Monocarboxylate transporter 4 (IPR030756)

Short name: MCT4

Overlapping homologous superfamilies

Family relationships


Monocarboxylate transporter 4 (MCT4), also known as SLC16A3, belongs to the MCT family. MCT4 is one the key transporters involved in the regulation of lactate metabolism in skeletal muscle. It is highly expressed in glycolytic fast-twitch muscle, and it is involved in the extrusion of lactate from muscle cells [PMID: 10926847, PMID: 9632638]. It is also expressed in the small intestine, where it may mediate butyrate transport [PMID: 23344966].

Monocarboxylate transporters (MCTs) catalyse the proton-linked transport of monocarboxylates such as L-lactate, pyruvate, and the ketone bodies across the plasma membrane [PMID: 9425115, PMID: 22131303]. All of the MCT family (also known as SLC16 solute carrier family) members share conserved sequence motifs. They are are predicted to have 12-transmembrane helices (TMs) with intracellular C and N termini and a large cytosolic loop between TMs 6 and 7. Four mammalian isoforms, MCTs 1-4, have been identified, each with distinct substrate and inhibitor affinities [PMID: 22131303]. MCT1-4 have been linked to cancer maintenance and aggressiveness [PMID: 22407107].

GO terms

Biological Process

GO:0015718 monocarboxylic acid transport

Molecular Function

GO:0015129 lactate transmembrane transporter activity
GO:0008028 monocarboxylic acid transmembrane transporter activity

Cellular Component

GO:0005887 integral component of plasma membrane

Contributing signatures

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