Translation regulation by molecular switch RNA-binding protein LARP1

该研究计划的目标是揭示rna结合蛋白的分子机制。 (RBP)调控基因表达、翻译的决定性阶段。为了维持动态平衡，发出信号 通路通过限制性商业惯例传递关于细胞环境的信息来指导细胞的翻译输出； 限制性商业惯例最终抑制或刺激相关mRNAs的翻译，取决于细胞 需要它编码的蛋白质产物。在分子水平上，信号是通过RBP构象传递的 从微妙到大规模的变化。这些变化进而改变了RBP表面的化学成分和形状 加强或削弱它们与RNA和其他蛋白质的相互作用。这些不断变化的分子 相互作用使RNA沿着适当的途径分流：翻译、存储或腐烂。一些RBP可以指导 将RNA靶向相反的端点，从而充当分子开关。令人惊讶的是，指导原则 令人惊讶的是，该细胞的这种基本决策没有得到足够的研究。 限制性商业惯例与其目标RNA之间的特定和非特定相互作用可以在几个层面上进行调整。 首先，大多数限制性商业惯例有多个rna结合域(Rbd)，它们的相对方向是保持不变的。 由连接区和可以根据RNA和蛋白质结合伙伴而改变。其次，大多数RBP都收到了 来自描述细胞环境的信号通路的输入，并相应地激活基因 表达变化；不同的途径最终导致不同的翻译后修饰(PTM)，这可以 通过相同的RBP导致不同的翻译结果。第三，RNA接受协同转录和转录后转录 向其RBP合作伙伴发送各种消息的修改；这些标记因此可以诱导RBP 构象变化，改变相互作用者和翻译结果。这些信号之间的相互作用 输入和翻译输出没有被很好地理解。我们建议使用RBP La相关蛋白1 (LARP1)作为一个模型系统，用于了解细胞如何整合来自多个RBD限制性商业惯例、PTM、 以及转录后的信使核糖核酸修饰，以指导特定转录本的翻译。 我们将使用生物化学、生物物理学和结构生物学来解决这些基本问题 翻译规则。我们将研究三个LARP1rbd-2是如何被400个氨基酸分开的 一级结构-通过空间传递它们的结合状态，以调节关联的翻译 成绩单。我们还将研究翻译后修饰如何影响RNA和蛋白质结合 LARP1的活动，管理不同类别的mRNAs的翻译。由于LARP1识别co-and 转录后RNA修改，我们也将利用这个系统来了解限制性商业惯例如何反应 来自RNA靶标的信息以调整结构-功能关系。我们的工作将推动LARP1生物学 推进并产生适用于许多(如果不是全部)翻译调节器限制性商业惯例的概念性进展。

The goal of this research program is to uncover the molecular mechanisms underlying RNA-binding protein (RBP) regulation of the decisive stage of gene expression, translation. To maintain homeostasis, signaling pathways direct the cell’s translational output by relaying information about its environment through RBPs; RBPs ultimately repress or stimulate the translation of associated mRNAs depending on whether the cell needs the protein product it encodes. At the molecular level, signals are transduced by RBP conformational changes, ranging from subtle to large-scale. Such changes alter RBP surface chemistry and shape, in turn strengthening or weakening their interactions with RNA and other proteins. These shifting molecular interactions shunt RNAs down the appropriate pathway: translation, storage, or decay. Some RBPs can guide target RNAs to opposing endpoints, thereby acting as molecular switches. Surprisingly, the principles guiding such fundamental decisions by the cell are surprisingly understudied. The specific and nonspecific interactions that RBPs have with their target RNAs are tunable on several levels. First, most RBPs have multiple RNA-binding domains (RBDs), the relative orientations of which are maintained by linker regions and can change based on RNA and protein binding partners. Second, most RBPs receive input from signaling pathways that describe the cellular environment and, in response, actuate gene expression changes; different pathways culminate in different post-translational modifications (PTMs) that can lead to divergent translational outcomes via the same RBP. Third, RNAs receive co- and post-transcriptional modifications that signal various messages to their RBP partners; these marks can thereby induce RBP conformational change, altering interactors and translational outcome. The interplay among these signaling inputs and translational output is not well understood. We propose to use the RBP La-related protein 1 (LARP1) as a model system for understanding how cells integrate information from multi-RBD RBPs, PTMs, and post-transcriptional mRNA modifications to direct the translation of specific transcripts. We will use biochemistry, biophysics, and structural biology to address these fundamental questions of translation regulation. We will examine how the three LARP1 RBDs—two separated by 400 amino acids in primary structure—communicate their binding statuses through space to regulate the translation of associated transcripts. We will also investigate how post-translational modifications affect the RNA- and protein-binding activities of LARP1 to manage the translation of distinct classes of mRNAs. Since LARP1 recognizes co- and post-transcriptional RNA modifications, we will also utilize this system to understand how RBPs respond to information from RNA targets to adjust structure-function relationships. Our work will propel LARP1 biology forward and also yield conceptual advances that are applicable to many, if not all, translation regulator RBPs.