Control of elongation of DNA replication

描述（由申请人提供）：准确和完整的DNA复制对所有生物体至关重要。复制延伸极易受到破坏，导致致命的后果，包括不完全复制、突变和基因组重排，这可能是细胞死亡、基因组紊乱、肿瘤形成和进展的基础。尽管最小化DNA复制延伸的破坏很重要，但细胞如何做到这一点仍然知之甚少。我们最近采用全基因组，系统的方法来鉴定革兰氏阳性杆菌枯草芽孢杆菌复制伸长的一种新的营养应答调节。我们认为，这种调控将复制延伸置于代谢控制之下，以防止复制中断，并与挽救和重新激活被破坏的复制叉的机制一起，强有力地维持基因组完整性。这样的机制很可能存在于其他生物体中，并发挥比以前想象的重要得多的作用。我们的目标是评估复制伸长调控的作用，它在其他细菌如大肠杆菌中的流行，并定义调控复制阻滞和破坏性复制阻滞之间的分子差异。我们的研究将有助于了解复制延伸复合体与其细胞环境之间的联系。这将加深对不受控制的复制在肿瘤发生和基因组疾病中的可能作用的理解，并阐明基因组完整性的基本原理。具体目标是：1。研究枯草芽孢杆菌复制延伸的新调控机制的作用2. 描述不同复制停止后复制分叉处的关键事件；3. 描述大肠杆菌复制延伸的控制。公共卫生相关性：我们发现了一种细菌控制其DNA复制的新方法。研究这一途径阐明了新的和保守的控制DNA复制的原则。失去这种控制可能导致基因组重排和突变，这是几种人类基因组疾病和癌症的基础。了解这一途径对于理解微生物产生抗生素耐药性也很重要。

DESCRIPTION (provided by applicant): Accurate and complete DNA replication is of paramount importance for all organisms. Replication elongation is highly susceptible to disruptions leading to fateful consequences including incomplete replication, mutations and genome rearrangements, which can underlie cell death, genomic disorders, tumor formation and progression. Despite the importance of minimizing disruption of DNA replication elongation, how cells manage to do so remains poorly understood. We recently employed genome-wide, systematic approaches to identify a novel nutrient-responsive regulation of replication elongation in the Gram-positive bacterium Bacillus subtilis. We propose that this regulation keeps replication elongation under metabolic control to prevent disruption of replication, and together with mechanisms that rescue and reactivate the disrupted replication forks, maintains genome integrity robustly. Such mechanisms are likely to exist in other organisms and play far more important roles than previously conceived. We aim to evaluate the role of regulation of replication elongation, its prevalence in other bacteria such as E. coli, and to define the molecular differences between regulated replication arrests and disruptive replication arrests. Our study will contribute significantly to knowledge of the connection between the replication elongation complex and its cellular environment. This will deepen the understanding of the possible roles of uncontrolled replication in tumorigenesis and genomic disorders and elucidate fundamental principles underlying genome integrity. The specific aims are: 1. Examine the role of a novel regulatory mechanism of replication elongation in B. subtilis; 2. Characterize key events at replication forks following diverse replication arrests; 3. Characterize the control of replication elongation in E. coli. PUBLIC HEALTH RELEVANCE: We discovered a new way that bacteria control duplication of their DNA. Investigating this pathway elucidates novel and conserved principles of control of DNA duplication. Loss of this control potentially leads to genome rearrangements and mutagenesis, which underlies several human genomic disorders and cancers. Understand this pathway is also important for understanding microbial development of antibiotic resistance.