Tuning of metabolic fluxes in Pseudomonas aeruginosa by the second messenger c-di-GMP

第二信使 c-di-GMP 调节铜绿假单胞菌的代谢通量

• 批准号: 423942285
• 负责人: Dr. Alexander Klotz
• 金额: --
• 依托单位: Biozentrum
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/423942285?language=en
• 关键词: Tuning; metabolic; fluxes; Pseudomonas; aeruginosa

Pseudomonas aeruginosa is an opportunistic human pathogen causing a wide array of life-threatening acute and chronic infections and has recently been listed as one of the highest priority infectious threats by the World Health Organization. With its highly versatile and tightly regulated metabolism, P. aeruginosa can adapt to various environmental conditions, infect a wide range of organisms and successfully dwell on different host tissues. However, little is known about the role of the central carbon metabolism and its complex regulation within the host. I have recently identified glyceraldehyde 3-phosphate dehydrogenase (GAPDH), a key enzyme of the central carbon metabolism, as a potential effector of the global bacterial second messenger c-di-GMP (cdG). P. aeruginosa possess three orthologs of GAPDH, GapA, GapB, and GapC. Preliminary experiments not only demonstrated that GapC binds cdG but also indicated that all three orthologs have specific roles in carbon metabolism. While GapA appears to be bi-functional, GapB and GapC only catalyze glycolytic and gluconeogenic reactions, respectively. This indicated that GapC and its potential regulation by cdG is at the center of carbon flux regulation in P. aeruginosa. Importantly, while the role of cdG in regulating important cellular processes like motility, surface adherence, or virulence is well established, its interference with bacterial metabolism is entirely unexplored.Here, I propose to study the cdG dependent regulation of GapC on the structural and biochemical level to unveil the atomic details of ligand interaction and its effect on catalysis. This information will provide the basis for the examination of the physiological role of GapC and its control by cdG during P. aeruginosa growth in vitro and eventually in surrogate host systems. Carbon flux analysis will be carried out in laboratory strains and in strains isolated from chronically infected patients under different growth conditions to clarify the role of cdG and of GapC. In addition, specific mutants and cellular markers will be developed to examine carbon flux control in vivo and at single cell level. These studies will address how carbon metabolism is adjusted by a global second messenger and by that provide detailed insight into the control of central metabolic processes in one of the most important human pathogens. The long-term goal is to use this information to assess important bacterial metabolic processes in the human patient.

铜绿假单胞菌（Pseudomonasaeruginosa）是一种机会性的人类病原体，其引起广泛的危及生命的急性和慢性感染，并且最近被世界卫生组织列为最高优先级的感染性威胁之一。凭借其高度通用和严格调节的代谢，铜绿假单胞菌可以适应各种环境条件，感染各种生物体并成功地驻留在不同的宿主组织上。然而，很少有人知道的作用，中央碳代谢及其复杂的调节在主机。我最近发现甘油醛3-磷酸脱氢酶（GAPDH），一个关键的酶的中心碳代谢，作为一个潜在的效应器的全球细菌第二信使c-di-GMP（cdG）。铜绿假单胞菌具有GAPDH的三种直系同源物，GapA、GapB和GapC。初步实验不仅证明GapC结合cdG，而且还表明所有三个直系同源物在碳代谢中具有特定的作用。虽然GapA似乎是双功能的，但GapB和GapC仅分别催化糖酵解和产酶反应。这表明GapC及其通过cdG的潜在调节是铜绿假单胞菌碳通量调节的中心。重要的是，虽然cdG在调节重要的细胞过程中的作用，如运动，表面粘附，或毒力是公认的，其干扰细菌代谢是完全unexplored. There，我建议研究的cdG依赖调节GapC的结构和生物化学水平上揭示的原子细节的配体相互作用及其对催化的影响。这一信息将为研究GapC的生理作用及其在铜绿假单胞菌体外生长和最终在替代宿主系统中的cdG控制提供基础。将在不同生长条件下对实验室菌株和从慢性感染患者分离的菌株进行碳通量分析，以阐明cdG和GapC的作用。此外，将开发特定的突变体和细胞标记物来检查体内和单细胞水平的碳通量控制。这些研究将解决全球第二信使如何调节碳代谢，并通过这一研究提供对最重要的人类病原体之一的中央代谢过程控制的详细见解。长期目标是利用这些信息来评估人类患者中重要的细菌代谢过程。