Premium
Functional analysis of rat renal organic anion transporter OAT‐K1: bidirectional methotrexate transport in apical membrane
Author(s) -
Masuda Satohiro,
Takeuchi Ayako,
Saito Hideyuki,
Hashimoto Yukiya,
Inui Ken-ichi
Publication year - 1999
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(99)01221-1
Subject(s) - membrane , methotrexate , organic anion transporter 1 , apical membrane , chemistry , organic cation transport proteins , brush border , transporter , efflux , organic anion , membrane transport , biochemistry , ion transporter , kidney , ion , medicine , endocrinology , biology , vesicle , organic chemistry , gene
Renal organic anion transporter OAT‐K1 was stably transfected in MDCK cells and examined for its transport characteristics and membrane localization. OAT‐K1 mediated both uptake and efflux of methotrexate in the apical membranes. Immunoblotting showed that the apparent molecular mass of the expressed OAT‐K1 was 50 kDa, which was comparable to that found in the rat renal brush‐border membranes. The OAT‐K1‐mediated methotrexate transport was significantly inhibited in the presence of several organic anions such as folate and sulfobromophthalein. These findings suggest that OAT‐K1 mediates bidirectional methotrexate transport across the apical membranes, and may be involved in the renal handling of methotrexate.