HIV VIRION RELEASE AND VIRAL PROTEIN U (VPU)

本提案中描述的实验旨在 了解“病毒蛋白U”（Vpu）介导 从细胞中分离出HIV-1颗粒。潘加尼班博士的实验 这里描述的是围绕一种新的细胞蛋白质的作用， 在酵母、体外和人体细胞中与Vpu直接相互作用。 这种新的细胞蛋白，“U-结合蛋白（Ubp）是一个成员， 蛋白质超家族，包括亲免素和一类 含三肽重复的丝氨酸/苏氨酸磷酸酶 （TPRs）。Panganiban博士和他的同事们有几个互补的 目标.他们将进行实验来研究 Vpu和UBP更详细。尤其是。特别是他们将 确定两种蛋白质的蛋白质-蛋白质相互作用所需的区域， 相互作用，分离显示出改变的结合稳定性的突变体，和 检验Vpu作用是通过Ubp介导的假设。Panganiban博士的 初步数据还表明Ubp与HIV-1 Gag直接相互作用， 在体外与HIV-1 Gag蛋白的衣壳结构域结合， 细胞因此，他将确定所需的Ubp和Gag上的站点 for this interaction互动.为了检查Ubp对颗粒释放的影响， 表达野生型和突变形式的Ubp和Gag的影响， 是这种互动所必需的。检查UBP对 颗粒释放，野生型和突变体形式表达的效果 将确定Ubp对颗粒释放的影响。同样，他们可能 确定内源性Ubp表达的消除是否影响 颗粒释放效率。最后，由于UBP以前没有 Panganiban博士和他的同事们将研究 Ubp的内在属性，并试图深入了解正常的作用 细胞中的UBP。这些研究的总体目标是制定一个 全面的图片，占分子机制， Vpu介导颗粒释放。

The experiments described in this proposal are directed toward understanding the mechanism by which "viral protein U" (Vpu) mediates the exist of HIV-1 particles from cells. Dr. Panganiban's experiments described here are centered around the role of a novel cellular protein that interacts directly with Vpu in yeast, in vitro and in human cells. This novel cellular protein, "U-binding protein (Ubp) is a member of a protein superfamily that includes the immunophilins and a class of serine/threonine phosphatases containing tetratrico-peptide repeats (TPRs). Dr. Panganiban and his colleagues have several complementary goals. They will carry out experiments to examine the interaction between Vpu and Ubp in more detail. In particular. In particular they will identify regions of the two proteins that are required for protein-protein interaction, isolate mutants that exhibit altered binding stability, and test the hypothesis that Vpu action is mediated via Ubp. Dr. Panganiban's preliminary data also indicated that Ubp interacts directly with Hiv-1 Gag protein in vitro, and with the capsid domain of HIV-1 Gag protein in human cells. Thus, he will identify the sites on Ubp and Gag that are required for this interaction. To examine the effect on Ubp on particle release, the effect of expression of wild type and mutant forms of Ubp and Gag that are required for this interaction. To examine the effect of Ubp on particle release, the effect of expression of wild type and mutant forms of Ubp on particle release will be determined. Similarly, they may determine whether ablation of endogenous Ubp expression affects the efficiency of particle release. Finally, since Ubp has not been previously characterized, Dr. Panganiban and his colleagues will examine the intrinsic properties of Ubp and try to gain insight into the normal role of Ubp in the cell. The overall goal of these studies to develop a comprehensive picture that accounts for the molecular mechanism by which Vpu mediates particle release.