| Function | Isoform 1: Energy-dependent phospholipid efflux translocator that acts as a positive regulator of biliary lipid secretion. Functions as a floppase that translocates specifically phosphatidylcholine (PC) from the inner to the outer leaflet of the canalicular membrane bilayer into the canaliculi of hepatocytes. Translocation of PC makes the biliary phospholipids available for extraction into the canaliculi lumen by bile salt mixed micelles and therefore protects the biliary tree from the detergent activity of bile salts. Plays a role in the recruitment of phosphatidylcholine (PC), phosphatidylethanolamine (PE) and sphingomyelin (SM) molecules to nonraft membranes and to further enrichment of SM and cholesterol in raft membranes in hepatocytes. Required for proper phospholipid bile formation. Indirectly involved in cholesterol efflux activity from hepatocytes into the canalicular lumen in the presence of bile salts in an ATP-dependent manner. Promotes biliary phospholipid secretion as canaliculi-containing vesicles from the canalicular plasma membrane. In cooperation with ATP8B1, functions to protect hepatocytes from the deleterious detergent activity of bile salts. Does not confer multidrug resistance. |
| Protein Name | Phosphatidylcholine Translocator Abcb4Atp-Binding Cassette Sub-Family B Member 4Multidrug Resistance Protein 3P-Glycoprotein 3 |
| Database Links | Reactome: R-HSA-1989781Reactome: R-HSA-382556Reactome: R-HSA-5678771 |
| Cellular Localisation | Cell MembraneMulti-Pass Membrane ProteinApical Cell MembraneMembrane RaftCytoplasmCytoplasmic VesicleClathrin-Coated VesicleLocalized At The Apical Canalicular Membrane Of The Epithelial Cells Lining The Lumen Of The Bile Canaliculi And Biliary DuctulesTransported From The Golgi To The Apical Bile Canalicular Membrane In A Rack1-Dependent MannerRedistributed Into Pseudocanaliculi Formed Between Cells In A Bezafibrate- Or Ppara-Dependent MannerLocalized Preferentially In Lipid Nonraft Domains Of Canalicular Plasma Membranes |
| Alternative Protein Names | Phosphatidylcholine Translocator Abcb4 proteinAtp-Binding Cassette Sub-Family B Member 4 proteinMultidrug Resistance Protein 3 proteinP-Glycoprotein 3 proteinABCB4 proteinMDR3 proteinPGY3 protein |
Information sourced from Uniprot.org
