Regulation and Localization of Mismatch Repair Proteins

首席研究员/项目主任(最后、第一、中间)：Haye、Joanna、Elizabeth 摘要： DNA错配修复(MMR)是一个高度保守的过程。一个功能正常的MMR途径对于 保持基因组的完整性；MMR的丢失会导致基因组的不稳定和高等真核生物的癌症。为 例如，MMR基因缺陷会导致Lynch综合征，这是一种常见的遗传性癌症综合征，可导致 早发性结肠癌、子宫内膜癌、卵巢癌、小肠癌、肝胆管癌、上尿路癌 以及其他组织。在我们最新的出版物中，我们展示了在酵母中，缺失的调节物 转录(也称为Not4)或一般控制不可降压基因5(Gcn5)调节 MSH2，一个主要的MMR组件。丢失Gcn5显著降低Msh2，而删除Not4则稳定 功能性Msh2。Not4和Gcn5分别是泛素化和乙酰化各种蛋白质的蛋白质。我们 假设Not4和GCN5修饰酵母MutSα(由MS2和MSH6组成)，并且这些修饰 影响络合物的稳定性。使用酵母酿酒酵母(S.cerevisiae)，第一个目的是 拟议的研究旨在确定Gcn5和Not4在调节重大错配中的作用 识别复合体MutSα。我们之前的实验也表明，酵母MutS与 DNA复制过程中的复制机制。人MutSα通过特异组蛋白被招募到染色质 通过结合增殖细胞核抗原，DNA聚合酶的处理能力，修饰并与复制机制相互作用 因素。然而，招募人MutSα的修饰在酵母中没有被利用。酵母MutSα是怎样的 被招募到染色质仍然难以捉摸。这项研究的第二个目标是确定后两者的作用 MutSα募集到染色质的翻译修饰。 PHS398(5/01版)页面延续格式页面

Principal Investigator/Program Director (Last, first, middle): Haye, Joanna, Elizabeth Abstract: DNA mismatch repair (MMR) is a highly conserved process. A functional MMR pathway is essential for maintaining genome integrity; loss of MMR results in genome instability and cancer in higher eukaryotes. For example, defects in MMR genes result in Lynch Syndrome, a common hereditary cancer syndrome resulting in early onset cancers of the colon, endometrium, ovaries, small intestine, hepatobiliary tract, upper urinary tract as well as other tissues. In our most recent publication, we showed that in yeast, deletion of Modulator of Transcription (also known as Not4) or General Control Nonderepressible 5 (Gcn5) modulate the levels of Msh2, a major MMR component. Loss of Gcn5 significantly decreases Msh2, whereas deleting Not4 stabilizes functional Msh2. Not4 and Gcn5 are proteins that ubiquitylate and acetylate various proteins respectively. We hypothesize that Not4 and Gcn5 modify yeast MutSα (comprised of Ms2 and Msh6) and that the modifications affect the stability of the complex. Using the yeast Saccharomyces cerevisiae (S. cerevisiae), the first aim of the proposed research is to establish the role of Gcn5 and Not4 in the regulation of the major mismatch recognition complex MutSα. Our previous experiments have also shown that yeast MutS tracks with the replication machinery during DNA replication. Human MutSα is recruited to chromatin through specific histone modifications and interacts with the replication machinery by binding PCNA, the DNA polymerase processivity factor. However, the modifications that recruit human MutSα are not utilized in yeast. How yeast MutSα is recruited to chromatin remains elusive. The second aim of this research is to determine the role of post- translational modifications in MutSα recruitment to chromatin. PHS398 (Rev. 5/01) Page Continuation Format Page