| ABCB4, ABC21, GBD1, ICP3, MDR2, MDR2/3, MDR3, PFIC-3, PGY3, ATP binding cassette subfamily B member 4|
OMIM: 171060 MGI: 97569 HomoloGene: 136368 GeneCards: ABCB4
Multidrug resistance protein 3 is a protein that in humans is encoded by the ABCB4 gene. ABCB4 is associated with progressive familial intrahepatic cholestasis type 3.
The membrane-associated protein encoded by this gene is a member of the superfamily of ATP-binding cassette (ABC) transporters. ABC proteins transport various molecules across extra- and intra-cellular membranes. ABC genes are divided into seven distinct subfamilies (ABC1, MDR/TAP, MRP, ALD, OABP, GCN20, White). This protein is a member of the MDR/TAP subfamily. Members of the MDR/TAP subfamily are involved in multidrug resistance as well as antigen presentation. This gene encodes a full transporter and member of the p-glycoprotein family of membrane proteins with phosphatidylcholine as its substrate (flippase activity). The function of this protein has not yet been determined; however, it may involve transport of phospholipids from liver hepatocytes into bile. Alternative splicing of this gene results in several products of undetermined function.