Super-resolution microscopy reveals specific recruitment of HIV-1 envelope proteins to viral assembly sites dependent on the envelope C-terminal tail.
Super-resolution microscopy reveals specific recruitment of HIV-1 envelope proteins to viral assembly sites dependent on the envelope C-terminal tail.
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DOI：
10.1371/journal.ppat.1003198
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发表时间：
2013-02
期刊：
影响因子：
6.7
通讯作者：
Kräusslich HG
中科院分区：
文献类型：
--
作者：
Muranyi W;Malkusch S;Müller B;Heilemann M;Kräusslich HG
人类免疫缺陷病毒（HIV-1）的内部结构Gag蛋白和包膜糖蛋白（Env）独立地运输到质膜，在那里它们组装新生病毒体。HIV-1在其膜中携带相对少量的糖蛋白，并且Env募集和病毒掺入的机制不完全清楚。我们采用双色超分辨率显微镜可视化Gag组装位点和HIV-1 Env蛋白在病毒生产和Env表达细胞。独特的HIV-1 Gag组装位点很容易被检测到，并与总是延伸到实际Gag组装位点之外的Env簇相关，并且通常在组装位点的外围和周围显示富集。这些Env簇的形成依赖于其他HIV-1蛋白的存在和Env的长胞质尾（CT）。CT缺失是一种基质突变，在不存在其他HIV-1蛋白的情况下影响Env掺入或Env表达，导致更小的Env簇，其在病毒组装位点不富集。这些结果表明，Env以CT依赖性方式被招募到HIV-1组装位点，而Env（ΔCT）似乎是随机掺入的。所观察到的Gag组装体周围的Env积累（在实际芽上具有较低的密度）可以促进病毒在体内的传播。保持新生病毒上的Env分子较低可能对逃避体液免疫应答很重要，而由周围Env分子介导的细胞-细胞接触可以促进HIV-1通过病毒学突触的传播。新形成的HIV-1颗粒聚集在病毒产生细胞的质膜上。感染性病毒颗粒的重要组成部分是内部结构蛋白Gag和包膜糖蛋白Env，它们通过不同的途径运输到膜。附着在膜的内侧，Gag组装成球形颗粒，将Env蛋白掺入其周围的脂质包膜中。然而，Env掺入的机制还不完全清楚。在这里，我们利用最近开发的超分辨率荧光显微镜技术，产生近分子的空间分辨率来分析HIV-1 Gag和Env在病毒产生细胞表面的分布模式。我们观察到招募的Env周围的Gag组装网站，依赖于其胞质结构域的存在。一个很大比例的Env被发现在附近的Gag组装sites，而不是直接co-localizing与it. These结果支持Env招聘的间接机制，推测介导的新生Gag组装环境中的病毒诱导的变化。此外，他们还表明Env蛋白在HIV-1传播中的作用超出了其作为病毒表面进入蛋白的功能。
The inner structural Gag proteins and the envelope (Env) glycoproteins of human immunodeficiency virus (HIV-1) traffic independently to the plasma membrane, where they assemble the nascent virion. HIV-1 carries a relatively low number of glycoproteins in its membrane, and the mechanism of Env recruitment and virus incorporation is incompletely understood. We employed dual-color super-resolution microscopy visualizing Gag assembly sites and HIV-1 Env proteins in virus-producing and in Env expressing cells. Distinctive HIV-1 Gag assembly sites were readily detected and were associated with Env clusters that always extended beyond the actual Gag assembly site and often showed enrichment at the periphery and surrounding the assembly site. Formation of these Env clusters depended on the presence of other HIV-1 proteins and on the long cytoplasmic tail (CT) of Env. CT deletion, a matrix mutation affecting Env incorporation or Env expression in the absence of other HIV-1 proteins led to much smaller Env clusters, which were not enriched at viral assembly sites. These results show that Env is recruited to HIV-1 assembly sites in a CT-dependent manner, while Env(ΔCT) appears to be randomly incorporated. The observed Env accumulation surrounding Gag assemblies, with a lower density on the actual bud, could facilitate viral spread in vivo. Keeping Env molecules on the nascent virus low may be important for escape from the humoral immune response, while cell-cell contacts mediated by surrounding Env molecules could promote HIV-1 transmission through the virological synapse. Newly formed HIV-1 particles assemble at the plasma membrane of virus producing cells. The inner structural protein Gag and the envelope glycoprotein Env, which are both essential components of infectious virus particles, traffic to the membrane via different pathways. Attached to the inner side of the membrane, Gag assembles into spherical particles that incorporate Env proteins in their surrounding lipid envelope. The mechanism of Env incorporation is incompletely understood, however. Here, we have exploited recently developed super-resolution fluorescence microscopy techniques that yield a near-molecular spatial resolution to analyze HIV-1 Gag and Env distribution patterns at the surface of virus producing cells. We observed recruitment of Env to the surroundings of Gag assembly sites, dependent on the presence of its cytoplasmic domain. A large proportion of Env was found in the vicinity of the Gag assembly sites rather than directly co-localizing with it. These results support an indirect mechanism of Env recruitment, presumably mediated through virus induced changes in the environment of the nascent Gag assembly. Furthermore, they suggest a role for the Env protein in HIV-1 transmission that goes beyond its well-characterized function as an entry protein on the viral surface.
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影响因子：
6.7
作者：
Ivanchenko S;Godinez WJ;Lampe M;Kräusslich HG;Eils R;Rohr K;Bräuchle C;Müller B;Lamb DC
通讯作者：
Lamb DC
DOI：
10.1155/2012/979765
发表时间：
2012-01-01
期刊：
Molecular biology international
影响因子：
--
作者：
Hogue, Ian B;Llewellyn, G Nicholas;Ono, Akira
通讯作者：
Ono, Akira
影响因子：
5.6
作者：
Checkley MA;Luttge BG;Freed EO
通讯作者：
Freed EO
DOI：
10.1073/pnas.0511136103
发表时间：
2006-02-21
影响因子：
11.1
作者：
Brügger, B;Glass, B;Kräusslich, HG
通讯作者：
Kräusslich, HG
影响因子：
5.4
作者：
DORFMAN, T;MAMMANO, F;GOTTLINGER, HG
通讯作者：
GOTTLINGER, HG