Plays a role in endosome to Golgi protein trafficking; mediates protein transport along the late endosome-bypass pathway from the early endosome to the Golgi. Localizes to cis and medial Golgi cisternae. Probably cycles between early Golgi and distal compartments like endosome. Phosphorylated probably by c-AMP-dependent kinases in its lumenal part. O-glycosylated; modified by sialic acid residues. N-glycosylated; N-glycans are probably of the complex type and modified by sialic acid residues. Belongs to the GOLIM4 family.