Project 3

项目三：VPR/GR(Aim Lla) 项目负责人：维尔潘迪·阿亚沃博士 VPR参与了前病毒的核定位和运输到未分裂细胞的核中， 如巨噬细胞和树突状细胞244‘245。虽然VPR对T细胞感染不是绝对必要的，但 VPR的存在增强了T细胞中的病毒复制，并激活了潜伏感染和静止的T细胞。VPR 通过改变进入细胞核的运输和促进细胞功能的改变来增强病毒的复制 和HIV-1的生命周期246。病毒粒子相关的VPR反式激活HIV-1长末端重复序列(LTR) 并通过与其他病毒蛋白的相互作用在从头合成其他病毒蛋白之前激活病毒转录 糖皮质激素受体(GR)。我们和其他研究人员最近使用vpr突变体的研究清楚地表明 证明VPR通过VPR中高度保守的富含亮氨酸的GR信号基序与GR相互作用， 提示VPR/GR的相互作用是特异的129‘。此外，VPR/GR的相互作用及其后续 功能调节独立于其他VPR功能，如细胞周期停滞。这表明一种 GR通路在VPR介导的病毒复制中的可能作用。在我们实验室所做的工作中，细胞 VPR的调节失调被发现与VPR通过诱导 IKB转录的方式类似于糖皮质激素248。VPR对核因子-kB的调节提示一个分子 VPR的细胞效应的基础，并支持该基因产物可能介导一些 病毒致病机制的各个方面。综上所述，这些结果表明，VPR可能通过GR途径，在 部分，有助于病毒复制和疾病进展。为了实现目标哈，项目三将奏效 紧密结合细胞和单粒子成像核心进一步表征VPR之间的相互作用 和GR，并将开始表达研究，以确定GR蛋白的大多数方法和结构域 适用于结构测定。

Project III: Vpr/GR (Aim lla) Project Leader: Velpandi Ayyavoo, PhD Vpr is involved in nuclear localization and trafficking of the provirus into the nucleus of non-dividing cells, such as macrophages and dendritic cells244'245. Though Vpr is not absolutely essential for T cell infection, the presence of Vpr enhances viral replication in T cells and activates latently infected and resting T cells. Vpr enhances viral replication by altering transport into the nucleus and by facilitating changes in cellular functions and the HIV-1 life cycle246. Virion-associated Vpr transactivates HIV-1 long terminal repeat sequences (LTR) and activates virus transcription prior to de novo synthesis of other viral proteins through an interaction with glucocorticoid receptor (GR). Recent studies using Vpr mutants by us and other investigators have clearly demonstrated that Vpr interacts with GR through a highly conserved leucine-rich GR signature motif in Vpr, suggesting that the Vpr/GR interaction is specific129' . Furthermore, Vpr/GR interaction and its subsequent functional regulations are independent of other Vpr functions such as cell cycle arrest. This suggests a possible role for the GR pathway in Vpr-mediated virus replication. In work done by our laboratory, the cellular dysregulation by Vpr was found to relate to the ability of Vpr to suppress NF-kB activity through the induction of IkB transcription in a manner similar to glucocorticoids248. The regulation of NF-kB by Vpr suggests a molecular basis for the cellular effects of Vpr and supports the possibility that this gene product might mediate some aspects of viral pathogenesis. Taken together, these results suggest that Vpr, via the GR pathway, could, in part, contribute to viral replication and disease progression. Toward accomplishing Aim Ha, Project III will work closely with the Cellular and Single Particle Imaging Core to further characterize the interaction between Vpr and GR in cells and will begin expression studies to identify methods and domains of the GR protein most suitable for structural determination.