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的抵抗力。 然而，在宿主中遇到的防御机制仍然缺乏特征性。这项建议旨在 描述结核分枝杆菌的纳米隔室系统，我们认为它有助于防御 氧化应激。纳米隔间是以蛋白质为基础的细胞器，它包裹着酶的货物，通常 一种与氧化防御有关的酶。尽管编码纳米隔间的基因在 细菌和古菌，它们的内源功能还不清楚，也不清楚 特定酶的封装提供了。我们发现结核分枝杆菌有一种细菌 纳米隔室系统，是防御氧化应激所必需的。这一系统由 包裹蛋白Cfp29和货运蛋白DypB，一种染料脱色过氧化物酶。我们的假设是 结核分枝杆菌DypB纳米隔室系统是抵抗在日本遇到的氧化压力所必需的 宿主巨噬细胞。在初步数据的基础上，我们表明DypB封装在突变体中 这些突变株在无菌条件下也对pH 4.5的H_2O_2敏感。 文化，我们从三个方面检验这一假设。1)确定封装是否提高了DypB的稳定性和 功能；2)确定是否需要结核分枝杆菌DypB包膜系统来防御 脂质过氧化；3)确定DypB纳米隔间在结核分枝杆菌毒力中的作用。如果 成功后，拟议中的实验将提供纳米隔间系统和 细菌的毒力，促进了我们对结核分枝杆菌，可能还有其他病原体，如何防御 对抗宿主体内遇到的不同氧化压力。此外，这些研究将提供对 囊膜系统的功能和壳蛋白的特定作用。最后，这些研究将会取得进展 我们对DyP过氧化物酶的内源性功能的理解，这种酶广泛存在于 细菌、古菌和真核生物 第6页 项目摘要/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