OAT-K1, a renal organic anion transporter, which mediates methotrexate uptake, was analyzed for mRNA distribution along microdissected nephron segments and the immunolozalization in isolated plasma membranes from rat kidney. By using a reverse transcription-coupled PCR, OAT-K1 mRNA was detected predominantly in the superficial and juxtamedullary proximal straight tubules. Western blotting with antiserum for OAT-K1 revealed that the transporter protein with the apparent molecular mass of 40 kDa was expressed exclusively in the brush-border membranes from rat kidney. These findings suggest that the OAT-K1 is localized in the brush-border membranes of the renal proximal straight tubules.
All Science Journal Classification (ASJC) codes
- Structural Biology
- Molecular Biology
- Cell Biology