Temporal coordination of stimulus-induced gene expression by RNA-binding proteins

总结 细胞对外界刺激的反应需要动态的基因调控，以促进快速激活和有效的 分辨率尽管转录反应是刺激诱导反应的教科书机制，但转录后 mRNA翻译和衰变的转录调控是硬币的另一面，对于快速转录至关重要。 和适应性刺激诱导的反应。例如，免疫激活产生了一个原型的时间 细胞因子mRNA的表达模式称为脉冲反应，这是一种快速的脉冲样增加， 减少表达。细胞因子mRNAs的不稳定是正确解决脉冲所必需的。 反应和预防过量的细胞因子产生。人们越来越认识到RNA结合蛋白 （RBP）通过调节细胞因子的表达，在实现适当的刺激诱导的基因表达反应中发挥关键作用。 RNA加工、衰变和靶RNA的翻译。我们研究计划的首要目标是 了解RBP如何在时间上协调刺激诱导的基因表达和细胞表型。 我们将使用该模型系统来研究动态RBP-RNA调控相互作用如何在时间上协调 刺激诱导的基因表达是人肾上腺类固醇生成。这是一个经典的配体诱导系统， 小肽血管紧张素II（AngII）与肾上腺髓质肾小球细胞中的受体结合， 醛固酮的产生，血压的主要调节器。因此，严格控制监管时间是 这是必需的，因为它必须响应AngII从胆固醇快速从头产生。我们最近 表明血管紧张素Ⅱ治疗永生化和原代肾上腺皮质细胞的结果在冲动 反应此外，我们发现特定的RBP和受调控的RNA衰变有助于快速实施 和AngII脉冲响应的分辨率。在本提案中，我们将检验MSI 2和ZFP 36 L2 是分别增强和减弱刺激诱导的mRNA动力学的反作用力 通过调节靶mRNA的衰减和翻译，以确保适当的时间和幅度的水平， 脉冲响应我们将利用尖端的方法，以获得时间和定量的见解，如何 刺激诱导的RBP结合变化决定靶mRNA表达反应的变化， 最终是细胞表型。我们使用的创新方法的使用将有助于将该领域从静态转变为 RBP-mRNA相互作用的动态视图，并实现关于如何调节RBP-mRNA的机制见解 相互作用控制mRNA命运决定以支配细胞反应。

SUMMARY Cellular responses to external stimuli require dynamic gene regulation to facilitate rapid activation and effective resolution. Although transcriptional responses are a textbook mechanism for stimulus-induced responses, post- transcriptional regulation of mRNA translation and decay are the other side of the coin and are essential for rapid and adaptable stimulus-induced responses. For example, immune activation generates a prototypical temporal expression pattern for cytokine mRNAs known as an impulse response, which is a rapid pulse-like increase and decrease in expression. The destabilization of cytokine mRNAs is required for proper resolution of the impulse response and prevention of excess cytokine production. It is increasingly recognized that RNA-binding proteins (RBPs) play critical roles in achieving an appropriate stimulus-induced gene expression response by regulating RNA processing, decay, and translation of target RNAs. The over-arching goal of our research program is to understand how RBPs temporally coordinate stimulus-induced gene expression and cellular phenotypes. The model system we will use to study how dynamic RBP-RNA regulatory interactions temporally coordinate stimulus-induced gene expression is human adrenal steroidogenesis. This is a classic ligand-induced system in which the small peptide Angiotensin II (AngII) binds to its receptor in adrenal zona glomerulosa cells to stimulate the production of aldosterone, the master regulator of blood pressure. Thus, tight control of regulatory timing is required since it must be rapidly produced de novo from cholesterol in response to AngII. We have recently demonstrated that AngII treatment of immortalized and primary adrenocortical cells results in an impulse response. Furthermore, we found specific RBPs and regulated RNA decay facilitates the rapid implementation and resolution of the AngII impulse response. In this proposal, we will test the hypothesis that MSI2 and ZFP36L2 are counteracting forces that, respectively, potentiate and attenuate the kinetics of stimulus-induced mRNA levels by modulating target mRNA decay and translation, to ensure the proper timing and amplitude of the impulse response. We will utilize cutting edge methods to gain temporal and quantitative insights into how stimulus-induced changes in RBP binding determine changes in target mRNA expression responses and ultimately cellular phenotype. The use of innovative approaches we use will help shift the field from a static to a dynamic view of RBP-mRNA interactions and achieve mechanistic insight on how regulatory RBP-mRNA interactions control mRNA fate decisions to govern cellular responses.