Alternative ribosomes and antibiotic tolerance in mycobacteria.

分枝杆菌中的替代核糖体和抗生素耐受性。

基本信息

批准号：
10165472
负责人：
Anil Kumar Ojha
金额：
$ 40.55万
依托单位：
WADSWORTH CENTER
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-06-01 至 2023-09-19
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10165472
关键词：
Acute Address Anti-Bacterial Agents Antibiotics Antitubercular Agents Bacterial Infections Binding Chronic Clinical Complex Cryoelectron Microscopy DNA Sequence Alteration Data Development Dietary Zinc Distant Drug Controls Drug Tolerance Drug resistance Drug resistance in tuberculosis Erythromycin Etiology Extreme drug resistant tuberculosis FDA approved Future Gene Expression Genes Genetic Transcription Genus Mycobacterium Goals Growth Incidence Infection Kanamycin Lead Linezolid Literature Macrolides Mediating Multi-Drug Resistance Mycobacterium Infections Mycobacterium smegmatis Mycobacterium tuberculosis Operon Pathogenesis Pharmaceutical Preparations Phase Phenotype Proteins Publishing Regimen Repression Resolution Ribosomal Proteins Ribosomes Role Starvation Streptomycin Structure Testing Tuberculosis Work Zinc antibiotic tolerance base cell growth chronic infection clinically relevant design drug synthesis extensive drug resistance extracellular improved insight interdisciplinary approach mouse model mutant mycobacterial novel novel strategies paralogous gene pathogen polypeptide promoter resistant strain response tuberculosis treatment uptake

项目摘要

Project Summary Evolutionarily distant bacterial species respond to zinc starvation by reprogramming their ribosome assembly, in which the constitutive ribosomal proteins with zinc-binding motifs CXXC (C+) are substituted with alternative zinc-free counterparts (C-) through a transcriptional de- repression mechanism involving the zinc uptake regulator, ZurB. The alternative ribosomes assembled with C- ribosomal proteins reduce the zinc requirement for cellular growth under zinc-limiting conditions. Mycobacterium tuberculosis (Mtb), the etiological agent for tuberculosis (TB), has four C+/C- ribosomal protein pairs. All four genes encoding C- proteins of the pair are organized in an operon and are co-expressed through a ZurB-repressible promoter. Co- expression implies simultaneous substitution of all four C+ proteins by C- paralogs, raising questions about the influence of the substitutions on ribosomal response to antibiotics. We have found that the alternative C- ribosomes in both Mtb and Mycobacterium smegmatis not only reduce the zinc requirement for cellular growth, but also confer tolerance to clinically relevant anti-TB ribosomal antibiotics. We further observed that Mtb express more alternative ribosomes during chronic infection than in early acute phase. We thus hypothesize that expression of alternative ribosomes are the primary reasons underlying the inefficacies of the clinically established ribosomal antibiotics against TB. To facilitate improved targeting of mycobacterial ribosomes we propose to: a) elucidate the mechanistic basis of differential responses of constitutive (C+) and alternative (C-) ribosomes to antibiotics (aim 1), b) identify strategies to target alternative (C-) ribosomes (aim 2) and c) determine the role of alternative ribosomes in pathogenesis of Mtb (aim 3). These studies will ultimately lead to new strategies to target both constitutive and alternative ribosomes in mycobacteria, and thus allow effective clearance of mycobacterial infections.

项目概要进化距离较远的细菌物种通过重新编程来应对锌饥饿核糖体组装，其中具有锌结合基序 CXXC 的组成型核糖体蛋白 (C+) 通过转录 de- 被替代的无锌对应物 (C-) 取代抑制机制涉及锌摄取调节剂 ZurB。替代核糖体与 C-核糖体蛋白组装可减少细胞生长所需的锌锌限制条件。结核分枝杆菌 (Mtb)，结核病的病原体 (TB)，具有四个 C+/C- 核糖体蛋白对。编码这对 C 蛋白的所有四个基因都是组织在操纵子中，并通过 ZurB 抑制型启动子共表达。共同表达意味着所有四种 C+ 蛋白同时被 C- 旁系同源物取代，从而提高关于取代对核糖体对抗生素反应的影响的问题。我们有发现 Mtb 和耻垢分枝杆菌中的替代 C-核糖体不仅减少细胞生长对锌的需求，同时也赋予临床相关的耐受性抗结核核糖体抗生素。我们进一步观察到 Mtb 表达更多的替代核糖体慢性感染期间比急性期早期要严重。因此我们假设表达式替代核糖体是临床上无效的主要原因建立了针对结核病的核糖体抗生素。促进改善分枝杆菌的靶向性我们建议：a）阐明核糖体差异反应的机制基础抗生素的组成型 (C+) 和替代型 (C-) 核糖体（目标 1），b) 确定策略目标替代核糖体 (C-) 核糖体（目标 2）和 c) 确定替代核糖体在 Mtb 的发病机制（目标 3）。这些研究最终将导致针对这两个目标的新策略分枝杆菌中的组成型和替代核糖体，从而可以有效清除分枝杆菌感染。