Identification of multidrug and toxin extrusion (MATE1 and MATE2-K) variants with complete loss of transport activity.
H(+)/organic cation antiporters (multidrug and toxin extrusion: MATE1 and MATE2-K) play important roles in the renal tubular secretion of cationic drugs. We have recently identified a regulatory single nucleotide polymorphism (SNP) of the MATE1 gene (-32G>A). There is no other information about SNPs of the MATE gene. In this study, we evaluated the functional significance of genetic polymorphisms in MATE1 and MATE2-K. We sequenced all exons of MATE1 and MATE2-K genes in 89 Japanese subjects and identified coding SNPs (cSNPs) encoding MATE1 (V10L, G64D, A310V, D328A and N474S) and MATE2-K (K64N and G211V). All the variants except for MATE1 V10L showed significant decrease in transport activity. In particular, MATE1 G64D and MATE2-K G211V variants completely lost transport activities. When membrane expression level was evaluated by cell surface biotinylation, those of MATE1 (G64D and D328A) and MATE2-K (K64N and G211V) were significantly decreased compared with that of wild type. These findings suggested that the loss of transport activities of the MATE1 G64D and MATE2-K G211V variants were due to the alteration of protein expression in cell surface membranes. This is the first demonstration of functional impairment of the MATE family induced by cSNPs.
Kajiwara
Moto
M
Department of Pharmacy, Kyoto University Hospital, Sakyo-ku, Kyoto, Japan.
Terada
Tomohiro
T
Ogasawara
Ken
K
Iwano
Junko
J
Katsura
Toshiya
T
Fukatsu
Atsushi
A
Doi
Toshio
T
Inui
Ken-ichi
K
D000595:Amino Acid Sequence; D001692:Biological Transport; D019921:Biotinylation; D015153:Blotting, Western; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D008687:Metformin / Q000378:metabolism; D008969:Molecular Sequence Data; D050505:Mutant Proteins / Q000378:metabolism*; D027701:Organic Cation Transport Proteins / Q000737:chemistry / Q000378:metabolism*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D019789:Tetraethylammonium / Q000378:metabolism
D050505:Mutant Proteins; D027701:Organic Cation Transport Proteins; C521869:SLC47A1 protein, human; C521870:SLC47A2 protein, human; D019789:Tetraethylammonium; D008687:Metformin