Isolation of Early Sporulation Genes

早期孢子形成基因的分离

• 批准号: 7904474
• 负责人: ABRAHAM Lincoln SONENSHEIN
• 金额: $ 4.84万
• 依托单位: TUFTS UNIVERSITY BOSTON
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-31 至 2011-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7904474
• 关键词: Address; Affect; Amino Acids; Anti-Infective Agents; Area; Bacillus subtilis; Bacteria; Bacterial Genes; Binding; Biochemical; Carbon; Cell physiology; Cells; Collaborations; Complex; DNA; Development; Developmental Process; Elements; Environment; Enzymes; Funding; Future; Gap Junctions; Gene Expression; Gene Expression Regulation; Genes; Genetic; Genetic Transcription; Goals; Gram-Negative Bacteria; Gram-Positive Bacteria; Growth; Guanosine Triphosphate; Homologous Gene; Isoleucine; Laboratory culture; Lead; Leucine; Life; Ligand Binding; Ligands; Link; Logic; Mediating; Metabolic; Metabolic Pathway; Metabolism; Microarray Analysis; Microbial Biofilms; Molecular; Molecular Models; Mutation; Nutrient; Nutritional; Operon; Organism; Outcome; Phase; Physiological; Play; Property; Proteins; Pyruvate; Pyruvates; Regulation; Regulator Genes; Regulon; Research; Resources; Role; Signal Transduction; Staphylococcus aureus; Structure; System; Toxin; Valine; Virulence; Virulence Factors; Work; alpha ketoglutarate; analog; capsule; deprivation; insight; interest; leucine-responsive regulatory protein; molecular modeling; mutant; nitrogen metabolism; novel; pathogen; public health relevance; response; transcription factor

DESCRIPTION (provided by applicant): Despite many years of research and despite great advances in our understanding of operon-specific regulation, we still do not have a clear view of how bacteria sense general nutrient insufficiency and how they integrate the multiple nutritional signals that they are constantly exposed to. These mechanisms are responsible for the remarkable ability of bacteria to adapt to constantly changing environments and influence the interactions, both symbiotic and parasitic, of bacteria with host cells and host organisms. In gram-negative bacteria, the leucine-responsive protein (Lrp) plays an important role in governing the expression of a wide variety of cellular functions in response to deprivation of leucine or certain other amino acids. In gram-positive bacteria, such as Bacillus subtilis, CodY protein seems to play an analogous role, even though CodY and Lrp are unrelated proteins. Prior work revealed that CodY has the unusual property of responding to two different, critical metabolites, GTP and isoleucine (or valine). CodY represses, directly or indirectly, the expression of hundreds of genes, most of which encode proteins that allow cells to adapt to limited nutritional resources. In collaboration with Dr. A. J. Wilkinson, the structure of CodY has been determined in its ligand-bound and ligand-free states, leading to a molecular model for the mechanism by which interaction with its ligands makes CodY an effective regulator. CodY has also been found to act as a positive regulator of genes of central metabolism. As a result, the CodY regulon overlaps in interesting and complex ways with other globally controlled regulons. Most CodY homologs are found in low G+C gram-positive bacteria, including major pathogens. Preliminary results indicate that CodY in such pathogens contributes in important ways to the control of virulence gene expression. The goals of this proposal are to determine how B. subtilis CodY structure and function intersect, to reveal the overall physiological role of CodY, to assess the effects of constitutive CodY activity, and to extend our understanding of the function of CodY by determining its role in the growth, adaptation and virulence of Staphylococcus aureus. PUBLIC HEALTH RELEVANCE: The CodY protein has been found to regulate the expression of many bacterial genes, including genes that encode toxins and other virulence factors. This proposal seeks to understand the physiological role of CodY in the life of the bacterium and to uncover the molecular mechanism by which CodY represses or activates gene expression.

描述（由申请人提供）：尽管多年的研究，尽管我们对操纵子特异性调控的理解取得了很大进展，但我们仍然不清楚细菌是如何感知一般营养不足的，以及它们是如何整合它们不断接触的多种营养信号的。这些机制是细菌适应不断变化的环境和影响细菌与宿主细胞和宿主生物的共生和寄生相互作用的显著能力的原因。在革兰氏阴性菌中，亮氨酸反应蛋白（leucine-responsive protein, Lrp）在控制多种细胞功能的表达中起着重要作用，以响应亮氨酸或某些其他氨基酸的剥夺。在革兰氏阳性菌（如枯草芽孢杆菌）中，CodY蛋白似乎起着类似的作用，尽管CodY和Lrp是不相关的蛋白。先前的研究表明，CodY具有不同寻常的特性，对两种不同的关键代谢物，GTP和异亮氨酸（或缬氨酸）有反应。CodY直接或间接地抑制数百种基因的表达，其中大多数基因编码蛋白质，使细胞能够适应有限的营养资源。与a . J. Wilkinson博士合作，确定了CodY在配体结合和无配体状态下的结构，从而建立了与配体相互作用使CodY成为有效调节剂的机制的分子模型。CodY还被发现是中枢代谢基因的积极调节因子。因此，CodY规则以有趣而复杂的方式与其他全局控制的规则重叠。大多数CodY同源物存在于低G+C革兰氏阳性细菌中，包括主要病原体。初步结果表明，这些病原体中的CodY在控制毒力基因表达方面起着重要作用。本课题的目标是通过确定枯草芽孢杆菌CodY在金黄色葡萄球菌生长、适应和毒力中的作用，确定CodY的结构和功能是如何交叉的，揭示CodY的整体生理作用，评估组成型CodY活性的影响，扩展我们对CodY功能的认识。公共卫生相关性：已发现CodY蛋白调节许多细菌基因的表达，包括编码毒素和其他毒力因子的基因。本研究旨在了解CodY在细菌生命中的生理作用，并揭示CodY抑制或激活基因表达的分子机制。