Binding component of Clostridium perfringens iota-toxin induces endocytosis in Vero cells
Binding component of Clostridium perfringens iota-toxin induces endocytosis in Vero cells
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DOI：
10.1128/iai.70.4.1909-1914.2002
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发表时间：
2002-04-01
影响因子：
3.1
通讯作者：
Sakurai, J
中科院分区：
文献类型：
--
作者：
Nagahama, M;Nagayasu, K;Sakurai, J
产气荚膜梭菌i毒素是由两种单独的蛋白质组成的二元毒素，即结合组分（Ib）和酶组分（Ia）。野生型Ib在4 ℃和37 ℃与Vero细胞结合，在37 ℃形成寡聚体，但在4 ℃不形成。Ib诱导的K+从细胞中释放依赖于Ib在细胞中的寡聚体形成，但寡聚体形成不诱导圆化活性或细胞毒性。将细胞与重组Ib（rIb）在37 ℃孵育后，细胞中的Ib寡聚体随着时间的推移对链霉蛋白酶处理产生抗性，但Ib单体对处理敏感。此外，在巴弗洛霉素、甲胺或乙胺存在下用rIb处理Vero细胞导致寡聚体在细胞中积累，但对K+释放没有影响。此外，在这些试剂存在的情况下与Ib和Ia一起孵育不会导致细胞变圆。这些观察结果表明，Ib结合到Vero细胞，本身寡聚化形成离子渗透通道，然后寡聚体的形成诱导内吞作用。
Clostridium perfringens iota-toxin is a binary toxin consisting of two individual proteins, the binding component (Ib) and the enzyme component (Ia). Wild-type Ib bound to Vero cells at 4 and 37 C and formed oligomers at 37degreesC but not at 4degreesC. The Ib-induced K+ release from the cells was dependent on the oligomer formation of Ib in the cells, but the oligomer formation did not induce rounding activity or cytotoxicity. After incubation of the cells with recombinant Ib (rIb) at 37degreesC, the Ib oligomer in the cell became resistant to pronase treatment with time, but the Ib monomer was sensitive to the treatment. Furthermore, treatment of Vero cells with rIb in the presence of bafilomycin, methylamine, or ethylamine resulted in accumulation of the oligomer in the cells but had no effect on K+ release. Moreover, incubation with Ib plus Ia in the presence of these agents caused no rounding in the cells. These observations suggest that Ib binds to Vero cells, itself oligomerizing to form ion-permeable channels and that the formation of oligomer then induces endocytosis.