Cytoplasmic mechanisms of gene regulation: intersections and coordination

摘要 不同的调控途径共同协调基因表达，我们的指导思想 因此，探索不同类型监管的界面是发现新的 也是重要的生物学。基于我们之前Mira奖的发现，我们建议将重点放在 了解转录后调控的不同策略--信使核糖核酸衰变、翻译和 蛋白质腐烂--共同控制基因的表达。 在我们两个主题的第一个fi中，我们将探索蛋白质衰变作为元调节因子的想法。 早期胚胎转录后的图景。以黑腹果蝇为模型 系统，我们将研究最早的发育步骤之一，母体到受精卵的转变。 在这个过程中，母体基因产物被合子基因产物取代，我们发现 三种母体RNA结合蛋白的去除至关重要，并决定了它们的破坏程度 发育受控的。我们建议将这一研究范围扩展到其他RNA结合蛋白 在早期胚胎中被不同的和未知的机制破坏。我们想回答三个问题 关键问题：这些其他RNA结合蛋白被破坏的机制是什么？ 它们的退化是如何在发育过程中得到控制的？它们的退化又是如何在 转录调控？我们的研究意义重大，因为我们的研究结果将揭示 母体蛋白塑造了早期胚胎的调控格局，它们可能会提供一种 适用于其他类型发展转型的概念框架。 在第二个主题中，我们将探索开放阅读如何调节mRNA的衰退和 翻译。糟糕的(或非最佳的)密码子会导致蛋白质产量的减少，并理解 潜在的机制仍然是fi领域的一个开放研究领域。我们兴奋地发现， 非最佳密码子的使用抑制了人类细胞中的翻译启动。这条途径至少有同样的效力 如前所述，像信使核糖核酸这样的衰变途径。我们提议的计划将以这些结果为基础 并将回答以下三个重要问题： 由非最佳密码子引起的翻译抑制中的Poly(A)？哪些因素会影响翻译 压抑？密码子介导的调控在早期发育过程中是如何变化的？最后一个问题 代表了我们实验室的新方向，并利用我们在果蝇方面的独特技能组合 MZT和密码子介导的调控。我们的研究将揭示一种主要镇压的分子基础 由非最佳密码子介导的途径。我们建立的系统有可能揭示出其他 发展协调的翻译控制类型，我们预计我们的研究将 为探索基因调控在生物空间和时间中的变化提供了一个起点。

SUMMARY Different regulatory pathways work together to coordinate gene expression, and our guiding philosophy has been that exploring the interface of different types of regulation is thus a good way to discover new and important biology. Building on discoveries from our previous MIRA award, we propose to focus on understanding how different strategies for post-transcriptional regulation—mRNA decay, translation, and protein decay—act together to control gene expression. In the first of our two themes, we will explore the idea that protein decay acts as a meta-regulator of the post-transcriptional landscape of the early embryo. Using Drosophila melanogaster as a model system, we will investigate one of the earliest steps of development, the maternal-to-zygotic transition. During this process, maternal gene products are replaced with zygotic ones, and we have discovered that removal of three maternal RNA binding proteins is critical and determined how their destruction is developmentally controlled. We propose to extend this line of investigation to other RNA binding proteins that are destroyed by distinct and unknown mechanisms in the early embryo. We want to answer three critical questions: what are the mechanisms by which these other RNA binding proteins are destroyed? How is their degradation developmentally controlled? How does their degradation in turn change post- transcription regulation? Our research is significant because our results will reveal how destruction of maternal proteins shapes the regulatory landscape of the early embryo, and they will likely provide a conceptual framework applicable to other types of developmental transitions. In the second theme, we will explore how the open reading regulates mRNA decay and translation. Poor (or “nonoptimal”) codons lead to reduced protein output, and understanding the underlying mechanisms remains an open area of research for the field. We have excitingly found that nonoptimal codon usage represses translation initiation in human cells. This pathway is at least as potent as previously described pathways like mRNA decay. Our proposed program will build upon these results at a mechanistic level and will answer the following three important questions: What is the role of the poly(A) in translational repression due to nonoptimal codons? What factors mediate translational repression? How does codon-mediated regulation change during early development? This last question represents a new direction for our lab and leverages our unique combination of skills in the Drosophila MZT and codon-mediated regulation. Our research will reveal the molecular basis for a major repressive pathway mediated by nonoptimal codons. The systems we establish have the potential to reveal other types of developmentally-coordinated translational control, and we anticipate that our research will provide a launching point to explore the how gene regulation changes in biological space and time.