The coxsackievirus 2B protein suppresses apoptotic host cell responses by manipulating intracellular Ca2+ homeostasis
The coxsackievirus 2B protein suppresses apoptotic host cell responses by manipulating intracellular Ca2+ homeostasis
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DOI：
10.1074/jbc.m309494200
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发表时间：
2004-04-30
影响因子：
4.8
通讯作者：
van Kuppeveld, FJM
中科院分区：
文献类型：
--
作者：
Campanella, M;de Jong, AS;van Kuppeveld, FJM
肠道病毒是一种小的溶细胞RNA病毒，它赋予受感染细胞一种抗凋亡状态，以抑制感染限制性凋亡宿主细胞反应。这种抗凋亡状态也提供了对代谢抑制剂如放线菌素D和放线菌酮诱导的细胞死亡的保护。病毒抗凋亡蛋白的身份和潜在的机制是未知的。在这里，我们提供的证据表明，柯萨奇病毒2B蛋白通过操纵细胞内Ca2+稳态调节细胞凋亡。使用荧光Ca2+指示剂和细胞器靶向水母发光蛋白，我们表明，在HeLa细胞中的异位表达2B降低了内质网和高尔基体的Ca2+含量，导致这些商店和线粒体之间的Ca2+信号转导的下调，并增加了细胞外Ca2+的流入。在我们对2B诱导的Ca2+信号转导改变的生理重要性的研究中，我们发现2B的表达抑制了由各种刺激（包括放线菌素D和放线菌酮）诱导的半胱天冬酶激活和凋亡性细胞死亡。2B的突变体，在减少钙含量的商店有缺陷，未能抑制细胞凋亡。这些数据暗示了肠道病毒策略中细胞内Ca2+区室化的扰动抑制内在凋亡宿主细胞反应的功能作用。假定下调内质网依赖的凋亡途径进行了讨论。
Enteroviruses, small cytolytic RNA viruses, confer an antiapoptotic state to infected cells in order to suppress infection-limiting apoptotic host cell responses. This antiapoptotic state also lends protection against cell death induced by metabolic inhibitors like actinomycin D and cycloheximide. The identity of the viral antiapoptotic protein and the underlying mechanism are unknown. Here, we provide evidence that the coxsackievirus 2B protein modulates apoptosis by manipulating intracellular Ca2+ homeostasis. Using fluorescent Ca2+ indicators and organelle-targeted aequorins, we demonstrate that ectopic expression of 2B in HeLa cells decreases the Ca2+ content of both the endoplasmic reticulum and the Golgi, resulting in down-regulation of Ca2+ signaling between these stores and the mitochondria, and increases the influx of extracellular Ca2+. In our studies of the physiological importance of the 2B-induced alterations in Ca2+ signaling, we found that the expression of 2B suppressed caspase activation and apoptotic cell death induced by various stimuli, including actinomycin D and cycloheximide. Mutants of 2B that were defective in reducing the Ca2+ content of the stores failed to suppress apoptosis. These data implicate a functional role of the perturbation of intracellular Ca2+ compartmentalization in the enteroviral strategy to suppress intrinsic apoptotic host cell responses. The putative down-regulation of an endoplasmic reticulum-dependent apoptotic pathway is discussed.