FunctionMember of the machinery of polarized transport. Required for the indirect transcytotic route at the step of the egress of the transcytosing cargo from perinuclear endosomes in order for it to travel to the apical surface via a raft-dependent pathway.
Tissue specificityPredominantly expressed in kidney, lung, and liver. Also found in thyroid gland, stomach and, at lower levels in testis and small intestine.
Sequence similaritiesBelongs to the MAL family. Contains 1 MARVEL domain.
Cellular localizationCell membrane. Apical cell membrane. Endomembrane system. Cytoplasm > perinuclear region. Associated with lipid rafts. In polarized epithelial cells, restricted to the apical surface. In hepatocytes, as well as in polarized hepatoma HepG2 cells, found in the canalicular membrane, equivalent to the apical surface, beneath the canalicular actin cytoskeleton. In non-polarized HepG2 cells, distributed to the perinuclear region.