The mammalian hair cell has two distinct plasma membrane domains separated by tight junctions, the apical domain which contains the stereocilia and the basolateral domain which contains the presynaptic region. Little is known concerning the mechanisms that regulate vesicle trafficking to these two domains. Using SNAP 25 and syntaxin as baits, we carried out a yeast two-hybrid screen of the organ of Corti. We identified a novel syntaxin interacting protein, ocsyn, that is enriched in inner hair cells and concentrated at the apical pole. Our results are consistent with ocsyn playing a role in vesicle trafficking to the apical membrane of the hair cell.