ABCB4

ABCB4
Identifiers
Aliases	ABCB4, ABC21, GBD1, ICP3, MDR2, MDR2/3, MDR3, PFIC-3, PGY3, ATP binding cassette subfamily B member 4
External IDs	OMIM: 171060; MGI: 97569; HomoloGene: 136368; GeneCards: ABCB4; OMA:ABCB4 - orthologs
EC number	7.6.2.2
Gene location (Human)
Chr.	Chromosome 7 (human)
End	87,480,435 bp
Gene location (Mouse)
Chr.	Chromosome 5 (mouse)
End	9,009,231 bp
RNA expression pattern
	Top expressed in
	right lobe of liver; ; secondary oocyte; ; buccal mucosa cell; ; testicle; ; right adrenal gland; ; left adrenal gland; ; right adrenal cortex; ; left adrenal cortex; ; biceps brachii; ; spleen;
	Top expressed in
	left lobe of liver; ; tibialis anterior muscle; ; vastus lateralis muscle; ; extensor digitorum longus muscle; ; plantaris muscle; ; tibiofemoral joint; ; ankle; ; gastrocnemius muscle; ; muscle of thigh; ; triceps brachii muscle;
	More reference expression data
	More reference expression data
Gene ontology
Molecular function	ATPase-coupled transmembrane transporter activity; nucleotide binding; ABC-type xenobiotic transporter activity; phosphatidylcholine transporter activity; phosphatidylcholine floppase activity; ATPase activity; protein binding; hydrolase activity; ATP binding; phospholipid transporter activity; ceramide floppase activity;
Cellular component	cytoplasm; integral component of membrane; membrane; plasma membrane; integral component of plasma membrane; intercellular canaliculus; apical plasma membrane; membrane raft; extracellular exosome; cytoplasmic vesicle; clathrin-coated vesicle; nucleoplasm; cytosol; focal adhesion; actin cytoskeleton; brush border membrane; apical part of cell;
Biological process	lipid transport; cellular response to bile acid; positive regulation of cholesterol transport; positive regulation of phospholipid translocation; xenobiotic transmembrane transport; lipid metabolism; positive regulation of phospholipid transport; response to fenofibrate; xenobiotic transport; transmembrane transport; lipid homeostasis; bile acid secretion; phospholipid translocation; response to hypoxia; placenta development; brain development; lactation; circadian rhythm; hormone transport; response to organic substance; response to mycotoxin; response to organic cyclic compound; response to isoquinoline alkaloid; response to nutrient levels; response to estradiol; response to vitamin A; carbohydrate export; response to vitamin D; maintenance of blood-brain barrier; cellular response to mycotoxin; daunorubicin transport; response to morphine; xenobiotic export; response to cadmium ion; intestinal absorption; negative regulation of cell death; establishment of blood-brain barrier; cellular response to external biotic stimulus; cellular response to antibiotic; cellular response to alkaloid; cellular response to estradiol stimulus; cellular response to organic cyclic compound; cellular hyperosmotic salinity response; response to dexamethasone; cellular response to dexamethasone stimulus; response to thyroxine; response to antineoplastic agent; ceramide translocation; response to L-glutamate; response to glycoside; cellular response to borneol; cellular response to L-glutamate; response to codeine; response to quercetin; response to cyclosporin A; xenobiotic transport across blood-brain barrier; establishment of blood-retinal barrier; positive regulation of response to drug; regulation of lipid metabolic process; regulation of intestinal absorption; transport;
	Sources:Amigo / QuickGO
Orthologs
	5244
	18670
	ENSG00000005471
	ENSMUSG00000042476
	P21439
	P21440
	NM_000443; NM_018849; NM_018850
	NM_008830
	NP_000434; NP_061337; NP_061338
	NP_032856
	Wikidata
View/Edit Human	View/Edit Mouse

The ATP-binding cassette 4 (ABCB4) gene encodes multidrug resistance protein 3. ABCB4 is associated with progressive familial intrahepatic cholestasis type 3 and intrahepatic cholestasis of pregnancy.

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.