Structural Insights Into Regulation of SOS Mutagenesis

SOS 诱变调控的结构见解

• 批准号: 6667937
• 负责人: MARTIN GONZALEZ
• 金额: $ 10.5万
• 依托单位: SOUTHWESTERN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6667937
• 关键词: DNA damage; DNA directed DNA polymerase; DNA repair; biological signal transduction; cell cycle; cell growth regulation; conformation; enzyme activity; protein degradation; protein sequence; protein structure function; site directed mutagenesis

DESCRIPTION (provided by applicant): The degradation of proteins is known to be an essential regulatory mechanism vital for biological processes and diseases including cell cycle progression, DNA repair, and cancer. While the majority of cellular proteins are stable, there are a small percentage of cellular proteins that are unstable, temporal acting, and function in a regulatory manner. An example of these are the Escherichia coli proteins UmuD' (UmuD) and UmuC. UmuD'C comprise an error-prone DNA polymerase, DNA polV, necessary for the survival of the bacterium following extensive DNA damage. The Umu proteins are part of a DNA damage tolerance system termed SOS mutagenesis. Recent work suggests that the mammalian counterparts of these prokaryotic error-prone polymerases may play a role in processes from cancer establishment to induction of somatic cell hypermutation of immunoglobulin genes. Therefore, DNA polV activity and regulation is an ideal model to study for two reasons: (i) the regulation of DNA polV is vital to the understanding of the SOS mutagenic response and will provide a scientific foundation for exploring the regulation of eukaryotic error-prone polymerases, and (ii) DNA polV is a highly suitable model for studying selective protein degradation, a process known to be vital for cell integrity. The mechanisms by which proteases selectively recognize these and other unstable proteins are unknown and determining these mechanisms is important in understanding how SOS mutagenesis and other biological processes are specifically regulated. It is also unknown how starvation conditions, such as those experienced by bacterial cells in stationary phase and in their natural environment, affects the protease-substrate interaction. The research proposed in this project will elaborate on the mechanism(s) of Umu instability and will address the processing of UmuD (and potentially the other Umu proteins) demonstrated during stationary phase growth. We will use numerous molecular, biochemical, and genetic techniques to achieve the following aims: 1. To test DNA polV function and regulation during stress conditions not known to induce significant DNA damage. 2. To evaluate the complexity of the degradation signals of the Umu proteins and their effect on regulation.

描述（由申请人提供）：已知蛋白质的降解是对生物过程和疾病（包括细胞周期进展，DNA修复和癌症）至关重要的调节机制。虽然大多数细胞蛋白是稳定的，但少数细胞蛋白不稳定，时间作用和以调节方式起作用。这些例子是大肠杆菌蛋白Umud'（Umud）和Umuc。 UMUD'C包含一个容易出错的DNA聚合酶DNA POLV，这对于广泛的DNA损伤后细菌的存活所必需。 UMU蛋白是称为SOS诱变的DNA损伤耐受系统的一部分。最近的工作表明，这些原核生物错误的聚合酶的哺乳动物对应物可能在从癌症建立到诱导免疫球蛋白基因的体细胞超女性的过程中起作用。 Therefore, DNA polV activity and regulation is an ideal model to study for two reasons: (i) the regulation of DNA polV is vital to the understanding of the SOS mutagenic response and will provide a scientific foundation for exploring the regulation of eukaryotic error-prone polymerases, and (ii) DN​​A polV is a highly suitable model for studying selective protein degradation, a process known to be vital for cell integrity.蛋白酶选择性地识别这些和其他不稳定蛋白质的机制是未知的，并且确定这些机制对于理解SOS诱变和其他生物学过程如何特别调节很重要。饥饿的条件（例如固定相和自然环境中细菌细胞经历的条件）也未知如何影响蛋白酶 - 基底相互作用。该项目中提出的研究将详细介绍UMU不稳定性的机制，并将解决在固定期生长期间所证明的UMUD（以及可能是其他UMU蛋白）的处理。我们将使用许多分子，生化和遗传技术来实现以下目的：1。在不知道会诱导明显的DNA损伤的压力条件下测试DNA POLV功能和调节。 2。评估UMU蛋白降解信号的复杂性及其对调节的影响。