The mature form of urokinase plasminogen activator receptor (uPAR) is attached to the plasma membrane by a glycosylphosphatidylinositol (GPI) anchor (Ploug et al. 1991). As nascent uPAR polypeptide moves into the lumen of the endoplasmic reticulum, it is attacked by a transamidase complex that cleaves the uPAR polypeptide after residue 305, releasing the carboxyterminal peptide of uPAR and replacing it with an acylated GPI moiety. In a second step, the GPI moiety is deacylated, yielding a uPAR-GPI conjugate that can be efficiently transported to the Golgi apparatus. This transport process and the other events needed to generate fully glycosylated uPAR-GPI associated with the plasma membrane will be annotated in a future release of Reactome.