CAREER: Biochemical and Structural Mechanism of the WASH Regulatory Complex

就像一座城市一样，牢房里挤满了繁忙的交通。蜂窝通信是由称为囊泡的微小包裹组成的，这些包裹包含要发送到正确目的地的分子。交通的移动使细胞能够执行重要的任务，如对环境做出反应，吸收营养，以及生存。被称为内小体的更大的膜封闭结构起到了“包裹分配中心”的作用，决定了分子被送往哪里。内体包裹着由一种名为肌动蛋白的蛋白质组成的纤维。与人体的肌肉和骨骼相似，肌动蛋白纤维使内体具有适当的形状和强度。没有肌动蛋白，内体就会崩溃，交通就会停滞不前。这个项目的总体目标是了解细胞如何产生肌动蛋白纤维来支持内小体的结构和功能。该项目的结果将提供关于内小体如何形成正确的结构和正确引导交通的基础知识。同时，PI将整合多种新的方法来改善生物化学教育和研究的基础设施，包括创建新的虚拟实验室软件来帮助本科生学习生物化学实验室课程，建立双月一次的校园生物科学论坛来帮助研究生和实验室共享研究和合作，以及在传统实验室环境和新的虚拟小组讨论形式下提供强大的本科生研究经验。这个项目的总体目标是了解肌动蛋白细胞骨架在内膜上的调节。该项目特别关注内体肌动蛋白的中央调节因子，称为WASH调节复合体(SHRC)，旨在：1)确定SHRC如何被各种膜配体激活；2)识别和表征新的膜配体；以及3)解决SHRC在各种激活状态下的高分辨率结构。该项目的成功完成将填补一个很大的空白，了解肌动蛋白结构是如何在内体膜上动态组装的，肌动蛋白重排如何调节内体结构和功能，以及细胞如何使用类似的原理来控制其他细胞内细胞器和运输途径的肌动蛋白动态。此外，该项目将开发新的蛋白质组工具，发现对内体贩运重要的新分子，并确定新的结构机制，这些共同将为生物学家提供前所未有的机会来操纵和研究细胞内体贩运。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。

Like a city, the cell is filled with heavy traffic. Cellular traffic is made up of tiny parcels called vesicles that contain molecules to be sent to their correct destinations. Movement of traffic allows the cell to perform important tasks, such as responding to the environment, absorbing nutrients, and surviving. Larger membrane-enclosed structures called endosomes act as a “parcel distribution center” to decide where the molecules are sent to. Endosomes are coated with fibers made up of a protein called actin. Similar to muscles and bones in the human body, actin fibers give endosomes proper shape and strength. Without actin, the endosome collapses, and the traffic stalls. The overall goal of this project is to understand how the cell produces actin fibers to support the structure and function of endosomes. Results of this project will provide fundamental knowledge about how endosomes form correct structures and direct traffic properly. In parallel, the PI will integrate multiple new approaches to improve the infrastructure of biochemical education and research, including creating new virtual lab software to help undergraduate students study biochemistry lab courses, establishing a bimonthly campus-wide biological science forum to help graduate students and labs share research and collaborate, and offering strong undergraduate research experiences both in the traditional lab setting and in a new virtual group-discussion format. The overall goal of this project is to understand actin cytoskeletal regulation at endosomal membranes. Specifically focused on a central regulator of endosomal actin named the WASH Regulatory Complex (SHRC), the project aims to: 1) determine how the SHRC is activated by various membrane ligands; 2) identify and characterize new membrane ligands, and; 3) solve high-resolution structures of the SHRC in various activation states. Successful completion of the project will fill a large gap in understanding how actin structures are dynamically assembled at endosomal membranes, how actin rearrangements regulate endosomal structure and function, and how the cell may use similar principles to control actin dynamics at other intracellular organelles and trafficking pathways. In addition, the project will develop new proteomic tools, discover new molecules important to endosomal trafficking, and identify new structural mechanisms, which together will provide unprecedented opportunities for biologists to manipulate and study endosomal trafficking in cells.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.