Mechanisms of DNA Motor Proteins in Genome Maintenance

描述(由申请人提供)： 长期目标是了解DNA结合的马达蛋白在促进和调节同源重组(HR)中的作用机制。重要的是，许多这样的DNA马达蛋白对于哺乳动物避免癌症是不可或缺的。例如，发动机蛋白BLm和RECQ5的突变会导致异常重组事件，并与肿瘤的发生有关，而Rad54和Rad54B的突变在各种类型的肿瘤中都被发现。了解这些马达蛋白的性质，并描述它们在基因组维护中的作用，对于揭示产生疾病表型的缺陷的分子基础是至关重要的。然而，这些蛋白质如何发挥作用的机制细节在很大程度上仍然难以捉摸。我们的假设是，DNA马达蛋白通过其沿DNA移位和从DNA中移除蛋白质的能力来促进基因组的维持，并且它们的功能是通过与其他DNA修复因子的特定相互作用来调节的。为了验证这一假设，我们将采取多学科的方法，整合我们在遗传学(H.Klein)、生物化学(P.Sung)和单分子生物物理学(E.Greene)方面的不同专业知识，对酿酒酵母DNA马达蛋白Rad54、Rdh54、TiD4和Srs2进行详细分析。这些蛋白质通过HR参与DNA双链断裂(DSB)修复的不同方面。我们的三个实验室通力合作，能够很好地破译这些马达蛋白的机制，并为理解哺乳动物的基因组维持和肿瘤抑制作用提供一个有价值的实验框架。与公共卫生相关：癌症的特点是基因组不稳定和重排，这是由复制、修复和重组中的错误促进的。这项拟议的研究将揭示新的基因和机制，以促进基因组在每次细胞分裂时持续的DNA损伤。

DESCRIPTION (provided by applicant): The long-term goals are to understand the mechanisms by which DNA-binding motor proteins act in the promotion and regulation of homologous recombination (HR). Importantly, many of these DNA motor proteins are indispensable for cancer avoidance in mammals. For instance, mutations in the motor proteins BLM and RECQ5 lead to aberrant recombination events and are associated with tumorigenesis, and mutations in Rad54 and Rad54B are found in a variety of tumor types. Understanding the properties of these motor proteins, and delineating their roles in genome maintenance, will be essential for revealing the molecular basis for defects that produce the disease phenotypes. However, the mechanistic details of how these proteins function have remained largely elusive. Our hypothesis is that DNA motor proteins contribute to genome maintenance through their ability to translocate along DNA and remove proteins from DNA, and that their functions are mediated through specific interactions with other DNA repair factors. To test this hypothesis we will take a multidisciplinary approach that integrates our distinct areas of expertise in genetics (H. Klein), biochemistry (P. Sung) and single-molecule biophysics (E. Greene) to conduct a detailed analysis of the S. cerevisiae DNA motor proteins Rad54, Rdh54, Tid4, and Srs2. Each of these proteins participates in different aspects of DNA double-strand break (DSB) repair through HR. Working together, our three laboratories are well positioned to decipher the mechanisms of these motor proteins and provide a valuable experimental framework for understanding the genom maintenance and tumor suppression roles of their mammalian counterparts. PUBLIC HEALTH RELEVANCE: Cancers are characterized by genomic instability and rearrangements, which are promoted by errors in replication, repair and recombination. The proposed studies will reveal new genes and mechanisms for promoting genome maintenance in the face of constant DNA damage that occurs every cell division.