Direct binding of retromer to human papillomavirus type 16 minor capsid protein L2 mediates endosome exit during viral infection.
Direct binding of retromer to human papillomavirus type 16 minor capsid protein L2 mediates endosome exit during viral infection.
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DOI：
10.1371/journal.ppat.1004699
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发表时间：
2015-02
期刊：
影响因子：
6.7
通讯作者：
DiMaio D
中科院分区：
文献类型：
--
作者：
Popa A;Zhang W;Harrison MS;Goodner K;Kazakov T;Goodwin EC;Lipovsky A;Burd CG;DiMaio D
在病毒进入过程中，人乳头瘤病毒向高尔基体的运输需要逆转录酶，这是一种内体外壳蛋白复合物，介导细胞跨膜蛋白从内体到高尔基体或质膜的囊泡转运。在这里，我们表明 HPV16 L2 小衣壳蛋白是逆转录体货物，尽管 L2 不是跨膜蛋白。我们发现，逆转录酶与 L2 羧基末端的保守序列直接结合是 L2 从早期内体退出并在病毒进入过程中递送至跨高尔基体网络所必需的。该结合位点不同于已知的逆转录酶结合基序，并且可以被来自细胞逆转录酶货物的分选信号取代。因此，HPV16是一种非常规的颗粒逆转录体货物，逆转录体结合在病毒进入过程中启动病毒成分从内体逆行运输到跨高尔基体网络。我们提出 L2 蛋白的羧基末端片段穿过内体膜并被细胞质中的逆转录酶接触。人乳头瘤病毒是重要的致癌物，但人们对这些无包膜病毒如何进入细胞核（基因组复制位点）知之甚少。我们使用成像、生化和遗传技术来证明，一种称为逆转录酶的多亚基细胞内运输机器直接与病毒颗粒中的 L2 小衣壳蛋白结合，启动其从内体运输到细胞内更远的其他膜结合细胞器。最值得注意的是，L2 中逆转录酶表达的敲低或新发现的逆转录酶结合位点的突变会导致传入的 HPV16 衣壳在内体中积累，并阻止转运到高尔基体。这些缺陷可以通过插入来自细胞货物的逆转录酶结合位点来纠正。由于所有先前已知的逆转录酶货物都是细胞跨膜蛋白，因此该病毒代表了一类新的逆转录酶货物。除了阐明病毒内体逃逸的机制之外，这些结果表明逆转录酶可能在细胞生物学中发挥比以前认识的更广泛的作用。
Trafficking of human papillomaviruses to the Golgi apparatus during virus entry requires retromer, an endosomal coat protein complex that mediates the vesicular transport of cellular transmembrane proteins from the endosome to the Golgi apparatus or the plasma membrane. Here we show that the HPV16 L2 minor capsid protein is a retromer cargo, even though L2 is not a transmembrane protein. We show that direct binding of retromer to a conserved sequence in the carboxy-terminus of L2 is required for exit of L2 from the early endosome and delivery to the trans-Golgi network during virus entry. This binding site is different from known retromer binding motifs and can be replaced by a sorting signal from a cellular retromer cargo. Thus, HPV16 is an unconventional particulate retromer cargo, and retromer binding initiates retrograde transport of viral components from the endosome to the trans-Golgi network during virus entry. We propose that the carboxy-terminal segment of L2 protein protrudes through the endosomal membrane and is accessed by retromer in the cytoplasm. The human papillomaviruses are important carcinogens, but little is known about how these non-enveloped viruses traffic to the nucleus, the site of genome replication. We use imaging, biochemical, and genetic techniques to show that a multi-subunit intracellular trafficking machine known as retromer binds directly to the L2 minor capsid protein in the virus particle to initiate its transport from the endosome to other membrane-bound organelles farther inside the cell. Most notably, knock-down of retromer expression or mutation of newly identified retromer binding sites in L2 cause the accumulation of incoming HPV16 capsids in the endosome and prevent trafficking to the Golgi. These defects can be corrected by insertion of a retromer binding site from a cellular cargo. Because all previously known retromer cargoes are cellular transmembrane proteins, the virus represents a new class of retromer cargo. In addition to elucidating the mechanism of viral endosome escape, these results suggest that retromer may play a more versatile role in cell biology than previously recognized.
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DOI：
10.1007/978-1-4614-0980-9_18
发表时间：
2012-01-01
期刊：
VIRAL MOLECULAR MACHINES
影响因子：
--
作者：
Buck, Christopher B.;Trus, Benes L.
通讯作者：
Trus, Benes L.
影响因子：
5.4
作者：
Magaldi, Thomas G.;Buch, Michael H. C.;DiMaio, Daniel
通讯作者：
DiMaio, Daniel
影响因子：
5.4
作者：
Giroglou, T;Florin, L;Sapp, M
通讯作者：
Sapp, M
影响因子：
5.4
作者：
Laniosz, Valerie;Dabydeen, Sarah A.;Meneses, Patricio I.
通讯作者：
Meneses, Patricio I.
影响因子：
4.8
作者：
Letian T;Tianyu Z
通讯作者：
Tianyu Z