mRNA regulation, localization, and dynamics in C. elegans embryogenesis

项目摘要/摘要： 秀丽线虫早期胚胎的细胞即使在缺乏DNA的情况下也会使其mRNA含量多样化。 从头开始转录。这一非凡的成就给了我的实验室一个独特的优势，可以用来研究后- 转录调控。令人惊讶的是，我们发现许多显示细胞特异性的mrna转录本 图案化也定位于离散的亚细胞结构，如生物分子凝聚物或膜。我的 实验室的目标是了解亚细胞信使核糖核酸模式是如何机械地产生的，它是如何发挥作用的 与蛋白质生产的联系，以及它如何影响发展。最近的进展已经确定了19万人 在65个物种的44个亚细胞位置发现了本地化的mRNA转录本(RNALocate数据库)。这些 转录本包括许多影响人类神经生物学的基因，其错误定位与 疾病。更多的代表通过未知的机制在细胞区域积累的mRNA和 用于未定义的目的，强调我们的目标是做出新发现的潜力。 在第一个资助阶段，我的团队确定了将mRNAs定位于P颗粒的机制 (细胞质凝聚物对生殖系发育和生育很重要)。与P相关的文字记录 颗粒经历暂时的隔离或永久的腐烂。在下一阶段，我们将解决 区分P颗粒相关mRNA隔离的信号、机制和动力学 防止腐烂。具体地说，我们将区分不同的竞争模型，解释保守的 转录产物nos-2(Nanos)退出P颗粒并启动其翻译，以确保生育。 在此之前，我们鉴定了几个与蛋白质一起定位于膜上的mrna转录本。 它们进行编码，这一发现在其他有机体中也得到了响应。其中包括ERM-1，一个保守家庭的成员 影响细胞形状和癌症的细胞骨架膜连接蛋白。我们发现ERM-1‘S基因 本地化依赖于翻译。接下来，我们将讨论解释的机制和原则 翻译erm-1的复合体如何以及为什么移动到膜上。我们还将利用基因组学来 鉴定膜丰富的转录组，以更好地理解膜上的局部翻译。 母体mRNA转录本在早期胚胎中经历衰退，通常会产生细胞特有的模式， 直接细胞分化。在第一个资金周期中，我们演示了对rna结合蛋白的需求。 SPN-4在某些转录本的清除性和细胞特异性中的作用。在下一阶段，我们将确定如何 SPN-4塑造转录组，并与其他清除信使核糖核酸的机制协同工作。 这些项目的总和将是创建一个总体研究计划，旨在 描述信使核糖核酸转录本如何在细胞内进行空间组织，以及该组织如何 影响基因表达和胚胎发育。

PROJECT SUMMARY/ABSTRACT: Cells of the Caenorhabditis elegans early embryo diversify their mRNA content even in the absence of de novo transcription. This remarkable feat has given my lab a unique vantage from which to study post- transcriptional regulation. Surprisingly, we found that many mRNA transcripts which exhibit cell-specific patterning also localize to discrete subcellular structures such as biomolecular condensates or membranes. My lab aims to understand how subcellular mRNA patterning arises mechanistically, how it functionally links to protein production, and how it impacts development. Recent advances have identified 190,000 localized mRNA transcripts found at 44 subcellular locales across 65 species (RNALocate Database). These transcripts include many that impact human neurobiology and whose mislocalization is associated with disease. Many more represent mRNAs that accumulate at cellular regions through unknown mechanisms and for undefined purposes, underscoring the potential for new discoveries that we aim to make. In the first funding phase, my group determined mechanisms that localize mRNAs to P granules (cytoplasmic condensates important for germline development and fertility). Transcripts that associate with P granules undergo either temporary sequestration or permanent decay. In the next phase, we will address the signals, mechanisms, and dynamics that distinguish P granule-associated mRNA sequestration from decay. Specifically, we will differentiate between competing models explaining how the conserved transcript nos-2 (nanos) exits P granules and initiates its translation to ensure fertility. Previously, we identified several mRNA transcripts that localize to membranes along with the proteins they encode, a finding echoed in other organisms. Among these were erm-1 a member of a conserved family of cytoskeletal membrane linker proteins that impacts cell shape and cancer. We found that erm-1’s mRNA localization is translation-dependent. Next, we will address the mechanisms and principles explaining how and why complexes of translating erm-1 move to membranes. We will also use genomics to characterize the membrane-enriched transcriptome to better understand localized translation at membranes. Maternal mRNA transcripts undergo decay in early embryos often creating cell-specific patterns that direct cell differentiation. In the first funding cycle, we demonstrated a requirement for the RNA binding protein SPN-4 in the clearance and cell-specificity of some transcripts. In the next phase, we will determine how SPN-4 shapes the transcriptome and works in concert with other mechanisms of mRNA clearance. The sum of these projects will be to create an overarching research program aimed at describing how mRNA transcripts organize spatially within the cell and how that organization can impact gene expression and embryogenesis.