RNA POLYMERASE AND BACTERIAL DIFFERENTIATION

RNA 聚合酶和细菌分化

• 批准号: 2173357
• 负责人: Richard Marc Losick
• 金额: $ 43.45万
• 依托单位: HARVARD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1976
• 资助国家: 美国
• 起止时间: 1976-02-01 至 2000-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2173357
• 关键词: Bacillus subtilis; DNA directed RNA polymerase; bacterial genetics; cell differentiation; developmental genetics; fusion gene; gene expression; gene mutation; gene rearrangement; genetic library; genetic mapping; genetic promoter element; genetic transcription; immunocytochemistry; immunoelectron microscopy; mutant; nucleic acid sequence; operon; site directed mutagenesis; sporogenesis; structural genes; transcription factor

The overall goals of our program of research are to understand temporal and spatial regulation of gene expression during endospore formation in the Gram-positive bacterium Bacillus subtilis and to understand how the programmed expression of sporulation genes is kept in register with the morphological events accompanying sporogenesis. Central to an investigation of these issues are five developmental-specific, RNA polymerase sigma factors and several auxiliary transcription factors that govern the program of sporulation gene expression. We propose to investigate how sigma factors mediate promoter recognition, how the appearance of sigma and auxiliary transcription factors is regulated temporally and spatially, which sets of genes are controlled by each factor and what kinds of feed-back mechanisms coordinate the appearance or activity of the factors with the course of sporogenesis. Specifically, we will" identify contact sites between a recognition helix for promoter "- 10" sequences in the sporulation sigma factor sigmaH and bases in cognate promoter, investigate the role of sigmaH in early sporulation gene expression, test the proposal that sigmaH governs the transcription of the gene for the sporulation sigma factor sigmaF, identify genes under the control of sigmaF and modify the promoter recognition specificity of sigmaF, study the roles of sigmaE, sigmaK and transcription factors SpoIIID, spoVP and GerE in cascade regulation of spore coat genes, investigate the mechanistic basis for a rearrangement in the mother-cell chromosome that generates the composite structural gene for the mother-cell sigma factor sigmaK, investigate the possible existence of a pro-protein precursor to sigmaK and test the hypothesis that the "morphological" coupling by the isolation of bypass mutations that permit coat gene expression in mutants blocked in forespore gene expression, and, finally, use immunoelectron microscopy to localize specific developmental proteins in spores and in sporulating cells. These goals address basic issues of temporal, spatial and morphological control of gene expression that are common to developmental systems of many kinds, including complex systems of norma and abnormal development in higher organisms.

我们研究计划的总体目标是了解时间和 内生孢子形成过程中基因表达的空间调控 革兰氏阳性细菌枯草芽孢杆菌并了解如何 孢子形成基因的程序化表达与 伴随孢子发生的形态事件。 中央 对这些问题的调查有五个发育特异性、RNA 聚合酶西格玛因子和一些辅助转录因子 控制孢子形成基因表达的程序。我们建议 研究西格玛因子如何介导启动子识别， 西格玛和辅助转录因子的出现受到调节 在时间和空间上，哪些基因组受每个因素控制 什么样的反馈机制可以协调外观或 因子的活性与孢子发生过程的关系。 具体来说，我们 将“识别启动子识别螺旋之间的接触位点”- 孢子形成因子 sigmaH 中的 10" 序列和同源碱基 启动子, 研究 sigmaH 在早期孢子形成基因中的作用 表达式，测试 sigmaH 控制转录的提议 孢子形成因子 sigmaF 的基因，确定以下基因 控制 sigmaF 并修改启动子识别特异性 sigmaF，研究sigmaE、sigmaK和转录因子的作用 SpoIIID、spoVP 和 GerE 在孢子外壳基因的级联调节中， 研究母细胞重排的机制基础 产生母细胞复合结构基因的染色体 sigma因子sigmaK，调查前蛋白的可能存在 sigmaK 的前身并检验“形态学”的假设 通过分离允许外壳基因的旁路突变进行耦合 前孢子基因表达受阻的突变体中的表达，最后， 使用免疫电子显微镜定位特定的发育蛋白 在孢子和产孢细胞中。 这些目标解决了以下基本问题 基因表达的时间、空间和形态控制 许多类型的发展系统所共有的，包括复杂的系统 高等生物的正常和异常发育。