An N-acetyltransferase required for ESAT-6 N-terminal acetylation and virulence in Mycobacterium marinum.
An N-acetyltransferase required for ESAT-6 N-terminal acetylation and virulence in Mycobacterium marinum.
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蛋白质N端乙酰化是一种普遍存在的翻译后修饰，影响着高等生物的多种细胞过程。细菌蛋白质也是N-末端乙酰化的，但对细菌中这种修饰的机制和后果知之甚少。主要毒力因子EsxA（ESAT-6，早期分泌抗原，6 kDa）是细菌中鉴定的第一个N-末端乙酰化蛋白质之一。EsxA在分枝杆菌病原体中是保守的，包括结核分枝杆菌和海分枝杆菌，一种在外温动物中引起结核样疾病的非结核分枝杆菌物种。然而，负责EsxA N-末端乙酰化的酶一直难以捉摸。在这里，我们使用遗传学、分子生物学和基于质谱的蛋白质组学来证明MMAR_1839（重命名为Emp 1，ESX-1修饰蛋白，1）是假定的N-乙酰转移酶（NAT），仅负责M中EsxA乙酰化。marinum。我们证明，ERD_3144，在M.结核病Erdman，在功能上等同于Emp 1。我们先前定量了致病性分枝杆菌中广泛存在的N-末端蛋白乙酰化（C。R.汤普森，M。M.冠军，和私人助理。Champion，J Proteome Res 17：3246-3258，2018，https：//doi：10.1021/acs.jproteome.8b00373）。我们确定了至少22个额外的蛋白质，需要Emp 1的乙酰化，证明这种假定的NAT不是专用于EsxA。最后，我们发现emp 1的缺失并不能阻止吞噬体逃逸，但会导致M.在感染期间，总的来说，本研究确定了N-末端乙酰化和分枝杆菌发病所需的NAT。N-末端乙酰化是一种广泛影响高等生物基本细胞功能和疾病的蛋白质修饰。虽然细菌蛋白质是N-末端乙酰化的，但很少了解N-末端乙酰化如何影响细菌生理学和发病机制。分枝杆菌病原体在人类和动物中引起急性和慢性疾病。大约15%的分枝杆菌蛋白质是N-末端乙酰化的，但负责的酶在很大程度上是未知的。我们确定了一个保守的分枝杆菌蛋白所需的N-末端乙酰化的23个分枝杆菌蛋白，包括EsxA毒力因子。从M.海水可减少巨噬细胞的杀伤和M. marinum到新的宿主细胞。确定负责N-末端蛋白乙酰化的基本毒力因子的乙酰转移酶可能会导致新的目标，对分枝杆菌的治疗。
N-terminal protein acetylation is a ubiquitous post-translational modification that impacts diverse cellular processes in higher organisms. Bacterial proteins are also N-terminally acetylated, but the mechanisms and consequences of this modification in bacteria are poorly understood. The major virulence factor EsxA (ESAT-6, early secreted antigen, 6 kDa) was one of the first N-terminally acetylated proteins identified in bacteria. EsxA is conserved in mycobacterial pathogens, including Mycobacterium tuberculosis and Mycobacterium marinum, a non-tubercular mycobacterial species that causes tuberculosis-like disease in ectotherms. However, the enzyme responsible for EsxA N-terminal acetylation has been elusive. Here, we used genetics, molecular biology, and mass-spectroscopy-based proteomics to demonstrate that MMAR_1839 (renamed Emp1, ESX-1 modifying protein, 1) is the putative N-acetyltransferase (NAT) solely responsible for EsxA acetylation in M. marinum. We demonstrated that ERD_3144, the orthologous gene in M. tuberculosis Erdman, is functionally equivalent to Emp1. We previously quantified widespread N-terminal protein acetylation in pathogenic mycobacteria (C. R. Thompson, M. M. Champion, and P. A. Champion, J Proteome Res 17:3246–3258, 2018, https:// doi: 10.1021/acs.jproteome.8b00373). We identified at least 22 additional proteins that require Emp1 for acetylation, demonstrating that this putative NAT is not dedicated to EsxA. Finally, we showed that loss of emp1 did not prevent phagosomal escape but resulted in a significant reduction in macrophage cytolysis by and cell-to-cell spread of M. marinum during infection. Collectively, this study identified a NAT required for N-terminal acetylation and pathogenesis in Mycobacterium. N-terminal acetylation is a protein modification that broadly impacts basic cellular function and disease in higher organisms. Although bacterial proteins are N-terminally acetylated, little is understood how N-terminal acetylation impacts bacterial physiology and pathogenesis. Mycobacterial pathogens cause acute and chronic disease in humans and in animals. Approximately 15% of mycobacterial proteins are N-terminally acetylated, but the responsible enzymes are largely unknown. We identified a conserved mycobacterial protein required for the N-terminal acetylation of 23 mycobacterial proteins including the EsxA virulence factor. Loss of this enzyme from M. marinum reduced macrophage killing and spread of M. marinum to new host cells. Defining the acetyltransferases responsible for the N-terminal protein acetylation of essential virulence factors could lead to new targets for therapeutics against mycobacteria.
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DOI：
10.1073/pnas.1718336115
发表时间：
2018-04-24
影响因子：
11.1
作者：
Drazic A;Aksnes H;Marie M;Boczkowska M;Varland S;Timmerman E;Foyn H;Glomnes N;Rebowski G;Impens F;Gevaert K;Dominguez R;Arnesen T
通讯作者：
Arnesen T
DOI：
10.1074/mcp.m112.017533
发表时间：
2012-09
期刊：
Molecular & cellular proteomics : MCP
影响因子：
--
作者：
Champion MM;Williams EA;Kennedy GM;Champion PA
通讯作者：
Champion PA
影响因子：
21.3
作者：
Behnia, R;Panic, B;Munro, S
通讯作者：
Munro, S
影响因子：
3.2
作者：
Errey, JC;Blanchard, JS
通讯作者：
Blanchard, JS
DOI：
10.1073/pnas.92.17.7714
发表时间：
1995-08-15
影响因子：
11.1
作者：
ARFIN, SM;KENDALL, RL;BRADSHAW, RA
通讯作者：
BRADSHAW, RA