REGULATION AND FUNCTION OF THE PUTATIVE TRANSCRIPTION FACTOR GADD153

假定转录因子 GADD153 的调节和功能

• 批准号: 3745539
• 负责人: N J HOLBROOK
• 金额: --
• 依托单位: NATIONAL INSTITUTE ON AGING
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3745539
• 关键词: DNA binding protein; DNA damage; aging; biological models; dimer; gene expression; gene induction /repression; genetic regulation; hybrid cells; transcription factor; yeasts

GADD153 is a highly conserved mammalian gene whose expression is increased in response to a variety of stresses including growth arrest and DNA damage. It is a member of the CCAAT/enhancer-binding protein (C/EBP) family of transcriptional activators and can dimerize with other C/EBPs through a leucine zipper domain. However, in contrast to other C/EBPs, it lacks the ability to bind to CCAAT DNA sequences and has therefore been proposed to serve as a negative regulator of other members of this family (by virtue of its ability to heterodimerize with them and inhibit their binding to DNA). Studies in this project have focused on the regulation and function of GADD153 expression in response to stress. The approaches taken have included (1) characterization of Gadd153 expression (and that of other C/EBPs) in response to diverse growth inhibitory and metabolic stimuli including PGA/2-mediated growth arrest, glucose deprivation, DNA damage, and inducers of the acute phase response in vivo and in vitro; (2) use of yeast hybrid protein systems to examine the interaction between the GADD153 protein and other members of the C/EBP family, and (3) development of transgenic models to address the expression and role of GADD153 during development and in response to stress in vivo. Of particular interest is our finding that the GADD153 protein provides a functional transactivation domain when fused to a yeast GAL4 transcription factor DNA binding site, suggesting that GADD153 can act directly (rather than as a dominant negative inhibitor as suggested above) to influence transcription perhaps through as yet unidentified sites. Using the yeast two hybrid system, we have found that in contrast to other C/EBP family members, GADD153 appears to be unable to form homodimers, suggesting that it must interact with other transcription factors to influence gene expression, or be functional as a monomer.

GADD 153是一个高度保守的哺乳动物基因，其表达增加 在应对各种压力，包括生长停滞和DNA 损害 它是CCAAT/增强子结合蛋白（C/EBP）的成员。 转录激活因子家族，可与其他C/EBP二聚化 通过亮氨酸拉链结构域。 然而，与其他C/EBP相比， 缺乏与CCAAT DNA序列结合的能力， 被提议作为这个家庭其他成员的负调节器 (by他们的能力，他们的能力， 与DNA结合）。 该项目的研究重点是 GADD153在应激反应中的表达和功能。 的方法 所采取的措施包括（1）Gadd153表达的表征（和， 其他C/EBP）对不同生长抑制和代谢 刺激包括PGA/2介导的生长停滞、葡萄糖剥夺、DNA 损伤，以及体内和体外急性期反应的诱导剂;（2） 使用酵母杂合蛋白质系统来检查蛋白质之间的相互作用。 GADD 153蛋白和C/EBP家族的其他成员，以及（3）发育 转基因模型，以解决GADD 153的表达和作用， 发育和体内应激反应。 特别感兴趣的是 我们发现GADD 153蛋白提供了一种功能性的反式激活， 当与酵母GAL4转录因子DNA结合位点融合时， 这表明GADD 153可以直接起作用（而不是作为一种显性的 负抑制剂，如上述建议），以影响转录可能 通过尚未确认的地点。 利用酵母双杂交系统， 我发现，与其他C/EBP家族成员相比，GADD 153似乎 不能形成同源二聚体，这表明它必须与 其他转录因子影响基因表达，或具有功能 作为单体。