Anti-MDR3 Monoclonal Antibody (Clone:IHC621)-Ready to Use

Multidrug Resistance 3 (MDR3), also known as ATP Binding Cassette Subfamily B Member 4 (ABCB4), is a membrane-associated protein belonging to the superfamily of ATP-binding cassette transporters. MDR3 is an energy-dependent phospholipid efflux translocator that mediates the translocation of phosphatidylcholine across the canalicular membrane of the hepatocyte, and also acts as a positive regulator of biliary lipid secretion. Defects in MDR3 are associated with progressive familial intrahepatic cholestasis type 3 and gallbladder disease type 1. Co-overexpression of MDR3 and MRP1 has been documented as correlating with blastemal subtype and high-risk prognosis of Wilms' tumor patients. Protein function: 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 (PubMed:7957936, PubMed:8898203, PubMed:9366571, PubMed:17523162, PubMed:23468132, PubMed:24806754, PubMed:24723470, PubMed:24594635, PubMed:21820390). 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 (PubMed:23468132). 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 (PubMed:24045840). Promotes biliary phospholipid secretion as canaliculi-containing vesicles from the canalicular plasma membrane (PubMed:9366571, PubMed:28012258). In cooperation with ATP8B1, functions to protect hepatocytes from the deleterious detergent activity of bile salts (PubMed:21820390). Does not confer multidrug resistance. [The UniProt Consortium]