-assisted self-assembly will also enable the rational engineering of biomimetic chaperones, which hold great potential for altering the production of complexes in vivo, thus guiding the development of therapeutic strategies for a wide range of protein-misassembly disorders.