ROLE OF ALGB AND P AERUGINOSA ALGINATE GENE EXPRESSION

ALGB 和铜绿藻藻酸盐基因表达的作用

• 批准号: 2517241
• 负责人: Daniel J Wozniak
• 金额: $ 10.63万
• 依托单位: WAKE FOREST UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-09-01 至 1999-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2517241
• 关键词: DNA binding protein; DNA footprinting; Escherichia coli; Pseudomonas aeruginosa; alginates; bacterial polysaccharides; carbohydrate biosynthesis; cystic fibrosis; gel mobility shift assay; gene deletion mutation; gene expression; gene interaction; genetic regulation; genetic strain; library; molecular cloning; molecular pathology; nucleic acid sequence; operon; plasmids; polymerase chain reaction; transcription factor

Most patients with the genetic disease cystic fibrosis (CF) become colonized and infected with mucoid strains of Pseudomonas aeruginosa. These strains are mucoid due to the overproduction of a polysaccharide called alginate, which plays a role in the pathogenesis of P. aeruginosa in the lungs of CF patients. This viscous polymer impairs lung function and makes it almost impossible to eradicate the organism from the CF respiratory tract, making P. aeruginosa infections the major cause of death in CF patients. Therefore, the long-term objective of this proposal is to understand the molecular basis for the overproduction of alginate by strains of P. aeruginosa which infect cystic fibrosis patients. The alginate biosynthetic genes are controlled by a complex, multigenic regulatory network. The research proposed here will focus on the role of a AlgB, a key alginate regulatory protein, in the control of alginate biosynthesis. In order to understand this, two critical questions which constitute the aims of this proposal will be addressed. The first goal is to identify the molecular targets of AlgB. This will be accomplished by DNA binding studies, a deletion analysis of algD, genetic characterization of algB suppressor strains, and the use of transcriptional fusions to isolate genes under AlgB control. Another aim of this proposal is to determine the mechanism of algB transcriptional activation. In particular, the roles of the alginate regulator AlgT and the DNA binding/bending protein integration host factor in algB expression will be investigated. The algB promoter(s) responsive to these proteins will be characterized by ribonuclease protection mapping and primerextension analysis. The combination of biochemical and genetic approaches utilized in these studies should provide insights into the complex regulation of this important virulence factor with the ultimate goal of an improved quality of lite for CF patients colonized with alginate-producing strains of P. aeruginosa.

大多数患有遗传性疾病囊性纤维化（CF）的患者