Extracellular simian virus 40 transmits a signal that promotes virus enclosure within caveolae
Extracellular simian virus 40 transmits a signal that promotes virus enclosure within caveolae
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DOI：
10.1006/excr.1998.4301
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发表时间：
1999-01-10
影响因子：
3.7
通讯作者：
Norkin, LC
中科院分区：
文献类型：
--
作者：
Chen, YZ;Norkin, LC
据报道，猴病毒40（SV 40）进入细胞是由病毒从细胞表面传递的信号促进的，SV 40通过小窝进入细胞。本文显示，在吸附后30分钟，结合的SV 40豆分配到富含小窝的Triton X-100不溶性膜部分中。在1 h时，在该组分中观察到最大水平的SV 40。甾醇结合剂制霉菌素，选择性地破坏富含胆固醇的小窝含有膜微区，选择性地阻断SV 40诱导的信号。这意味着SV 40信号是从该膜微区传输的。酪氨酸激酶抑制剂染料木黄酮，这是早期显示，以阻止SV 40诱导的信号和感染性的进入，并没有阻止分区的SV 40到洗涤剂不溶性膜部分。这表明该信号不是SV 40易位到洗涤剂不溶性膜所必需的，并且与该信号可能从该膜微区传递的发现一致。然而，Triton X-100不溶性膜部分的电子显微镜显示染料木素导致SV 40颗粒在小窝的环或口处积聚。相比之下，在来自未处理的对照细胞的平行样品中，发现大多数SV 40颗粒封闭在小窝内。总之，这些结果表明，SV 40最初结合到平坦的洗涤剂可溶性膜。然后，病毒易位到含有洗涤剂不溶性膜微区的小窝。从膜微区的平坦部分，病毒诱导信号，促进其进入小窝。(C)北京：科学出版社.
It was reported earlier that entry of simian virus 40 (SV40) into cells is promoted by a signal transmitted by the virus from the cell surface and that SV40 enters cells through caveolae, It is shown here that bound SV40 beans to partition into a caveolae-enriched Triton X-100-insoluble membrane fraction at 30 min postadsorption. Maximal levels of SV40 were seen in that fraction at 1 h. The sterol-binding agent nystatin, which selectively disrupts the cholesterol-enriched caveolae-containing membrane microdomain, selectively blocked the SV40-induced signal. This implies that the SV40 signal is transmitted from that membrane microdomain. The tyrosine kinase inhibitor genistein, which was earlier shown to block the SV40-induced signal and infectious entry, did not block the partitioning of SV40 into the detergent-insoluble membrane fraction. This shows that the signal is not required for the translocation of SV40 to the detergent-insoluble membrane and is consistent with the finding that the signal is likely transmitted from that membrane microdomain, However, electron microscopy of the Triton X-100-insoluble membrane fraction showed that genistein caused SV40 particles to accumulate at the annuli or mouths of the caveolae. In contrast, most SV40 particles were found enclosed within caveolae in parallel samples from untreated control cells. Together, these results imply that SV40 initially binds to flat detergent-soluble membrane. The virus then translocates to a caveolae-containing detergent-insoluble membrane microdomain. From the flat portion of that membrane microdomain the virus induces a signal which promotes its entry into caveolae. (C) 1999 Academic Press.