Coxsackievirus B3 proteases 2A and 3C induce apoptotic cell death through mitochondrial injury and cleavage of eIF4GI but not DAP5/p97/NAT1
Coxsackievirus B3 proteases 2A and 3C induce apoptotic cell death through mitochondrial injury and cleavage of eIF4GI but not DAP5/p97/NAT1
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DOI：
10.1007/s10495-006-0013-0
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发表时间：
2007-03-01
期刊：
影响因子：
7.2
通讯作者：
Yang, Decheng
中科院分区：
文献类型：
--
作者：
Chau, David H. W.;Yuan, Ji;Yang, Decheng
通过将柯萨奇病毒B3(CVB3)单独的蛋白水解酶基因导入HeLa细胞，我们证实了2A(Pro)和3C(Pro)通过多条汇聚途径诱导细胞凋亡。首先，2A(Pro)和3C(Pro)均可诱导caspase-8介导的caspase-3活化，并显著降低细胞存活率。其次，它们都激活了线粒体介导的内在凋亡途径，导致细胞色素c从线粒体释放，并激活caspase-9。然而，3C(Pro)通过上调Bax和切割Bid来诱导这些事件，而2A(Pro)仅通过切割Bid来诱导这些事件。然而，这两种药物都没有改变Bc l-2的表达。第三，两种蛋白水解酶均通过切割或下调翻译和转录的细胞因子诱导细胞死亡：2A(Pro)和3C(Pro)均可切割真核细胞翻译起始因子4GI，但其切割产物不同，显示不同的切割位点；此外，2A(Pro)和3C(Pro)均下调转录因子cAMP反应元件结合蛋白的表达，其中2A(Pro)的作用强于3C(Pro)。令人惊讶的是，这两种酶都不能切割翻译调节因子DAP5/p97/Nat1，尽管这种切割是在CVB3感染期间观察到的，并且不能被caspase抑制剂z-VAD-fmk阻断。综上所述，这些数据表明，2A(PRO)和3C(PRO)通过激活促凋亡介质和抑制翻译和转录而诱导细胞凋亡。
By transfection of Coxsackievirus B3 (CVB3) individual protease gene into HeLa cells, we demonstrated that 2A(pro) and 3C(pro) induced apoptosis through multiple converging pathways. Firstly, both 2A(pro) and 3C(pro) induced caspase-8-mediated activation of caspase-3 and dramatically reduced cell viability. Secondly, they both activated the intrinsic mitochondria-mediated apoptosis pathway leading to cytochrome c release from mitochondria and activation of caspase-9. However, 3C(pro) induced these events via both up-regulation of Bax and cleavage of Bid, and 2A(pro) induced these events via cleavage of Bid only. Nevertheless, neither altered Bcl-2 expression. Thirdly, both proteases induced cell death through cleavage or down regulation of cellular factors for translation and transcription: both 2A(pro) and 3C(pro) cleaved eukaryotic translation initiation factor 4GI but their cleavage products are different, indicating different cleavage sites; further, both 2A(pro) and 3C(pro) down-regulated cyclic AMP responsive element binding protein, a transcription factor, with 2A(pro) exhibiting a stronger effect than 3C(pro). Surprisingly, neither could cleave DAP5/p97/NAT1, a translation regulator, although this cleavage was observed during CVB3 infection and could not be blocked by caspase inhibitor z-VAD-fmk. Taken together, these data suggest that 2A(pro) and 3C(pro) induce apoptosis through both activation of proapoptotic mediators and suppression of translation and transcription.