Coupled axonal protein synthesis and lipidation in axon growth and homeostasis

随着轴突的生长和生长，轴突不断对环境中的外部信号做出反应 在发育过程中导航到目标组织，并进行维护和修复 在成人生活中。MRNA定位和局部蛋白质合成是一种保守的机制， 允许对外部营养和引导提示做出快速和轴突自主的反应。 尽管轴突蛋白质合成的功能越来越受到重视，但在 我们的知识是了解新生蛋白质是如何进一步加工的 定位于轴突以产生全功能蛋白质。我们的初步结果表明 一种神经营养因子(神经生长因子)强烈地调节局部蛋白质的合成 以及轴突中新生成的蛋白质的脂化(苯丙基化)。人们一直认为 蛋白质预烯基化是一种结构性机制，它发生在整个细胞质和 对于细胞功能是允许的。与之形成鲜明对比的是，我们发现，在神经元中，苯丙基化 受到外部信号的精细时空控制。此应用程序的目标是 是确定耦合的轴突蛋白合成和预烯基化是否作为 调节机制定位和丰富轴突间的蛋白质，以确保 对外在促进生长线索的动态和空间反应。我们将使用 影像、生化和功能分析的组合 神经元培养，以及在老鼠体内的分析，以实现这一目标。这些 研究将推进对神经元信号空间模式的了解 轴突的发育、维持和再生。

Axons continuously respond to external signals in their environment as they grow and navigate toward their target tissues during development, and for maintenance and repair in adult life. mRNA localization and local protein synthesis is a conserved mechanism that allows for rapid and axon-autonomous responses to external trophic and guidance cues. Despite growing appreciation for the functions of axonal protein synthesis, a major gap in our knowledge is in understanding how the nascent proteins are further processed and localized in axons to generate fully functional proteins. Our preliminary results suggest that a neurotrophic factor (Nerve Growth Factor) acutely regulates local protein synthesis and lipidation (prenylation) of newly-made proteins in axons. It has been assumed that protein prenylation is a constitutive mechanism that occurs throughout the cytoplasm and is permissive for cellular functions. In striking contrast, we find that, in neurons, prenylation is under exquisite spatio-temporal control by extrinsic signals. The goal of this application is to define whether coupled axonal protein synthesis and prenylation serves as a regulatory mechanism to localize and enrich proteins in axonal compartments to ensure dynamic and spatial responses to extrinsic growth-promoting cues. We will use a combination of imaging, biochemical, and functional analyses in compartmentalized neuronal cultures, as well as in vivo analyses in mice to accomplish this goal. These studies will advance the knowledge of spatial modes of signaling in neurons that underlie axon development, maintenance, and regeneration.