IGF2R
Domain
Contains 15 repeating units of approximately 147 AA harboring four disulfide bonds each. The most highly conserved region within the repeat consists of a stretch of 13 AA that contains cysteines at both ends.
Function
Mediates the transport of phosphorylated lysosomal enzymes from the Golgi complex and the cell surface to lysosomes (PubMed:18817523, PubMed:2963003). 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 (PubMed:18817523, PubMed:2963003). The receptor is then recycled back to the Golgi for another round of trafficking through its binding to the retromer (PubMed:18817523). This receptor also binds IGF2 (PubMed:18046459). Acts as a positive regulator of T-cell coactivation by binding DPP4 (PubMed:10900005).
Post-translational modifications
Palmitoylated (PubMed:18817523). Undergoes cysteine S-palmitoylation which promotes interaction with the retromer cargo-selective complex which mediates its retrograde trafficking to the Golgi apparatus (PubMed:18817523).
Sequence Similarities
Belongs to the MRL1/IGF2R family.
Cellular localization
- Golgi apparatus membrane
- Single-pass type I membrane protein
- Endosome membrane
- Single-pass type I membrane protein
- Mainly localized in the Golgi at steady state and not detectable in lysosome (PubMed:18817523). Colocalized with DPP4 in internalized cytoplasmic vesicles adjacent to the cell surface (PubMed:10900005).
Alternative names
CD222, MPRI, IGF2R, Cation-independent mannose-6-phosphate receptor, CI Man-6-P receptor, CI-MPR, M6PR, 300 kDa mannose 6-phosphate receptor, Insulin-like growth factor 2 receptor, Insulin-like growth factor II receptor, M6P/IGF2 receptor, MPR 300, IGF-II receptor, M6P/IGF2R