Interaction between Simian Virus 40 Major Capsid Protein VP1 and Cell Surface Ganglioside GM1 Triggers Vacuole Formation.
Interaction between Simian Virus 40 Major Capsid Protein VP1 and Cell Surface Ganglioside GM1 Triggers Vacuole Formation.
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DOI：
10.1128/mbio.00297-16
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发表时间：
2016-03-22
期刊：
影响因子：
6.4
通讯作者：
DiMaio D
中科院分区：
文献类型：
--
作者：
Luo Y;Motamedi N;Magaldi TG;Gee GV;Atwood WJ;DiMaio D
猴病毒40（SV 40）是一种多瘤病毒，已成为了解生物学许多方面的重要模型，在猴宿主细胞的生产性感染后期诱导显著的细胞质空泡化。虽然这种活动导致了1960年发现的病毒，空泡化的机制仍然是未知的。SV 40主要衣壳蛋白VP 1的五聚体与神经节苷脂GM 1结合，后者是病毒的细胞受体。在这份报告中，我们表明，VP 1的细胞表面GM 1的结合在SV 40感染诱导的空泡化中起着关键作用。我们以前表明，SV 40 VP 1突变体GM 1结合缺陷不能诱导空泡化，即使他们有效地复制。在这里，我们表明，干扰GM 1-VP 1的结合，通过敲低GM 1感染后建立废除空泡形成的野生型SV 40。在允许感染过程中的空泡形成需要有效的病毒释放，并且在SV 40感染过程中晚期收获的条件培养基以VP 1和GM 1依赖的方式快速诱导空泡。此外，空泡化也可以由非复制型SV 40假病毒以GM 1依赖性方式诱导，并且BK假病毒VP 1中产生GM 1结合的突变赋予空泡诱导活性。纯化的野生型SV 40 VP 1五聚体也可以触发烯醇化，但GM 1结合缺陷五聚体或VP 1的细胞内表达不能触发烯醇化。这些结果表明，SV 40感染诱导的空泡化是由释放的子代病毒与GM 1结合引起的，从而确定了导致发现SV 40的活性的分子触发因素。DNA肿瘤病毒SV 40在世纪以前被发现是脊髓灰质炎病毒疫苗储备的污染物，因为它引起容许宿主细胞的显著细胞质空泡化。尽管SV 40在分子和细胞生物学、限制性酶切图谱、分子克隆和全基因组测序的发展中发挥了历史性的重要作用，但这种空泡化表型的基础尚不清楚。在这里，我们表明，SV 40诱导的空泡化的主要病毒衣壳蛋白，VP 1，细胞表面神经节苷脂受体，GM 1的结合触发。液泡的形成不需要其他病毒蛋白或病毒复制。其他多瘤病毒利用不同的神经节苷脂受体，但它们不诱导空泡化。这项工作确定了导致发现这种重要病毒的表型的分子触发因素，并首次从分子上深入了解了病毒感染引起的不寻常和神秘的细胞病变效应。
Simian virus 40 (SV40), a polyomavirus that has served as an important model to understand many aspects of biology, induces dramatic cytoplasmic vacuolization late during productive infection of monkey host cells. Although this activity led to the discovery of the virus in 1960, the mechanism of vacuolization is still not known. Pentamers of the major SV40 capsid protein VP1 bind to the ganglioside GM1, which serves as the cellular receptor for the virus. In this report, we show that binding of VP1 to cell surface GM1 plays a key role in SV40 infection-induced vacuolization. We previously showed that SV40 VP1 mutants defective for GM1 binding fail to induce vacuolization, even though they replicate efficiently. Here, we show that interfering with GM1-VP1 binding by knockdown of GM1 after infection is established abrogates vacuolization by wild-type SV40. Vacuole formation during permissive infection requires efficient virus release, and conditioned medium harvested late during SV40 infection rapidly induces vacuoles in a VP1- and GM1-dependent fashion. Furthermore, vacuolization can also be induced by a nonreplicating SV40 pseudovirus in a GM1-dependent manner, and a mutation in BK pseudovirus VP1 that generates GM1 binding confers vacuole-inducing activity. Vacuolization can also be triggered by purified pentamers of wild-type SV40 VP1, but not by GM1 binding-defective pentamers or by intracellular expression of VP1. These results demonstrate that SV40 infection-induced vacuolization is caused by the binding of released progeny viruses to GM1, thereby identifying the molecular trigger for the activity that led to the discovery of SV40. The DNA tumor virus SV40 was discovered more than a half century ago as a contaminant of poliovirus vaccine stocks, because it caused dramatic cytoplasmic vacuolization of permissive host cells. Although SV40 played a historically important role in the development of molecular and cellular biology, restriction mapping, molecular cloning, and whole-genome sequencing, the basis of this vacuolization phenotype was unknown. Here, we show that SV40-induced vacuolization is triggered by the binding of the major viral capsid protein, VP1, to a cell surface ganglioside receptor, GM1. No other viral proteins or virus replication is required for vacuole formation. Other polyomaviruses utilize different ganglioside receptors, but they do not induce vacuolization. This work identifies the molecular trigger for the phenotype that led to the discovery of this important virus and provides the first molecular insight into an unusual and enigmatic cytopathic effect due to virus infection.