Mechanism of CsrA-Mediated Global Control

CsrA介导的全局控制机制

• 批准号: 7859596
• 负责人: PAUL L BABITZKE
• 金额: $ 39.48万
• 依托单位: UNIVERSITY OF FLORIDA
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-16 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7859596
• 关键词: Affect; Affinity; Animals; Attention; Bacteria; Bacterial Infections; Bacterial Physiology; Behavior; Binding; Binding Sites; Biochemical; Bioinformatics; Biological Assay; Biological Process; Carbon; Cell membrane; Cells; Complementary DNA; Complex; Consensus; Development; Escherichia coli; Eubacterium; Functional RNA; Gene Expression; Genes; Genetic; Genetic Transcription; Genomics; Goals; Growth; Half-Life; Homeostasis; Homologous Gene; In Vitro; Investigation; Life; Mediating; Membrane; Messenger RNA; Metabolism; Microbial Biofilms; Modeling; Molecular; Molecular Genetics; N-terminal; Organism; Pathogenesis; Peptide Transport; Phase; Physiological; Physiology; Plants; Post-Transcriptional Regulation; Process; Processed Genes; Protein Binding; Protein Biosynthesis; Proteins; RNA; RNA Binding; RNA-Binding Proteins; Regulation; Regulator Genes; Regulon; Repression; Ribosomes; Site; Specificity; Structure; System; Tertiary Protein Structure; Transcript; Translation Initiation; Translations; Virulence Factors; X-Ray Crystallography; base; bis(3' ,5' )-cyclic diguanylic acid; cell motility; dimer; endonuclease; high throughput analysis; insight; mRNA Stability; mRNA Transcript Degradation; melting; novel; novel strategies; novel therapeutic intervention; nuclease; pathogen; reconstitution; research study; ribonuclease E; stem; stoichiometry

DESCRIPTION (provided by applicant): Insight into post-transcriptional regulatory mechanisms will be sought through the study of a novel paradigm in global regulation, the carbon storage regulatory (Csr) system of Escherichia coli. Csr includes CsrA, an RNA binding protein that regulates translation and/or modulates the stability of target mRNAs. CsrB and CsrC are non-coding regulatory RNAs that antagonize CsrA by sequestering this protein and CsrD is a protein that specifically targets CsrB and CsrC for degradation by RNase E. In E. coli, CsrA affects metabolism, physiology, motility and multicellular behavior on a broad scale, repressing certain genes expressed during the transition from exponential to stationary phase growth and activating various genes expressed during exponential phase. CsrA homologues are widely distributed among eubacteria and regulate the expression of virulence factors in both plant and animal pathogens. Thus, the proposed studies will also provide fundamental understanding of the regulation of bacterial physiology and pathogenesis, and may suggest novel therapeutic approaches for bacterial infections. The specifc aims of this proposal are: 1) Elucidate the molecular mechanisms by which CsrA activates or inhibits gene expression. This aim will include an analysis of CsrA-mediated autoregulation, as well as an investigation into the factors that influence the stability of CsrA target transcripts. 2) Establish the Csr global regulon using a combination of bioinformatic, genomic, molecular genetic and biochemical approaches. 3) Stoichiometric and structural characterization of CsrA-RNA complexes. This aim will include NMR structural determination of a model CsrA target RNA, as well as the structure of CsrA-RNA complexes by X-ray crystallography. 4) Elucidate the molecular mechanism of CsrD action. We will conduct experiments to elucidate the mechanism by which CsrD specifically targets CsrB and CsrC for degradation by RNase E. The long-range objectives of these studies are to fully understand the regulatory components, genetic circuitry, molecular mechanisms, and biological functions of the Csr system. Insight into post-transcriptional regulatory mechanisms will be sought through the study of a novel paradigm in global genetic regulation, the carbon storage regulatory (Csr) system of Escherichia coli. Csr controls bacterial metabolism, physiology, motility and biofilm development on a broad scale, and regulates the expression of virulence factors in both plant and animal pathogens. Thus, the proposed studies will provide fundamental understanding of the regulation of bacterial physiology and pathogenesis, and may suggest novel therapeutic approaches for bacterial infections.

描述（由申请人提供）：将通过研究全球调节的新范式，即大肠杆菌的碳储存调节（Csr）系统，寻求对转录后调节机制的深入了解。 Csr 包括 CsrA，一种调节靶 mRNA 翻译和/或稳定性的 RNA 结合蛋白。 CsrB 和 CsrC 是非编码调节 RNA，通过隔离 CsrA 蛋白来拮抗 CsrA，而 CsrD 是一种专门针对 CsrB 和 CsrC 并被 RNase E 降解的蛋白。在大肠杆菌中，CsrA 广泛影响新陈代谢、生理学、运动性和多细胞行为，抑制从指数到稳定转变期间表达的某些基因 生长期并激活指数生长期表达的各种基因。 CsrA 同源物广泛分布于真细菌中，调节植物和动物病原体中毒力因子的表达。因此，拟议的研究还将提供对细菌生理学和发病机制调节的基本了解，并可能提出细菌感染的新治疗方法。该提案的具体目标是：1）阐明CsrA激活或抑制基因表达的分子机制。这一目标将包括对 CsrA 介导的自动调节的分析，以及对影响 CsrA 靶转录本稳定性的因素的调查。 2) 结合生物信息学、基因组学、分子遗传学和生化方法建立 Csr 全局调节子。 3) CsrA-RNA 复合物的化学计量和结构表征。该目标将包括通过 NMR 确定 CsrA 靶标 RNA 模型的结构，以及通过 X 射线晶体学确定 CsrA-RNA 复合物的结构。 4）阐明CsrD作用的分子机制。我们将通过实验来阐明CsrD特异性靶向CsrB和CsrC并被RNase E降解的机制。这些研究的长期目标是充分了解Csr系统的调控成分、遗传回路、分子机制和生物学功能。通过研究全球基因调控的新范式，即大肠杆菌的碳储存调控（Csr）系统，将寻求对转录后调控机制的深入了解。 Csr 在广泛范围内控制细菌代谢、生理、运动和生物膜发育，并调节植物和动物病原体中毒力因子的表达。因此，拟议的研究将为细菌生理学和发病机制的调节提供基本了解，并可能提出细菌感染的新治疗方法。