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

细胞通过引起基因表达变化的化学通讯网络（信号通路）来适应环境的变化。 对其他蛋白质进行化学修饰的酶是信号通路的关键组成部分。 赖氨酸乙酰化是一种从细菌到人类都保守的蛋白质修饰。 研究表明它广泛存在于细胞蛋白中，但其在信号调节基因表达中的作用却知之甚少。 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KDACs集中在活性基因上并可以促进其表达，但其潜在机制尚不清楚。 基因的表达是在转录活动爆发的过程中穿插着不活动的时期。 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多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方面的培训，这将使他们能够从事有助于加强国家科学队伍并使之多样化的职业。 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的演讲来传播。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。 第二个目标是利用全局连载测序来确定 KDAC 在基因内部和周围区域中对转录做出贡献的位置。 研究结果将有助于建立信号诱导转录调控的改进模型，该模型将转录动力学和 KDAC 对转录周期的积极贡献结合起来。

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.