... MRP1localized to the a pical membrane of polarized Madin–Darbycanine kidney cells (MDCKII) indicating involvement of the carboxy-proximal part of human MRP2 in apical sorting.When compared to other ... the apical (vacuolar) membrane,and, in addition, in intracellular vesicular structures of varying size. In contrast, l umGFP (C) was observed in the basolateral and in t he apicalmembrane in ... Laboratories(Burlingame, CA, USA). All other chemicals were of analytical grade and obtained either from M erck (Da rm-stadt, Germany) or Sigma. The polyclonal rabbit antibody directed against the C-terminus...