PRB2--A NOVEL TARGET FOR THE AD5 E1A ONCOPROTEINS

腺病毒E1 A癌蛋白已被证明是一种有效的工具， 鉴定调节基本细胞的蛋白质因子， 转录、RNA加工、DNA复制和细胞增殖 周期调节 与生长有关的几种细胞蛋白质 调节与E1 A的转化区相互作用。 这些蛋白质 已发现具有33 kD，60 kD，105 kD， 107kD、107kD、130kD和300kD。 上述四种蛋白质具有 现已被确认。 105 kD蛋白（P105-Rb）是细胞凋亡的产物。 视网膜母细胞瘤易感基因，107 kD蛋白（p107）， 结构上与p105-Rb相关，60 kD蛋白是 细胞周期蛋白A基因 此外，还出现了几种不太丰富的蛋白质， 与E1 A相关;其中之一是细胞周期蛋白依赖性激酶2 cdk 2是一种与细胞周期密切相关的33 kD蛋白， 调节激酶CDC 2。 在这项资助中，重点将放在一个基因上， 我们最近克隆并鉴定了它编码E1 A相关的 蛋白质，p130。 我们通过序列分析证明， 该蛋白在结构上与视网膜母细胞瘤蛋白相关， 第107页。 通过利用我们以前使用的技术和试剂， 我们将对结构进行系统的检查， p130的功能，并评估该蛋白在调节细胞凋亡中的作用。 增殖和肿瘤转化。 p130与E1 A转化区相互作用的证明 p130与pRB相关的事实表明，这种蛋白质可能 在细胞周期进程中发挥重要的调节作用。 此外，本发明还 与p105-Rb一样，p130可能被证明是通过以下途径失活的靶点： 转化病毒或染色体畸变，发生在广泛的 肿瘤谱。 因此，本提案的目标是： (1)制备免疫学试剂，以简化 p130蛋白，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.