Mechanisms of KSHV posttranscriptional gene regulation

KSHV转录后基因调控机制

• 批准号: 9217575
• 负责人: NICHOLAS K CONRAD
• 金额: $ 40.5万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-03-01 至 2021-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9217575
• 关键词: Binding; Biology; Cell Nucleus; Cells; Cellular biology; DNA Viruses; Data; Data Set; Etiology; Family; Gene Expression; Gene Expression Regulation; Genes; Herpesviridae; Human; Human Herpesvirus 8; Integration Host Factors; Learning; Life Cycle Stages; Light; Link; Lymphoproliferative Disorders; Lytic; Mediating; Modeling; Molecular; Nuclear; Nuclear RNA; Pathogenicity; Pathway interactions; Poly(A) Tail; Poly(A)+ RNA; Poly(A)-Binding Proteins; Polynucleotide Adenylyltransferase; Proteins; Publishing; Quality Control; RNA; RNA Binding; RNA Decay; RNA-Binding Proteins; Regulation; Regulator Genes; Ribonucleoproteins; Role; Testing; Trans-Activators; Transcript; Translations; Up-Regulation; Viral; Viral Genes; Virus; Virus Replication; Work; crosslinking and immunoprecipitation sequencing; human disease; insight; mRNA Expression; particle; pathogen; programs; public health relevance; therapeutic target; viral RNA; virtual; virus host interaction

 DESCRIPTION (provided by applicant): Productive viral replication requires the expression of viral genes in the context of an infected host cell. By studying host-virus interactions involved i viral gene expression, the underlying biology of both the pathogen and the host are uncovered. The Kaposi's sarcoma-associated herpesvirus (KSHV) is a double-stranded nuclear DNA virus and an important human pathogen that causes several lymphoproliferative disorders. The KSHV ORF57 (Mta) protein is conserved among herpesviruses and is essential for viral replication, so elucidation of its mechanisms informs our understanding of the KSHV life cycle. ORF57 has been proposed to function in nearly every stage of mRNA expression from synthesis to processing to translation, but emerging data show that a central function of ORF57 is to increase the stability of viral RNAs in the nucleus. We recently described a cellular nuclear RNA decay pathway that involves the poly (A)-binding protein PABPN1 and poly (A) polymerases PAPα/γ, and preliminary studies strongly suggest that ORF57 protects viral RNAs from this decay pathway. The work proposed here seeks to uncover the mechanistic links between KSHV ORF57 and host- mediated nuclear RNA decay. Specific Aim 1 uses an ORF57-null KSHV BACmid clone to test the importance of ORF57-mediated inhibition of nuclear RNA decay in the context of lytic reactivation. In this aim, we further test whether this activity is conserved amon herpesviruses. Specific Aim 2 will determine the molecular mechanism by which ORF57 inactivates this cellular RNA decay pathway. Specific Aim 3 seeks to define the cis- and trans-acting factors that make certain RNAs ORF57-respononsive while other transcripts are relatively unaffected by ORF57. ORF57 is absolutely required for replication, but its mechanisms remain largely unknown, so this work informs KSHV biology by defining the activities of an essential KSHV factor. In addition, PABPN1-mediated decay is a recently described discovered host pathway whose importance is only beginning to be realized, but it appears to be widespread. As such, the proposed studies will significantly impact the current understanding of the molecular mechanisms of gene regulation for both virus and human cells.

 描述（由申请方提供）：生产性病毒复制需要在感染的宿主细胞中表达病毒基因。通过研究病毒基因表达所涉及的宿主-病毒相互作用，揭示了病原体和宿主的潜在生物学。卡波西肉瘤相关疱疹病毒（KSHV）是一种双链核DNA病毒，是一种重要的人类病原体，可引起多种淋巴组织增生性疾病。KSHV ORF 57（Mta）蛋白在疱疹病毒中是保守的，对病毒复制至关重要，因此阐明其机制有助于我们了解KSHV的生命周期。已经提出ORF 57在mRNA表达的几乎每个阶段（从合成到加工再到翻译）中发挥作用，但是新的数据表明ORF 57的中心功能是增加病毒RNA在细胞核中的稳定性。我们最近描述了一种涉及多聚腺苷酸结合蛋白PABPN 1和多聚腺苷酸聚合酶PAPα/γ的细胞核RNA衰变途径，初步研究强烈表明ORF 57保护病毒RNA免受这种衰变途径的影响。本文提出的工作旨在揭示KSHV ORF 57与宿主介导的核RNA衰变之间的机制联系。特异性目的1使用ORF 57无效的KSHV BACmid克隆来测试在裂解再活化的情况下ORF 57介导的核RNA衰变抑制的重要性。在这个目标中，我们进一步测试这种活性是否是保守的疱疹病毒。特异性目标2将确定ORF 57使该细胞RNA衰变途径失活的分子机制。特定目标3试图定义使某些RNA ORF 57响应而其他转录物相对不受ORF 57影响的顺式和反式作用因子。ORF 57是复制所必需的，但其机制在很大程度上仍然未知，因此这项工作通过定义KSHV重要因子的活动来告知KSHV生物学。此外，PABPN 1介导的衰变是最近发现的一种宿主途径，其重要性才刚刚开始被认识到，但它似乎很普遍。因此，拟议的研究将显著影响目前对病毒和人类细胞基因调控分子机制的理解。