RADIATION INDUCED RNA BINDING PROTEINS

在它们的整个生命过程中，细胞必须不断地监测和修复它们的细胞。 对他们的DNA造成伤害。 产生的自由基和过氧化物 在正常的生理过程和炎症，以及 环境污染物、紫外线和电离辐射是 最常见的DNA破坏剂来源 如果没有感知到， 如果修复得当，这种损伤可能会导致恶性转化， 部分是通过某些癌基因特定位点的突变。 在 正常的人类细胞，基因毒性应激反应是相当复杂的。 它包括诱导几个基因， 随着许多重要的细胞事件如细胞周期控制， 信号转导，复制，诱变，转录，DNA修复 和病毒激活。 我们建议研究的一个特定方面， 涉及RNA结合诱导的遗传毒性应激反应 特定蛋白质的活性。 我们的初步数据首次证明， 细胞蛋白质的活性可由DNA损伤诱导。这 暗示了细胞基因调控的重要意义 基因毒性应激后，以及可能参与DNA损伤 识别和修复。 这些的诱导结合活性 蛋白质，如前所述组成型RNA结合蛋白质 (RBP)，可以在RNA加工水平上调节基因表达， mRNA稳定性更重要的是，这些RBP识别特定的RNA， 结构，双茎环。 可以想象，这种结构 部分分离后的新生转录本可以形成 DNA模板 在损伤部位，这些新生的 成绩单可能会拖延 通过与这些早熟序列结合， RBP可以作为终止子并促进DNA修复的某些方面。 有趣的是，这些RBP识别的RNA结构也是 这让人联想到HIV-1感染者体内产生的病毒TAR RNA结构， 细胞 在遗传毒性后调节病毒活化中的作用 压力暴露似乎也可能对这些RBP。 使用原始 西北印迹法，我们检测到多种RBP在 全核提取物 一个40 kDa的蛋白质已被分离的亲和 通过使用特异性RNA寡聚物柱的柱色谱法来纯化。 我们计划 对该蛋白质进行测序并分离其cDNA，以确定其 在遗传毒性应激反应中的作用。 我们还计划研究 A-18，一个独立分离的克隆，编码由 紫外线，在应激反应中。

Throughout their lives cells have to constantly monitor and repair the damage inflicted on their DNA. Free radicals and peroxides, generated during normal physiological processes and inflammation, as well as environmental pollutants, ultra-violet light, and ionizing radiation are the most common sources of DNA damaging agents. If not sensed and properly repaired, this damage can cause malignant transformation, in part through mutations at specific sites in certain oncogenes. In normal human cells, the genotoxic stress response is rather complex. It includes the induction of several genes that have been associated with a number of important cellular events such as cell cycle control, signal transduction, replication, mutagenesis, transcription, DNA repair and viral activation. We propose to study a particular aspect of the genotoxic stress response involving the induction of RNA-binding activity of specific proteins. Our initial data demonstrated for the first time that RNA-binding activity of cellular proteins can be inducible by DNA damage. This suggested important implications for the regulation of cellular genes after genotoxic stress, as well as possible involvement in DNA damage recognition and repair. The inducible binding activity of these proteins, as previously described constitutive RNA Binding Proteins (RBP), could regulate gene expression at the level of RNA processing and mRNA stability. More importantly, these RBP recognized a specific RNA structure, double stem loop. It is conceivable that such structures could be formed by nascent transcripts after partial separation from their DNA template. At sites of damage, transcription of these nascent transcripts might stall. By binding to these pre-mature sequences, the RBP may act as terminators and facilitate some aspect of DNA repair. Interestingly, the RNA structure recognized by these RBP is also reminiscent of the viral TAR RNA structure generated in HIV-1 infected cells. A role in the regulation of viral activation following genotoxic stress exposure seems also possible for these RBP. Using an original Northwestern blotting approach, we have detected a variety of RBP in whole nuclear extracts. A 40 kDa protein has been isolated by affinity chromatography using a specific RNA oligomer column. We plan to sequence this protein and isolate its cDNA in order to determine its role in the genotoxic stress response. We also plan to study the role of A-18, an independently isolated clone coding for a RBP induced by ultra-violet light, in the stress response.