Vacuolar Protein Sorting 18 (VPS18)

VPS18 encodes the human homolog of yeast class C Vps18 protein. The mammalian class C Vps proteins are predominantly associated with late endosomes/lysosomes, and like their yeast counterparts, may mediate vesicle trafficking steps in the endosome/lysosome pathway.The deduced 973-amino acid protein has a calculated molecular mass of 110.2 kD. VPS18 contains a clathrin repeat domain and a RING-H2 finger domain, and it is likely a cytosolic protein. VPS18 shares 22% amino acid identity with yeast Vps18. ESTs sharing significant identity were also identified in mouse, rat, bovine, and pig databases. Northern blot analysis detected a 2.3-kb VPS18 mRNA in all tissues examined, with highest expression in heart and lowest expression in lung.