MATE1 (SLC47A1) and MATE2 (SLC47A2) are multidrug and toxin extrusion transporter 1 and 2 function as cationic pumps in the kidneys, liver, and intestine¹. Both MATEs excrete molecules with a positive net-charge from renal tubular epithelial cells in the kidney (where they are co-expressed with organic anion- and cation-transporters; OATs and OCTs), and into the urine. In the liver, MATE1, but not MATE2, regulates the transportation of tetraethylammonium (TEA) and 1-methyl-4-phenylpyridinium (MPP) – again, by cation-powered pumps².

Fairly recent X-ray crystallography has revealed that mammalian MATE1 has 13 transmembrane helices and a long cytoplasmic tail. Cysteine and histidine residues are responsible for the protein's functionality¹.

Overexpression of MATE1 is helpful in the delivery of metal-based anti-cancer drugs, such as cisplatin and oxaliplatin, as it effectively accumulates platinum intracellularly³. Furthermore, a rare increase in copy number of MATE1 in maize protects the plant from aluminum (Al) toxicity⁴. On the other hand, inhibition of MATE1 may lead to potentially dangerous drug-drug interactions, due to damaged drug extrusion regulation⁵.