Regulation of DNA recombination in Saccharomyces cerevisiae

描述（由申请人提供）：我们的长期目标是通过重组了解DMA修复过程的机制。DNA重组修复DNA双链断裂（DSBs）和间隙自发发生或由化学物质或辐照诱导。相同类型的DNA损伤可以通过不同的重组途径修复，这取决于细胞状态。决定以何种方式修复损伤对细胞维持基因组稳定性至关重要。本项目的目的是了解模式生物酿酒酵母选择重组途径的机制。DNA修复过程在进化过程中是保守的，因此提出的研究与我们对人类DNA重组修复机制的理解高度相关。我们使用了一种新的方法来鉴定参与DNA重组调控的重要蛋白质。采用荧光显微镜、染色质免疫沉淀和双向凝胶电泳等方法，研究了重组途径选择的机制和相关蛋白的功能。我们将定义细胞周期调节的分子开关之间的同源和非同源dsb修复途径的机制。本研究对人类细胞基因治疗的新策略具有重要意义。我们已经开发了一种测定方法来确定和表征调节交叉和非交叉重组选择的因素。交叉通路控制对于避免杂合性丧失、有丝分裂周期中的基因组重排以及防止染色体不分离导致减数分裂细胞的非整倍体（三体或单体）至关重要。非整倍体是人类最常见的染色体异常，在所有临床确认的妊娠中至少有5%发生，是导致妊娠丢失的主要遗传原因。编码我们研究的蛋白质的基因突变会导致人类严重的疾病，增加患癌症的倾向。因此，在遗传和分子水平上了解它们的功能对人类健康至关重要。

DESCRIPTION (provided by applicant): Our long-term goal is to understand the mechanisms of DMA repair process via recombination. DNA recombination repairs DNA double-strand breaks (DSBs) and gaps that occur spontaneously or are induced by chemicals or irradiation. The same type of DNA damage can be repaired by different pathways of recombination, depending on the cellular state. The decision as to which way to repair damage is crucial for cells to maintain genome stability. The objective of this project is to understand the mechanisms underlying the choice of recombination pathway in the model organism Saccharomyces cerevisiae. DNA repair processes are conserved in evolution, so the proposed research is highly relevant to our understanding of the mechanisms of DNA repair via recombination in humans. We used a new approach to identify important proteins involved in DNA recombination regulation. Fluorescence microscopy, chromatin immunoprecipitation and two-dimensional gel electrophoresis, we applied to study the mechanisms of recombination pathway choice and the function of proteins involved. We will define the mechanism of the cell cycle-regulated molecular switch between homologous and nonhomologous DSBs repair pathways. This study has important implications for new strategies for gene therapy in human cells. We have developed an assay to identify and characterize factors regulating choice of crossover and noncrossover recombination. Crossover pathway control is crucial to avoid loss of heterozygosity, genomic rearrangements in mitotic cycle and to prevent chromosome nondisjunction that causes aneuploidy (trisomy or monosomy) in meiotic cells. Aneuploidy is the most commonly identified chromosome abnormality in humans, occurring in at least 5% of all clinically recognized pregnancies and is the leading genetic cause of pregnancy loss. Mutations in genes encoding the proteins we study cause severe disorders in humans with increased predisposition to cancer. Therefore understanding their function, on the genetic and molecular levels is a critically important subject for human health.