Regulating Microbial Biofilm Formation: A Novel Prokaryotic Multi-protein Complex

调节微生物生物膜的形成：一种新型原核多蛋白复合物

• 批准号: 7134699
• 负责人: JEFFREY L URBAUER
• 金额: $ 22.13万
• 依托单位: UNIVERSITY OF GEORGIA
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-06-01 至 2008-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7134699
• 关键词: Pseudomonas aeruginosa; biofilm; cystic fibrosis; lung; proteins

DESCRIPTION (provided by applicant): The long term goals of the research are to identify and understand the details of the elaborate regulatory mechanisms utilized by Pseudomonas aeruginosa that result in biofilm formation and chronic infections of compromised individuals. Pseudomonas aeruginosa is the quintessential opportunistic pathogen. Chronic Pseudomonas aeruginosa infections of the lung are the most common cause of death in cystic fibrosis patients, underscoring the notoriety of Pseudomonas aeruginosa as a pathogen. There are many keys to the ability of this bacterium to colonize and survive in environments such as the cystic fibrosis lung and to thwart antibiotic regimes and circumvent the body's immune responses. These include the ability to form biofilms, to produce the exomucopolysaccharide alginate - a natural barrier and virulence factor, the ability to act as a community to coordinate biological responses via multiple quorum sensing systems, and the ability to sense and adapt to conditions of high oxidative stress, iron limitation, and available carbon sources. Not surprisingly, these attributes are tightly intertwined, and together reflect the complexity and elegance of the regulatory network in Pseudomonas aeruginosa. We have discovered a novel multi-protein complex in Pseudomonas aeruginosa that includes proteins integral to quorum sensing, alginate biosynthesis regulation, the oxidative stress response and the response to environmental iron and carbon, including the novel protein AlgH whose function is not understood. Based on the identities of the proteins in the complex, and based on fact that these responses are integral to biofilm formation and colonization and survival in the cystic fibrosis lung, it functions to integrate the responses to a variety of key biological signals and is essential for survival in the cystic fibrosis lung. Furthermore, because these systems (the quorum sensing system(s), the alginate biosynthesis regulatory system, etc.) are good targets for controlling Pseudomonas aeruginosa infections, targeting this novel protein complex pharmaceutically should be quite advantageous as multiple systems will simultaneously be disrupted. Our overall hypothesis is that the intricate regulatory and adaptive mechanisms used by Pseudomonas aeruginosa to survive and thrive in the cystic fibrosis lung as biofilms can be disrupted and controlled by regulating the formation/functions) of this multi-protein complex. To begin to address this broad hypothesis, we propose to; 1) Establish the requirements for formation of the multi-protein complex, 2) Identify the interprotein interactions in the multi-protein complex and determine the structural topology of the complex, 3) Solve the structures of component proteins of the multi-protein complex at high resolution, and 4) Initiate functional studies of the complex. The results of the research should provide important new strategies for prevention and treatment of infections by bacteria that form biofilms.

描述(由申请人提供)：这项研究的长期目标是确定和了解铜绿假单胞菌利用的复杂调控机制的细节，这些机制导致生物被膜形成和受影响个人的慢性感染。铜绿假单胞菌是典型的条件致病菌。肺部慢性铜绿假单胞菌感染是囊性纤维化患者最常见的死亡原因，突显了铜绿假单胞菌作为病原体的臭名昭著。这种细菌在囊性纤维化肺等环境中定居和生存的能力，以及阻止抗生素制度和绕过身体免疫反应的能力，有许多关键。这些能力包括形成生物膜的能力，产生胞外粘多糖海藻酸盐的能力--一种天然屏障和毒力因子，作为一个群体通过多个群体感应系统协调生物反应的能力，以及感知和适应高氧化应激、铁限制和可用碳源条件的能力。毫不奇怪，这些属性紧密交织在一起，共同反映了铜绿假单胞菌监管网络的复杂性和优雅。我们在铜绿假单胞菌中发现了一个新的多蛋白复合体，它包括与群体感应、藻酸盐生物合成调控、氧化应激反应以及对环境铁和碳的响应有关的蛋白，包括功能尚不清楚的新蛋白algH。基于复合体中蛋白质的特性，基于这些反应是囊性纤维化肺中生物膜形成、定植和生存所必需的事实，它的功能是整合对各种关键生物信号的反应，对于囊性纤维化肺中的生存是必不可少的。此外，因为这些系统(群体感应系统(S)、藻酸盐生物合成调控系统等)。是控制铜绿假单胞菌感染的良好靶点，靶向这种新的蛋白质复合体在药物上应该是相当有利的，因为多个系统将同时被破坏。我们的总体假设是，铜绿假单胞菌作为生物膜在囊性纤维化肺中生存和茁壮成长所使用的复杂的调节和适应机制可以通过调节这种多蛋白复合体的形成/功能来破坏和控制。为了解决这一广泛的假设，我们建议：1)建立形成多蛋白质复合体的要求，2)确定多蛋白质复合体中蛋白质间的相互作用并确定复合体的结构拓扑，3)高分辨率地解决多蛋白质复合体的组成蛋白质的结构，以及4)启动复合体的功能研究。这项研究的结果将为预防和治疗形成生物膜的细菌感染提供重要的新策略。