内质网膜形态维持的分子机制

内质网（endoplasmic reticulum,ER）是广泛存在于真核生物中的一类形态多样、功能重要的细胞器。内质网的连续膜系统由细胞核核膜、核周区域和外周区域组成。从形态上来看,内质网可以分为片状及管状两种结构,并且这两种形态又发挥着不同的生理功效。近年来的一些研究逐渐揭示了内质网这一复杂膜结构维持的机制,许多新发现的蛋白参与到内质网形态的维持过程中,其中整合膜蛋白reticulons和DP1/Yop1p既能诱导内质网管状结构的形成,又可能参与片状内质网的塑形,而atlastins和Sey1p则通过介导膜融合促进内质网管状网络的构建。更重要的是,一类称做遗传性痉挛性截瘫的人类神经退行性疾病与内质网形态的完整性有直接的关联。以近几年的研究结果为基础,对内质网膜形态的维持机制进行简要阐述。

Molecular mechanisms for shaping the ER membranes

The endoplasmic reticulum（ER） is morphologically and functionally conserved organelle.It is comprised by a continuous membrane system with nuclear envelop,perinuclear region and peripheral region.Morphologically speaking,the ER can be divided into two different compartments： tubules and sheets,which may play different physiological roles.Recent studies gradually unveil the mechanisms of how the ER morphology was generated,and many new proteins have been identified in this process.Two families of integral membrane proteins,the reticulons and DP1/Yop1,are involved in generating ER tubules as well as sheets.In addition,atlastins and Sey1p facilitate tubular network formation by mediating ER membrane fusion.More importantly,a neuronal degenerative disease called hereditary spastic paraplegia is directly linked to the integrity of the ER.Based on recent findings,we will discuss the molecular mechanisms of how ER is shaped and maintained.