Identification of genes involved in transport of GPI-anchored proteins

糖基磷脂酰肌醇（GPI）锚定蛋白质是发生在内质网（ER）中的翻译后修饰。在这里，我们建立了突变细胞系，选择性地在运输GPI锚定蛋白从ER到高尔基体的缺陷。我们确定了一个负责的基因，命名为PGAP 5（后GPI附着蛋白5）。PGAP 5催化GPI-AP上聚糖部分的重塑。我们的数据表明，GPI聚糖作为ER-退出信号，并表明PGAP 5介导的聚糖重塑调节GPI-AP转运在早期分泌途径

Glycosylphosphatidylinositol (GPI) anchoring of proteins is a post-translational modification occurring in the endoplasmic reticulum (ER). Here, we established mutant cell lines that were selectively defective in transport of GPI-anchored proteins from the ER to the Golgi. We identified a responsible gene, designated PGAP5 (post-GPI-attachment to proteins 5). PGAP5 catalyzed the remodeling of the glycan moiety on GPI-APs. Our data demonstrate that GPI glycan acts as an ER-exit signal and suggest that glycan remodeling mediated by PGAP5 regulates GPI-AP transport in the early secretory pathway