Genetic control of denitrification in Pseudomonas aeruginosa

铜绿假单胞菌反硝化作用的遗传控制

• 批准号: 7739427
• 负责人: Valley J. Stewart
• 金额: $ 7.65万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-06-19 至 2011-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7739427
• 关键词: Applications Grants; Area; Arginine; Binding; Binding Sites; Cystic Fibrosis; DNA; Discrimination; Energy Metabolism; Enzymes; Fermentation; Future; Gene Expression; Genetic; Genetic Transcription; Goals; Grant; Growth; Individual; Infection; Knowledge; Laboratories; LacZ Genes; Lung; Measures; Metabolism; Monitor; Morbidity - disease rate; Mucous body substance; Nitric Oxide; Nitrites; Operon; Organism; Oxygen; Pathogenesis; Pattern; Physiological; Primer Extension; Proteins; Pseudomonas aeruginosa; Publishing; Race; Regulation; Research Design; Resources; Respiration; Role; Site; Specificity; Test Result; Testing; Time; Transcription Coactivator; Transcription Initiation Site; base; denitrification; design; member; mortality; mutant; nitrous oxide reductase; promoter; public health relevance; research study; response

DESCRIPTION (provided by applicant): Pseudomonas aeruginosa infection is the major cause of morbidity and mortality in cystic fibrosis. The organism persists in airways in large part through its ability to generate energy under the oxygen-limited conditions that define the dehydrated mucus in diseased lungs. This small-grant project will advance knowledge of transcription regulatory mechanisms that control energy metabolism. The Anr and Dnr proteins, members of the Crp-Fnr superfamily of transcription activators, are thought to differentially regulate expression of genes whose products are required for microaerobic or anaerobic respiration. The mechanism for this differential regulation is unclear. One hypothesis is that distinct specificity determinants for Anr and Dnr binding serve to direct each regulator to the appropriate operons. An alternative hypothesis is that Anr and Dnr have similar binding specificity determinants, but that these regulators function under different physiological conditions. I propose to distinguish between these two hypotheses by comparing expression from two representative transcription control regions. In previous studies by others, the arcD operon encoding arginine fermentation enzymes has been suggested to be regulated exclusively by Anr, whereas the nosR operon encoding nitrous oxide reductase has been suggested to be regulated exclusively by Dnr. Experiments will monitor arcD- and nosR-directed transcription under different growth conditions, in anr and dnr null mutants, and in strains in which anr and dnr are expressed constitutively. Results from these tests will provide the basis for further analysis of Anr and Dnr control of microaerobic and anaerobic respiration. If the first hypothesis is correct, the determinants for differential binding specificity will be identified. If the second hypothesis is correct, specific roles for Anr- and Dnr- regulated gene expression will be examined further in order to document specific responses to physiological parameters such as oxygen limitation and nitric oxide. PUBLIC HEALTH RELEVANCE: Pseudomonas aeruginosa infection is the major cause of morbidity and mortality in cystic fibrosis. The organism persists in airways in large part through its ability to generate energy under the oxygen-limited conditions that define the dehydrated mucus in diseased lungs. This small-grant project will advance knowledge of transcription regulatory mechanisms that control energy metabolism.

描述（由申请人提供）：铜绿假单胞菌感染是囊性纤维化发病率和死亡率的主要原因。该生物在很大程度上始终在氧气限制的疾病下产生能量的能力，从而在气道中持续存在，从而定义了患病肺中脱水的粘液。这个小赠款项目将促进控制能量代谢的转录调节机制的知识。 ANR和DNR蛋白是转录激活剂的CRP-FNR超家族的成员，被认为是差异地调节其产物的基因表达，其产物需要微恐惧或厌氧呼吸。这种差异调节的机制尚不清楚。一个假设是，ANR和DNR结合的不同特异性决定因素可以将每个调节剂引导到适当的操纵子。另一种假设是ANR和DNR具有相似的结合特异性决定因素，但是这些调节剂在不同的生理条件下起作用。我建议通过比较来自两个代表性转录控制区的表达来区分这两个假设。在其他人的先前研究中，编码精氨酸发酵酶的ARCD操纵子已被ANR专门调节，而编码一氧化氧化物还原酶的NOSR操纵子已被DNR仅由DNR调节。实验将在不同的生长条件下，ANR和DNR无效突变体以及ANR和DNR的菌株中监测ARCD和NOSR指导的转录。这些测试的结果将为进一步分析微恐惧和厌氧呼吸的ANR和DNR控制提供基础。如果第一个假设是正确的，则将确定差异结合特异性的决定因素。如果第二个假设是正确的，则将进一步检查ANR和DNR调控基因表达的特定作用，以记录对生理参数（例如氧限制和一氧化物）的特定反应。公共卫生相关性：铜绿假单胞菌感染是囊性纤维化中发病率和死亡率的主要原因。该生物在很大程度上始终在氧气限制的疾病下产生能量的能力，从而在气道中持续存在，从而定义了患病肺中脱水的粘液。这个小赠款项目将促进控制能量代谢的转录调节机制的知识。