Mechanisms Governing Bacillus Mother Cell Gene Expression

芽孢杆菌母细胞基因表达的调控机制

• 批准号: 6983685
• 负责人: LEE R KROOS
• 金额: $ 31.47万
• 依托单位: MICHIGAN STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-12-01 至 2009-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6983685
• 关键词: Bacillus subtilis; DNA directed RNA polymerase; Escherichia coli; bacterial genetics; bacterial proteins; binding proteins; developmental genetics; endopeptidases; gene expression; genetic manipulation; genetic promoter element; genetic regulatory element; genetic screening; genetic transcription; laboratory rabbit; microorganism reproduction; protease inhibitor; protein structure function; proteolysis; regulatory gene; spores; transcription factor; Bacillus subtilis; DNA directed RNA polymerase; Escherichia coli; bacterial genetics; bacterial proteins; binding proteins; developmental genetics; endopeptidases; gene expression; genetic manipulation; genetic promoter element; genetic regulatory element; genetic screening; genetic transcription; laboratory rabbit; microorganism reproduction; protease inhibitor; protein structure function; proteolysis; regulatory gene; spores; transcription factor

DESCRIPTION (provided by applicant): The objective of this research is to understand how gene expression is regulated temporally and spatially in bacteria. Sporulation of Bacillus subtilis provides an attractive experimental system to elucidate novel mechanisms of signaling and gene regulation likely to be used by other bacteria, including pathogens. During sporulation, the cell is divided into mother cell and forespore compartments, each with a copy of the genome. Different sigma subunits of RNA polymerase (RNAP) become active in each compartment at different times, accounting for much of the temporal and spatial gene regulation. In addition, transcription factors activate or repress expression of many genes. This proposal focuses on mechanisms of gene regulation in the mother cell compartment, where two sigma factors and two transcription factors are organized in a hierarchical cascade with the order sigmaE, SpoIIID, sigmaK, then GerE. Activity of each sigma is governed by a unique signaling pathway that begins in the forespore and ends with proteolytic removal of an inhibitory pro-sequence in the mother cell. Components of these signaling pathways are known, but the molecular mechanisms of signaling and proteolytic processing remain to be elucidated. One aim is to understand the mechanism of pro-sigmaK processing and its regulation by BofA. This pathway involves regulated intramembrane proteolysis (RIP) of pro-sigmaK by SpoIVFB metalloprotease. RIP is involved in crucial biological processes, but is poorly understood. RIP of pro-sigmaK by SpoIVFB provides a fantastic opportunity to break new ground. Processing of pro-sigmaE does not appear to involve RIP, but its mechanism and its regulation by a signal from the forespore are unclear. To clarify this pathway, approaches used successfully to study pro-sigmaK processing will be applied. Another aim is to investigate the importance of a feedback loop by which sigmaK RNAP negatively regulates early gene expression. This will give insight into the switch from one regulon to another, a common feature in bacterial and phage gene regulation. Finally, SpoIIID's small size and essential role in sporulation make it attractive for structure/function and genetic analyses that will add knowledge about mechanisms of transcriptional activation in bacteria.

描述（由申请人提供）：这项研究的目的是了解基因表达如何在细菌中的时间和空间调节。枯草芽孢杆菌的孢子形成提供了一个有吸引力的实验系统，以阐明其他细菌（包括病原体）可能使用的信号传导和基因调节机制。在孢子形成过程中，细胞分为母细胞和前室室，每个细胞都带有基因组的副本。 RNA聚合酶（RNAP）的不同Sigma亚基在不同时间在每个隔室中都活跃，这是时间和空间基因调节的大部分。此外，转录因子激活或抑制许多基因的表达。该建议的重点是母细胞室中基因调节的机制，其中有两个Sigma因子和两个转录因子在分层级联中组织了Sigmae，Sigmae，Spoiiid，Sigmak，然后是Gere。每个Sigma的活性受到唯一的信号通路，该途径始于前孔，并以蛋白水解去除母细胞中的抑制作用。这些信号通路的组成部分是已知的，但是信号传导和蛋白水解处理的分子机制仍有待阐明。一个目的是了解亲西格马克加工的机制及其对美国银行的调节。该途径涉及spoiVFB金属蛋白酶的促膜膜内蛋白水解（RIP）。 RIP参与了关键的生物学过程，但知之甚少。 SpoiVFB的Pro-Sigmak Rip提供了一个绝佳的机会，可以打破新的地面。亲智的处理似乎并不涉及RIP，但是它的机制及其对前孔信号的调节尚不清楚。为了阐明这一途径，将采用成功研究促进加工的方法。另一个目的是调查反馈循环的重要性，通过该循环，Sigmak RNAP负责调节早期基因表达。这将洞悉从一个调节子到另一个调节的转换，这是细菌和噬菌体基因调节中的共同特征。最后，Spoiiid在孢子形成中的小尺寸和重要作用使其对结构/功能和遗传分析具有吸引力，这些分析将增加有关细菌转录激活机制的知识。