| A yeast two hybrid screen identified HAX 1 as a binding partner for BSEP , MDR 1 , and MDR 2 . ^^^ HAX 1 was bound to BSEP , MDR 1 , and MDR 2 in canalicular membrane vesicles and co localized with BSEP and MDR 1 in the apical membrane of Madin Darby canine kidney ( MDCK ) cells . ^^^ |