Mannose 6-phophate receptors (MPRs) deliver lysosomal
hydrolase from the Golgi to endosomes and then return to the Golgi
complex. The protein encoded by this gene interacts with the
cytoplasmic domains of both cation-independent and cation-dependent
MPRs, and is required for endosome-to-Golgi transport. This protein
also binds directly to the GTPase RAB9 (RAB9A), a member of the RAS
oncogene family. The interaction with RAB9 has been shown to
increase the affinity of this protein for its cargo. Multiple
transcript variants encoding different isoforms have been found for
this gene.
