Chen Yu T, Lin Chi H, Ji Wen T, Li Shu K, Liu Hung J
Graduate Institute of Biotechnology, National Pingtung University of Science and Technology, Pingtung, Taiwan.
J Virol Methods. 2008 Jul;151(1):95-100. doi: 10.1016/j.jviromet.2008.03.016. Epub 2008 May 2.
The interplay between avian reovirus (ARV) replication and apoptosis and proteasome pathway was studied in cultured cells. It is shown that inhibition of the proteasome did not affect viral entry and host cell translation but had influence on ARV replication and ARV-induced apoptosis. Evidence is provided to demonstrate that ubiquitin-proteasome blocked ARV replication at an early step in viral life cycle. However, viral transcription and protein translation were also reduced markedly after addition of proteasome inhibitor MG132. Treatment of BHK-21 cells with the MG132 markedly decreased virus titer as well as prevented virus-induced apoptosis. The expression of ARV proteins sigmaC, sigmaA, and sigmaNS was also reduced markedly, suggesting that suppression of virus replication is due to down-regulation of these ARV proteins by ubiquitin-proteasome system. MG132 was also shown to suppress ARV sigmaC-induced phosphrylation of p53 on serine 46, caspase 3 activities, and DNA fragmentation leading to complete inhibition of ARV-induced apoptosis.
在培养细胞中研究了禽呼肠孤病毒(ARV)复制与细胞凋亡及蛋白酶体途径之间的相互作用。结果表明,蛋白酶体的抑制不影响病毒进入和宿主细胞翻译,但对ARV复制及ARV诱导的细胞凋亡有影响。有证据表明泛素-蛋白酶体在病毒生命周期的早期阶段阻断了ARV复制。然而,添加蛋白酶体抑制剂MG132后,病毒转录和蛋白质翻译也显著降低。用MG132处理BHK-21细胞可显著降低病毒滴度,并防止病毒诱导的细胞凋亡。ARV蛋白sigmaC、sigmaA和sigmaNS的表达也显著降低,这表明病毒复制的抑制是由于泛素-蛋白酶体系统对这些ARV蛋白的下调所致。MG132还显示可抑制ARV sigmaC诱导的p53丝氨酸46位点的磷酸化、半胱天冬酶3活性及DNA片段化,从而完全抑制ARV诱导的细胞凋亡。