Predicted to enable SH3 domain binding activity. Involved in endosome to lysosome transport via multivesicular body sorting pathway and receptor catabolic process. Located in cytosol and endosome membrane. Part of ESCRT I complex. Expressed in amphid neurons; hypodermis; intestine; and
pm7. Is an ortholog of human MVB12B (multivesicular body subunit 12B).