Molecular Biology of the Cell · 2011 · 129 citations · 40 references
Life SciencesCell BiologyMolecular BiologyIntracellular TransportMembrane TraffickingMolecular Cell BiologyEndomembrane SystemEndoplasmic Reticulum TransportIntracellular TraffickingSecretory PathwayVesicle FormationVesicle TraffickingCopi Vesicle CoatCopi VesiclesCopi-mediated TransportCopii Vesicle CoatCopii VesiclesCopii-mediated TransportSecretory VesiclesYeast Protein Trafficking
Glycosylphosphatidylinositol (GPI)-anchored proteins are secretory proteins that are attached to the cell surface of eukaryotic cells by a glycolipid moiety. Once GPI anchoring has occurred in the lumen of the endoplasmic reticulum (ER), the structure of the lipid part on the GPI anchor undergoes a remodeling process prior to ER exit. In this study, we provide evidence suggesting that the yeast p24 complex, through binding specifically to GPI-anchored proteins in an anchor-dependent manner, plays a dual role in their selective trafficking. First, the p24 complex promotes efficient ER exit of remodeled GPI-anchored proteins after concentration by connecting them with the COPII coat and thus facilitates their incorporation into vesicles. Second, it retrieves escaped, unremodeled GPI-anchored proteins from the Golgi to the ER in COPI vesicles. Therefore the p24 complex, by sensing the status of the GPI anchor, regulates GPI-anchored protein intracellular transport and coordinates this with correct anchor remodeling.
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