Viral RNPs, mRNA Stability and Export

病毒 RNP、mRNA 稳定性和输出

• 批准号: 6989639
• 负责人: JOAN A. STEITZ
• 金额: $ 11.06万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-02 至 2009-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6989639
• 关键词: B lymphocyte; Epstein Barr virus; Herpesvirus saimiri; RNA interference; T lymphocyte; Xenopus; cell transformation; crosslink; gene deletion mutation; gene expression; host organism interaction; human herpesvirus 8; messenger RNA; microarray technology; neoplasm /cancer genetics; oncogenic virus; phenotype; protein protein interaction; regulatory gene; viral carcinogenesis; virus RNA; virus protein

The roles of non-coding nuclear RNAs in lymphoid cells harboring three transforming herpesviruses are being investigated. Epstein-Barr virus (EBV) infects and transforms human B cells and is the causative agent of infectious mononucleosis, as well as being associated with several human cancers. Herpesvirus saimiri induces fatal lymphomas and leukemias in New World monkeys and transforms human and monkey T lymphocytes in culture, resulting in a mature, activated phenotype. Kaposi sarcoma-associated herpesvirus (KSHV) afflicts AIDS and other immunocompromised patients and, like other herpesviruses, persists in a latent form until activation of the lytic phase. Among the few viral gene products expressed in transformed cells are the two EBV-encoded EBERs and the seven H. saimiri-encoded HSURS; yet, they are not essential for viral growth or transformation. Upon induction, KSHV produces PAN, a capped, polyadenylated RNA that does not leave the nucleus. These viral RNAs are all relatively small (<1.1 kb), abundant, conserved, and associate with host proteins that - in the case of EBERs and HSURs - are autoantigens. They are therefore excellent probes for dissecting host cell pathways, as well as mechanisms of viral transformation or lytic growth. Proposed experiments will test both the hypothesis that EBERs, HSURs and PAN may perturb cellular metabolism by sequestering important host proteins, and the possibility that their RNPs perform some function critical for the virus. The molecular details of the interactions of protein L22, PKR and La with EBER1 will be probed by structural studies and nucleotide analog interference mapping. Components of the EBER2 RNP will be identified. EBERs will be examined for possible shuttling between the nucleus and cytoplasm, and their contribution to host gene expression assessed by microarray analyses, Microarray evidence that HSURs 1 and 2 enhance the activated state of transformed T cells will be confirmed in rescue experiments using lentiviral vectors, their interaction with TTP and its effects examined, and the level at which HSURs modulate host gene expression determined. RNA elements and trans-acting factors essential for PAN accumulation in the nucleus will be characterized. PAN function in KSHV lytic infection will be investigated by siRNA knockdown and/or genomic PAN deletion, followed by complementation experiments.

非编码核RNA的作用，淋巴细胞窝藏三个转化疱疹病毒正在调查。EB病毒（EBV）感染并转化人类B细胞，并且是传染性单核细胞增多症的病原体，以及与几种人类癌症相关。松鼠猴疱疹病毒在新世界猴中诱导致命的淋巴瘤和白血病，并在培养中转化人和猴的T淋巴细胞，导致成熟的活化表型。卡波西肉瘤相关疱疹病毒（KSHV）折磨艾滋病和其他免疫功能低下的患者，像其他疱疹病毒一样，以潜伏形式持续存在，直到裂解期激活。在转化细胞中表达的少数病毒基因产物中有两个EBV编码的EBER和七个H。”““对，““She said。 对病毒生长或转化不是必需的。在诱导时，KSHV产生PAN，一种加帽的， 不离开细胞核的多聚腺苷酸化RNA。这些病毒RNA都相对较小（<1.1 kb），丰富，保守，并与宿主蛋白质相关-在EBER和HSUR的情况下-是自身抗原。因此，它们是用于解剖宿主细胞途径以及病毒转化或裂解生长机制的优秀探针。拟议的实验将测试EBER、HSUR和PAN可能通过隔离重要的宿主蛋白质来扰乱细胞代谢的假设，以及它们的RNP执行某些对病毒至关重要的功能的可能性。蛋白质L22、PKR和La与细胞凋亡相互作用的分子细节 EBER 1将通过结构研究和核苷酸类似物干扰图谱来探测。将确定EBER 2 RNP的组成部分。将检查EBER在细胞核和细胞质之间的可能穿梭，并通过微阵列分析评估其对宿主基因表达的贡献。将在使用慢病毒载体的拯救实验中证实HSUR 1和2增强转化T细胞的活化状态的微阵列证据，检查其与TTP的相互作用及其影响，并确定HSUR调节宿主基因表达的水平。RNA元件和反式作用因子PAN积累在细胞核中必不可少的特点。PAN在KSHV裂解性感染中的功能将通过siRNA敲低和/或基因组PAN缺失，然后进行互补实验来研究。