Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France.
Institut National de la Santé et de la Recherche Médicale (INSERM), U1258, Illkirch, France.
EMBO Rep. 2018 Jul;19(7). doi: 10.15252/embr.201745453. Epub 2018 Jun 1.
Membrane contact sites are cellular structures that mediate interorganelle exchange and communication. The two major tether proteins of the endoplasmic reticulum (ER), VAP-A and VAP-B, interact with proteins from other organelles that possess a small VAP-interacting motif, named FFAT [two phenylalanines (FF) in an acidic track (AT)]. In this study, using an unbiased proteomic approach, we identify a novel ER tether named motile sperm domain-containing protein 2 (MOSPD2). We show that MOSPD2 possesses a Major Sperm Protein (MSP) domain which binds FFAT motifs and consequently allows membrane tethering MOSPD2 is an ER-anchored protein, and it interacts with several FFAT-containing tether proteins from endosomes, mitochondria, or Golgi. Consequently, MOSPD2 and these organelle-bound proteins mediate the formation of contact sites between the ER and endosomes, mitochondria, or Golgi. Thus, we characterized here MOSPD2, a novel tethering component related to VAP proteins, bridging the ER with a variety of distinct organelles.
膜接触位点是介导细胞器间交换和通讯的细胞结构。内质网 (ER) 的两种主要的 tether 蛋白,VAP-A 和 VAP-B,与其他细胞器的蛋白质相互作用,这些蛋白质具有一个小的 VAP 相互作用基序,称为 FFAT [两个在酸性轨道 (AT) 中的苯丙氨酸 (FF)]。在这项研究中,我们使用一种无偏的蛋白质组学方法,鉴定了一种新的 ER 接头蛋白,命名为运动精子域蛋白 2 (MOSPD2)。我们表明 MOSPD2 具有 Major Sperm Protein (MSP) 结构域,该结构域可以结合 FFAT 基序,从而允许膜连接。MOSPD2 是一种 ER 锚定蛋白,它与来自内体、线粒体或高尔基体的几种含有 FFAT 的 tether 蛋白相互作用。因此,MOSPD2 和这些细胞器结合的蛋白介导了 ER 与内体、线粒体或高尔基体之间接触位点的形成。因此,我们在这里描述了 MOSPD2,一种与 VAP 蛋白相关的新型 tethering 成分,将 ER 与各种不同的细胞器联系起来。