Cytoplasmic mechanisms of gene regulation: intersections and coordination

总结 不同的调控途径共同作用，协调基因表达，我们的指导思想是 因此，探索不同类型监管的界面是发现新监管的好方法。 重要的生物学。基于我们之前MIRA奖的发现，我们建议专注于 理解不同的策略如何转录后调节-mRNA衰变，翻译， 蛋白质衰变-共同作用以控制基因表达。 在我们的两个主题中的第一个，我们将探讨蛋白质衰变作为元调节器的想法 早期胚胎的转录后景观。以黑腹果蝇为模型 系统，我们将调查的最早的发展步骤之一，母亲到合子的过渡。 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结合蛋白的去除是至关重要的，并决定了它们的破坏方式。 发展控制。我们建议将这条研究路线扩展到其他RNA结合蛋白 在早期胚胎中被不同的未知机制破坏。我们想回答三个 关键问题：这些其他RNA结合蛋白被破坏的机制是什么？ 如何在发育过程中控制其退化？它们的退化又是如何改变的- 转录调控我们的研究是重要的，因为我们的结果将揭示如何破坏 母体蛋白质塑造了早期胚胎的调控格局，它们可能会提供一个 适用于其他类型发展转型的概念框架。 在第二个主题中，我们将探讨开放阅读如何调节mRNA的衰变， 翻译.差的（或"非最佳"）密码子导致蛋白质输出减少，并且理解密码子的功能。 潜在的机制仍然是该领域的开放研究领域。我们激动地发现， 非最佳密码子使用抑制人细胞中的翻译起始。这条途径至少 就像之前描述的mRNA降解途径一样。我们提出的计划将建立在这些结果的基础上 在一个机械的水平，并将回答以下三个重要的问题：什么是作用的 poly（A）在翻译抑制中的作用哪些因素介导翻译 镇压？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一个新方向，并利用了我们在果蝇中独特的技能组合， MZT和密码子介导的调节。我们的研究将揭示一种主要的抑制剂的分子基础 非最佳密码子介导的途径。我们建立的系统有可能揭示其他 类型的发展协调翻译控制，我们预计，我们的研究将 为探索基因调控如何在生物空间和时间上发生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.