从效应蛋白视角看革兰氏阴性细菌VI型蛋白分泌系统底物转运机理

Effector recognition and translocation by type VI protein secretion system in Gram-negative bacteria

摘要:

蛋白质分泌系统是细菌与外界交流的重要工具。革兰氏阴性细菌的VI型蛋白分泌系统(T6SS)可以转运分泌蛋白至细菌和真核细胞内，在菌间竞争中发挥重要作用，是细菌的一种重要的生存适应性武器。分泌蛋白主要包括起到运载作用的结构蛋白和有细胞毒性的效应蛋白这两类。本文主要从效应蛋白的视角讨论T6SS如何识别并转运效应蛋白的作用机理，回顾了以VgrG和PAAR为端部载体蛋白的转运途径、依赖端部运输的效应蛋白、T6SS伴侣蛋白等重要发现的背景和过程，并综述了T6SS分泌途径的新进展。

Abstract:

Protein secretion systems are crucial tools that microbes use to interact with their surrounding environment. The type VI protein secretion system (T6SS) is widely distributed in Gram-negative bacteria and capable of delivering effector to both eukaryotic and prokaryotic cells. Here we discuss, from effector study perspective, the mechanism of substrate recognition and translocation by T6SS, focusing on the key discoveries of VgrG-PAAR (proline-alanine-alanine-aRginine) dependent secretion pathway, and its cognate effectors and chaperone proteins.