TRANSCRIPTION CONTROL BY THE NUCLEAR ONCOPROTEIN, E1A

这项提议的长期目标是阐明转录 也是癌基因作用靶点的调控途径，如 腺病毒Ela。目前已鉴定出几种癌基因产物。 这些癌基因产物的生化功能测定 最终将阐明导致转变和 肿瘤发生学。越来越多的证据表明，大多数人 癌基因产物参与基因表达的调控。这 提案涉及对ELA癌基因产物的功能分析 关于它们对细胞蛋白质活性的影响，如 E2F、E4F和E2FBP。E2F和E4F是细胞转录因子， 都参与了腺病毒早期基因的控制性。E2FBP是一种 E2F结合蛋白，通过与E2F形成复合体来调节E2F活性 E2F又受ELA蛋白的调节。ElA解离E2F/E2FBP 需要ELA的结构域1和2的复合体，这两个结构域是 也参与了该癌蛋白的转化功能。因此，一个 这项建议的主要焦点是E2FBP的生化特征和 抗E2FBP特异性抗血清的制备及分析 ELA控制的基础。SV40T抗原与HPVE7蛋白 与ELA的结构域1和2以及这两个区域具有序列同源性 癌蛋白还反式激活腺病毒E2启动子，这取决于 E2F结合位点。这两种蛋白质也将被分析其 能够控制E2F/E2FBP相互作用。这件事的另一个利益 建议分析DNA结合的控制机制 ELA调节转录因子E4F的活性。特定的 试剂，如多肽抗血清和cdna克隆，将使用 多肽序列信息。这些试剂将会是非常 在研究E4F的磷酸化调节以及 由腺病毒ELA基因产物。该提案还侧重于 鉴定一种可能与细胞外信号转导有关的细胞激酶 E4F DNA结合活性的调节。

The long term goal of this proposal is to elucidate the transcription regulatory pathways that are also targets of oncogene action such as the adenovirus ElA. Several oncogene products have been identified. Determination of the biochemical functions of these oncogene products will eventually elucidate the pathways that lead to transformation and tumorigenesis. Evidence is accumulating that the majority of the oncogene products are involved in the control of gene expression. This proposal involves functional analysis Of ElA oncogene products with regard to their effect on the activities on the cellular proteins such as E2F, E4F and E2FBP. E2F and E4F are cellular transcription factors that are involved in the control of the adenovirus early genes. E2FBP is an E2F binding protein that modulates E2F activity by forming a complex with E2F which in turn is regulated by ElA proteins.ElA dissociates E2F/E2FBP complex requiring the domains 1 and 2 of ElA and these two domains are also involved in the transformation function of this oncoprotein. Thus a major focus of this proposal is biochemical characterization of E2FBP and production of specific antisera against E2FBP which will help analyzing the basis of ElA control. The SV40 T antigen and the HPV E7 protein possess sequence homology with domains 1 and 2 of ElA and these two oncoproteins also trans-activate adenovirus E2 promoter depending on the E2F binding site. These two proteins will also be analyzed for their ability to control E2F/E2FBP interaction. The other interest of this proposal is to analyze the mechanism that control the DNA binding activity of the ElA-regulated transcription factor E4F. Specific reagents, like peptide antisera and cDNA clones, will be obtained using the peptide sequence information. These reagents will be extremely valuable in the studies of E4F regulation by phosphorylation as well as by the adenovirus ElA gene products. The proposal also focuses on identification of a cellular kinase that might be involved in the regulation of E4F DNA binding activity.