Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611.
Microbiol Spectr. 2015 Jun;3(3). doi: 10.1128/microbiolspec.VE-0002-2014.
Multifunctional-autoprocessing repeats-in-toxin (MARTX) toxins are a heterogeneous group of toxins found in a number of Vibrio species and other Gram-negative bacteria. The toxins are composed of conserved repeat regions and an autoprocessing protease domain that together function as a delivery platform for transfer of cytotoxic and cytopathic domains into target eukaryotic cell cytosol. Within the cells, the effectors can alter biological processes such as signaling or cytoskeletal structure, presumably to the benefit of the bacterium. Ten effector domains are found in the various Vibrio MARTX toxins, although any one toxin carries only two to five effector domains. The specific toxin variant expressed by a species can be modified by homologous recombination to acquire or lose effector domains, such that different strains within the same species can express distinct variants of the toxins. This review examines the conserved structural elements of the MARTX toxins and details the different toxin arrangements carried by Vibrio species and strains. The catalytic function of domains and how the toxins are linked to pathogenesis of human and animals is described.
多功能自加工重复毒素（MARTX）是一组存在于多种弧菌属物种和其他革兰氏阴性菌中的异质毒素。这些毒素由保守的重复区和自加工蛋白酶结构域组成，共同作为将细胞毒性和细胞病变结构域转移到靶真核细胞质中的传递平台。在细胞内，效应物可以改变信号转导或细胞骨架结构等生物学过程，这可能对细菌有利。在各种弧菌 MARTX 毒素中发现了十个效应结构域，尽管任何一种毒素只携带两到五个效应结构域。同种物种表达的特定毒素变体可以通过同源重组进行修饰，以获得或失去效应结构域，从而使同一物种内的不同菌株可以表达不同的毒素变体。这篇综述检查了 MARTX 毒素的保守结构元件，并详细介绍了由弧菌属物种和菌株携带的不同毒素排列。描述了结构域的催化功能以及毒素与人类和动物发病机制的关系。
