Characterization of stably transfected kidney epithelial cell line expressing rat H+/peptide cotransporter PEPT1: localization of PEPT1 and transport of beta-lactam antibiotics.

Article Details

Citation

Terada T, Saito H, Mukai M, Inui K

Characterization of stably transfected kidney epithelial cell line expressing rat H+/peptide cotransporter PEPT1: localization of PEPT1 and transport of beta-lactam antibiotics.

J Pharmacol Exp Ther. 1997 Jun;281(3):1415-21.

PubMed ID
9190878 [ View in PubMed
]
Abstract

We established stably transfected LLC-PK1 cells expressing the rat H+/peptide cotransporter PEPT1 (designated LLC-rPEPT1) and examined membrane localization and uptake by rat PEPT1 of oral beta-lactam antibiotics. The LLC-rPEPT1 cells expressed a novel PEPT1 protein with an apparent molecular mass of 75 kdaltons, which was found in rat intestinal membranes. The cell surface biotinylation of LLC-rPEPT1 cell monolayers grown on membrane filters showed that PEPT1 was localized predominantly on the apical membranes and, to a lesser extent, on the basolateral membranes. The amount of [14C]glycylsarcosine uptake in LLC-rPEPT1 cell monolayers was 3-fold greater from the apical, than from the basolateral side, which suggested that rat PEPT1 expressed on both membranes was functionally active. LLC-rPEPT1 cells grown on plastic dishes transported differently charged oral cephalosporins such as ceftibuten (divalent anion lacking an alpha-amino group) and cephradine (zwitterion with an alpha-amino group) in the presence of an inward H+ gradient, whereas those transfected with the vector alone did not have transport activity. Kinetic analysis revealed that the LLC-rPEPT1 cells had much higher affinity for ceftibuten than for cephradine. Di- and tripeptides and bestatin, a dipeptide-like antineoplastic drug, potently inhibited the uptake of these cephalosporins. These results suggest that the LLC-rPEPT1 cells serve as a useful model with which to analyze the mechanisms involved in membrane targeting and substrate recognition by rat PEPT1.

DrugBank Data that Cites this Article

Drug Transporters
DrugTransporterKindOrganismPharmacological ActionActions
CefiximeSolute carrier family 15 member 1ProteinHumans
Unknown
Substrate
Inhibitor
Details
CefradineSolute carrier family 15 member 1ProteinHumans
Unknown
Substrate
Inhibitor
Details
CeftibutenSolute carrier family 15 member 1ProteinHumans
Unknown
Substrate
Inhibitor
Details
UbenimexSolute carrier family 15 member 1ProteinHumans
Unknown
Inhibitor
Details