TRANSFORMING FUNCTIONS OF THE V-MYB ONCOGENE PRODUCT

改变 V-MYB 癌基因产品的功能

• 批准号: 2099131
• 负责人: SCOTT A. NESS
• 金额: $ 17.88万
• 依托单位: NORTHWESTERN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-02-01 至 2000-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2099131
• 关键词: DNA binding protein; antiserum; cell transformation; chick embryo; complementary DNA; fibroblasts; gene expression; gene induction /repression; genetic promoter element; genetic regulation; genome; intermolecular interaction; laboratory rabbit; myeloid stem cell; northern blottings; oncogenes; oncoproteins; phenotype; polymerase chain reaction; tissue /cell culture; transcription factor; transfection; yeasts

The v-myb oncogene is the transforming component of two independently- isolated chicken leukemia viruses. Activation of the c-myb proto-oncogene has been implicated in chicken, murine and human leukemias, including acute myelogenous leukemias (AML), and c-myb expression has been associated with control of cell differentiation, proliferation and the cell cycle. However, v-myb is tissue-specific, and by itself does not transform fibroblasts or other cell types, suggesting that the Myb oncoprotein cooperates with a myeloid-specific cofactor to transform cells. Interestingly, regulation of mim-1, the only known myeloid- specific cellular gene which is directly regulated by v-myb, has been shown to be absolutely dependent on a myeloid-specific transcription factor named NF-M, which is highly related to the mammalian protein known as NF-IL6 or C/EBPb. In addition, overexpression of Myb plus NF-M in heterologous cells can induce the expression of mim-1 and. other genes which are usually myeloid-specific. Thus, Myb and NF-M appear to constitute a bipartite, combinatorial code for myeloid gene activation. The parallel between mim-1 gene regulation and the tissue-specificity of transformation by v-myb is striking, and suggests that the latter process may also depend on the combinatorial action of Myb plus NF-M. We propose to examine the interactions between Myb and NF-M at several levels. Cotransfection assays will be used to determine what other myeloid-specific genes, like mim-1, can be activated by Myb plus NF-M in either chicken or mammalian cells. A truncated, dominant-negative form of NF-M, which has been shown to block the expression of the mim-1 gene, will be used to interfere with endogenous NF-M (or NF-IL6) protein in v- myb-transformed cells. This will test whether the transforming activity of Myb depends on the collaboration of active NF-M. Coexpression of v-myb and NF-M in fibroblasts will test whether the "host range" of the oncogene can be expanded when NF-M activity is supplied in trans. An analysis of a newly-identified mammalian gene related to mim-1, which is apparently regulated like its chicken counterpart, will be performed to glean new information about mammalian promoters which are regulated by the combinatoriaI signal of Myb plus NF-M. Finally, biochemical and genetic analyses will test whether Myb and NF-M bind cooperatively to DNA, interact physically with one another in a multiprotein complex, or affect each other's biological activity. These experiments will test some of the basic mechanisms of tissue- specific gene regulation, the combinatorial functions of transcription factors, and the target specificity of transforming oncogenes. The results should shed light on differentiation, growth control and the onset of leukemias in humans.

V-myb癌基因是两个独立的转化成分 - 孤立的鸡肉白血病病毒。 C-MYB原型癌基因的激活 与鸡肉，鼠和人类白血病有关，包括 急性骨髓性白血病（AML）和C-MYB表达一直是 与控制细胞分化，增殖和 细胞周期。但是，V-MYB是组织特异性的，并且本身不是 转换成纤维细胞或其他细胞类型，表明MYB 癌蛋白与髓样特异性辅助因子合作以转化 细胞。有趣的是，MIM-1的调节，唯一已知的髓样的调节 由v-myb直接调节的特定细胞基因已是 被证明完全取决于髓样特异性转录 名为NF-M的因子，它与已知的哺乳动物蛋白高度相关 作为NF-IL6或C/EBPB。此外，Myb Plus NF-M的过表达 异源细胞可以诱导MIM-1和。其他基因 通常是髓样特异性的。因此，MYB和NF-M似乎 构成了骨髓基因激活的两分，组合代码。 MIM-1基因调节与组织特异性之间的平行性 V-MYB的转换令人震惊，并表明后一个过程 也可能取决于MyB加NF-M的组合作用。 我们建议检查MYB和NF-M之间的相互作用 水平。共转染测定将用于确定其他什么 MyB加NF-M可以激活髓样特异性基因，例如MIM-1 鸡或哺乳动物细胞。截短的，主导的阴性形式 NF-M的of nf-m，已证明可以阻止MIM-1基因的表达， 将用于干扰V-中内源性NF-M（或NF-IL6）蛋白 MYB转换的细胞。这将测试转换活动是否 MYB的工作取决于主动NF-M的协作。 V-MYB的共表达 成纤维细胞中的NF-M将测试是否的“主机范围”是否 当trans提供NF-M活动时，可以扩展癌基因。一个 分析与MIM-1有关的新识别的哺乳动物基因 显然像鸡肉一样受到监管，将进行 收集有关哺乳动物启动子的新信息 MYB Plus NF-M的组合信号。最后，生化和 遗传分析将测试MYB和NF-M是否合作 DNA，在多蛋白复合物中彼此之间的身体相互作用，或 影响彼此的生物学活动。 这些实验将测试组织的某些基本机制 特定基因调节，转录的组合函数 因素以及转化癌基因的目标特异性。这 结果应阐明分化，生长控制和 人类白血病发作。