Contribution of the peptidome to CA-MRSA virulence

肽组对 CA-MRSA 毒力的贡献

• 批准号: 10382426
• 负责人: David J Gonzalez
• 金额: $ 39.5万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-05-18 至 2025-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10382426
• 关键词: Address; Area; Bacteria; Binding; Biochemical; Biological Assay; Biological Process; Biology; Cells; Communities; Complex; Cytolysins; Data; Development; Discipline; Disease; Environment; Epithelial; Etiology; Genome; Genomics; Genus staphylococcus; Health; Host Defense; Human; In Vitro; Infection; Infectious Skin Diseases; Keratin; Knowledge; Lead; Libraries; Lipoproteins; Mass Spectrum Analysis; Microbiology; Modeling; Molecular; Mus; Pathogenesis; Pathogenicity; Pathway interactions; Penetration; Peptides; Phenols; Play; Process; Proteins; Proteome; Proteomics; PubMed; Publishing; Regulator Genes; Research; Role; Serum; Staphylococcal Infections; Staphylococcus aureus; Structure; System; Targeted Toxins; Testing; Tissues; Transcript; Virulence; Virulence Factors; Work; base; cell type; human pathogen; in vivo; innovation; methicillin resistant Staphylococcus aureus; mortality; multiple omics; mutant; novel; novel therapeutics; pathogen; prohibitin; rational design; skin lesion; synthetic peptide

PROJECT SUMMARY A comprehensive understanding of bacterial pathogenesis not only requires a detailed knowledge of the genome and proteome, but also the peptidome elaborated during the progression of infection. The overall objective of this proposal is to build upon our exciting preliminary observations describing the identification of endogenous microproteins and peptides detected in cell-free supernatants of community-associated (CA) MRSA cultures. Within this group we identified two novel microproteins originating from an unannotated locus in the CA-MRSA TCH1516 genome. We found that these microproteins, termed S. aureus microprotein 1 (SAM1) and S. aureus microprotein 2 (SAM2), are highly conserved among Staphylococci and are regulated by the classical accessory gene regulatory system. We have started to characterize these factors, showing that SAM1 appears to act as a canonical cytolysin. Intriguingly, SAM2 possesses unique bioactivity, the perturbation of keratin networks that promotes an in vivo switch from a localized S. aureus skin infection to an invasive dissemination to the underlying tissues. The central hypothesis of this proposal is that SAMs significantly contribute to CA-MRSA’s ability to cause disease in a host. In Aim 1, we will dissect the pathogenic contributions of SAM1 as a functional cytolysin in vitro and in vivo. Given the bioactivity of SAM1 is inhibited by serum lipoproteins, we will focus on its role once CA-MRSA is in an intracellular environment. Our strong preliminary data suggests SAM1 selectively binds to prohibitins (PHBs) across differential host cell types. Thus, we will take the study of CA-MRSA cytolysins in a new direction by dissecting the potential role of PHBs as targets of SAM1. In Aim 2, we will perform a structure and function analysis of the interaction between SAM2 and keratin. Our data shows that this interaction has an important in vivo consequence during the shift from a local to invasive infection type. By a powerful combination of microbiology and multi-omic approaches, we will define the SAM2 structural contact points required for pathogenesis and will detail host pathways that are impacted by SAM2 during the invasive switch. In Aim 3, to assess the broader significance of our discovery, we will determine the pathogenic roles SAMs play in a diverse library of CA-MRSA strains, in addition to other Staphylococcal pathogens that express bioactive SAM homologs. Aim 3 is critical given that the importance of SAMs in other Staphylococci beyond CA-MRSA TCH1516 remains unknown. This proposal is highly innovative because it departs from the current focus of investigating host-pathogen interactions through the more established genomic and proteomic workflows. The proposed work is highly significant given it can drive the development of anti-Staphylococcal therapies based on a relatively new and largely mysterious molecular paradigm - the peptidome.

项目摘要 对细菌发病机理的全面了解不仅需要对 基因组和蛋白质组，但在感染进展过程中也阐述了胡椒体。总体 该提议的目的是建立我们令人兴奋的初步观察，描述了 在社区相关（CA）的无细胞上清液中检测到的内源性微蛋白和胡椒粉 MRSA文化。在这一组中，我们确定了两个源自未经注释的基因座的新型微蛋白 在CA-MRSA TCH1516基因组中。我们发现这些微蛋白称为金黄色葡萄球菌微蛋白1 （SAM1）和金黄色葡萄球菌微蛋白2（SAM2）在葡萄球菌中高度配置，并受到调节 由经典的附属基因调节系统。我们已经开始描述这些因素，表明 SAM1似乎充当典型的细胞溶蛋白。有趣的是，SAM2具有独特的生物活性， 角蛋白网络的扰动，该网络可促进体内从局部的金黄色葡萄球菌感染到 侵入性向基础组织传播。该提议的中心假设是SAMS 显着有助于CA-MRSA在宿主中引起疾病​​的能力。在AIM 1中，我们将剖析 SAM1作为功能性细胞溶蛋白在体外和体内的致病作用。鉴于SAM1的生物活性是 血清脂蛋白抑制，一旦CA-MRSA处于细胞内环境，我们将重点关注其作用。我们的 强大的初步数据表明，SAM1在差异宿主细胞上有选择地结合了禁止素（PHB） 类型。这是，我们将通过剖析剖析的潜在作用来研究新方向的Ca-Mrsa细胞赛蛋白 PHB作为SAM1的靶标。在AIM 2中，我们将对交互作用进行结构和功能分析 在SAM2和角蛋白之间。我们的数据表明，这种相互作用在体内具有重要的后果 从局部感染类型到侵入性感染类型的转变。通过微生物学和多摩变的强大组合 方法，我们将定义发病机理所需的SAM2结构接触点，并将详细介绍宿主 在侵入性开关过程中受SAM2影响的途径。在AIM 3中，评估更广泛的意义 在我们的发现中，我们将确定Sams在CA-MRSA菌株的潜水库中扮演的致病作用， 除其他表达生物活性SAM同源物的葡萄球菌病原体外。 AIM 3至关重要 SAM在CA-MRSA TCH1516以外的其他葡萄球菌中的重要性仍然未知。这个建议 具有高度创新性，因为它远离了研究宿主 - 病原体相互作用的重点 通过更具成熟的基因组和蛋白质组学工作流。拟议的工作非常重要 它可以推动基于相对较新且在很大程度上神秘的抗稳定局疗法的发展 分子范式 - 胡椒。