Developmental Control of DNA Replication in Caulobacter

柄杆菌 DNA 复制的发育控制

• 批准号: 7982524
• 负责人: LUCILLE SHAPIRO
• 金额: $ 30.14万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-08-01 至 2014-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7982524
• 关键词: Actins; Antibiotics; Antisense RNA; Behavior; Binding; Biochemical; Boron; Caulobacter; Cell Cycle; Cell Cycle Regulation; Cells; Centromere; Chromosome Segregation; Chromosomes; Complex; DNA; DNA Methylation; DNA Replication Timing; DNA Sequence; DNA biosynthesis; Development; Event; Family; Free Ribosome; Gene Expression; Gene Proteins; Genes; Genetic; Genetic Transcription; Goals; Image; In Vitro; Individual; Life; Link; Mediating; Methylation; Movement; Phase; Positioning Attribute; Proteins; Replication Initiation; Resolution; Rest; Role; Running; Structure; System; Time; Transcript; Transcriptional Regulation; base; cdc Genes; chromosome replication; design; in vivo; inhibitor/antagonist; mutant; partition protein parB; promoter; protein function; public health relevance; research study; segregation; small molecule; time use; transcription factor

DESCRIPTION (provided by applicant): Our goal is to define how a bacterial cell integrates the timing of DNA replication and the polar positioning of the chromosomal origin region to control the temporal and spatial expression of cell cycle events. A lynch-pin in the temporal coordination of replication initiation and the transcription of genes encoding global cell cycle regulators is DnaA. This protein functions both to initiate replication and to activate the transcription of over 40 cell cycle-controlled genes. DnaA is controlled at multiple levels, including transcriptional regulation by differential methylation of its promoter that is linked to the progression of the replication fork, and the control of its activity by the replisome-associated HdaA protein. We will determine if changes in DNA methylation state that functions to 'clock' the sequential transcription of both dnaA and ctrA controls the temporal transcription of multiple cell cycle regulated genes, including those controlled by GcrA master regulator. We will also determine if a temporally-controlled dnaA anti- sense transcript contributes to the control of dnaA expression. The dynamic spatial deployment of proteins and the origin region of the chromosome are critical factors in cell cycle control. We have shown that upon replication of the chromosomal origin, the actual DNA sequence that moves toward, and is captured by, the cell pole is parS bound to the ParB partition protein. If the ParB/parS complex is not anchored to the pole, segregation of the rest of the chromosome is impaired and the FtsZ division ring is misplaced. We have recently identified PopZ as a protein that forms a polar polymeric network and functions to anchor ParB/parS to the new cell pole. Important questions are how the polar ribosome free zone formed by the PopZ network is established and how it functions. To define how ParB/parS moves across the cell to be captured by PopZ, we have initiated an analysis of the essential ParA segregation protein. We have generated multiple mutants of ParA and visualized ParA behavior both in vivo and in vitro. We will now identify and characterize the factors that mediate its role in DNA movement and determine the mechanism that drives chromosome segregation. PUBLIC HEALTH RELEVANCE: Based on our elucidation of the genetic circuitry that runs a bacterial cell cycle, we designed a new class of boron-based antibiotics that are in phase two trials. In addition, we identified a small molecule inhibitor of the MreB bacterial actin, with the goal of using this as the basis for a new family of antibiotics.

描述（由申请人提供）：我们的目标是定义细菌细胞如何整合DNA复制的时间和染色体起源区域的极性定位，以控制细胞周期事件的时间和空间表达。 DNAA是在复制启动的时间协调和编码全球细胞周期调节剂基因的转录中的lynch针。该蛋白质既起启动复制，又激活40多个细胞周期控制基因的转录。 DNAA在多个级别上受到控制，包括通过其启动子的差异甲基化来调节，该甲基化与复制叉的进展有关，以及通过复制体相关的HDAA蛋白来控制其活性。我们将确定DNA甲基化状态的变化是否功能为“时钟” dnaA和CTRA的顺序转录控制多个细胞周期调控基因的时间转录，包括由GCRA主调节器控制的基因。我们还将确定时间控制的DNAA抗感觉转录本是否有助于控制DNAA表达。蛋白质的动态空间部署和染色体的原点区域是细胞周期控制中的关键因素。我们已经表明，在复制染色体起源后，朝向并被捕获的实际DNA序列与PARB分区蛋白结合在一起。如果PARB/PARS复合物不能固定在极点上，则染色体的其余部分的隔离受损，FTSZ分裂环被放错了位置。我们最近将Popz确定为形成极性聚合网络的蛋白质，并将功能锚定在新细胞极。重要的问题是如何建立POPZ网络形成的极性核糖体无区域以及它的功能。为了定义PARB/PARS如何在细胞中移动以被Popz捕获，我们开始对必需的PARA分离蛋白进行分析。我们已经产生了Para的多个突变体，并在体内和体外可视化了Para行为。现在，我们将确定并表征介导其在DNA运动中的作用的因素，并确定驱动染色体分离的机制。 公共卫生相关性：基于我们阐明运行细菌细胞周期的遗传回路，我们设计了一种新的基于硼的抗生素，这些抗生素正在第二阶段试验中。此外，我们确定了MREB细菌肌动蛋白的小分子抑制剂，目的是将其作为新的抗生素家族的基础。