Involved in the regulation of endosome-to-lysosome trafficking, including endocytic trafficking of EGF-EGFR complexes and GABA-A receptors (PubMed:18675823). Involved in mitochondrial motility. When O-glycosylated, abolishes mitochondrial motility. Crucial for recruiting OGT to the mitochondrial surface of neuronal processes (PubMed:24995978). TRAK1 and RHOT form an essential protein complex that links KIF5 to mitochondria for light chain-independent, anterograde transport of mitochondria (By similarity). {ECO:0000250|UniProtKB:Q960V3, ECO:0000269|PubMed:18675823, ECO:0000269|PubMed:24995978}. This is the function of Ensembl gene identifier ENSG00000182606 (TRAK1, trafficking kinesin protein 1).