LOC681989 plays a role in lysosomal trafficking, probably via association with the core HOPS complex in a discrete population of endosomes. It may play a role in epithelial polarization through stabilization of apical membrane protein content, possibly via the RAB11A-dependent apical recycling pathway. It is also involved in direct or indirect transcriptional regulation of E-cadherin and may play a role in vesicular trafficking during spermatogenesis.