Biwer L A, Isakson B E
Department of Molecular Physiology and Biophysics, University of Virginia, Charlottesville, VA, USA.
Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA, USA.
Acta Physiol (Oxf). 2017 Jan;219(1):162-175. doi: 10.1111/apha.12675. Epub 2016 Apr 5.
The endoplasmic reticulum (ER) is a prime mediator of cellular signalling due to its functions as an internal cellular store for calcium, as well as a site for synthesis of proteins and lipids. Its peripheral network of sheets and tubules facilitates calcium and lipid signalling, especially in areas of the cell that are more distant to the main cytoplasmic network. Specific membrane proteins shape the peripheral ER architecture and influence the network stability to project into restricted spaces. The signalling microdomains are anatomically separate from the cytoplasm as a whole and exhibit localized protein, ion channel and cytoskeletal element expression. Signalling can also occur between the ER and other organelles, such as the Golgi or mitochondria. Lipids made in the ER membrane can be sent to the Golgi via specialized transfer proteins and specific phospholipid synthases are enriched at ER-mitochondria junctions to more efficiently expedite phospholipid transfer. As a hub for protein and lipid synthesis, a store for intracellular calcium [Ca ] and a mediator of cellular stress, the ER is an important cellular organelle. Its ability to organize into tubules and project into restricted spaces allows for discrete and temporal signalling, which is important for cellular physiology and organism homoeostasis.
内质网（ER）是细胞信号传导的主要介质，因为它具有作为细胞内钙储存库的功能，以及作为蛋白质和脂质合成的场所。其由片层和小管组成的外周网络促进钙和脂质信号传导，特别是在细胞中距离主要细胞质网络较远的区域。特定的膜蛋白塑造外周内质网结构，并影响网络稳定性以伸入受限空间。信号微区在解剖学上与整个细胞质分开，并表现出局部的蛋白质、离子通道和细胞骨架元件表达。信号传导也可在内质网与其他细胞器之间发生，如高尔基体或线粒体。在内质网膜中合成的脂质可通过专门的转运蛋白被输送到高尔基体，并且特定的磷脂合成酶在内质网 - 线粒体连接处富集，以更有效地加速磷脂转移。作为蛋白质和脂质合成的中心、细胞内钙[Ca]的储存库以及细胞应激的介质，内质网是一种重要的细胞器。它组织成小管并伸入受限空间的能力允许进行离散和瞬时的信号传导，这对细胞生理学和机体稳态很重要。
