ACTIVATING TRANSCRIPTION FACTOR 2 PROTEIN INTERACTIONS

转录激活因子-2（ATF-2）是CREB（环 AMP反应元件结合蛋白）/转录因子ATF家族。 虽然ATF-2广泛存在于哺乳动物组织中，但它的作用 在正常细胞功能是未知的。 实验表明，ATF-2 具有细胞周期相关的作用：a）ATF-2易位到细胞核， G1和G2/M期细胞，和B）ATF-2的类似核转位是 在对促有丝分裂生长因子刺激的反应中观察到， 表皮生长因子 尽管它被证明是中介- 腺病毒E1 a蛋白的转录激活，一种内源性 ATF-2功能的细胞调节剂尚未被鉴定。 腺病毒 Ela蛋白不直接与DNA结合，它能够激活基因， 通过与DNA结合的ATF-2相互作用进行转录。 我们假设ATF- 2以类似的方式与内源性细胞蛋白相互作用， 调节细胞周期依赖基因的转录复合物 表情 本提案中所述实验的目标是 鉴定与ATF-2相互作用以形成 转录复合物，其表达阳性或阴性信号， RNA聚合酶影响特定基因的表达。 这将是 通过筛选由小鼠胚胎cDNA表达的蛋白质来完成 在酵母双杂交系统中与ATF-2相互作用的基因。 与ATF-2相互作用的蛋白质将被表达、纯化并 测序 组织特异性、DNA结合能力和 这些蛋白质的转录激活潜力将是 表征了 CREB/ATF转录因子家族在细胞凋亡中的作用 细胞信号传导和细胞生长的调节 分化 基于结构/功能的实验 CREB和ATF-2的特性将对指导 未来的癌症治疗方案。 蛋白质作用的描述- 转录激活中的蛋白质相互作用对于 了解参与正常和异常的机制 调节基因表达、细胞生长、细胞分化和 肿瘤发生

Activating transcription factor-2 (ATF-2) is a member of the CREB (cyclic AMP response element binding protein)/ATF family of transcription factors. Though it is present ubiquitously in mammalian tissues, the role of ATF-2 in normal cellular function is not known. Experiments suggest that ATF-2 has a cell cycle-related role: a) ATF-2 is translocated to the nucleus in Gl and G2/M phase cells, and b) similar nuclear translocation of ATF-2 is seen in response to stimulation with mitogenic growth factors, including epidermal growth factor. Though it has been shown to mediate - transcriptional activation by adenoviral E1a protein, an endogenous cellular regulator of ATF-2 function has not been identified. Adenoviral Ela protein does not directly bind DNA; it is able to activate gene transcription by interacting with DNA-bound ATF-2. We postulate that ATF- 2 interacts with endogenous cellular proteins in a similar fashion to form transcriptional complexes which regulate cell cycle-dependent gene expression. The goal of the experiments described in this proposal is the identification of mammalian proteins that interact with ATF-2 to form transcriptional complexes which transduce positive or negative signals to RNA-polymerase to effect expression of specific genes. This will be accomplished by screening for proteins, expressed by a mouse embryo cDNA library, which interact with ATF-2 in the yeast two-hybrid system. Proteins which interact with ATF-2 will be expressed, purified and sequenced. The tissue specificities, DNA-binding capabilities and transcriptional activation potential of these proteins will be characterized. The CREB/ATF family of transcription factors function in cellular signal transduction and in the regulation of cell growth and differentiation. Experiments based on the structure/function characteristics of CREB and ATF-2 will have implications for guiding future protocols of cancer therapy. Delineation of the role of protein- protein interactions in transcriptional activation is important for understanding the mechanisms involved in the normal and abnormal regulation of gene expression, cell growth, cell differentiation and oncogenesis.