The yeast p24 complex regulates GPI-anchored protein transport and quality control by monitoring anchor remodeling

• Published in: Molecular biology of the cell Vol. 22; no. 16; pp. 2924 - 2936
• Main Authors: Castillon, Guillaume A., Aguilera-Romero, Auxiliadora, Manzano-Lopez, Javier, Epstein, Sharon, Kajiwara, Kentaro, Funato, Kouichi, Watanabe, Reika, Riezman, Howard, Muñiz, Manuel
• Format: Journal Article
• Language: English
• Published: United States The American Society for Cell Biology 15.08.2011
• Subjects: Binding Sites; Cell surface; Endoplasmic reticulum; Endoplasmic Reticulum - metabolism; Endoplasmic Reticulum Stress; Gene Knockout Techniques; Glycolipids; Glycosylphosphatidylinositol; Glycosylphosphatidylinositols - metabolism; Golgi apparatus; Golgi Apparatus - metabolism; GPI-Linked Proteins - metabolism; Lipids; Membrane Proteins - metabolism; Multiprotein Complexes - chemistry; Multiprotein Complexes - genetics; Multiprotein Complexes - metabolism; Protein Binding; Protein Transport; Quality control; Saccharomyces cerevisiae - metabolism; Saccharomyces cerevisiae Proteins - chemistry; Saccharomyces cerevisiae Proteins - genetics; Saccharomyces cerevisiae Proteins - metabolism; Unfolded Protein Response; Vesicles; Vesicular Transport Proteins - chemistry; Vesicular Transport Proteins - genetics; Vesicular Transport Proteins - metabolism
• ISSN: 1059-1524; 1939-4586; 1939-4586
• DOI: 10.1091/mbc.e11-04-0294

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.