FUNCTIONAL ORGANIZATION OF BK VIRUS PROMOTER/ENHANCER

乳多空病毒BK广泛分布于人群中。 与其他乳多空病毒一样，它在啮齿动物中具有致瘤性。 的 BK的整体基因组结构与井- 特征性猴乳多空病毒SV 40，具有早期和晚期 RNA从一个共同的 转录控制区 不同的BK分离株显示 控制区中的重排、缺失和插入， 导致病毒致瘤潜力的改变。 这 控制区是BK基因组中唯一一个 序列同源性SV 40，似乎BK相互作用 一组不同的宿主细胞转录因子。 我们提出了一些实验，试图了解如何 BK控制区工作。 使用DNA酶I足迹和其他 DNA结合的分析，我们将绘制精确的位点， 宿主细胞蛋白质的相互作用，然后将确定是否 结合这些位点的蛋白质与 已知与其他病毒和细胞结合的转录因子 启动子/增强子区域。 使用绑定中的信息 分析，我们将着手关联序列特异性结合 具有生物功能。 我们将开发一种体外转录 系统依赖于一些或所有被鉴定为 结合到控制区，并且将另外在体内发展 能够分别测量早期和晚期启动子的测定 功能和转录增强子活性。 我们将对比BK（Dunlop）中的序列特异性蛋白结合， 菌株）与其他BK变体中的相同，特别注意 可能由高变连接形成的位点 直接序列重复的区域。 实验沿着 这里提出的路线应该彻底阐明的工作， BK控制区，因此将允许合理的解释 与致瘤性相关的当前和未来观察结果，或 BK病毒及其变异体的其他致病作用。

The papovavirus BK is widely distributed in the human population. Like other papovaviruses, it is tumorigenic in rodents. The overall genome structure of BK is similar to the well- characterized monkey papovavirus SV40, with early and late RNAs transcribed in opposite directions from a common transcriptional control region. Different BK isolates show rearrangements, deletions, and insertions in the control region, leading to alterations in the virus's tumorigenic potential. This control region is the only part of the BK genome with little sequence homology to SV40, and it seems likely that BK interacts with a different set of host cell transcription factors. We propose a number of experiments to try a understand how the BK control region works. Using DNase I footprinting and other assays of DNA binding, we will map the precise sites of interaction of host cell proteins, and then will determine whether the proteins that bind these sites are the same or different from transcription factors known to bind other viral and cellular promoter/enhancer regions. Using information from the binding assays, we will proceed to correlate sequence-specific binding with biological function. We will develop an in vitro transcription system dependent on some or all of the proteins identified as binding to the control region, and will in addition develop in vivo assays capable of separately measuring early and late promoter function, and transcriptional enhancer activity. We will contrast sequence-specific protein binding in BK (Dunlop strain) with that in other BK variants, with special attention to sites that may be formed by the hyper-variable junctions within the region of direct sequence repeats. Experiments along the lines proposed here should thoroughly illuminate the workings of the BK control region, and thus will allow rational interpretation of present and future observations relating to tumorigenicity or other pathogenic effects of BK virus and its variants.