Regulation of selective endocytic transport

该项目将研究细胞内吞作用的机制，内吞作用是细胞膜的一部分被拉入细胞内部的过程。内吞作用调节细胞如何吸收营养物质，与其他细胞交流，以及适应环境条件的变化。虽然这项研究将使用酵母进行，但发现将广泛适用，因为介导内吞作用的细胞成分在不同物种中是保守的。研究内吞作用对于理解细胞的功能是至关重要的，并且这种知识可以有许多应用，例如提高作物产量和粮食生产。该项目将通过培训高中生、本科生和研究生来支持科学和教育的多样性，其中许多学生属于在科学领域代表性不足的群体。参与该项目的本科生和研究生都将参与到小学的推广活动中，在那里年轻的学生将亲自进行酵母实验，并使用最先进的研究显微镜观察细胞成分。这次外展活动的主要目的是激发年轻学生对科学的兴趣。通过这项研究获得的知识将发表在广泛的科学期刊上，在专业和广泛的细胞生物学会议上发表，并整合到研究人员教授的本科和研究生课程中。在网格蛋白介导的内吞过程中，支链肌动蛋白聚合提供了驱动囊泡内化所需的力。本研究将探讨关于肌动蛋白网络在内吞过程中的调节的三个基本和未解决的问题。目的1将确定肌动蛋白聚合是如何在内吞作用位点开始的。特别是，Aim 1将阐明控制肌动蛋白网络每个新分支启动的分子机制。目的2将确定肌动蛋白封盖蛋白被招募到内吞作用位点的机制，以及肌动蛋白网络中两个鲜为人知的蛋白质成分（Aim21和Bsp1）如何调节其功能。目的3将定义Twinfilin在内吞位点的功能。虽然Twinfilin一直被认为是肌动蛋白网络的一个组成部分，但它的细胞功能是有争议的，最近一些备受瞩目的文章得出了截然不同的结论。该项目将测试Twinfilin在capping蛋白下游作为肌动蛋白丝解盖和内吞作用位点的拆卸因子的前提。强大的酿酒酵母系统将允许在体内和体外研究内吞调节因子。这项研究将是多学科的，包括酵母遗传学、活细胞荧光显微镜、电子显微镜和冷冻电子断层扫描、生物化学、x射线蛋白质晶体学、平衡结合分析和动力学分析，以及建模方法。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This project will investigate the cellular machinery that carries out endocytosis, a process in which a portion of the cell membrane is pulled into the cell interior. Endocytosis regulates how cells take up nutrients, communicate with other cells, and adapt to changes in environmental conditions. While this research will be performed using yeast, discoveries will be broadly applicable because the cellular components that mediate endocytosis are conserved among different species. Studying endocytosis is essential to understanding how cells function, and this knowledge could have a number of applications such as improving crop yields and food production. This project will contribute to supporting diversity in science and education through training of high school, undergraduate and graduate students, many of whom belong to groups underrepresented in the sciences. Both undergraduate and graduate students who work on this project will be involved in outreach at elementary schools where young students will perform hands-on yeast experiments and visualize cellular components using state-of-the-art research microscopes. The main goal of this outreach activity is to excite young students about science. Knowledge gained through this research will be published in wide-ranging scientific journals, presented at both specialized and broad cell biology conferences, and integrated into undergraduate and graduate courses taught by the researchers. During clathrin-mediated endocytosis, branched actin polymerization provides force needed to drive vesicle internalization. This research will explore three essential and unresolved questions regarding the regulation of the actin network during endocytosis. Aim 1 will establish how actin polymerization is initiated at sites of endocytosis. In particular, Aim 1 will elucidate the molecular mechanism that controls initiation of each new branch of the actin network. Aim 2 will determine the mechanism by which actin capping protein is recruited to sites of endocytosis and how two poorly understood protein components of the endocytic machinery actin network (Aim21 and Bsp1) regulate its function. Aim 3 will define the function of Twinfilin at endocytic sites. While Twinfilin has long been known as a component of actin networks, its cellular function is controversial, with recent high-profile articles reaching disparate conclusions. This project will test the premise that Twinfilin functions downstream of capping protein as an actin filament uncapping and disassembly factor at sites of endocytosis. The powerful Saccharomyces cerevisiae system will allow for the study of endocytosis regulators both in vivo and in vitro. The research will be multidisciplinary employing yeast genetics, live cell fluorescence microscopy, electron microscopy and cryo-electron tomography, biochemistry, X-ray protein crystallography, equilibrium binding assays and kinetic assays, as well as modeling approaches.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.