Structure and Functions of ER/Plasma Membrane Junctions

内质网/质膜(ER/PM)连接是钙离子(Ca~(2+))内流的场所。最近，PI发现这些连接起着插入和去除质膜蛋白的运输中心的作用。此外，PI还发现电压门控钾通道Kv2.1与内质网相互作用，显著增加了ER/PM连接表面积，并从结构上改变了连接的形态。PI的研究结果表明，Kv2.1钾通道重塑为皮质内质网，可能在质膜30 nm以内。Kv2.1发挥着与Orai相似的结构作用，因为PI认为Kv2.1与ER膜蛋白结合。因此，Kv2.1介导的内质网在细胞表面的浓缩是一种新的专化细胞器，在细胞信号转导中具有特殊的蛋白质运输功能。目前的项目侧重于了解ER/PM连接的生物学，特别强调ER/PM连接结构的调节及其在调节膜蛋白运输中的功能。PI将回答以下问题：Kv2.1在ER/PM连接的蛋白质运输中起什么作用？Kv2.1如何动态调节ER/PM连接？皮质细胞骨架、内质网和Kv2.1之间有什么关系？哪个理论框架可以用来描述这些域的组装和维护？Kv2.1和ER之间的相互作用是如何产生大规模膜行为的？融合活细胞中的多色单分子跟踪和先进的随机过程分析，这是该项目不可或缺的，将为这些问题提供答案。这项研究将通过两个具有非常不同背景的实验室之间的合作，为研究生和本科生参与跨学科研究提供极好的机会。该研究计划将通过为当地一所小学的学生开发一个显微镜实验室，与外展部分相结合。该推广计划的目标是促进科学探究，并激励学生从小欣赏科学。这个实验室提供了一个独特的机会来利用教育和研究的整合，让学生有机会亲身实践学习。这个项目由物理系的生命系统物理学项目和分子和细胞生物科学系的细胞动力学和功能项目共同支持。

Endoplasmic reticulum/plasma membrane (ER/PM) junctions are known to be sites of calcium ion (Ca2+) influx. Recently, the PI discovered that these junctions function as trafficking hubs for insertion and removal of plasma membrane proteins. Furthermore, the PI has found that the voltage gated potassium channel Kv2.1 interacts with the endoplasmic reticulum, dramatically increasing ER/PM junction surface area and structurally changing the junction morphology. The PI's findings show that the Kv2.1 potassium channel remodels to cortical ER, which is likely within 30 nm of the plasma membrane. Kv2.1 is playing a structural role similar to that of Orai, for the PI proposes that Kv2.1 is binding an ER membrane protein. Thus, Kv2.1-mediated ER enrichment on the cell surface is a novel specialized organelle with specific functions in protein transport vital to cell signaling. The current project focuses on understanding the biology of ER/PM junctions with particular emphasis on the regulation of the ER/PM junction structure and its function in the modulation of membrane protein trafficking. The PI will answer the following questions: What is the role of Kv2.1 in protein trafficking at ER/PM junctions? How are ER/PM junctions dynamically regulated by Kv2.1? What are the relationships between the cortical cytoskeleton, ER, and Kv2.1? Which theoretical framework can be used to describe the assembly and maintenance of these domains? How does large-scale membrane behavior emerge from the interactions between Kv2.1 and ER? The fusion of multicolor single-molecule tracking in living cells and advanced stochastic process analysis, which are integral to the project, will provide answer to these questions. This research will offer excellent opportunities for graduate and undergraduate student participation in interdisciplinary research through the collaboration between two laboratories with very different backgrounds. The research program will be integrated with an outreach component by developing a microscopy laboratory for students at a local elementary school. The goal of the outreach program is to foster scientific enquiry and to motivate students to appreciate science from an early age. This lab presents a unique opportunity to leverage integration of education and research, giving students access to hands-on practical learning.This project is being jointly supported by the Physics of Living Systems program in the Division of Physics and the Cellular Dynamics and Function Program in the Division of Molecular and Cellular Biosciences.