Regulatory network of a conserved polar factor in Sinorhizobium meliloti

苜蓿中华根瘤菌保守极性因子的调控网络

基本信息

批准号：
8724515
负责人：
Joseph Chiung-Chu Chen
金额：
$ 11.44万
依托单位：
SAN FRANCISCO STATE 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：
2012-08-01 至 2016-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8724515
关键词：
Affect Alfalfa Alleles Alphaproteobacteria Anabolism Anti-Bacterial Agents Antibiotic Therapy Architecture Area Bacteria Bacterial Proteins Bartonella Biological Assay Brucella Caulobacter crescentus Cell Polarity Cell division Cells Detergents Development Development Polarity Drug Targeting Ensure Event Exhibits Fabaceae Flagella Gene Expression Regulation Genes Genetic Glean Homologous Gene Infection Investigation Knowledge Life Location Measures Melilotus Microarray Analysis Microbe Microscopy Modeling Molecular Morphology Nitrogen Organelles Organism Orthologous Gene Pattern Phenotype Physiological Physiology Pilum Plant Roots Plants Play Positioning Attribute Process Production Proteins Proteobacteria Recruitment Activity Research Resistance Role Signal Pathway Sinorhizobium meliloti Site Stress Structural Protein Symbiosis System Time Transcription Coactivator Work anthropogenesis antimicrobial assault cell envelope cell motility coping mechanism daughter cell environmental change fitness genetic regulatory protein improved insight member microbial mutant null mutation pathogen programs protein-histidine kinase succinoglycan

项目摘要

DESCRIPTION (provided by applicant): Despite their minute size, bacterial cells exhibit an extensive degree of dynamic, programmed organization at the subcellular and molecular levels. A plethora of dedicated cellular components localize to and assemble at appropriate positions and times to ensure fitness in ever-changing environmental conditions, including those encountered when intruding into other organisms. The proposed project seeks to clarify how the functional network of a conserved polar factor controls multiple cell envelope-associated activities in the alpha- proteobacterium Sinorhizobium meliloti, which infects the roots of legume plants to form symbiosis. Specifically, the PodJ1 protein (SMc02230) localizes to the newer cell pole and deletion of the podJ1 gene interferes with flagellar motility, exopolysaccharide production, cell division, and resistance against detergents and osmotic stress. Microarray analysis indicated that podJ1 affects the expression of 129 genes, the majority of which correlate with phenotypes observed in the podJ1 mutant. In the absence of PodJ1, the gene whose expression was most severely reduced is tacA (SMc04011), which encodes a conserved transcriptional activator. In addition, suppressor analysis led to the identification of nine factos that interact genetically with podJ1. Null mutations in two of the suppressors (SMc00067 and SMc03872) appear to abolish synthesis of succinoglycan, an exopolysaccharide critical for symbiosis. Another suppressor encodes the conserved histidine kinase PleC (SMc02369). The proposed research will (1) examine the roles of SMc00067 and SMc03872 in succinoglycan production, (2) investigate the regulatory activities of the essential histidine kinase PleC, and () determine the function of the TacA transcriptional activator. How these factors contribute to different aspects of S. meliloti physiology will be assessed using multiple approaches, including genetic and microarray analyses, phenotypic assays, and microscopy. Results from the investigation will help elucidate regulatory circuits that appear to be iterated in the alpha-proteobacteria group, which includes pathogens such as Brucella and Bartonella. The insights generated will provide better understanding of the spatial and temporal coordination that occurs during infection.

描述（由申请人提供）：尽管它们的大小很小，但细菌细胞在亚细胞和分子水平上表现出广泛的动态，程序性组织。有很多专用的细胞成分定位于适当的位置和时间组装，以确保在不断变化的环境条件下（包括侵入其他生物体时遇到的环境条件）的适应性。拟议的项目旨在阐明保守极性因子的功能网络如何控制梅洛蒂（Sinorhizobium sinorhizobium sinorhizobium Meliloti）中与细胞包膜相关的多个相关活性，该活性如何感染豆类植物的根以形成共生。具体而言，PODJ1蛋白（SMC02230）定位于较新的细胞极，PODJ1基因的缺失会干扰鞭毛运动，外多糖产生，细胞分裂，对洗涤剂和渗透胁迫的抗性。微阵列分析表明，PODJ1影响了129个基因的表达，其中大多数与在PODJ1突变体中观察到的表型相关。在没有PODJ1的情况下，表达最严重降低的基因是TACA（SMC04011），该基因编码保守的转录激活剂。此外，抑制剂分析导致鉴定了与PODJ1遗传相互作用的九种事实。两个抑制剂（SMC00067和SMC03872）中的无效突变似乎废除了琥珀酸酯的合成，这是一种对共生至关重要的外多糖。另一种抑制剂编码保守的组氨酸激酶PLEC（SMC02369）。拟议的研究将（1）检查SMC00067和SMC03872在琥珀糖生产中的作用，（2）研究必需的组氨酸激酶PLEC的调节活性，以及（）确定TACA转录激活剂的功能。这些因素如何使用多种方法进行评估，包括遗传和微阵列分析，表型测定和显微镜，如何评估梅洛蒂链球菌生理的不同方面。调查的结果将有助于阐明在α-甲状腺细菌组中似乎迭代的调节回路，其中包括布鲁氏菌和巴托拉等病原体。产生的见解将更好地理解感染过程中发生的空间和时间协调。