ROLE OF INTRACELLULAR TRAFFIC IN HIV INFECTION

病毒成分必须通过核膜运输 发生在人类生命周期的许多阶段 免疫缺陷病毒(HIV)和其他逆转录病毒。一次在 细胞质，HIV RNA被逆转录成双链DNA 然后进入原子核。越来越多的证据表明 作为核介体的HIV病毒基质蛋白 交通事件。基质蛋白已在重组细胞中分离出来 形式和它的核定位检查。其他逆转录病毒 调节蛋白也进入细胞核来执行它们的功能， 病毒转录本被输出到细胞质中。病毒式传播 蛋白质，rev和tat，已被确定为关键的调节因子。 HIV包膜基因的转录和核外转运。 这些蛋白质包含的序列是必要和充分的 瞄准核仁。一种使用渗透剂的体外系统 已经开发出细胞来检测核仁靶向 带有这种靶向信号的蛋白质。我们观察到， 向核仁的运输是一个活跃的过程。除了它的 核仁转运速度主动从细胞核输出。当一个 已经确定了介导REV核输出的特定信号 蛋白质输出的机制还知之甚少。要检查这一点 核出口事件我们已经构建了一个嵌合蛋白，包括 与绿色荧光蛋白(GFP)偶联的REV。嵌合体 还含有糖皮质激素的类固醇结合域 因此，可以对核进口进行精确控制。添加 荷尔蒙的减少导致核运输；荷尔蒙的去除启动了 导出，但不允许后续导入。这些方法应该 允许我们对核出口进行分析和生化解剖 进程。

Viral components must be transported across the nuclear membrane occurs at numerous steps in the life cycle of the human immunodeficiency virus (HIV) and other retroviruses. Once in the cytoplasm, HIV RNA is reverse-transcribed into double-stranded DNA which then enters the nucleus. A growing amount of evidence points to the viral matrix protein of HIV as a mediator of the nuclear transport event. The matrix protein has been isolated in recombinant form and its nuclear localization examined. Other retroviral regulatory proteins also enter the nucleus to perform their function, and viral transcripts are exported out to the cytoplasm. The viral proteins, rev and tat, have been identified as a key regulators of the transcription and transport of HIV envelope mRNA out of the nucleus. These proteins contain sequences that are necessary and sufficient for targeting to the nucleolus. An in vitro system using permeabilized cells has been developed to examine the nucleolar targeting of proteins bearing such targeting signals. We have observed that transport to the nucleolus is an active process. In addition to its nucleolar transport rev is actively exported from the nucleus. While a specific signal mediating nuclear export of rev has been identified the mechanism of protein export is poorly understood. To examine this nuclear export event we have constructed a chimeric protein consisting of rev coupled to the green fluorescent protein (GFP). The chimera also contains the steroid binding domain of the glucocorticoid receptor thus allowing precise control over nuclear import. Addition of hormone leads to nuclear transport; removal of hormone initiates export but does not allow subsequent import. These approaches should allow us to analyze and biochemically dissect the nuclear export process.