Effect of HIV-1 Vpr on Basic Cellular Functions (II)

HIV-1 Vpr对细胞基本功能的影响（二）

• 批准号: 6832233
• 负责人: RICHARD YUQI ZHAO
• 金额: $ 29.7万
• 依托单位: UNIVERSITY OF MARYLAND BALTIMORE
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-01-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6832233
• 关键词: Effect; HIV; Vpr; Basic; Cellular

EXCEED THE SPACE PROVIDED. HIV-1 Vpr plays a pivotal role in viral pathogenesis, as its functions are being linked to nuclear transport of viral pre-integration complex, viral replication and suppression of human immune function. However, little is known about the molecular mechanisms underlying these effects. In this proposal, we will focus on studying two related effects of Vpr on cell cycle G2/M control and proteolysis, which will help us to further understand the molecular basis of these viral effects on the host cellular functions. With support of the NIH R29 First Award, we have successfully accomplished the three proposed Specific Aims, i.e., 1) to define the functional domains of Vpr responsible for nuclear localization, G2 arrest and cell killing, 2) to identify the cellular pathways affected by Vpr when it interrupts the cell cycle, and 3) to investigate the specific role of PP2A in Vpr-induced G2 arrest. We showed that Vpr activities in fission yeast cells are very similar to those in mammalian cells. We also found that Vpr does not induce G2 arrest through the classic DNA damage or replication checkpoints but instead uses an alternative PP2A-mediated regulatory pathway. In addition, we have identified a number of genes which when overexpressed suppress the G2 arrest and nuclear localization of Vpr, and these suppressors led us to uncover a new role for Vpr in the regulation of proteolysis. For the proposed studies, we hypothesize that Vpr induces G2 arrest through a novel PP2A-mediated regulatory pathway(s), and Vpr affects proteolysis by interaction with the proteasome on the nuclear periphery. Three new specific aims are proposed to test these hypotheses. 1) To define and characterize the cellular components of the new PP2A-mediated regulatory pathway by which Vpr induces G2 arrest. 2) To test the potential effect of Vpr on proteasome-related activities including proteolysis and MHC class I antigen processing and presentation. 3) To investigate biological significance of the Vpr-HHR23A interaction and its specific role in proteolysis. The proposed studies combine the use of biochemical and genetic approaches in both mammalian and fission yeast model system, which should yield important new insights into fundamental aspects of the effect of Vpr on these two basic cellular functions. PERFORMANCE SITE ========================================Section End===========================================

超过提供的空间。 HIV-1 VPR在病毒发病机理中起关键作用，因为其功能与病毒前整合复合物的核转运，病毒复制和对人类免疫功能的抑制有关。然而，对于这些作用的分子机制知之甚少。在此提案中，我们将重点研究VPR对细胞周期G2/M控制和蛋白水解的两个相关影响，这将有助于我们进一步了解这些病毒效应对宿主细胞功能的分子基础。 在NIH R29第一奖的支持下，我们成功完成了三个提出的特定目标，即1）定义VPR负责核本地化的功能域，G2逮捕和细胞杀戮，2）确定在中断细胞周期时受VPR影响的细胞途径，并在中断细胞周期以及3）中调查PP2A中的特定角色，以研究PP2A的特定角色，以pp2a carts prasted carts cart-inded cancust in vpr-inded ofd cand ins in vpr-inded of drest of vpr-inded of g2 rasted cand ofd inded of g2 inded of drest of vpr-inded of vpr-inded of vpr-inded of drest。我们表明，裂变酵母细胞中的VPR活性与哺乳动物细胞中的活性非常相似。我们还发现，VPR不会通过经典的DNA损伤或复制检查点诱导G2停滞，而是使用替代PP2A介导的调节途径。此外，我们已经确定了许多基因，这些基因过表达抑制了G2的停滞和VPR的核定位，这些抑制剂使我们发现了VPR在调节蛋白水解中的新作用。 在拟议的研究中，我们假设VPR通过新的PP2A介导的调节途径诱导G2停滞，而VPR通过与核周围的蛋白酶体相互作用来影响蛋白：蛋白水解。提出了三个新的特定目标来检验这些假设。 1）定义和表征新的PP2A介导的调节途径的细胞成分，VPR诱导G2停滞。 2）测试VPR对蛋白酶体相关活性的潜在影响，包括蛋白水解和MHC I类抗原加工和表现。 3）研究VPR-HHR23A相互作用的生物学意义及其在蛋白水解中的特定作用。拟议的研究结合了在哺乳动物和裂变酵母模型系统中生化和遗传方法的使用，这应该对VPR对这两个基本细胞功能的影响的基本方面产生重要的新见解。表演站点=============================================================================================