Generation of Asymmtery During Caulobacter Development

柄杆菌发育过程中不对称性的产生

• 批准号: 6687727
• 负责人: JAMES W GOBER
• 金额: $ 30.21万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-08-01 至 2005-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6687727
• 关键词: Caulobacter; adenosinetriphosphatase; bacterial genetics; cell cycle; enzyme activity; flagellum; gene expression; gene induction /repression; gene mutation; genetic translation; microarray technology; microorganism culture; microorganism growth; protein kinase; transcription factor

DESCRIPTION: The bacterium Caulobacter crescentus undergoes a simple cellular differentiation within each cell cycle. Cell division generates two distinct cell types: a motile swarmer cell and a sessile stalked cell. These two cell types differ with respect to their relative programs of gene expression and DNA replication. The generation of asymmetry upon cell division is a fundamental aspect of development in diverse organisms, including Drosophila, nematodes and fungi. In progeny stalked cells, the components of the polar flagellum are expressed under cell cycle control and assembled at the pole of the predivisonal cell that lies opposite the stalk. Two well-defined developmental checkpoints regulate flagellar morphogenesis. First, the transcription of early flagellar genes is triggered by an unknown cell cycle event that is linked to the initiation of DNA replication. Later in the cell cycle, the transcription of late flagellar genes is activated by a cell division event and the assembly of early flagellar structures. We propose that these events result in the compartmentalized transcription of both late and early flagellar genes. The overall objectives of this proposal are to define the mechanisms that couple early flagellar assembly to cell-type-specific expression of late flagellar genes. The proposed experiments, for the most part, focus on the activation of the response regulator transcription factor, FlbD, and its role in regulating temporal and spatial transcription. In addition, in order to explore cell-type specific translation, we describe experiments designed to identify the factors that regulate FlbT and the translation of flagellin genes. Finally, w e propose to identify genes outside of the flagellar regulon that are also controlled by FIbD. In order to accomplish these goals the biochemical properties of constitutive alleles of FlbD will be characterized and their effect on temporal and spatial transcription will be analyzed. In addition, the FlbD kinase will be identified. The role of the novel regulator FliX in coupling flagellum morphogenesis to gene expression will be determined by dissecting the mechanisms underlying FliX-mediated repression and activation of FlbD, and determining how the assembly of a flagellar structure regulates FbX activity. In order, to investigate the role of posttranscriptional regulation of cell-type-specific gene expression, proteins that regulate FlbT activity will be identified. Finally, DNA microarray gene expression assays will be conducted in order to identify critical cell cycle-related genes that are regulated by FIbD. The role of these genes in cell cycle progression will then be analyzed.

描述：细菌花椰菜牙齿牙齿经历一个简单的细胞 每个细胞周期内的分化。细胞分裂产生两个不同的 细胞类型：一个通活动的蜂群和一个无梗茎细胞。这两个细胞 类型在其基因表达和DNA的相对程序方面有所不同 复制。细胞分裂的不对称产生是基本的 多种生物的发展方面，包括果蝇，线虫和 真菌。在后代茎细胞中，极性鞭毛的成分是 在细胞周期控制下表达，并在 位于茎对面的前细胞。两个定义明确的发育检查点调节鞭毛形态发生。首先，早期的转录 鞭毛基因是由未知的细胞周期事件触发的，该事件链接到 DNA复制的启动。在细胞周期的后期，转录 晚期鞭毛基因被细胞分裂事件和组装激活 早期的鞭毛结构。我们建议这些事件导致 晚期和早期鞭毛基因的分隔转录。这 该提案的总体目标是定义夫妇的机制 早期的鞭毛装配到晚期鞭毛的细胞型特异性表达 基因。提出的实验大部分都集中在激活上 响应调节剂转录因子FLBD及其在调节中的作用 时间和空间转录。另外，为了探索细胞类型 具体翻译，我们描述了旨在识别因素的实验 调节FLBT和鞭毛蛋白基因的翻译。最后，我们建议 识别鞭毛法规之外的基因 纤维。为了实现这些目标， FLBD的本构等位基因将被表征，并且它们对时间的影响 和空间转录将进行分析。此外，FLBD激酶将 被识别。新型调节器flix在耦合鞭毛中的作用 对基因表达的形态发生将通过解剖来确定 FLBD的Flix介导的抑制和激活的基础机制， 确定鞭毛结构的组装如何调节FBX活性。 为了调查转录后调节的作用 细胞型特异性基因表达，调节FLBT活性的蛋白质将 被识别。最后，将进行DNA微阵列基因表达测定法 为了识别与细胞周期相关的关键基因 纤维。然后将分析这些基因在细胞周期进程中的作用。