Volkman L E, Zaal K J
Department of Entomology, University of California, Berkeley 94720.
Virology. 1990 Mar;175(1):292-302. doi: 10.1016/0042-6822(90)90211-9.
Progressive reorganization and depolymerization of microtubules corresponded with virus-induced rounding of Autographa californica M nuclear polyhedrosis virus (AcMNPV)-infected Spodoptera frugiperda IPLB-Sf-21 cells, suggesting that microtubules were instrumental in maintaining the normal shape of these cells. Depolymerization of all cortical and most of the paranuclear microtubules with colchicine also resulted in cell rounding, confirming this hypothesis. Studies with aphidicolin and cycloheximide indicated the virus-induced effects on the microtubules were mediated by both early and late viral gene products. Microtubules in cells infected with a p10 deletion mutant depolymerized microtubules in a manner similar to those in wild-type virus-infected cells, indicating p10 was not responsible for virus-induced changes in the microtubules. Nevertheless, evidence for the association of p10 and microtubules was obtained by fluorescence microscopy and immunoelectron microscopy. Colchicine depolymerization of microtubules before and throughout infection did not interfere with virus replication, but treatment of cells with taxol, a microtubule-stabilizing agent, both delayed and depressed virus replication. The taxol-induced effect was relieved by the addition of colchicine. These results suggested that AcMNPV-induced depolymerization of microtubules may be a necessary event in, rather than a tangential effect of, virus replication. Attempts to monitor the effects of virus infection on intermediate filaments were unsuccessful due to the lack of cross-reactivity between antibodies to intermediate filament proteins and IPLB-Sf-21 cells, indicating these proteins are not highly conserved in lepidopteran insect cells.
微管的渐进性重组和解聚与苜蓿银纹夜蛾核型多角体病毒（AcMNPV）感染的草地贪夜蛾IPLB - Sf - 21细胞因病毒诱导而变圆相对应，这表明微管对于维持这些细胞的正常形态至关重要。用秋水仙碱使所有皮质微管和大部分核旁微管解聚也导致细胞变圆，证实了这一假设。用阿非科林和放线菌酮进行的研究表明，病毒对微管的诱导作用是由早期和晚期病毒基因产物介导的。感染p10缺失突变体的细胞中的微管以与野生型病毒感染细胞中微管相似的方式解聚，这表明p10与病毒诱导的微管变化无关。然而，通过荧光显微镜和免疫电子显微镜获得了p10与微管相关的证据。在感染前和感染过程中用秋水仙碱使微管解聚并不干扰病毒复制，但用微管稳定剂紫杉醇处理细胞会延迟并抑制病毒复制。加入秋水仙碱可缓解紫杉醇诱导的效应。这些结果表明，AcMNPV诱导的微管解聚可能是病毒复制过程中的一个必要事件，而非附带效应。由于中间丝蛋白抗体与IPLB - Sf - 21细胞之间缺乏交叉反应性，监测病毒感染对中间丝影响的尝试未成功，这表明这些蛋白在鳞翅目昆虫细胞中并非高度保守。
