Polarized epithelial cells have functionally distinct apical and basolateral membranes through which they communicate with external and internal bodily environments, respectively. The establishment and maintenance of this asymmetric structure depend on polarized trafficking of specific cargos, but the precise molecular mechanism is incompletely understood. We previously showed that Rab35, a member of the Rab family small GTPases, differentially regulates the trafficking of an apical cargo, podocalyxin (PODXL), in two-dimensional (2D) and three-dimensional (3D) Madin–Darby canine kidney (MDCK) II cell cultures through specific interactions with two distinct effectors, OCRL inositol polyphosphate-5-phosphatase (OCRL) and ArfGAP with coiled-coil, ankyrin repeat and pleckstrin homology domains 2 (ACAP2), respectively.
