Gammaherpesviral tegument proteins - crucial effectors of viral infection

伽马疱疹病毒被膜蛋白 - 病毒感染的关键效应物

基本信息

批准号：
392416179
负责人：
Professor Dr. Armin Ensser
金额：
--
依托单位：
Virologisches Institut - Klinische und Molekulare Virologie
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2017
资助国家：
德国
起止时间：
2016-12-31 至 2021-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/392416179?language=en
关键词：
Gammaherpesviral tegument proteins crucial effectors

项目摘要

All Gammaherpesviruses encode tegument proteins with homology to cellular PFAS (FGARAT), a purine nucleotide synthesis pathway enzyme conserved in all life forms. The viruses, however, have evolved these enzyme homologs toward diverse effector functions that interfere with ND10 mediated intrinsic immunity. Since high-resolution structural information is lacking from both viruses and eukaryotes, we will perform a structure-based analysis of viral FGARAT interactions (KSHV ORF75, RRV ORF75, and HVS ORF3) with their cellular counterpart, the human PFAS. Hitherto, protein expression of viral ORF75 (KSHV, RRV) and cellular PFAS (human) for structural analysis is in progress. The KSHV ORF75 protein is essential for replication and thus a target for the development of a new class of antiviral inhibitors. The molecular and biochemical analysis will include MS-based technologies and CRISPR/Cas9 mediated knockout as well as synthetic activation mediator (SAM) technologies established in the laboratory. The broader effects of viral FGARATs on the nuclear and cytoplasmic proteome will be quantitatively analyzed by SILAC in cells conditionally expressing the viral effectors. MS-based identification of interaction partners has already revealed SMCHD1, cellular PFAS, and USP15 as important targets. Notably, the cellular tumor suppressor SMCHD1 is being relocated by KSHV ORF75 to ND10. SMCHD1 is a crucial mediator of X-chromosome compaction and inactivation, and it is involved in DNA-Damage response, suggesting a link between viral interference with SMCHD1 and cancer. USP15 is a known promoter of TGFbeta signaling and oncogenesis. From the current results, we propose that viral FGARATs tackle several lines of cellular defense, and the project plan will address the following hypotheses:- Rhadinoviral vFGARAT tegument proteins target distinct ND10 associated chromatin remodeling factors to achieve a chromatin status favorable for viral gene expression during de-novo infection and during reactivation.- KSHV vFGARAT contributes to the development of viral cancers through interactions with cellular targets that have roles in human cancer and DNA repair.Uncovering the mechanisms of newly identified viral effector interactions with host cell proteins will extend knowledge on viral and cellular replication and central biosynthesis pathways, and on predisposition to virus-associated cancer.

所有伽马疱疹病毒都编码与细胞 PFAS (FGARAT) 同源的外皮蛋白，FGARAT 是一种在所有生命形式中保守的嘌呤核苷酸合成途径酶。然而，病毒已将这些酶同源物进化为干扰 ND10 介导的内在免疫的不同效应子功能。由于病毒和真核生物都缺乏高分辨率的结构信息，我们将对病毒 FGARAT（KSHV ORF75、RRV ORF75 和 HVS ORF3）与其细胞对应物（人类 PFAS）的相互作用进行基于结构的分析。迄今为止，用于结构分析的病毒 ORF75（KSHV、RRV）和细胞 PFAS（人）的蛋白质表达正在进行中。 KSHV ORF75 蛋白对于复制至关重要，因此是开发新型抗病毒抑制剂的目标。分子和生化分析将包括基于MS的技术和实验室建立的CRISPR/Cas9介导的基因敲除以及合成激活介体（SAM）技术。 SILAC 将在条件表达病毒效应子的细胞中定量分析病毒 FGARAT 对核和细胞质蛋白质组的更广泛影响。基于 MS 的相互作用伙伴识别已经揭示了 SMCHD1、细胞 PFAS 和 USP15 是重要目标。值得注意的是，细胞肿瘤抑制因子 SMCHD1 被 KSHV ORF75 重新定位为 ND10。 SMCHD1 是 X 染色体压缩和失活的重要介质，它参与 DNA 损伤反应，表明病毒对 SMCHD1 的干扰与癌症之间存在联系。 USP15 是 TGFbeta 信号传导和肿瘤发生的已知启动子。根据目前的结果，我们建议病毒 FGARAT 解决细胞防御的几道防线，并且该项目计划将解决以下假设：-Rhadinoviral vFGARAT 被膜蛋白靶向不同的 ND10 相关染色质重塑因子，以在病毒感染过程中实现有利于病毒基因表达的染色质状态。从头感染和再激活过程中。- KSHV vFGARAT 通过与在人类癌症和 DNA 中发挥作用的细胞靶标相互作用，促进病毒性癌症的发展揭示新发现的病毒效应子与宿主细胞蛋白相互作用的机制将扩展对病毒和细胞复制、中央生物合成途径以及病毒相关癌症易感性的认识。