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Regulatory Circuits Controlling Development of Dormant Microbial Cysts

控制休眠微生物囊肿发育的调节电路

基本信息

批准号：
8789366
负责人：
CARL Eugene BAUER
金额：
$ 25.42万
依托单位：
TRUSTEES OF INDIANA UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-02-01 至 2017-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8789366
关键词：
Address Animal Model Antibiotics Azospirillum Azospirillum brasilense Bacteria Binding Biochemical Biological Assay Biological Models Burkholderia mallei Caring Catalytic Domain Cell Line Cells ChIP-seq Code Complement Complex Consensus Sequence Control Locus Cyclic AMP Cyclic GMP Cyst DNA Binding Data Delftia acidovorans Desiccation Development Enzymes Escherichia coli Eukaryota Excretory function Gene Expression Gene Expression Profile Genes Genetic Genetic Transcription Goals Gram-Negative Bacteria Growth Inhibitors Guanylate Cyclase Homologous Gene Hybrids In Vitro Individual Interphase Cell Light Measures Modeling Molecular Genetics Morphogenesis Muscle Contraction Mutation Nitrogen Pathway interactions Physiology Plants Platelet aggregation Production Proteobacteria RNA Regulation Regulon Resistance Rest Rhizobium leguminosarum Rhodospirillum centenum Signal Transduction Signal Transduction Pathway Sinorhizobium Sinorhizobium fredii Sinorhizobium meliloti Starvation Stress Structure Techniques Technology Testing Time Variant Vision X-Ray Crystallography bacterial cyst cGMP production cell type genetic analysis genome sequencing genome-wide in vivo microbial mutant novel pathogen protein-histidine kinase reconstitution response transcription factor transcriptome sequencing yeast two hybrid system

项目摘要

DESCRIPTION (provided by applicant): This proposal is centered on genetic and biochemical characterization of regulatory factors that control development of metabolically quiescent cysts in gram-negative bacteria. Numerous beneficial bacteria that fix nitrogen for plants, as well as harmful bacterial pathogens, are capable of synthesizing cysts. Cysts are metabolically dormant resting cells that are extremely resistant to desiccation as well as to growth inhibitors such as to antibiotics. This study analyzes cyst formation in the gram-negative model organism R. centenum for which numerous cyst developmental regulatory mutants have been isolated. One class of mutants dramatically overproduces cysts while a second class of mutants dramatically inhibits cyst formation. Molecular genetic analysis of mutant cell lines led to a surprising discovery that regulation of cyst formation involved production and excretion of cGMP. cGMP is a well known messenger in eukaryotes where it is involved in vision, muscle contraction, platelet aggregation, and development. However, its involvement in bacteria has until now been quite controversial. Our recent definitive studies have unequivocally demonstrated the involvement of cGMP in R. centenum cyst development and has implicated cGMP production in many other important bacterial species such as Azospirillum brasilense, Rhizobium leguminosarum, Mesorhizobium loti, Sinorhizobium medicae, Sinorhizobium meliloti, Sinorhizobium fredii, Delftia acidovorans (Comamonas acidovorans), Burkholderia mallei (Pseudomonas mallei)). Biochemical characterization of cGMP production, and its involvement in bacterial signal transduction, is a major goal of this proposal. We have also isolated numerous additional cyst developmental regulatory mutations that contain genetic disruptions in a variety of bacterial signal transduction components and in various transcription factors. Changes in genome wide gene expression will be undertaken with each of these mutants cell lines in order to develop detailed models of the regulatory circuits that are involved in controlling bacterial cyst formation.

描述（由申请人提供）：该提案的重点是控制革兰氏阴性细菌中代谢静止包囊发育的调节因子的遗传和生化特征。许多为植物固氮的有益细菌以及有害的细菌病原体都能够合成包囊。囊肿是代谢休眠的休眠细胞，对干燥以及抗生素等生长抑制剂具有极强的抵抗力。本研究分析了革兰氏阴性模式生物 R. centenum 中的包囊形成，已分离出许多包囊发育调节突变体。一类突变体显着过量产生包囊，而第二类突变体显着抑制包囊形成。对突变细胞系的分子遗传学分析得出了一个令人惊讶的发现，即囊肿形成的调节涉及 cGMP 的产生和排泄。 cGMP 是真核生物中众所周知的信使，参与视觉、肌肉收缩、血小板聚集和发育。然而，迄今为止，它与细菌的关系仍存在很大争议。我们最近的权威研究明确证明了 cGMP 参与了百年根瘤菌包囊的发育，并暗示了许多其他重要细菌物种的 cGMP 产生，如巴西固氮螺菌、豆根瘤菌、中索根瘤菌、Medicahizobium medicae、苜蓿中华根瘤菌、弗雷中华根瘤菌、代尔夫特中华根瘤菌食酸丛毛单胞菌 (Comamonasacidovorans)、鼻疽伯克霍尔德氏菌 (Pseudomonas mallei))。 cGMP 生产的生化特征及其在细菌信号转导中的参与是该提案的主要目标。我们还分离出许多额外的囊肿发育调节突变，这些突变包含各种细菌信号转导成分和各种转录因子的遗传破坏。将对这些突变细胞系中的每一个进行全基因组基因表达的改变，以便开发参与控制细菌包囊形成的调节回路的详细模型。