INTERACTIONS AMONG REPLICATION AND MUTATION PROTEINS

复制和突变蛋白之间的相互作用

• 批准号: 2750083
• 负责人: PATRICIA LORRAINE FOSTER
• 金额: $ 17.44万
• 依托单位: BOSTON UNIVERSITY MEDICAL CAMPUS
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-08-01 至 1999-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2750083
• 关键词: DNA damage; DNA directed DNA polymerase; DNA repair; DNA replication; Escherichia coli; bacterial genetics; enzyme activity; intermolecular interaction; microorganism culture; nucleic acid sequence; oligonucleotides

Genetic damage by environmental and endogenous agents can lead to birth defects, heritable diseases, cancer, and possibly contributes to aging. Thus, understanding how mutations are produced is fundamental to understanding and, perhaps, preventing many human disorders. Mutations are created when damaged DNA fails to be repaired, but, instead, is replicated. The long-term goal of this research is to understand what happens When the DNA replication complex encounters a DNA lesion, and to elucidate what cellular factors determine whether DNA repair or mutation prevails. In Escherichia coli, DNA damage induces about 20 proteins, which together are called the SOS response. The research proposed will investigate the interactions between the DNA replication complex and RecA, UmuD, and UmuC, the SOS proteins that are required for mutagenic replication past DNA lesions. This mutagenic activity is mediated by protein-protein interactions, probably resulting in a transient modification of the replication complex, DNA polymerase III holoenzyme (Pol III HE). The proofreading activity of Pol III HE is performed by a distinct subunit, epsilon. High cellular levels of epsilon inhibit SOS mutagenesis, but this inhibition can be relieved by concurrent overproduction of UmuDC. These and other results suggest that the SOS proteins may interact with epsilon as part of their alteration of Pol III HE. There are three specific aims of this research. (i) to identify any interactions between epsilon and the SOS proteins and to determine the functional significance of any interaction; (2) to generate and characterize new defects in the replication subunits that interfere with SOS mutagenesis; and (3) to investigate if the SOS proteins interact with replication subunits other than epsilon. These studies will elucidate the complex interactions that take place when damaged DNA is replicated and may provide a model for similar processes occurring in higher organisms.

环境和内源性因素造成的遗传损害可能导致 出生缺陷，遗传性疾病，癌症，以及可能的贡献 为衰老干杯。因此，了解突变是如何产生的是 对于理解，也许是防止许多人类 精神错乱。当受损的DNA未能被修复时，就会产生突变 被修复了，但却被复制了。这样做的长期目标是 研究是为了了解当DNA复制时会发生什么 复合体遇到DNA损伤，并阐明什么细胞 决定DNA修复或突变的因素是占上风的。 在大肠杆菌中，DNA损伤诱导了大约20种蛋白质，其中 一起被称为SOS响应。提出的研究将 研究DNA复制复合体之间的相互作用 以及RecA、UmuD和UMUC，这是必需的SOS蛋白 用于诱变复制通过DNA损伤。这一诱变活动 是由蛋白质-蛋白质相互作用介导的，可能导致 复制复合体DNA聚合酶的瞬时修饰 III全酶(POLIII HE)。POL III的校对活动 他是由一个不同的亚单位--epsilon执行的。高细胞水平 抑制SOS的诱变，但这种抑制可以 由于UmuDC同时出现生产过剩，情况有所缓解。这些和其他 结果表明，SOS蛋白可能与epsilon AS相互作用。 他们对波尔三世的一部分改装。有三个具体目标 这项研究的最新进展。(I)确定epsilon和epsilon之间的任何互动 SOS蛋白并确定其功能意义 相互作用；(2)产生和表征新的缺陷 干扰SOS突变的复制亚基；以及(3) 研究SOS蛋白是否与复制亚基相互作用 而不是埃西隆。这些研究将阐明这种复合体。 当受损的DNA复制时发生的相互作用 可以为类似的过程提供一个模型 有机体。