DEVELOPMENTAL CONTROL OF DNA REPLICATION IN CAULOBACTER

描述：该提案的目标是定义 使DNA复制的启动与细胞周期进程相协调。 新月形杆菌特别适合于鉴定和鉴定 介导复制起始和复制的调控因素分析 具有明确细胞的简单细菌细胞中的染色体运动 周而复始。铜绿假单胞菌的独特特性包括细胞易感性 同步性，每个细胞的单个染色体只有一次复制 周期，一个明确的G1，S，G2周期，和一个不对称的除法，收益率 具有不同形态特征和不同细胞命运的后代。这个 DNA复制的启动受CtrA的负调控 与复制起始点绑定的响应调节因子。CTRA是 受磷酸化和蛋白水解酶的时间控制，是 不对称地局限于非复制的子代沼泽细胞。在……里面 此外，编码复制机制的基因的表达是 在复制启动时诱导并协调调节， 而一种新的DNA甲基化酶CCRM有助于控制 复制启动，提供其他层的调控。这个 拟议的实验将寻求将这些控制层与 控制编码基因的细胞周期诱导的因素 复制机制，确定DNA甲基化位点在 复制起源，并定义限制 CCRM DNA甲基转移酶到细胞周期后期的特定时间段。 还将确定染色体分离装置的组件 以及它们如何提示染色体复制的进展将是 下定决心。

DESCRIPTION:The goal of this proposal is to define the genetic network that coordinates the initiation of DNA replication with cell cycle progression. Caulobacter crescentus is particularly well suited to the identification and analysis of the regulatory factors that mediate replication initiation and chromosome movement in a simple bacterial cell with a well-defined cell cycle. The unique characteristics of Caulobacter include ease of cell synchrony, one and only one replication of the single chromosome per cell cycle, a clear G1, S, and G2 period, and an asymmetric division that yield progeny with distinct morphological features and different cell fates. The initiation of DNA replication is under the negative control of the CtrA response regulator which binds to the replication origin. CtrA is temporally controlled by phosphorylation and proteolysis, and is asymmetrically restricted to the non-replicating progeny swarmer cell. In addition, expression of the genes encoding the replication machinery are induced at the time of replication initiation and coordinately regulated, and a new DNA methylating enzyme, CcrM, contributes to the control of replication initiation, providing yet other layers of regulation. The proposed experiments will seek to coordinate these layers of control with the factors that control cell cycle induction of the genes encoding the replication machinery, determine the role of DNA methylation sites in the replication origin, and define the regulatory mechanisms that confine the CcrM DNA methyltransferase to a specific time period late in the cell cycle. Components of the chromosome segregation apparatus will also be identified and how they are cued to the progression of chromosome replication will be determined.