肌动蛋白激活铜绿假单胞菌 ExoY 核苷酸环化酶毒素和 MARTX 毒素中的 ExoY 样效应结构域。
Actin activates Pseudomonas aeruginosa ExoY nucleotidyl cyclase toxin and ExoY-like effector domains from MARTX toxins.
机构信息
Institut Pasteur, CNRS UMR3528, Unité de Biochimie des Interactions Macromoléculaires, Département de Biologie Structurale et Chimie, 25-28 rue du Docteur Roux, 75724 Paris cedex 15, France.
Department of Bacterial Infections, Gamaleya Research Center, Moscow 123098, Russia.
出版信息
Nat Commun. 2016 Dec 5;7:13582. doi: 10.1038/ncomms13582.
The nucleotidyl cyclase toxin ExoY is one of the virulence factors injected by the Pseudomonas aeruginosa type III secretion system into host cells. Inside cells, it is activated by an unknown eukaryotic cofactor to synthesize various cyclic nucleotide monophosphates. ExoY-like adenylate cyclases are also found in Multifunctional-Autoprocessing Repeats-in-ToXin (MARTX) toxins produced by various Gram-negative pathogens. Here we demonstrate that filamentous actin (F-actin) is the hitherto unknown cofactor of ExoY. Association with F-actin stimulates ExoY activity more than 10,000 fold in vitro and results in stabilization of actin filaments. ExoY is recruited to actin filaments in transfected cells and alters F-actin turnover. Actin also activates an ExoY-like adenylate cyclase MARTX effector domain from Vibrio nigripulchritudo. Finally, using a yeast genetic screen, we identify actin mutants that no longer activate ExoY. Our results thus reveal a new sub-group within the class II adenylyl cyclase family, namely actin-activated nucleotidyl cyclase (AA-NC) toxins.
核苷酸环化酶毒素 ExoY 是铜绿假单胞菌 III 型分泌系统注入宿主细胞的毒力因子之一。在细胞内，它被一种未知的真核辅助因子激活，以合成各种环核苷酸单磷酸。多功能自加工重复毒素（MARTX）毒素也存在于各种革兰氏阴性病原体产生的 ExoY 样腺苷酸环化酶中。在这里，我们证明丝状肌动蛋白（F-actin）是 ExoY 的迄今未知的辅助因子。与 F-actin 的结合在体外将 ExoY 的活性刺激超过 10000 倍，并导致肌动蛋白丝的稳定。ExoY 在转染细胞中被募集到肌动蛋白丝上，并改变 F-actin 的周转率。肌动蛋白还激活了来自 Vibrio nigripulchritudo 的 ExoY 样腺苷酸环化酶 MARTX 效应结构域。最后，我们使用酵母遗传筛选，鉴定出不再激活 ExoY 的肌动蛋白突变体。因此，我们的结果揭示了 II 类腺苷酸环化酶家族中的一个新亚群，即肌动蛋白激活的核苷酸环化酶（AA-NC）毒素。
Zotero 插件