Journal of Integrative Agriculture ›› 2026, Vol. 25 ›› Issue (8): 3387-3399.DOI: 10.1016/j.jia.2025.02.011

• • 上一篇    下一篇

布鲁氏菌效应蛋白BspF通过乙酰化修饰SNAP29调控宿主细胞自噬

  

  • 收稿日期:2024-07-04 修回日期:2025-02-12 接受日期:2025-01-26 出版日期:2026-08-20 发布日期:2026-07-09

Brucella effector protein BspF manipulates the host cell autophagy by acetylating SNAP29

Ruitong Shen1, 2*, Yuqi Wang1, 2*, Qiao Dong1, 2, 4, Jinying Zhu1, 2, Yukai Xing1, 2, Ang Li1, 2, Gen Lu1, 2, Sijiao Wu1, 2, Ze Yu1, 2, Fangyuan Du1, 2, Jingbo Gao1, 2, Qingqing Wei5, Xiaoyue Chen1, 2, Jinling Liu1, 2 , Huan Zhang1, 2#, Zeliang Chen1, 2, 3#   

  1. 1 Key Laboratory of Livestock Infectious Disease of Ministry of Education, Shenyang Agricultural University, Shenyang 110866, China

    2 Key Laboratory of Ruminant Infectious Disease Prevention and Control (East), Ministry of Agriculture and Rural Affairs, Shenyang Agricultural University, Shenyang 110866, China

    3 Department of Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China

    4 Liaodong University, Dandong 118001, China

    5 First People's Hospital of NingYang, Tai’an 271400, China

  • Received:2024-07-04 Revised:2025-02-12 Accepted:2025-01-26 Online:2026-08-20 Published:2026-07-09
  • About author:#Correspondence Huan Zhang, E-mail: zhanghuan1988@syau.edu.cn; Zeliang Chen, E-mail: zeliangchen@yahoo.com * These authors contributed equally to this study.
  • Supported by:

    This work was supported by the Educational Department of Liaoning Province, China (JYTQN2024017).

PDF

摘要：

胞内细菌通过调控宿主信号通路以促进其胞内存活，这一策略在病原菌与宿主的相互作用中具有普遍性。布鲁氏菌（Brucella spp.）作为一种典型的胞内寄生菌，依赖其IV型分泌系统（T4SS）调控宿主信号通路，从而维持其在细胞内的生存和复制。然而，这一过程中涉及的分子机制尚未完全阐明。蛋白质翻译后修饰是调控蛋白质功能的关键机制之一，其中赖氨酸乙酰化修饰作为一种可逆、动态且高度保守的修饰类型，在细胞信号转导、代谢调控及免疫应答中发挥重要作用。研究表明，布鲁氏菌效应蛋白BspF能够通过抑制反式高尔基体网络的逆向运输，特异性促进布鲁氏菌液泡（Brucella-containing vacuoles, BCVs）内的细菌复制，从而增强其胞内生长能力。基于此，本研究通过对BspF蛋白的结构域分析，发现其含有Gcn5相关N-乙酰转移酶（GNAT）家族的特征性乙酰转移酶结构域，提示布鲁氏菌可能通过乙酰化修饰宿主蛋白来干扰宿主免疫通路，进而促进其胞内存活与复制。为验证这一假设，本研究利用大肠杆菌表达系统对BspF蛋白进行高效表达与纯化，并建立了体内外实验体系，系统评估了BspF对宿主蛋白的乙酰化修饰活性。通过布鲁氏菌胞内存活实验，我们发现宿主细胞的乙酰化修饰显著促进了布鲁氏菌的胞内存活。进一步研究表明，布鲁氏菌效应蛋白BspF能够通过与宿主细胞蛋白的相互作用，调控宿主蛋白的乙酰化修饰。为全面解析乙酰化修饰对宿主蛋白的影响，本研究采用液相色谱-串联质谱（LC-MS/MS）技术鉴定了由BspF介导的宿主蛋白乙酰化修饰。蛋白质组学数据分析显示，BspF能够特异性触发SNAP29蛋白K103位点的乙酰化修饰。进一步的实验验证表明，乙酰化修饰的SNAP29抑制了其与STX17的相互作用，从而调控自噬过程，为布鲁氏菌的胞内存活提供了有利环境。这是首次报道细菌效应蛋白通过乙酰化修饰影响宿主SNAP29-STX17-VAMP8 SNARE复合物，进而抑制宿主免疫防御系统的机制。

本研究通过对布鲁氏菌T4SS效应蛋白BspF的组学分析，揭示了其在宿主先天免疫应答中的关键作用，为阐明布鲁氏菌效应蛋白BspF调控先天免疫应答的分子机制提供了新的理论依据。同时，本研究为布鲁氏菌感染相关疾病的治疗策略提供了潜在靶点，并为蛋白质乙酰化修饰在宿主-病原体相互作用中的功能研究提供了重要参考。这些发现不仅拓展了对布鲁氏菌致病机制的理解，也为其他胞内病原菌的研究提供了新的思路。

Abstract:

Brucella spp., an intracellular bacterium, uses its type IV secretion system (T4SS) to regulate host signaling pathways and promote intracellular survival, but the molecular mechanism of this process remains largely unknown.  Here we found that increasing the abundance of acetylated protein in host cells promotes the intracellular survival of Brucella.  Moreover, our results demonstrated that the Brucella effector protein BspF can impact protein acetylation modification in host cells by interacting with other intracellular acetyltransferases.  We conducted liquid chromatography-tandem mass spectrometry (LC-MS/MS) to characterize the protein acetylation mediated by BspF.  We identified that synaptosome associated protein 29 (SNAP29) K103 was acetylated, and that acetylated SNAP29 inhibited its interaction with syntaxin 17 (STX17), thereby regulating the autophagy and providing an environment for the intracellular survival of Brucella.  Furthermore, our results provide the first report of a bacterial effector using acetylation to affect the SNAP29-STX17-VAMP8 complex, and inhibit the host’s defense system.  Our results suggest a vital role of SNAP29 acetylation in autophagy of host cells under intracellular infection, by specifically regulating the assembly of soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE).

Key words: Brucella ,  BspF ,  crotonylation ,  autophagy ,  SNAP29