Cytoskeleton association and virion incorporation of the human immunodeficiency virus type 1 Vif protein
Cytoskeleton association and virion incorporation of the human immunodeficiency virus type 1 Vif protein
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DOI：
10.1128/jvi.70.1.494-507.1996
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发表时间：
1996-01-01
影响因子：
5.4
通讯作者：
Strebel, K
中科院分区：
文献类型：
--
作者：
Karczewski, MK;Strebel, K
人类免疫缺陷病毒1型（HIV-1）Vif蛋白在病毒感染性的调节中具有重要作用。Vif的这种功能是细胞类型特异性的，并且在限制性细胞中不存在Vif的情况下产生的病毒粒子具有大大降低的感染性。我们在这里表明，Vif的细胞内定位依赖于中间丝波形蛋白的存在。急性感染的T细胞或瞬时转染的HeLa细胞的分级显示存在可溶性和细胞骨架形式，并且在较小程度上存在洗涤剂可提取形式的Vif。共聚焦显微镜表明，在HeLa细胞中，Vif主要存在于细胞质中，并与中间丝波形蛋白密切共定位。用影响波形蛋白细丝结构的药物处理细胞会相应地影响Vif的定位，这表明Vif与这种细胞骨架组分密切相关。Vif与波形蛋白的结合可导致中间丝网络塌陷成核周聚集体。相比之下，波形蛋白阴性细胞中的Vif的分析揭示了除了弥漫性细胞质染色之外的细胞核和核膜的显著染色。除Vif与中间丝的结合外，对病毒体制剂的分析表明Vif被掺入病毒颗粒中。在蔗糖密度梯度中，Vif与衣壳蛋白共沉淀，即使在洗涤剂处理的病毒制剂，表明Vif与HIV颗粒的内核。我们提出了一个模型，其中Vif作为病毒体组分具有重要的功能，无论是通过调节病毒成熟或病毒进入宿主细胞后，可能涉及与细胞骨架网络的相互作用。
The human immunodeficiency virus type 1 (HIV-1) Vif protein has an important role in the regulation of virus infectivity. This function of Vif is cell type specific, and virions produced in the absence of Vif in restrictive cells have greatly reduced infectivity. We show here that the intracellular localization of Vif is dependent on the presence of the intermediate filament vimentin. Fractionation of acutely infected T cells or transiently transfected HeLa cells demonstrates the existence of a soluble and a cytoskeletal form and to a lesser extent the presence of a detergent-extractable form of Vif. Confocal microscopy suggests that in HeLa cells, Vif is predominantly present in the cytoplasm and closely colocalizes with the intermediate filament vimentin. Treatment of cells with drugs affecting the structure of vimentin filaments affect the localization of Vif accordingly, indicating a close association of Vif with this cytoskeletal component. The association of Vif with vimentin can cause the collapse of the intermediate filament network into a perinuclear aggregate. In contrast, analysis of Vif in vimentin-negative cells reveals significant staining of the nucleus and the nuclear membrane in addition to diffuse cytoplasmic staining. In addition to the association of Vif with intermediate filaments, analyses of virion preparations demonstrate that Vif is incorporated into virus particles. In sucrose density gradients, Vif cosediments with capsid proteins even after detergent treatment of virus preparations, suggesting that Vif is associated with the inner core of HIV particles. We propose a model in which Vif has a crucial function as a virion component either by regulating virus maturation or following virus entry into a host cell possibly involving an interaction with the cellular cytoskeletal network.