Involved in transport of proteins from the cis/medial-Golgi to the trans-Golgi network.
Subcellular locations: Golgi apparatus, Cis-Golgi network membrane, Golgi apparatus membrane, Endoplasmic reticulum membrane
Concentrated most in the intermediate compartment/cis-Golgi network and the cis-Golgi cisternae 1 and 2. Greatly reduced in concentration at the trans end of the Golgi apparatus.