Distinct Pathway of Human T-Cell Leukemia Virus Type 1 Gag Punctum Biogenesis Provides New Insights into Enveloped Virus Assembly.
Distinct Pathway of Human T-Cell Leukemia Virus Type 1 Gag Punctum Biogenesis Provides New Insights into Enveloped Virus Assembly.
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DOI：
10.1128/mbio.00758-18
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发表时间：
2018-09-04
期刊：
影响因子：
6.4
通讯作者：
Mansky LM
中科院分区：
文献类型：
--
作者：
Eichorst JP;Chen Y;Mueller JD;Mansky LM
本报告描述了研究人类逆转录病毒 Gag 蛋白被募集至质膜内叶位点（Gag 泪点生物发生发生）的途径的实验结果。特别是，设计了巧妙而灵敏的实验方法，在活细胞中对质膜上人类 T 细胞白血病病毒 1 型 (HTLV-1) 和人类免疫缺陷病毒 1 型 (HIV-1) 的 Gag 蛋白衍生物进行荧光标记。策略性地利用了光转换荧光蛋白 mEos2，因为质膜上 Gag 的荧光发射可以与胞质 Gag 的荧光发射区分开。该实验策略允许确定 Gag 招募途径进入 Gag 斑点。对于 HTLV-1 Gag，puncta 主要从质膜招募 Gag，而 HIV-1 Gag 则从细胞质招募。这些观察结果代表了 HTLV-1 颗粒生物发生及其与 HIV-1 颗粒生物发生的首次报告。 HTLV-1 和 HIV-1 Gag 使用的 Gag 招募途径中观察到的差异提供了关键信息，有助于发现旨在消除病毒感染性和传播的抗逆转录病毒疗法的新靶点。病毒颗粒的组装是病毒传播的一个重要方面。对于逆转录病毒，Gag 多蛋白是病毒颗粒组装的关键驱动因素。为了产生子代病毒，一旦 Gag 被翻译，它必须从细胞质中合成的位置易位到质膜并形成寡聚晶格，从而产生 Gag 斑点。成熟Gag puncta的生物发生可以触发出芽过程，从而产生病毒颗粒。虽然在人类免疫缺陷病毒 1 型 (HIV-1) 中观察到了 Gag 寡聚化和颗粒生物发生动力学的某些方面，但 Gag 泪点生物发生过程仍然知之甚少，特别是对于其他逆转录病毒。在这里，我们对人类 T 细胞白血病病毒 1 型 (HTLV-1) 的 Gag 泪点生物发生进行了迄今为止最详细的研究。使用 mEos2 光转换荧光蛋白和全内反射荧光显微镜 (TIRF)，我们发现 HTLV-1 Gag 主要从质膜招募到 Gag 斑点。这与从细胞质中招募的 HIV-1 Gag 形成鲜明对比。这些观察结果表明，逆转录病毒之间在 Gag 泪点生物发生的编排方面存在根本差异，这对包膜病毒颗粒组装具有重要的一般意义。
This report describes the results of experiments examining the pathway by which the human retroviral Gag protein is recruited to sites along the inner leaflet of the plasma membrane where Gag punctum biogenesis occurs. In particular, clever and sensitive experimental methods were devised to image in living cells fluorescently labeled Gag protein derivatives from human T-cell leukemia virus type 1 (HTLV-1) and human immunodeficiency virus type 1 (HIV-1) at the plasma membrane. The photoconvertible fluorescent protein mEos2 was strategically utilized, as the fluorescence emission of Gag at the plasma membrane could be differentiated from that of cytosolic Gag. This experimental strategy allowed for the determination of the Gag recruitment pathway into Gag puncta. For HTLV-1 Gag, puncta recruited Gag primarily from the plasma membrane, while HIV-1 Gag was recruited from the cytoplasm. These observations represent the first report of HTLV-1 particle biogenesis and its contrast to that of HIV-1. The observed differences in the Gag recruitment pathways used by HTLV-1 and HIV-1 Gag provide key information that is useful for informing the discovery of novel targets for antiretroviral therapies directed at eliminating virus infectivity and spread. The assembly of virus particles is a crucial aspect of virus spread. For retroviruses, the Gag polyprotein is the key driver for virus particle assembly. In order to produce progeny virus, once Gag is translated, it must translocate from the location in the cytoplasm where it is synthesized to the plasma membrane and form an oligomeric lattice that results in Gag puncta. The biogenesis of mature Gag puncta can trigger the budding process, resulting in virus particle production. While some aspects of the dynamics of Gag oligomerization and particle biogenesis have been observed with human immunodeficiency virus type 1 (HIV-1), the process of Gag punctum biogenesis remains poorly understood, particularly for other retroviruses. Here, we have conducted the most detailed studies thus far on Gag punctum biogenesis for human T-cell leukemia virus type 1 (HTLV-1). Using mEos2 photoconvertible fluorescent proteins and total internal reflection fluorescence microscopy (TIRF), we have found that HTLV-1 Gag was recruited to Gag puncta primarily from the plasma membrane. This was in stark contrast to HIV-1 Gag, which was recruited from the cytoplasm. These observations imply fundamental differences among retroviruses regarding the orchestration of Gag punctum biogenesis, which has important general implications for enveloped virus particle assembly.