REGULATION OF THE EBV BRLF1 AND BZLF1 PROMOTERS

病毒潜伏期的控制是EB病毒的关键问题。 生物学。过表达的即刻早期蛋白BZLF1(Z)是 足以扰乱病毒潜伏期。细胞和病毒的调控 因此这种基因产物在确定病毒是否 感染是潜伏性的，而不是生产性的。Z蛋白可以来源于 两种消息之一：1.0kb消息(转录自BZLF1 启动子)仅制造Z蛋白，或2.8kb的双顺反子信息 (从BRLF1启动子转录而来)，它可以使Z和BRLF1 (R)即刻早期蛋白质。病毒潜伏期的中断可能 可能通过激活BZLF1或 BRLF1启动子。 在这项资助中，我们建议确定细胞转录因子 通过激活以下两种方式之一来调节病毒潜伏期的中断 BZLF1或BRLF1启动子，并确定其生物学作用 作为Z蛋白来源的1.0kb消息与2.8kb消息。我们 最近发现BZLF1和BRLF1启动子都受 细胞内的阴阳1(YY-1)蛋白以及OCT样蛋白。 我们已经证明了BRLF1(但不是BZLF1)启动子被激活 通过细胞转录因子Sp1。此外，我们还发现， BRLF1启动子含有Zif268和WT1的结合位点 转录因子。 在我们的第一个具体目标中，我们将确定 BZLF1和BRLF1结合的各种转录因子 启动子，并产生定点突变，消除这些位点。在……里面 第二个具体目标是，我们将考察 与BZLF1和BRLF1结合的各种转录因子中的每一个 不同细胞类型的启动子。在第三个具体目标中，我们将 研究Z和R即刻早期蛋白与 调控BZLF1和BRLF1启动子的细胞转录因子 功能。在第四个具体目标中，我们将确定 作为Z蛋白来源的1.0kb与2.8kb的信息在不同的 用聚合酶链式反应分析EBV感染类型。在最终的具体目标中，我们 将构建突变病毒，其中Z蛋白或R蛋白 已被废除，或其中2.8kb的双顺反子性质 消息已经被摧毁，并确定了 这些突变。这些研究应该有助于确定 导致病毒潜伏期的细胞因素以及病毒的作用 BZLF1与BRLF1启动子在破坏病毒潜伏期方面的比较。

The control of viral latency is a key issue in Epstein-Barr virus (EBV) biology. Overexpression of the immediate-early protein, BZLF1 (Z), is sufficient to disrupt viral latency. the cellular and viral regulation of this gene product is therefore crucial in determining whether virus infection is latent versus productive. The Z protein can be derived from either of two messages: a 1.0 kb message (transcribed from the BZLF1 promoter) making only Z protein, or a 2.8 kb bicistronic message (transcribed from the BRLF1 promoter) which can make both the Z and BRLF1 (R) immediate-early proteins. Disruption of viral latency could potentially be mediated through activation of either the BZLF1 or the BRLF1 promoter. In this grant we propose to identify the cellular transcription factors mediating disruption of viral latency through activation of either the BZLF1 or the BRLF1 promoter and to determine the biological role of the 1.0 kb message versus the 2.8 kb message as a source of Z protein. We have recently found that both the BZLF1 and BRLF1 promoters are bound by the cellular Yin Yang 1 (YY-1) protein as well as an oct-like protein. We have shown that the BRLF1 (but not the BZLF1) promoter is activated by the cellular transcription factor, Sp1. In addition, we have found that the BRLF1 promoter contains binding sites for the zif268 and WT1 transcription factors. In our first specific aim we will determine the exact binding sites of the various transcription factors binding to the BZLF1 and BRLF1 promoters and create site-directed mutations abolishing these sites. In the second specific aim we will examine the functional significance of each of the various transcription factors binding to the BZLF1 and BRLF1 promoters in different cell types. In the third specific aim we will examine the interaction of the Z and R immediate-early proteins with the cellular transcription factors shown to regulate BZLF1 and BRLF1 promoter function. In the fourth specific aim we will determine the role of the 1.0 kb versus the 2.8 kb message as a source of Z protein in various types of EBV infection using PCR analysis. In the final specific aim we will construct mutant viruses in which either the Z or the R proteins have been abolished, or in which the bicistronic nature of the 2.8 kb message has been destroyed, and determine the biological consequences of these mutations. These studies should help to establish the nature of the cellular factors contributing to viral latency and the role of the BZLF1 versus the BRLF1 promoter in the disruption of viral latency.