PRB2--A NOVEL TARGET FOR THE AD5 E1A ONCOPROTEINS

腺病毒E1a癌蛋白已被证明是一种有效的工具 调控基础细胞的蛋白质因子的鉴定 转录、RNA加工、DNA复制和细胞等过程 周期调节。几种与生长有关的细胞蛋白 调控与E1a的转化区相互作用。这些蛋白质 表观分子量分别为33kD、60kD、105kD、 107kD、107kD、130kD和300kD。上述四种蛋白质中有四种 现在已经确定了。105kD蛋白(p105-Rb)是由 视网膜母细胞瘤易感基因，107kD蛋白(P107)是 在结构上与p105-Rb相关，60kD蛋白是 细胞周期蛋白A基因。此外，还出现了几种丰度较低的蛋白质 与E1a相关；其中之一是细胞周期蛋白依赖性激酶2 (CDK2)，与细胞周期密切相关的33kD蛋白 调节激酶cdc2。在这项拨款中，重点将放在一种基因上 我们最近克隆并鉴定了编码E1a相关基因的基因 蛋白质，p130。我们已经通过序列分析证明了这一点 蛋白质在结构上与视网膜母细胞瘤蛋白相关，并与 第107页。通过利用我们以前使用的技术和试剂 研究后，我们将对该组织的结构和 P130的功能，并评估该蛋白在细胞调节中的作用 增殖和肿瘤性转化。 P130与E1a转化区相互作用的证明 而p130与pRb相关的事实表明，这种蛋白可能 在细胞周期进程中起着重要的调节作用。此外， P130，像p105-Rb一样，可能被证明是失活的目标 转化病毒或通过广泛发生的染色体异常 肿瘤谱。因此，这项建议的目标是： (1)制备可简化研究的免疫学试剂 P130，并鉴定与p130相互作用的新蛋白种类。 (2)分析细胞周期不同阶段的p130。 (3)进行p130的结构/功能研究 (4)p130的基因组结构研究。

The Adenovirus E1A oncoprotein has been shown to be an effective tool in the identification of protein factors that regulate fundamental cellular processes such as transcription, RNA processing, DNA replication and cell cycle regulation. Several cellular proteins implicated in growth regulation interact with the transforming region of E1A. These proteins have been found to have apparent molecular weights of 33kD, 60kD, 105kD, 107kD, 107kD, 130kD and 300kD. Four of the above mentioned proteins have now been identified. The 105kD protein (P105-Rb) is the product of the retinoblastoma susceptibility gene, the 107kD protein (p107) is structurally related to p105-Rb and the 60kD protein is the product of the cyclin A gene. In addition, several less abundant proteins appear to associate with E1A; one of these is the cyclin-dependent kinase 2 (cdk2), a 33kD protein that is closely related to the cell cycle regulating kinase cdc2. In this grant the focus will be on a gene recently cloned and characterized by us which encodes the E1A-associated protein, p130. We have demonstrated by sequence analysis that this protein is structurally related to the retinoblastoma protein and to p107. By utilizing the technology and reagents employed in our previous studies, we will undertake a systematic examination of the structure and function of p130, and assess the protein's role in regulating cellular proliferation and neoplastic transformation. The demonstration that p130 interacts with the transforming region of E1A and the fact that p130 is related to pRB suggests that this protein may play an important regulatory role in cell cycle progression. Further, p130, like p105-Rb, may prove to be target for inactivation by transforming viruses or by chromosomal aberrations which occur in a wide spectrum of neoplasm. The goals of this proposal are thus: (1) To prepare immunological reagents that will simplify the study of p130 and to identify new protein species that interact with p130. (2) To analyze p130 at different stages of the cell cycle. (3) To conduct structure/function studies of p130 (4) Genomic organization studies of p130.