Department of Chemical and Systems Biology, School of Medicine, Stanford University, Stanford, California 94305, USA.
Annu Rev Biochem. 2011;80:973-1000. doi: 10.1146/annurev-biochem-061609-165311.
Eukaryotic organelles can interact with each other through stable junctions where the two membranes are kept in close apposition. The junction that connects the endoplasmic reticulum to the plasma membrane (ER-PM junction) is unique in providing a direct communication link between the ER and the PM. In a recently discovered signaling process, STIM (stromal-interacting molecule) proteins sense a drop in ER Ca(2+) levels and directly activate Orai PM Ca(2+) channels across the junction space. In an inverse process, a voltage-gated PM Ca(2+) channel can directly open ER ryanodine-receptor Ca(2+) channels in striated-muscle cells. Although ER-PM junctions were first described 50 years ago, their broad importance in Ca(2+) signaling, as well as in the regulation of cholesterol and phosphatidylinositol lipid transfer, has only recently been realized. Here, we discuss research from different fields to provide a broad perspective on the structures and unique roles of ER-PM junctions in controlling signaling and metabolic processes.
真核细胞器可以通过稳定的连接相互作用，两个膜保持紧密接近。连接内质网和质膜的连接（ER-PM 连接）是独特的，它提供了内质网和质膜之间的直接通讯连接。在最近发现的信号传递过程中，STIM（基质相互作用分子）蛋白感知内质网 Ca(2+)水平下降，并直接在连接空间激活 Orai 质膜 Ca(2+)通道。在相反的过程中，电压门控质膜 Ca(2+)通道可以直接打开横纹肌细胞中的内质网 Ryanodine 受体 Ca(2+)通道。尽管 ER-PM 连接最初是在 50 年前描述的，但它们在 Ca(2+)信号传递以及胆固醇和磷脂酰肌醇脂质转移的调节中的广泛重要性直到最近才被认识到。在这里，我们讨论来自不同领域的研究，以提供关于控制信号传递和代谢过程的 ER-PM 连接的结构和独特作用的广泛视角。
