DIRECT TARGET GENES OF THE MYC ONCOPROTEIN

MYC 癌蛋白的直接靶基因

基本信息

批准号：
6513102
负责人：
CARLA GRANDORI
金额：
$ 12.64万
依托单位：
FRED HUTCHINSON CANCER RESEARCH CENTER
依托单位国家：
美国
项目类别：
财政年份：
1998
资助国家：
美国
起止时间：
1998-04-01 至 2004-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/6513102
关键词：
B lymphocyte antiantibody binding sites chromatin fibroblasts genes genetic mapping genetic regulation genetic transcription human tissue immunoprecipitation messenger RNA nucleic acid probes nucleic acid sequence oncoproteins protein structure function tissue /cell culture ubiquitin

项目摘要

The Myc family on oncogenes is involved in the pathogenesis of several human tumors. In vitro Myc onco-proteins can trigger unscheduled DNA synthesis and contribute to the transforming ability of other oncogenes. At the molecular level Myc works by binding to specific DNA sequences and by activating transcription. This proposal aims at identifying and characterizing the genes that are directly altered by Myc. Toward this goal, a library of selected human genomic sequences was obtained by immunoprecipitation of chromatin with specific anti-Myc and its dimerization partner Max antibodies. In vivo Myc-Max binding sites allowed identification of several new Myc-responsible mRNAs; among those, one encoding for an RNA helicase, MrDb. The first aim will focus to further establish a direct transcriptional response of MrDb to Myc. This will be achieved by characterizing the promoter region of MrDb and analyzing the transcriptional role of the Myc-Max binding site identified by immunoprecipitation in its natural context. The genomic clone will also allow monitoring in vivo binding of Myc-Max to the predicted site and other possible sites by exonuclease protection and in vivo footprinting techniques. In addition, the biological role of MrDb as mediator of Myc function will be studied. The second aim will focus on the remaining 18 potential in vivo binding sites so far sequenced. Preliminary results indicate that Myc-Max heterodimers bind cooperatively to multiple sites present in some of the genomic clones. Cooperativity provides a potential important mechanism for in vivo selection of binding sites among many potential non-specific binding sites. The requirements for cooperativity at the protein level (i.e. Myc and Max mutant) and DNA level (i.e. binding site mutations) will be defined. The final aim will be to identify additional Myc-responsive genes. This will be achieved by employing the Myc-Max binding sites so far characterized as probes to screen a human genomic library in an exon- trapping vector. These studies will provide several pieces of the puzzle necessary to understand how Myc functions as an oncogene.

MYC家族的致病基因参与了几种的发病机理人类肿瘤。体外MYC ONCO蛋白可以触发外界的DNA 综合并有助于其他人的转变能力癌基因。在分子水平上，MYC通过与特定DNA结合起作用序列和激活转录。该提议的目的是识别和表征直接改变的基因妈妈。朝向这个目标，选定的人类基因组序列的库是通过特异性抗Myc和其二聚伴侣最大抗体。体内myc-max绑定位点允许识别几个新的MYC责任mRNA；之中这些，一种编码RNA解旋酶的MRDB。第一个目标将集中于进一步建立直接转录 MRDB对MYC的反应。这将通过表征 MRDB的启动子区域并分析通过免疫沉淀在其自然中鉴定的MYC-MAX结合位点语境。基因组克隆还将允许监测体内结合通过外切酶的Myc-Max到预测的站点和其他可能的站点保护和体内足迹技术。另外，将研究MRDB作为MYC功能的介体的生物学作用。第二个目标将集中于剩余的18个潜力体内结合到目前为止的站点进行了测序。初步结果表明MYC-MAX 异二聚体与某些中存在的多个站点合作结合基因组克隆。合作提供了潜在的重要机制用于在许多潜在的非特异性的体内选择结合位点绑定位点。蛋白质水平合作的要求（即myc和max突变体）和DNA水平（即结合位点突变）将定义。最终目标是确定其他MYC响应基因。这到目前为止，将通过使用MYC-MAX绑定站点来实现以筛选外显子中的人类基因组文库的探针为特征捕获向量。这些研究将提供几部分了解MYC如何用作癌基因所必需的难题。