ABCB4 Antibody – Rabbit Polyclonal

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. 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. [provided by RefSeq, Jul 2008]

ABCB4: a transporter that mediates ATP-dependent export of organic anions and drugs from the cytoplasm. Hydrolyzes ATP with low efficiency. Human ABCB4 is not capable of conferring drug resistance. Mediates the translocation of phosphatidylcholine across the canalicular membrane of the hepatocyte. Interacts with HAX1. Defects are the cause of gallstones, and progressive familial intrahepatic cholestasis 3, an autosomal recessive liver disorder that progresses to cirrhosis and liver failure before adulthood. Two alternatively spliced human isoforms have been described.

Protein type: Membrane protein, integral; Transporter; Transporter, ABC family; EC 3.6.3.44; Hydrolase; Membrane protein, multi-pass

Chromosomal Location of Human Ortholog: 7q21.1

Cellular Component: apical plasma membrane; clathrin-coated vesicle; cytoplasm; integral to plasma membrane; intercellular canaliculus; lipid raft; membrane; plasma membrane

Molecular Function: ATP binding; ATPase activity, coupled to transmembrane movement of substances; phosphatidylcholine transmembrane transporter activity; protein binding; xenobiotic-transporting ATPase activity

Biological Process: antigen processing and presentation of endogenous peptide antigen via MHC class I via ER pathway, TAP-dependent; antigen processing and presentation of endogenous peptide antigen via MHC class Ib via ER pathway, TAP-dependent; antigen processing and presentation of exogenous protein antigen via MHC class Ib, TAP-dependent; bile acid secretion; cellular lipid metabolic process; lipid homeostasis; lipid metabolic process; multidrug transport; phospholipid translocation; positive regulation of antigen processing and presentation of peptide antigen via MHC class I; positive regulation of cholesterol transport; response to drug; transmembrane transport; transport; xenobiotic transport

Disease: Cholestasis, Intrahepatic, Of Pregnancy 3; Cholestasis, Progressive Familial Intrahepatic, 3; Gallbladder Disease 1