Intercellular Communication and Pheromone Maturation in Gram-Positive Bacteria.

革兰氏阳性细菌的细胞间通讯和信息素成熟。

基本信息

批准号：
10153696
负责人：
Francis Alonzo
金额：
$ 37.7万
依托单位：
LOYOLA UNIVERSITY CHICAGO
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-05-01 至 2025-04-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10153696
关键词：
Active Sites Affect Amino Acid Sequence Attenuated Behavior Biochemical Biochemistry Cell Communication Cell membrane Cells Characteristics Cleaved cell Communicable Diseases Communities Competence Congenic Strain Cyclic Peptides Cysteine Data Defect Development Disease Elements Enterococcus Event Family Gene Expression Genes Genetic Screening Genus staphylococcus Goals Gram-Positive Bacteria Grant Health Infection Infectious Skin Diseases Knowledge Link Listeria Lung infections Mass Spectrum Analysis Mechanics Mediator of activation protein Membrane Membrane Proteins Metal Binding Site Metalloproteases Microbe Microbial Biofilms Modeling Mus Mutation N-terminal Open Reading Frames Pathogenesis Pathogenicity Peptide Biosynthesis Peptide Hydrolases Peptide Leader Sequences Peptide Signal Sequences Peptides Periodicity Pheromone Process Production Protein Precursors Proteins Recombinants Regulator Genes Role Signal Induction Signal Transduction Specificity Staphylococcus aureus System Testing Variant Virulence Virulence Factors attenuation base genetic approach improved insight intercellular communication mutant novel therapeutics pathogen protein aminoacid sequence quorum sensing trait

项目摘要

Project Summary Gram-positive bacteria process and release small peptides, or “pheromones”, that act as critical signals for the induction of adaptive traits including those involved in virulence. One class of small signaling pheromones is the cyclic auto-inducing peptide (AIP), which regulates the expression of genes that orchestrate virulence and persistence in Staphylococci, Listeria, Clostridia, and Enterococci. Defects in cyclic AIP production and signaling can compromise virulence traits of these microbes, underscoring the relevance of peptide-based signaling to health and disease. Staphylococcus aureus harbors a cyclic peptide signaling system known as the accessory gene regulatory (Agr) system. This “quorum sensing” system depends on the synthesis, processing, and export of a cyclic AIP, derived from its precursor protein, AgrD, for function. AIP signaling through Agr leads to the production of S. aureus virulence factors, whereas disruption of signaling causes significant attenuation in skin and lung infection models. Despite clear connections between Agr and S. aureus pathobiology, there exist major gaps in our knowledge of the mechanics of AIP biosynthesis. Most notably: (i) the proteins needed for peptide processing of AIP have not been elucidated; (ii) a transporter for AIP or its leader peptide has not been identified; (iii) differential processing of AIP variants has not been investigated; and (iv) conservation in cyclic peptide processing events between bacterial species is not known. In this grant, we provide data related to our discovery of a putative peptidase in S. aureus, MroQ, that we hypothesize acts directly or indirectly on Agr system components to promote the final steps in the processing and/or export of AIP. The overall goals of this grant are to interrogate the previously unknown mechanics of cyclic peptide maturation in S. aureus and provide insight into the potential conservation of function in Gram positive pathogens. Aim 1 will define how MroQ promotes AIP processing, export, or both. Aim 2 will interrogate the extent with which MroQ interacts with Agr system or other membrane components and will use biochemistry to test if MroQ directly cleaves AgrD. Aim 3 will determine the extent with which MroQ promotes activity of Agr variants both within species and among other species and identify the AgrD sequence characteristics that dictate MroQ specificity.

项目概要革兰氏阳性细菌处理并释放小肽，或“信息素”，作为细菌的关键信号。适应性特征的诱导，包括涉及毒力的特征的一类小信号信息素是。环状自诱导肽（AIP），它调节基因的表达，从而协调毒力和葡萄球菌、李斯特菌、梭状芽胞杆菌和肠球菌的持续存在以及循环 AIP 生产中的缺陷。信号传导可能会损害这些微生物的毒力特征，强调了基于肽的相关性金黄色葡萄球菌含有一种环肽信号系统，称为健康和疾病信号。辅助基因调节（Agr）系统这种“群体感应”系统取决于合成，加工和输出源自其前体蛋白 AgrD 的环状 AIP，以实现功能。通过 Agr 导致金黄色葡萄球菌毒力因子的产生，而信号传导的破坏则导致尽管 Agr 和金黄色葡萄球菌之间存在明显的联系，但皮肤和肺部感染模型中的显着减弱。病理生物学方面，我们对 AIP 生物合成机制的了解存在重大差距。 AIP 肽加工所需的蛋白质尚未阐明 (ii) AIP 或其转运蛋白；尚未鉴定前导肽；(iii) 尚未研究 AIP 变体的差异加工； (iv) 细菌物种之间环肽加工事件的保守性尚不清楚。我们提供与我们在金黄色葡萄球菌中发现的假定肽酶 MroQ 相关的数据，我们勇敢地采取行动直接或间接地作用于农业系统组件，以促进加工和/或出口的最后步骤 AIP。这项资助的总体目标是探究以前未知的环肽机制。金黄色葡萄球菌中的成熟，并深入了解革兰氏阳性菌中功能的潜在保守性目标 1 将定义 MroQ 如何促进 AIP 处理、导出或两者兼而有之。 MroQ 与 Agr 系统或其他膜组件相互作用的程度，并将利用生物化学来测试 MroQ 是否直接裂解 AgrD 目标 3 将确定 MroQ 促进 Agr 活性的程度。物种内和其他物种之间的变异，并确定 AgrD 序列特征规定 MroQ 特异性。