ADENOVIRUS 243R E1A PROTEIN AND CELLULAR TRANSCRIPTION

对人类致癌机制的重要见解来自于 DNA肿瘤病毒的研究。 DNA肿瘤病毒腺病毒 提供了一个理想的系统，研究转录事件， 细胞转化 我们研究的长期目标是 了解腺病毒E1 A蛋白改变细胞增殖的机制。 正常的细胞转录程序，从而诱导转化。 在这里，我们集中在转录调控的细胞c-fos 腺病毒243 R E1 A蛋白与基因的功能相互作用 E1 A和细胞转录机制之间的联系。 我们以前的 研究已经确定了E1 A的作用与一个重要的 细胞内信号系统，cAMP依赖性蛋白激酶途径。 这种相互作用导致一组基因的激活， 参与细胞生长控制和转化。 获得的知识 通过研究E1 A对细胞转录调控的影响， 将导致更好地了解参与的分子事件， 转型 1)参与c-fos激活的识别性处理因子 通过E1 A和cAMP，一个22个核苷酸的“E1 A-反应元件”（ERE）已被 鉴定了通过243 R E1 A蛋白介导c-fos的激活。 ERE含有转录因子ATF/CREB的结合位点， YY 1. 将确定与ERE结合的因素，并且E1 A的作用 和cAMP对它们的水平和活性的影响。 2)ATF/CREB-YY 1复合物的结构和功能。YY 1物理 与转录因子的AFT/CREB家族的成员相互作用。 作为研究ATF/CREB-YY 1复合物在 激活B E1 A，ATF/CREB-YY 1的结构/功能分析 将进行互动。 DNA结合和转录 还将研究复合物的抑制作用。 3)ATF/CREB-YY 1复合物作为E1 A的靶点。 E1 A可以与YY 1结合， 改变其DNA结合特性。 E1 A和YY 1之间的相互作用， 研究E1 A与ATF/CREB-YY 1复合物之间的相互作用。 实验 将包括E1 A-YY 1相互作用的结构/功能分析， 以及在体外和体内结合测定中。 这些实验将导致 E1 a激活thec-fos基因的分子基础的模型。

Important insights into the mechanisms of human carcinogenesis have come from the study of DNA tumor viruses. The DNA tumor virus adenovirus provides an ideal system for investigating transcriptional events in cellular transformation. The long-term goal of our research is to understnd the mechanism by which the adenovirus E1A protein alters the normal cellular transcriptional program so as to induce transformation. Here, we focus on the transcriptional regulation of the cellular c-fos gene by the adenovirus 243R E1A protein, and the functional interaction between E1A and the cellular transcriptional machinery. Our previous studies have identified a link between the action of E1A and an important intracellular signling system, the cAMP-dependent protein kinase pathway. This interaction results in the activation of a set of genes that are involved in cellular growth control and transformation. Knowledge gained from studying the effects ofE1A on cellular transcriptional regulation wil lead to better understanding of the molecular events involved in transformation. 1) Identifiction transacting factors involved in the activation of c-fos by E1A and cAMP, A 22 nucleotide "E1A-response element" (ERE) has been identified that mediates activation of c-fos by the 243R E1A protein. The ERE contains binding sites for transcription factors ATF/CREB and YY1. Factors tht bind the ERE will be identified, and the effects of E1A and cAMP on their level and activity will be determined. 2) Structure and function of the ATF/CREB-YY1 complex. YY1 physically interacts with members of the AFT/CREB family of transcription factors. As a prelude to investigating the role of the ATF/CREB-YY1 complex in activation b E1A, structure/function analysis of the ATF/CREB-YY1 interaction will be performed. DNA-binding and transcriptional repression by the complex will also be investigated. 3) The ATF/CREB-YY1 complex as a target ofE1A. E1A can bind to YY1 and alter its DNA-binding properties. The interaction between E1A and YY1, and between E1A and the ATF/CREB-YY1 complex will e studied. Experiments will include structure/function analysis of the E1A-YY1 interaction, as well as in itro and in vivo binding assays. These experiments will lead to a model for the molecular basis of E1a activation of thec-fos gene.