Clostridium perfringens TpeL Glycosylates the Rac and Ras Subfamily Proteins
Clostridium perfringens TpeL Glycosylates the Rac and Ras Subfamily Proteins
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DOI：
10.1128/iai.01019-10
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发表时间：
2011-02-01
影响因子：
3.1
通讯作者：
Sakurai, Jun
中科院分区：
文献类型：
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作者：
Nagahama, Masahiro;Ohkubo, Akiko;Sakurai, Jun
产气荚膜梭菌TpeL是由艰难梭菌毒素A(TcdA)、艰难梭菌毒素B(TcdB)和索氏梭菌致死毒素(TcsL)组成的一个大的细胞毒素家族。我们在这里报告了TpeL催化的小GTP酶修饰的鉴定。重组蛋白(TpeL1-525)源于TpeL N-末端催化结构域，在链溶素O(Streptolysin O，SLO)存在下诱导Vero细胞圆整和细胞内rac1糖基化。在所测试的几种己糖中，UDP-N-乙酰氨基葡萄糖(UDP-GlcNAc)和UDP-葡萄糖(UDP-GLC)作为TpeL1-525催化的修饰的辅助底物。TpeL1-525催化UDP-GLC掺入Ha-RAS、Rap1B和Rala，UDP-GlcNAc掺入rac1、Ha-RAS、Rap1B和Rala。在rac1中，TpeL和TcdB具有相同的糖基化受体氨基酸Thr-35。在存在SLO的情况下，用TpeL1-525处理Vero细胞，糖基化导致大多数rac1和Ha-Ras移位到膜上。我们首次证明TpeL同时使用UDP-GlcNAc和UDP-GLC作为供体共底物，并通过糖基化修饰rac1和RAS亚家族来介导其细胞毒作用。
Clostridium perfringens TpeL belongs to a family of large clostridial cytotoxins that encompasses Clostridium difficile toxin A (TcdA) and B (TcdB) and Clostridium sordellii lethal toxin (TcsL). We report here the identification of the TpeL-catalyzed modification of small GTPases. A recombinant protein (TpeL1-525) derived from the TpeL N-terminal catalytic domain in the presence of streptolysin O (SLO) induced the rounding of Vero cells and the glycosylation of cellular Rac1. Among several hexoses tested, UDP-N-acetylglucosamine (UDP-GlcNAc) and UDP-glucose (UDP-Glc) served as cosubstrates for TpeL1-525-catalyzed modifications. TpeL1-525 catalyzed the incorporation of UDP-Glc into Ha-Ras, Rap1B, and RalA and of UDP-GlcNAc into Rac1, Ha-Ras, Rap1B, and RalA. In Rac1, TpeL and TcdB share the same acceptor amino acid for glycosylation, Thr-35. In Vero cells treated with TpeL1-525 in the presence of SLO, glycosylation leads to a translocation of the majority of Rac1 and Ha-Ras to the membrane. We demonstrate for first time that TpeL uses both UDP-GlcNAc and UDP-Glc as donor cosubstrates and modifies the Rac1 and Ras subfamily by glycosylation to mediate its cytotoxic effects.