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目的:肿瘤抑制因子p53和主反应基因Egr-1是细胞核转录因子,在介导细胞增殖、分化及细胞凋亡和生长停止的信号传导通路中扮演调控的角色。我们试图证明在体内、外这两种调控蛋白间有一种物理上的联系。方法:体内实验中,用免疫沉淀法和Western blot3分析含有高水平Egr-1活性的细胞裂解物的血清和过度表达Egr-1和突变型p53的人肺癌细胞株中两种蛋白间的相互作用。结果:p53突变在154密码子时与Egr-1没有联系,而当p53蛋白突变点在156,246,247和273殖基则与此锌指转录因子有联系。p53结合全长的Egr-1和1个Egr-1缺失5’活化范围的Egr-1突变体,但不能结合1个缺少包含头两个锌指区的内部片断的Egr-1蛋白,说明结合需要完整的锌指基序存在。肺成纤维细胞系MRC-9表达不同大小的Egr-1蛋白,该蛋白也同样与p53结合。结论:两种调控蛋白之间存在联系,它们之间的相互作用可能改变了它们的多种生物学活性尤其是关于转录控制的特性。
OBJECTIVE: The tumor suppressor p53 and the primary response gene Egr-1 are nuclear transcription factors that play a regulatory role in signaling pathways that mediate cell proliferation, differentiation, and apoptosis and growth arrest. We are trying to prove that there is a physical connection between these two regulatory proteins in and out of the body. METHODS: In vivo experiments, immunoprecipitation and Western blot 3 were used to analyze the interaction between the serum of cell lysates containing high levels of Egr-1 activity and two proteins in human lung cancer cell lines overexpressing Egr-1 and mutant p53 . RESULTS: The p53 mutation was not associated with Egr-1 at codon 154, but was associated with this zinc finger transcription factor when p53 mutations were found at 156, 246, 247, and 273. p53 binds to full length Egr-1 and 1 Egr-1 deletes a 5 ’activation range Egr-1 mutant but does not bind an Egr-1 protein lacking an internal fragment containing the first two zinc finger regions, indicating that binding Need a complete zinc finger motif exists. The lung fibroblast cell line MRC-9 expresses Egr-1 proteins of different sizes, which also bind to p53 as well. CONCLUSIONS: There is a link between the two regulatory proteins, and the interactions between them may alter their diverse biological activities, especially with regard to transcriptional control.