MOLECULAR INTERACTIONS OF A YEAST HOMEODOMAIN PROTEIN

酵母同源域蛋白的分子相互作用

• 批准号: 2186845
• 负责人: ANDREW VERSHON
• 金额: $ 19.37万
• 依托单位: RUTGERS, THE STATE UNIV OF N.J.
• 依托单位国家: 美国
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-05-01 至 1998-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2186845
• 关键词: DNA binding protein; Saccharomyces cerevisiae; X ray crystallography; crosslink; fungal genetics; gene expression; genetic operator element; intermolecular interaction; molecular cloning; nuclear magnetic resonance spectroscopy; nucleoproteins; protein structure; site directed mutagenesis; transcription factor

Gene expression in eukaryotes is often under the control of multiple nuclear proteins that work in combination to regulate transcription. The combined interactions between these proteins will often create a new form of regulatory activity that is distinctly different than the function of either protein alone. The protein-protein interactions may dictate whether a regulatory protein functions as a transcriptional activator or repressor, as well as determine which genes are regulated by the protein. We are interested in how the combined interactions between these transcriptional regulatory proteins alter their function and site of action. We have chosen to study this problem using a simple regulatory system that determines cell type in the yeast Saccharomyces cerevisiae. This system involves the alpha2 and a1 proteins, members of the highly conserved homeodomain family of DNA-binding proteins; and MCM1, a protein with strong sequence similarity to the DNA-binding domain of the mammalian serum response factor, SRF. The alpha2 protein works in combination with MCM1 to repress one set of genes, and with the a1 to repress a different set of genes. Interactions between alpha2 and MCM1, and alpha2 and a1 therefore determine the target specificity of alpha2 repression. We are interested in how these protein-protein interactions effect DNA-binding affinity and specificity of alpha2. We propose to: (1) Examine the mechanism of DNA binding by the alpha2 homeodomain. This analysis may indicate whether there are any general principals that can be applied to DNA recognition by homeodomain proteins in higher eukaryotes. (2) Determine how MCM1 binds DNA. These experiments will provide knowledge about how members of this growing class of DNA-binding proteins function. (3) Determine which residues in alpha2 and MCM1 are involved in protein-protein interactions between the two proteins, and how these interactions effect the mechanism of DNA-binding by each protein. (4) Examine the mechanism of DNA-binding by alpha2 when it is associated with the a1 protein. The proteins in this simple regulatory system are similar in structure to regulatory proteins in mammals and plants. It therefore seems likely that the information we learn about the interactions between these classes of proteins will be relevant to more complex systems in higher eukaryotes.

真核生物中的基因表达通常在多重的控制之下 结合起作用的核蛋白来调节转录。 这些蛋白质之间的组合相互作用通常会产生 调节活动的新形式与 任何一种蛋白质的功能。 蛋白质 - 蛋白质相互作用可能 决定调节蛋白是否功能作为转录 激活剂或抑制剂，并确定哪些基因受调节 由蛋白质。 我们对合并互动如何感兴趣 在这些转录调节蛋白之间改变其功能 和行动地点。 我们选择使用简单的调节系统研究这个问题 这决定了酿酒酵母中的酵母菌中的细胞类型。 这 系统涉及α2和A1蛋白，高度成员 DNA结合蛋白的保守同源域家族；和mcm1，a 与与DNA结合结构域相似的蛋白质 哺乳动物血清反应因子SRF。 α2蛋白在 与MCM1结合使用以抑制一组基因，并与A1相结合 抑制一组不同的基因。 alpha2和 因此，MCM1，Alpha2和A1确定了目标特异性 alpha2抑制。 我们对这些蛋白质蛋白如何感兴趣 相互作用影响α2的DNA结合亲和力和特异性。 我们建议：（1）检查α2的DNA结合的机理 同源域。 该分析可能表明是否有任何一般 可以应用于同源区域DNA识别的校长 较高的真核生物中的蛋白质。 （2）确定MCM1如何结合DNA。 这些实验将提供有关如何成员的知识 生长类的DNA结合蛋白功能。 （3）确定哪个 Alpha2和MCM1中的残基参与蛋白质 - 蛋白质 两种蛋白质之间的相互作用以及这些相互作用如何 影响每种蛋白质DNA结合的机制。 （4）检查 α2与A1相关的DNA结合的机制 蛋白质。 这个简单调节系统中的蛋白质在 哺乳动物和植物中调节蛋白的结构。 因此 似乎我们可能了解有关互动的信息 在这些类别的蛋白质之间将与更复杂的 高等真核生物的系统。