Control of fimbrial gene expression in Pseudomonas aeruginosa

铜绿假单胞菌菌毛基因表达的控制

基本信息

批准号：
9189673
负责人：
SIMON L DOVE
金额：
$ 44.25万
依托单位：
BOSTON CHILDREN'S HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-01-01 至 2018-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9189673
关键词：
Acetylation Acetylesterase Adenine Nucleotides Aerobic Anaerobic Bacteria Anaerobiosis Antibiotic Resistance Antibiotics Antibodies Bacteria Binding Proteins Cells Cessation of life Chronic Columbidae Communities Complex Cystic Fibrosis DNA-Binding Proteins Environment Exhibits Family Family member Gene Cluster Gene Expression Genes Glycine decarboxylase Growth Histones Human Hydrolase Immune response Immune system Infection Intercistronic Region Lung Mediating Microbial Biofilms Morbidity - disease rate Morphology Names Nosocomial pneumonia Organism Orthologous Gene Phase Physiological Play Polymers Population Prevention Protein Acetylation Proteins Pseudomonas Pseudomonas aeruginosa Pulmonary Fibrosis RNA Rattus Regulator Genes Resistance Respiratory Failure Role Structure Surface System Testing Variant Ventilator Virulence Work cystic fibrosis patients family structure fitness insight member microbial mortality new therapeutic target novel outcome forecast pathogen pathogenic bacteria protein structure public health relevance

项目摘要

DESCRIPTION (provided by applicant): Pseudomonas aeruginosa is an important opportunistic pathogen of humans that is notorious for being the principal cause of morbidity and mortality in Cystic Fibrosis (CF) patients. In the chronically infected CF lung the organism persists as a biofilm-a surface attached community of bacteria encased in a polymeric matrix. This biofilm mode of growth augments the resistance of P. aeruginosa to antibiotics and facilitates evasion of the host immune response. Prominent amongst those genes that play an important role in biofilm formation in P. aeruginosa are the cupA genes, which encode components of a fimbrial structure that facilitates surface- attachment and host colonization. We have identified three genes (cgrABC), whose products are required for phase-variable (i.e. reversible ON/OFF) expression of the cupA fimbrial gene cluster. None of the products of the cgr genes resembles any classical positive regulator of gene expression; cgrA is predicted to encode a member of the adenine nucleotide �-hydrolase superfamily, whereas cgrB encodes a putative acetylase, and cgrC encodes a protein with homology to the ParB family of DNA-binding proteins. In Aim 1 we propose to determine how the Cgr proteins exert their control. We will explicitly test the hypotheses that CgrB functions by acetylating CgrA and that phase-variable expression of the cupA genes is mediated by changes in the acetylation state of CgrA. Because many other pathogenic bacteria contain cgr orthologs, we expect that the relevance of our studies will extend beyond P. aeruginosa. Recently, we identified PrrA, a novel small regulatory RNA (sRNA), as an additional positive regulator of the cupA genes. Preliminary evidence suggests that PrrA exerts its effects on cupA expression by antagonizing the silencing effects of a member of the H-NS family of histone-like nucleoid structuring proteins. In Aim 2 we propose to determine how PrrA functions as an anti-silencer. We anticipate that the proposed studies will enable us to (i) define roles for protein acetylation and an sRNA in the control of phase-variable virulence gene expression in P. aeruginosa and (ii) determine precisely how the local and global regulatory networks that influence cupA gene expression become effectively integrated.

描述（由申请人提供）：铜绿假单胞菌是人类的重要机会病原体，由于成为囊性纤维化（CF）患者发病率和死亡率的主要原因而臭名昭著。在慢性感染的CF肺中，生物体作为一个生物膜-A表面连接的细菌群落包裹在聚合物基质中。这种生长模式增强了铜绿假单胞菌对抗生素的耐药性，并促进了宿主免疫反应的进化。在铜绿假单胞菌中生物膜形成中起重要作用的那些基因中，CUPA基因是cupa基因的，该基因编码了纤维化结构的成分，可促进表面附着和宿主定植。我们已经确定了三个基因（CGRABC），它们的产物是库布尔纤维基因簇的相变（即可逆的/OFF）表达所必需的。 CGR基因的产物都不类似于基因表达的任何经典阳性调节剂。预计CGRA可以编码腺嘌呤核丁物 - 水解酶超家族的成员，而CGRB编码假定的乙酰基酶，CGRC编码与DNA结合蛋白的PARB家族具有同源性的蛋白质。在AIM 1中，我们建议确定CGR蛋白如何施加其控制。我们将明确测试CGRB通过 CGRA和CUPA基因的相变表达是由CGRA乙酰化状态的变化介导的。由于许多其他病原细菌含有CGR直系同源物，因此我们期望我们的研究相关性将延伸到铜绿假单胞菌之外。最近，我们确定了一种新型的小调节RNA（SRNA），它是CUPA基因的附加阳性调节剂。初步证据表明，PRRA通过对抗组蛋白样核苷结构蛋白的H-NS家族的沉默效应来使其对CUPA表达的影响到期。在AIM 2中，我们建议确定PRRA如何充当反偿让者。我们预计拟议的研究将使我们能够（i）定义蛋白质乙酰化的作用，而SRNA在铜绿假单胞菌中控制相位可变病毒基因表达中的作用，并且（ii）确切地确定影响CUPA基因表达的局部和全球调节网络如何有效地整合。