RNA Localization in Xenopus Oocytes

项目概要 细胞质 RNA 定位是产生胚胎和体细胞的广泛机制 极性。在脊椎动物中，Vg1 mRNA 是局部 mRNA 的一个突出例子，它在 胚胎图案。 Vg1 mRNA 编码肽生长因子，在卵子发生期间定位于 非洲爪蟾卵母细胞的植物细胞质。 Vg1蛋白在植物半球中的限制性表达 卵子对于胚胎的正确形成至关重要，这使得 Vg1 mRNA 的定位成为胚胎发育的重要模型。 了解母体分子如何定位以影响模式和极性。 该研究项目的目标是研究 RNA 分子如何靶向特定区域 细胞质通过空间限制的蛋白质表达产生细胞极性。的基础 我们对控制这一过程的分子相互作用的研究进展奠定了这项研究的基础。 我们的实验已经定义了导致组装的关键RNA-蛋白质和蛋白质-蛋白质相互作用 具有运输能力的 RNP 复合体，并发现了定位途径中的不同步骤。我们目前的 提案旨在通过研究这些步骤之间的动态转变来扩展这些发现 本土化途径。我们将结合体内和体外方法来确定分子 负责 Vg1 mRNA 局部表达的机制。提出了三个具体目标： 在目标 I 中， 我们将表征细胞质 Vg1 RNP 复合物的动力学和运输，在 Aim II 中，我们将 分析 RNP 转运颗粒的组装和活性，在目标 III 中我们将研究其机制 将翻译抑制和 RNA 定位结合起来 拟议的研究旨在揭示 mRNA 分子的运输机制 在细胞内产生空间限制的蛋白质表达，并将提供对发育如何进行的深入了解 信号在脊椎动物胚胎中呈空间分布。这项工作将影响与人类健康相关的问题 例如出生缺陷，以及与 RNA 运输缺陷有关的神经系统疾病 局部蛋白质合成。

Project Summary Cytoplasmic RNA localization is a widespread mechanism for generating both embryonic and somatic cell polarity. Among vertebrates, Vg1 mRNA is a prominent example of a localized mRNA that plays a role in embryonic patterning. Vg1 mRNA encodes a peptide growth factor, and is localized during oogenesis to the vegetal cytoplasm of Xenopus oocytes. Restricted expression of Vg1 protein in the vegetal hemisphere of the egg is critical for correct patterning of the embryo, making localization of Vg1 mRNA an important model for understanding how maternal molecules are localized to influence pattern and polarity. The goal of this research project is to investigate how RNA molecules can be targeted to specific regions of the cell cytoplasm to generate cell polarity through spatially restricted protein expression. The foundation for this investigation has been laid by our progress studying the molecular interactions that govern this process. Our experiments have defined critical RNA-protein and protein-protein interactions leading to assembly of a transport-competent RNP complex and have uncovered distinct steps in the localization pathway. Our current proposal seeks to extend these findings by studying the dynamic transitions between these steps in the localization pathway. We will use a combination of in vivo and in vitro approaches to determine the molecular mechanisms responsible for localized expression of Vg1 mRNA. Three specific aims are proposed: In Aim I, we will characterize the dynamics and transport of the cytoplasmic Vg1 RNP complex, in Aim II, we will analyze the assembly and activity of RNP transport granules and in Aim III we will investigate the mechanisms that couple translational repression and RNA localization The proposed research is designed to reveal the mechanisms by which mRNA molecules are transported within cells to generate spatially restricted protein expression, and will provide insight into how developmental signals are spatially distributed in the vertebrate embryo. This work will impact issues related to human health such as birth defects, as well as neurological diseases that have been linked to defective RNA transport and localized protein synthesis.