Lysine acetylation of DosR regulates the hypoxia response of <i>Mycobacterium tuberculosis</i>

Tuberculosis caused by <i>Mycobacterium tuberculosis</i> (<i>Mtb</i>) infection remains a large global public health problem. One striking characteristic of <i>Mtb</i> is its ability to adapt to hypoxia and trigger the ensuing transition to a dormant state for persistent infection, but how the hypoxia response of <i>Mtb</i> is regulated remains largely unknown. Here we performed a quantitative acetylome analysis to compare the acetylation profile of <i>Mtb</i> under aeration and hypoxia, and showed that 377 acetylation sites in 269 <i>Mtb</i> proteins were significantly changed under hypoxia. In particular, deacetylation of dormancy survival regulator (DosR) at K182 promoted the hypoxia response in <i>Mtb</i> and enhanced the transcription of DosR-targeted genes. Mechanistically, recombinant DosR^K182R protein demonstrated enhanced DNA-binding activity in comparison with DosR^K182Q protein. Moreover, Rv0998 was identified as an acetyltransferase that mediates the acetylation of DosR at K182. Deletion of Rv0998 also promoted the adaptation of <i>Mtb</i> to hypoxia and the transcription of DosR-targeted genes. Mice infected with an <i>Mtb</i> strain containing acetylation-defective DosR^K182R had much lower bacterial counts and less severe histopathological impairments compared with those infected with the wild-type strain. Our findings suggest that hypoxia induces the deacetylation of DosR, which in turn increases its DNA-binding ability to promote the transcription of target genes, allowing <i>Mtb</i> to shift to dormancy under hypoxia.

由结核分枝杆菌（Mycobacterium tuberculosis，简称Mtb）感染引发的结核病仍是全球性重大公共卫生难题。结核分枝杆菌的一个显著特征是其能够适应低氧环境，并由此启动向休眠状态的转变以维持持续感染，但目前学界对结核分枝杆菌低氧应答的调控机制仍知之甚少。本研究通过定量乙酰化组学分析（quantitative acetylome analysis），对比了结核分枝杆菌在有氧与低氧条件下的乙酰化谱，发现在269个结核分枝杆菌蛋白上共计377个乙酰化位点在低氧条件下发生了显著变化。特别是，休眠存活调节因子（DosR）在K182位点的去乙酰化，能够促进结核分枝杆菌的低氧应答，并增强其DosR靶向基因的转录。从机制层面来看，与DosR^K182Q蛋白相比，重组DosR^K182R蛋白展现出更强的DNA结合活性。此外，本研究鉴定出Rv0998是一种乙酰转移酶（acetyltransferase），可介导DosR在K182位点的乙酰化。敲除Rv0998同样能够促进结核分枝杆菌对低氧环境的适应，以及DosR靶向基因的转录。相较于感染野生型菌株的小鼠，感染携带乙酰化缺陷型DosR^K182R的结核分枝杆菌菌株的小鼠，其体内细菌载量显著更低，组织病理损伤（histopathological impairments）也更轻微。本研究结果表明，低氧环境可诱导DosR发生去乙酰化，进而提升其DNA结合能力以促进靶基因转录，使结核分枝杆菌能够在低氧条件下转向休眠状态。

搜集汇总

背景与挑战

背景概述

该数据集聚焦于结核分枝杆菌缺氧反应中DosR蛋白的赖氨酸乙酰化调控机制。研究通过定量乙酰组分析发现缺氧条件下377个乙酰化位点发生显著变化，并揭示DosR在K182位点的去乙酰化能增强其DNA结合活性，促进靶基因转录，从而帮助细菌适应缺氧环境并进入休眠状态。数据集包含实验原始数据，如乙酰化谱分析结果和动物感染模型数据，支持相关分子机制和病理学发现的验证。