Mediates the transport of phosphorylated lysosomal enzymes from the Golgi complex and the cell surface to lysosomes (, ). Lysosomal enzymes bearing phosphomannosyl residues bind specifically to mannose-6-phosphate receptors in the Golgi apparatus and the resulting receptor-ligand complex is transported to an acidic prelysosomal compartment where the low pH mediates the dissociation of the complex (, ). The receptor is then recycled back to the Golgi for another round of trafficking through its binding to the retromer . This receptor also binds IGF2 . Acts as a positive regulator of T-cell coactivation by binding DPP4 .
Subcellular locations: Golgi apparatus membrane, Endosome membrane
Mainly localized in the Golgi at steady state and not detectable in lysosome . Colocalized with DPP4 in internalized cytoplasmic vesicles adjacent to the cell surface .