The role of nanocompartments in M. tuberculosis pathogenesis

联系PD/PI：Stanley，Sarah A 项目摘要。细菌病原体结核分枝杆菌对氧化应激具有高度抗性 在主机中遇到的，但防御机制仍然很差的特点。这项建议旨在 表征M中的纳米室系统。我们认为结核病有助于防御 氧化应激纳米隔室是基于蛋白质的细胞器，其封装酶货物，通常 一种与氧化防御有关的酶。尽管编码纳米区室的基因在 细菌和古细菌，它们的内源性功能还没有很好地理解，也不清楚什么有益于 提供了特定酶的包封。我们发现M。结核病有一种细菌， 纳米区室系统，需要防御氧化应激。该系统由 标记蛋白Cfp 29和货物蛋白DypB，染料脱色过氧化物酶。我们的假设是 分枝结核病DypB纳米区室系统是抵抗结核病中遇到的氧化应激所必需的。 宿主巨噬细胞基于初步数据，我们表明DypB β蛋白突变体是 在巨噬细胞中的生长减弱，并且这些突变体在无菌环境中在pH 4.5时也对H2 O2敏感。 文化我们测试这个假设在三个目标。1)确定包封是否促进DypB稳定性， 函数; 2）确定M.结核病需要DypB介导系统来防御 脂质过氧化物; 3）确定DypB纳米区室在M.结核如果 如果成功，拟议的实验将提供纳米隔室系统与 细菌的毒力，推进我们对M.结核病和其他病原体， 抵抗宿主中遇到的各种氧化应激。此外，这些研究还将为以下方面提供见解： 的功能和壳蛋白的具体作用。最后，这些研究将推进 我们对DyP过氧化物酶的内源性功能的理解，这是广泛存在于整个 细菌、古生菌和真核生物 第6页 项目概要/摘要

Contact PD/PI: Stanley, Sarah A Project Summary. The bacterial pathogen Mycobacterium tuberculosis is highly resistant to oxidative stress encountered in the host, however defense mechanisms remain poorly characterized. This proposal seeks to characterize a nanocompartment system in M. tuberculosis that we propose contributes to defense against oxidative stress. Nanocompartments are protein-based organelles that encapsulate an enzymatic cargo, often an enzyme related to oxidative defense. Although genes encoding nanocompartments are widespread in bacteria and archaea, their endogenous functions are not well understood and it is not clear what benefit the encapsulation of specific enzymes provides. We have discovered that M. tuberculosis has a bacterial nanocompartment system that is required for defense against oxidative stress. This system consists of the encapsulin protein Cfp29 and the cargo protein DypB, a dye decolorizing peroxidase. Our hypothesis is that the M. tuberculosis DypB nanocompartment system is required for resisting oxidative stresses encountered in host macrophages. Building on preliminary data in which we show that DypB encapsulin mutants are attenuated for growth in macrophages, and that these mutants are also susceptible to H2O2 at pH 4.5 in axenic culture we test this hypothesis in three aims. 1) Determine whether encapsulation promotes DypB stability and function; 2) Determine whether the M. tuberculosis DypB encapsulin system is required for defense against lipid peroxides; 3) Determine the role of the DypB nanocompartment in virulence of M. tuberculosis. If successful, the proposed experiments will provide the first link between a nanocompartment system and bacterial virulence, advancing our understanding of how M. tuberculosis, and possibly other pathogens, defend against diverse oxidative stresses encountered in the host. In addition, these studies will provide insights into the function of encapsulin systems and the specific role of the shell protein. Finally, these studies will advance our understanding of the endogenous functions of DyP peroxidases, which are widespread throughout bacteria, archaea, and eukaryotes Page 6 Project Summary/Abstract