Multidrug resistance-associated protein 4 (IPR030240)

Short name: ABCC4

Overlapping homologous superfamilies


Family relationships



This entry represents the multidrug resistance-associated protein 4 (MRP4 or ABCC4) from animals. It belongs to the MRP (multidrug resistance protein) subfamily of the ATP-binding cassette (ABC) transporter family [PMID: 21103974]. MRP4 is a broad specificity organic anion exporter that seems to be able to mediate the transport of conjugated steroids, prostaglandins, and glutathione [PMID: 15747503]. It can localise to both basolateral and apical membranes in polarised cells, depending on the tissue where it is found [PMID: 21740521]. Together with CFTR, MRP4 functions in the regulation of cAMP and beta-adrenergic contraction in cardiac myocytes [PMID: 22381067].

MRP4 has been implicated in the high proliferative growth of some tumors including prostate tumors and neuroblastoma [PMID: 21740521, PMID: 20075923]. It confers resistance to anticancer agents including thiopurine analogs, MTX and topotecan [PMID: 21740521].

The ABC transporter family is a group of membrane proteins that use the hydrolysis of ATP to power the translocation of a wide variety of substrates across cellular membranes. ABC transporters minimally consist of two conserved regions: a highly conserved nucleotide-binding domain (NBD) and a less conserved transmembrane domain (TMD). Eukaryotic ABC proteins are usually organised either as full transporters (containing two NBDs and two TMDs), or as half transporters (containing one NBD and one TMD), that have to form homo- or heterodimers in order to constitute a functional protein [PMID: 11441126].

GO terms

Biological Process

GO:0055085 transmembrane transport

Molecular Function

GO:0005524 ATP binding
GO:0042626 ATPase activity, coupled to transmembrane movement of substances

Cellular Component

GO:0016021 integral component of membrane

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.