CAMP RECEPTOR PROTEIN IN GENE TRANSCRIPTION

基因转录中的 CAMP 受体蛋白

• 批准号: 3916310
• 负责人: Y S CHO-CHUNG
• 金额: --
• 依托单位: DIVISION OF CANCER BIOLOGY AND DIAGNOSIS
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3916310
• 关键词: cyclic AMP receptors; gene expression; genetic promoter element; genetic transcription; molecular oncology; neoplasm /cancer genetics; neoplasm /cancer remission /regression; neoplastic growth; oncogenes; viral carcinogenesis

In prokaryotes, cAMP is known to regulate the transcription of specific genes by a well-defined mechanism. cAMP binds to the prokaryotic cAMP receptor protein (CRP), and this complex interacts with specific DNA sequences at the 5'ends of targeted genes, modulating the ability of RNA polymerase to bind to the pro- moters. cAMP has also been shown to alter the transcription of specific eukaryotic genes. Recent evidence suggests a direct action of cAMP on mammalian genes in which the regulatory subunit (R) of cAMP-dependent protein kinase might interact directly with target genes. Nagamine and Reich proposed that the R subunit of cAMP-dependent protein kinase could be envisaged as a cAMP- and DNA-binding molecule which regulates gene transcription, the vertebrate counterpart of bacterial CRP. However, this hypothesis lacked evidence for a direct interaction between DNA and cAMP- dependent protein kinase or the R subunit. In this study, we examined the role of cAMP receptor protein, R, in gene transcription. Since cAMP-dependent protein kinase is exclusively present in the cytoplasm, any nuclear function of the protein kinase must be accompanied by its translocation to the nucleus. It was found that the ras gene suppression, growth inhibition, and phenotypic reversion of Ha-MuSV-transformed NIH/3T3 cells by site- selective cAMP analogs correlated with the nuclear translocation of the RII cAMP receptor protein, the regulatory subunit of protein kinase type II. Within 30 min after treatment of the transformed cells with the analogs, immunofluorescence against the RII protein markedly increased in the cell nucleus. Thus, the nuclear translocation of the RII cAMP receptor protein is an early event in the reverse transformation induced by the cAMP analogs. The goal of this study is to provide direct evidence of interaction between the cAMP consensus sequences and cAMP receptor protein (RII) and/or a phosphoprotein substrate of protein kinase.

在原核生物中，已知cAMP调节 通过明确的机制对特定基因进行修饰。 cAMP结合到 原核cAMP受体蛋白（CRP），这种复合物相互作用 在靶基因的5 '端具有特定的DNA序列， 调节RNA聚合酶与前体结合的能力， 发动机 cAMP也被证明可以改变 特定的真核基因。 最近的证据表明， cAMP对哺乳动物基因的作用，其中调节亚基 (R)cAMP依赖性蛋白激酶可能直接与 靶基因 Nagamine和赖希提出， cAMP依赖性蛋白激酶可以设想为cAMP-和 调节基因转录的DNA结合分子， 细菌CRP的脊椎动物对应物。 然而，这一假设 缺乏DNA和cAMP之间直接相互作用的证据， 依赖性蛋白激酶或R亚基。 本研究 研究了cAMP受体蛋白R在基因表达中的作用， 转录。 由于cAMP依赖性蛋白激酶仅 存在于细胞质中，蛋白质的任何核功能 激酶必须伴随其易位到细胞核。 发现ras基因抑制、生长抑制和 Ha-MuSV转化的NIH/3 T3细胞通过位点- 与核转位相关的选择性cAMP类似物 RII cAMP受体蛋白的调节亚基， 激酶II型。 在处理转化后30分钟内 细胞与类似物，针对RII蛋白的免疫荧光 细胞核中明显增加。 因此，核 RII cAMP受体蛋白的易位是一个早期事件， 在cAMP类似物诱导的逆转中。 的 本研究的目的是提供直接的证据， cAMP共有序列与cAMP受体蛋白之间 (RII)和/或蛋白激酶的磷蛋白底物。