Regulation of an Error-Prone Polymerase

描述(申请人提供)：基因组稳定性对生物体的健康和物种的保存至关重要。这种稳定性受到来自内源和外源的DNA损伤的威胁；这种损伤可能导致导致癌症和遗传疾病的突变。为了应对DNA损伤，所有生物体都有损伤特异性和一般DNA修复途径。这个军火库包括新发现的Y家族DNA聚合酶，它可以复制受损的DNA。然而，这些聚合酶非常容易出错，即使在复制未受损的DNA时也会频繁出错。如果这些聚合酶的诱变活性得不到控制，它们可能成为遗传不稳定的一个重要来源。这项研究的目标是阐明调控容易出错的DNA聚合酶的细胞通路。这里采用的方法是以来自大肠杆菌的DNA聚合酶IV为模型。大肠杆菌的DNA聚合酶IV与在包括人类在内的高等生物体中活跃的容易出错的聚合酶密切相关。这种简单的细菌控制POL IV活性的机制可能为所有生物体中类似的机制提供一个范例。 已经确定了一些影响POL IV的细胞因素。拟议的研究将确定它们如何控制Pol IV的丰度和活性。具体目标是：(1)确定Pol IV的丰度是如何调节的；(2)确定Pol IV的诱变活性是如何调节的；(3)识别和表征影响Pol IV的蛋白质相互作用。

DESCRIPTION (provided by applicant): Genomic stability is vital to the health of the organism and the preservation of the species. This stability is threatened by DNA damage from endogenous and exogenous sources; such damage can cause mutations that lead to cancer and genetic disorders. To cope with DNA damage all organisms have both damage specific and general DNA repair pathways. This arsenal includes the newly-discovered Y-family DNA polymerases that can replicate damaged DNA. However, these polymerases are highly error-prone, making frequent errors even when replicating undamaged DNA. If the mutagenic activities of these polymerases are not controlled, they could become a potent source of genetic instability. The goal of this research project is to elucidate the cellular pathways that regulate error-prone DNA polymerases. The approach taken here focuses on DNA polymerase IV from the bacterium Escherichia coli as a model. E. coli's DNA polymerase IV is very closely related to the error-prone polymerases that are active in higher organisms, including humans. The mechanisms by which this simple bacterium controls the activity of Pol IV may provide a paradigm for similar mechanisms in all organisms. A number of cellular factors that affect Pol IV have already been identified. The research proposed will establish how these control the abundance and the activity of Pol IV. The specific aims are: (1) to determine how the abundance of Pol IV is regulated; (2) to establish how the mutagenic activity of Pol IV is regulated; (3) to identify and characterize protein interactions that affect Pol IV.