MYC ONCOPROTEIN FUNCTION

MYC 癌蛋白功能

• 批准号: 2517571
• 负责人: Robert Neil Eisenman
• 金额: $ 36.48万
• 依托单位: FRED HUTCHINSON CANCER RESEARCH CENTER
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-09-30 至 1998-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2517571
• 关键词: DNA binding protein; Saccharomyces cerevisiae; apoptosis; cell differentiation; cell growth regulation; developmental genetics; fungal genetics; gene deletion mutation; gene expression; laboratory mouse; laboratory rat; molecular cloning; nucleic acid sequence; oncogenes; oncogenic virus; oncoproteins; protein sequence; protein structure function; site directed mutagenesis; transcription factor

The Myc family of oncoproteins (c-, N-, and L-Myc) have been implicated in a wide range of cellular behavior including cell cycle entry and maintenance, differentiation, and apoptosis. In addition rearrangements at myc gene loci have been associated with many types of neoplasia in numerous species, including humans. Despite a vast amount of information on the properties and biological effects of Myc we lack a direct molecular link between these cellular processes and the Myc oncoprotein itself. Recently Max, a specific Myc dimerization partner, has been identified which forms a sequence-specific DNA binding complex with Myc. The Myc:Max complex appears to function as a transcriptional activator and evidence suggests that the relative abundances of constitutively expressed Max protein and highly regulated Myc protein may serve to determine the activity of this transcriptional 'switch'. In this application we propose to extend our studies on Myc and Max and to examine in detail the biochemical and biological properties of a new Max binding protein, Mad. Mad competes with Myc for binding to Max and appears to act as a repressor which can antagonize Myc's transcriptional activation function. This suggests that Myc, Max, and Mad may form a small network of interacting proteins. To explore the dynamics of this network we plan to characterize the properties and interactions of Mad in vivo and determine whether it may negatively influence Myc's transforming activity and act as a tumor suppressor gene. We will also probe the effects of both Max and Mad expression on the G0/G1 transition, cell proliferation, differentiation, and apoptosis. Biological roles for Mad in development will be studied by means of targeted gene disruptions in mice. Another series of experiments will examine the transcriptional properties of myc, Mad, and Max by analyzing, through site specific mutagenesis, the domains of these proteins that contribute to transcription activation and repression. The effects of alternative binding sites and promoter structure will also be analyzed. An in vitro transcription system will be developed to study the biochemical properties of these proteins in greater detail and the effects of other transcription factors on their activities. Finally we will attempt to extend our knowledge of the network of protein interactions involved in Myc function by using interaction cloning strategies to identify new binding partners for Myc, Max and Mad. The information gained from the studies proposed here should enable us to understand both how Myc functions at the molecular level and the manner in which this function is regulated.

癌蛋白 Myc 家族（c-、N- 和 L-Myc）与此有关 广泛的细胞行为，包括细胞周期进入和 维持、分化和凋亡。 另外重新安排 myc 基因位点与许多类型的肿瘤相关 许多物种，包括人类。 尽管信息量巨大 关于 Myc 的特性和生物效应，我们缺乏直接的了解 这些细胞过程与 Myc 癌蛋白之间的分子联系 本身。 最近，Max，一种特定的 Myc 二聚化伙伴，已被 鉴定出它与 Myc 形成序列特异性 DNA 结合复合物。 Myc:Max 复合物似乎具有转录激活剂的功能 并且有证据表明，本构的相对丰度 表达的 Max 蛋白和高度调节的 Myc 蛋白可能有助于 确定该转录“开关”的活性。 在此应用中，我们建议扩展对 Myc 和 Max 的研究， 详细检查新物质的生化和生物学特性 最大结合蛋白，疯狂。 Mad 与 Myc 竞争与 Max 的结合 似乎充当阻遏物，可以拮抗 Myc 的转录 激活函数。 这表明 Myc、Max 和 Mad 可能会形成一个 相互作用蛋白质的小网络。 探索这一动态 我们计划描述 Mad 网络的属性和相互作用 体内并确定它是否可能对 Myc 产生负面影响 转化活性并充当肿瘤抑制基因。 我们也会 探究 Max 和 Mad 表达对 G0/G1 转变的影响， 细胞增殖、分化和凋亡。 生物学作用 将通过有针对性的基因破坏来研究疯狂的发育 在小鼠中。 另一系列实验将检查转录 通过分析、通过特定站点来分析 myc、Mad 和 Max 的属性 诱变，这些蛋白质的结构域有助于 转录激活和抑制。 替代方案的影响 还将分析结合位点和启动子结构。 体外 将开发转录系统来研究生化 更详细地了解这些蛋白质的特性以及其他蛋白质的影响 转录因子对其活性的影响。 最后我们将尝试 扩展我们对涉及的蛋白质相互作用网络的了解 Myc功能通过使用相互作用克隆策略来识别新的 Myc、Max 和 Mad 的绑定伙伴。 从获得的信息 这里提出的研究应该使我们能够理解 Myc 如何 分子水平上的功能以及该功能的方式 受到监管。