May regulate endosome-to-lysosome trafficking of membrane cargo, including EGFR. Interacts with GABA-A receptor and O-GlcNAc transferase. Interacts with HGS (By similarity). Interacts with RHOT1/Miro-1 and RHOT2/Miro-2. Colocalizes with MGARP at the mitochondria. Translocates from the cytoplasm to the mitochondria in a MGARP-dependent manner (By similarity). Widely expressed, with highest expression in heart. O-glycosylated. Belongs to the milton family.