Identification of a host protein that is necessary for the initial stage of HPV infection

鉴定 HPV 感染初期所需的宿主蛋白

基本信息

批准号：
22590425
负责人：
ISHII Yoshiyuki
金额：
$ 2.91万
依托单位：
National Institute of Infectious Diseases
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2010
资助国家：
日本
起止时间：
2010 至 2012
项目状态：
已结题

项目摘要

The human papillomavirus (HPV) is a member of the papillomaviridae family of non-enveloped DNA tumor viruses. Differing from enveloped viruses, HPVs are thought to gain cell entry and escape into the cytoplasm using their own strategy. However, the cellular machinery required for the initial infection stage is poorly understood. Here we report that transport protein particle complex subunit 8 (TRAPPC8), a host protein that interacts with HPV minor capsid protein L2, plays a crucial role in the HPV entry process. TRAPPC8-knockdown epithelial cells showed reduced susceptibility to pseudovirus (PsV) transduction and authentic virus infection. TRAPPC8 was present in cytosolic and microsomal fractions of HeLa cells. The C-terminal region was exposed on the cell surface and co-localized with PsV after inoculation with PsV. The entry of PsV and L2-deficient PsV into TRAPPC8-knockdown cells was severely impaired, suggesting that TRAPPC8 plays an important role in HPV entry in a L2 interaction-independent manner. On the other hand, expression of GFP-fused L2s that can interact with TRAPPC8 induced dispersal of Golgi stack structure in HeLa cells, which is a phenotype observed by TRAPPC8 knockdown. These results imply a possibility that during viral intracellular trafficking L2 binding to TRAPPC8 inhibits its function and results in Golgi de-stabilization, which may help an escape of the HPV genome from the trans-Golgi network into the cytoplasm or nucleus after attaining cell entry.

人乳头瘤病毒（HPV）是非发育DNA肿瘤病毒的乳头状瘤科家族的成员。与包裹病毒不同，HPV被认为可以通过自己的策略逃脱细胞的细胞质。但是，最初感染阶段所需的细胞机制知之甚少。在这里，我们报告说，转运蛋白质颗粒复合物亚基8（TRAPPC8）是一种与HPV次要衣壳蛋白L2相互作用的宿主蛋白，在HPV进入过程中起着至关重要的作用。 TRAPPC8敲击上皮细胞显示出对假病毒（PSV）转导和正宗病毒感染的敏感性降低。 TRAPPC8存在于HeLa细胞的胞质和微粒体分数中。与PSV接种后，将C末端区域暴露在细胞表面，并与PSV共定位。 PSV和L2缺陷型PSV进入TRAPPC8敲低细胞被严重损害，这表明TRAPPC8在L2相互作用的非依赖性方式中在HPV进入中起重要作用。另一方面，可以与TRAPPC8诱导的Golgi堆栈结构在HeLa细胞中相互作用的GFP融合的L2s的表达，这是TrappC8敲低观察到的表型。这些结果表明，在病毒内运输期间，L2结合与TRAPPC8的结合抑制了其功能，并导致高尔基体稳定化，这可能有助于HPV基因组从转基因网络中逃脱到进入细胞质或核中，后者在进入细胞质或细胞核中。