The Role the AAA+ Lon Proteases in Bacterial Pathogenesis

AAA Lon 蛋白酶在细菌发病机制中的作用

• 批准号: 9927592
• 负责人: A. WALI KARZAI
• 金额: $ 46.18万
• 依托单位: STATE UNIVERSITY NEW YORK STONY BROOK
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-06-01 至 2022-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9927592
• 关键词: ATP phosphohydrolase; Adaptor Signaling Protein; Bacteria; Binding; Binding Sites; Biological Process; Blood; Borrelia; Borrelia burgdorferi; Cells; Collaborations; Elements; Environment; Escherichia coli; Etiology; Evaluation; Exposure to; Fleas; Gene Expression; Genes; Goals; Growth; Human; In Vitro; Invertebrates; Ixodes; Life; Lyme Disease; Maintenance; Mediating; Orthologous Gene; Pathogenesis; Pathway interactions; Peptide Hydrolases; Physiological; Plague; Play; Proteins; Proteolysis; Proteome; Public Health; Regulation; Research Personnel; Research Project Grants; Role; Signal Transduction; Specificity; Substrate Specificity; System; Testing; Ticks; Type III Secretion System Pathway; Up-Regulation; Virulence; Work; Yersinia; Yersinia pestis; base; cofactor; design; endopeptidase La; enhancing factor; environmental change; feeding; fitness; genetic regulatory protein; human disease; in vivo; insight; member; novel; pathogenic bacteria; proteostasis; quality assurance; response; selective expression; transmission process; vector; vector-borne pathogen

Energy-dependent AAA+ proteases have been implicated in controlling numerous physiologically significant pathways. The Lon AAA+ protease, which is conserved from bacteria to humans, has emerged as key contributor to the capacity of the cell to adapt to its ever-changing growth environment. Lon protease play a fundamental role in maintaining the ideal concentration of key regulatory proteins, and in re-sculpting the proteome by removing unfolded, aberrant, or damaged proteins in response to internal and external signals. Knowing how this versatile AAA+ protease and its cofactor(s) select target substrates for degradation is crucial to our understanding of its biological functions. Recent studies have provided compelling evidence to demonstrate that the Lon AAA+ proteases play critical roles in the regulation of virulence gene expression in a number of pathogenic bacteria. The long-term goal of this proposal is to establish the role of the AAA+ Lon proteases in the pathogenesis of bacteria that are required to adapt to environmental changes during their transmission from invertebrate vectors to mammalian hosts. The two specific aims of the proposal are designed to guide us in studies of two vector borne pathogens, Yersinia pestis, transmitted by fleas, and Borrelia burgdorferi, transmitted by ticks. Our aims are motivated by the hypothesis that ATP-fueled Lon proteases facilitate important physiological transitions by selectively removing key regulatory proteins surplus unwanted substrates. Further, we hypothesize that Lon protease selectivity is mediated by specificity enhancing factors (adaptor proteins) or selective expression of unique Lon orthologs with distinct substrate specificities. In Aim I, we will focus on the role and regulation of Lon protease in Yersinia pestis, the causative agent of plague, during the key physiological transition resulting in expression of the type III secretion system. We will focus particularly on the discovery and characterization of a novel and much sought after specificity-enhancing factor for Lon protease. We will investigate the mechanism by which this novel adaptor protein regulates substrate selection and degradation by Lon protease. In Aim II, we will focus on the role and regulation of Lon proteases in Borrelia burgdorferi, the etiological agent of Lyme diseases, with special focus on the unusual occurrence of two Lon proteases (Bb-Lon-1 and Bb-Lon-2), of which the former is expressed in blood. We will examine the merits of the hypothesis that the Bb-Lon-1 has a distinct substrate range and specificity, uniquely different from the canonical Lon proteases of other bacteria, including the Bb-Lon-2 protease. We will determine the substrate range and specificity of Borrelia Lon proteases and elucidate how Bb-Lon-1 remodels the spirochetal proteome and maintains ideal concentration of key regulatory proteins to facilitate the physiological transition triggered by exposure to mammalian blood. A detailed understanding of the substrate range and specificity of Lon proteases, and how remodeling of the bacterial proteome by Lon contributes to the fitness, survival, and virulence of bacteria will provide significant new insight into the principles of general and selective proteolysis.

能量依赖的AAA+蛋白酶与控制众多有关 生理上重要的途径。从细菌到人类保守的LON AAA+蛋白酶已成为细胞适应其不断变化的生长环境的能力的关键。 LON Protease玩 在维持关键调节蛋白的理想浓度以及在 通过去除展开，异常或受损的蛋白质来重新雕刻蛋白质组 内部和外部信号。知道该多功能AAA+蛋白酶及其辅助因子如何选择 降解的靶标底物对于我们对其生物学功能的理解至关重要。 最近的研究提供了令人信服的证据，以证明LON AAA+蛋白酶发挥作用 在许多致病细菌中毒力基因表达的调节中的关键作用。 该提议的长期目标是确定AAA+ LON蛋白酶在 细菌的发病机理需要适应环境变化。 从无脊椎动物向量传播到哺乳动物宿主。提案的两个具体目标 旨在指导我们研究两种媒介传播病原体的研究， 跳蚤和Borrelia Burgdorferi，由tick虫传播。我们的目标是由假设的动机 ATP燃料的LON蛋白酶通过选择性地促进了重要的生理转变 去除关键的调节蛋白剩余不需要的底物。此外，我们假设LON 蛋白酶选择性是由特异性增强因子（适配器蛋白）或选择性介导的 具有独特底物特异性的独特LON直系同源物的表达。在目标一世中，我们将集中精力 关于LON蛋白酶在鼠疫的耶尔森氏菌中的作用和调节，鼠疫的病因， 在关键的生理过渡期间，导致III型分泌系统的表达。 我们将特别关注小说和广受欢迎的发现和表征 LON蛋白酶的特异性增强因素。我们将调查此机制 新型衔接蛋白调节LON蛋白酶的底物选择和降解。在AIM II中，我们 将重点关注LON蛋白酶在Borrelia Burgdorferi（病因）中的作用和调节 莱姆病的药物，特别关注两种LON蛋白酶的异常发生（BB-LON-1 和BB-LON-2），前者用血液表达。我们将研究 BB-LON-1具有独特的底物范围和特异性的假设，独特 来自其他细菌的典型LON蛋白酶，包括BB-LON-2蛋白酶。我们将 确定Borrelia Lon蛋白酶的底物范围和特异性，并阐明BB-LON-1 重塑螺旋体蛋白质组并保持理想的关键调节蛋白 促进暴露于哺乳动物血液引发的生理过渡。详细的 了解LON蛋白酶的底物范围和特异性，以及如何重塑 LON的细菌蛋白质组有助于细菌的适应性，存活和毒力 将为一般和选择性蛋白水解原理提供重大的新见解。