Mechanism of homology search in homologous recombination by Rad51 and Rad54.

Rad51和Rad54同源重组中同源搜索的机制。

• 批准号: 7483425
• 负责人: Dana Novak Moses
• 金额: $ 4.48万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-04-01 至 2011-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7483425
• 关键词: ATP Hydrolysis; Binding; Biochemical; Breast; Cancer Biology; Complex; DNA; DNA Repair; DNA repair protein; DNA-Binding Proteins; Defect; Excision; Goals; Health; Human Development; Individual; Label; Malignant Neoplasms; Malignant neoplasm of ovary; Nucleosomes; Pathway interactions; Process; Proteins; Reaction; Research; Sequence Homologs; Techniques; Testing; Total Internal Reflection Fluorescent; cancer type; homologous recombination; improved; presynaptic; research study

DESCRIPTION (provided by applicant): The goal of this research is to elucidate the mechanisms underlying how DNA repair proteins locate and repair damaged DNA. The health implications of this process extend to breast and ovarian cancers, as these cancers are associated with defects in this pathway. Improved understanding of homologous recombination and DNA repair will in turn allow better understanding of the development of human cancers. The focus of this proposal is to determine how the DNA repair proteins Rad51 and Rad54 interact with DNA and with other protein components of homologous recombination, and how DNA molecules are aligned during homologous recombination. This proposal hypothesizes that the presynaptic complex formed by Rad51, Rad54, and ssDNA searches dsDNA for regions of homology using ATP hydrolysis to drive translocation. In addition, it is hypothesized that ATP hydrolysis is a vehicle for the removal of nucleosomes and other DNA binding proteins from the dsDNA that would otherwise hinder access to homologous regions of dsDNA. The specific aims of this project are to (1) investigate the biochemical mechanism used by the presynaptic complex to probe dsDNA for homologous sequence and to (2) detail the interaction of the presynaptic complex with nucleosomes bound to the dsDNA. To test this hypothesis, reactions involving fluorescently labeled DNA molecules, Rad51, and Rad54 will be observed using total internal reflection fluorescent microscopy. This technique is able to directly visualize individual proteins interacting with individual molecules of DNA. DNA repair is an absolutely essential process to maintain cellular health. The proposed research is directly relevant to cancer biology, and the successful completion of the experiments contained in this research will contribute immensely to understanding of various types of cancers.

描述（由申请人提供）：这项研究的目的是阐明DNA修复蛋白如何定位和修复受损的DNA的机制。该过程的健康影响扩展到乳腺癌和卵巢癌，因为这些癌症与该途径中的缺陷有关。对同源重组和DNA修复的理解得以提高，反过来又可以更好地了解人类癌症的发展。该建议的重点是确定DNA修复蛋白RAD51和RAD54如何与DNA相互作用以及其他同源重组的蛋白质成分，以及在同源重组过程中如何对齐DNA分子。该提议假设由Rad51，Rad54和SsDNA形成的突触前复合物搜索DSDNA使用ATP水解驱动易位的同源性区域。另外，假设ATP水解是从DSDNA中去除核小体和其他DNA结合蛋白的载体，否则它将阻碍进入DSDNA的同源区域。该项目的具体目的是（1）研究突触前复合物用于探测同源序列的生化机制，以及（2）详细介绍了突触前复合物与核小体与DSDNA结合的核小体的相互作用。为了检验这一假设，将使用总内反射荧光显微镜观察到涉及荧光标记的DNA分子，RAD51和RAD54的反应。该技术能够直接可视化与DNA单个分子相互作用的单个蛋白质。 DNA修复是维持细胞健康的绝对必要过程。拟议的研究与癌症生物学直接相关，这项研究中包含的实验的成功完成将极大地理解各种类型的癌症。