Regulation of selective endocytic transport

这个项目将研究执行内吞作用的细胞机制，在这个过程中，细胞膜的一部分被拉入细胞内部。内吞作用调节细胞如何吸收营养，如何与其他细胞交流，以及如何适应环境条件的变化。虽然这项研究将使用酵母进行，但这些发现将广泛适用，因为介导内吞作用的细胞成分在不同物种之间是保守的。研究内吞作用对于了解细胞的功能至关重要，这一知识可能会有许多应用，如提高作物产量和粮食产量。该项目将通过培训高中生、本科生和研究生，帮助支持科学和教育的多样性，他们中的许多人属于在科学界代表性不足的群体。参与这个项目的本科生和研究生都将参与小学的推广活动，在那里，年轻的学生将进行亲身实践的酵母实验，并使用最先进的研究显微镜可视化细胞成分。这项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，在专门和广泛的细胞生物学会议上发表，并纳入研究人员教授的本科生和研究生课程。在网状蛋白介导的内吞作用中，分支肌动蛋白聚合提供驱动囊泡内化所需的力量。这项研究将探索关于肌动蛋白网络在内吞作用中的调节的三个基本和未解决的问题。目标1将确定肌动蛋白聚合是如何在内吞作用部位启动的。特别是，目标1将阐明控制肌动蛋白网络每个新分支的启动的分子机制。目的2将确定肌动蛋白帽蛋白被招募到内吞作用部位的机制，以及内吞机械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。目标3将定义Twinfilin在内吞饮部位的功能。虽然Twinfilin长期以来一直被认为是肌动蛋白网络的一个组成部分，但它的细胞功能存在争议，最近一些备受瞩目的文章得出了不同的结论。这个项目将测试这样一个前提，即双丝蛋白在覆盖蛋白下游作为肌动蛋白细丝解帽和内吞作用部位的分解因子发挥作用。功能强大的酿酒酵母系统将使体内和体外的内吞调节研究成为可能。这项研究将是多学科的，使用酵母遗传学、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射线蛋白质结晶学、平衡结合分析和动力学分析以及建模方法。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.