FLAGGING OF DNA DAMAGE SITES BY RNA POLYMERASE II

通过 RNA 聚合酶 II 标记 DNA 损伤位点

• 批准号: 2458310
• 负责人: DAVID B BREGMAN
• 金额: $ 8.05万
• 依托单位: ALBERT EINSTEIN COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-08-01 至 1999-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2458310
• 关键词: ADP ribosylation; DNA damage; DNA directed RNA polymerase; DNA repair; HeLa cells; biological signal transduction; crosslink; enzyme activity; enzyme complex; genetic transcription; nucleic acid sequence; site directed mutagenesis; transfection; ubiquitin

Certain proteins essential for DNA repair are also required for transcriptional initiation by RNA polymerase II, the multisubunit enzyme that transcribes protein endoding genes. In addition, DNA lesions located on the transcribed strand of active genes are repaired more rapidly than other DNA lesions. It has therefore been proposed that RNA polymerase Ii may function to identify such lesions as it "needs" the DNA. Nevertheless, a critical question remains: how does RNA polymerase II signal to the rest of the DNA repair system that it has encountered damaged DNA and that the machinery must switch from "transcription mode" to "repair mode"? This investigator has identified novel, upper molecular weight forms of RNA polymerase II's largest subunit (Pol II LS) which are induced shortly after cells are exposed to DNA damaging agents. Preliminary studies indicate that two covalent modifications already implicated in DNA repair, ubiquitination the ADP-ribosylation, may be involved in generating the upper molecular weight forms." In vitro and in vivo approaches will be utilized to (1) determine whether the upper molecular weight forms of Pol II LS are the result of ubiquitination and/or ADP-ribosylation. (2) determine whether the modification maps tot he regulatory C-terminal domain of Pol II and (3) determine whether the subset of RNA Polymerase II molecules which get modified represent elongating molecules which have stalled at DNA lesions. Because maintaining the accuracy of DNA is a sine qua non of normal cell function and because defective DNA repair contributes to the development of cancer this topic impacts profoundly on the study of human disease.

对于DNA修复必不可少的某些蛋白质也需要 RNA聚合酶II的转录启动，多基因酶 这转录蛋白质恩典基因。 另外，DNA病变位于 在抄录的活性基因的链链上，修复的速度比 其他DNA病变。 因此，已经提出RNA聚合酶II 可以识别“需要” DNA的病变的功能。 尽管如此， 一个关键的问题仍然存在：RNA聚合酶II如何向其他人信号 它遇到损坏的DNA的DNA修复系统的 机械必须从“转录模式”切换到“维修模式”？ 这 研究者已经确定了新型RNA的新型分子量形式 聚合酶II最大的亚基（pol II LS），不久后引起 细胞暴露于DNA损伤剂中。 初步研究表明 已经与DNA修复有关的两个共价修改， 泛素化ADP-核糖基化可能参与 上分子量形成。” 体外和体内方法将用于（1）确定是否 pol ii ls的上分子量形式是 泛素化和/或ADP-核糖基化。 （2）确定是否 修改地图POL II的调节性C末端结构域和（3） 确定RNA聚合酶II分子的子集是否获得 修饰表示已停滞在DNA病变处的细长分子。 因为保持DNA的准确性是正常细胞的正弦物质 功能和由于DNA修复有缺陷有助于发展 癌症这个话题对人类疾病的研究深远影响。