The Role of Lysine Deacetylases in Regulating Transcriptional Dynamics at Glucocorticoid-activated Genes

赖氨酸脱乙酰酶在调节糖皮质激素激活基因转录动力学中的作用

• 批准号: 1715019
• 负责人: Catharine Smith
• 金额: $ 30万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-15 至 2020-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1715019&HistoricalAwards=false
• 关键词: Role; Lysine; Deacetylases; Regulating; Transcriptional

Cells adapt to changes in their environment through chemical communication networks (signaling pathways) that cause changes in gene expression. Enzymes that chemically modify other proteins are key components of signaling pathways. Lysine acetylation is a protein modification conserved from bacteria to humans. Studies have revealed its widespread occurrence on cellular proteins but its roles in signaling-modulated gene expression are poorly understood. The enzymes that regulate acetylation, lysine acetyltransferases (KATs) and lysine deacetylases (KDACs), are considered to promote and impair gene expression, respectively. However, recent studies have shown that KDACs are concentrated at active genes and can promote their expression, but the underlying mechanisms are unknown. Genes are expressed in bursts of transcriptional activity interspersed with periods of inactivity. Signaling pathways change gene expression by modulating the frequency and/or the size of active bursts. Understanding how KDACs affect bursting patterns of genes will allow insight into the mechanisms underlying their ability to promote gene expression. This is important because chemicals that inhibit KDACs are present in the environment as natural products of unicellular organisms, pollutants, and drugs. Increased knowledge of the function of KDACs in gene expression is essential to assessing the impact of their inhibitors on living organisms. The work will be performed by several undergraduates and a postdoctoral fellow. The incorporation of undergraduates into the research team will provide mentoring experience to the postdoctoral fellow and serve under-represented groups through several University of Arizona programs that provide research opportunities to undergraduates from these groups. Research team members will be trained in critical thinking, problem-solving, and communication skills that will enable them to pursue careers that contribute to strengthening and diversifying the national scientific workforce. The research findings will be disseminated through publication in peer-reviewed journals and presentations at local and national conferencesThe goal of this project is to determine how KDACs regulate transcriptional bursting patterns of genes that are activated by glucocorticoids, a type of steroid hormone. The first aim will use single molecule fluorescent in situ hybridization and live cell imaging of transcription to assay the effects of KDAC inhibitors on bursting kinetics. The second aim is focused on determining where KDACs contribute to transcription in the regions in and around genes using global run-on sequencing. The study results will contribute to building improved models of signaling-induced transcriptional regulation that incorporate transcriptional dynamics and the positive contributions of KDACs to the transcriptional cycle.

细胞通过化学通讯网络（信号通路）适应环境的变化，从而引起基因表达的变化。 化学修饰其他蛋白质的酶是信号通路的关键组成部分。 赖氨酸乙酰化是从细菌到人类保守的蛋白质修饰。 研究表明它广泛存在于细胞蛋白质中，但其在信号调节基因表达中的作用知之甚少。 调节乙酰化的酶，赖氨酸乙酰转移酶（KAT）和赖氨酸脱乙酰酶（KDAC），被认为分别促进和损害基因表达。 然而，最近的研究表明，KDAC集中在活性基因，并能促进其表达，但其潜在机制尚不清楚。 基因以转录活性爆发的形式表达，其间穿插着无活性的时期。 信号通路通过调节活性爆发的频率和/或大小来改变基因表达。 了解KDAC如何影响基因的爆发模式将有助于深入了解其促进基因表达能力的机制。 这一点很重要，因为抑制KDAC的化学物质作为单细胞生物、污染物和药物的天然产物存在于环境中。 增加对KDAC在基因表达中的功能的了解对于评估其抑制剂对生物体的影响至关重要。这项工作将由几名本科生和一名博士后研究员完成。 将本科生纳入研究团队将为博士后研究员提供指导经验，并通过亚利桑那大学的几个项目为代表性不足的群体提供服务，这些项目为这些群体的本科生提供研究机会。 研究团队成员将接受批判性思维，解决问题和沟通技巧的培训，使他们能够从事有助于加强和多样化国家科学工作队伍的职业。 该研究结果将通过在同行评审期刊上发表以及在地方和国家会议上发表演讲来传播。该项目的目标是确定KDAC如何调节由糖皮质激素（一种类固醇激素）激活的基因的转录爆发模式。 第一个目标将使用单分子荧光原位杂交和活细胞转录成像来测定KDAC抑制剂对爆发动力学的影响。 第二个目标是使用全局连续测序来确定KDAC在基因内部和周围区域中对转录的贡献。 研究结果将有助于建立改进的信号诱导的转录调控模型，将转录动力学和KDAC的转录周期的积极贡献。