ER-plasma membrane junctions: Why and how do we study them?

摘要

Abstract Endoplasmic reticulum (ER)-plasma membrane (PM) junctions are membrane microdomains important for communication between the ER and the PM. ER-PM junctions were first reported in muscle cells in 1957, but mostly ignored in non-excitable cells due to their scarcity and lack of functional significance. In 2005, the discovery of stromal interaction molecule 1 (STIM1) mediating a universal Ca 2+ feedback mechanism at ER-PM junctions in mammalian cells led to a resurgence of research interests toward ER-PM junctions. In the past decade, several major advancements have been made in this emerging topic in cell biology, including the generation of tools for labeling ER-PM junctions and the unraveling of mechanisms underlying regulation and functions of ER-PM junctions. This review summarizes early studies, recently developed tools, and current advances in the characterization and understanding of ER-PM junctions. This article is part of a Special Issue entitled: Membrane Contact Sites edited by Christian Ungermann and Benoit Kornmann. Highlights ? ER-PM junctions are essential for Ca 2+ signaling and homeostasis. ? ER-PM junctions are miniature structures best visualized by electron microscopy. ? New methods enabling visualization of ER-PM junctions in live cells are summarized. ? Recent studies identifying proteins enriched at ER-PM junctions are discussed. ? ER-PM junctions are hubs for non-vesicular transport of phospholipids and sterol. ]]>