Identification of lactate as a driving force for prostanoid transport by prostaglandin transporter PGT.
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Chan BS, Endo S, Kanai N, Schuster VL
Identification of lactate as a driving force for prostanoid transport by prostaglandin transporter PGT.
Am J Physiol Renal Physiol. 2002 Jun;282(6):F1097-102.
- PubMed ID
- 11997326 [ View in PubMed]
- Abstract
We previously characterized the prostaglandin (PG) transporter PGT as an exchanger in which [(3)H]PGE(2) influx is coupled to the efflux of a countersubstrate. Here, we cultured HeLa cells that stably expressed human PGT under conditions known to favor glycolysis (glucose as a carbon source) or oxidative phosphorylation (glutamine as a carbon source) and studied the effect on PGT-mediated [(3)H]PGE(2) influx. PGT-expressing cells grown in glutamine exhibited a 2- to 4-fold increase in [(3)H]PGE(2) influx compared with the antisense control, whereas cells grown in glucose exhibited a 14-fold increase. In the presence of 10 vs. 25 mM glucose during the uptake, there was a dose-dependent increment in [(3)H]PGE(2) influx. Cis inhibition of [(3)H]PGE(2) influx occurred with lactate at physiological concentrations (apparent K(m) = 48 +/- 12 mM). Preloading with lactate caused a dose-dependent trans stimulation of PGT-mediated [(3)H]PGE(2) uptake, and external lactate caused trans stimulation of PGT-mediated [(3)H]PGE(2) release. Together, these data are consistent with PGT-mediated PG-lactate exchange. Cells engaged in glycolysis would then be poised energetically for prostanoid uptake by means of PGT.
DrugBank Data that Cites this Article
- Drug Transporters
Drug Transporter Kind Organism Pharmacological Action Actions beta-D-fructofuranose 1,6-bisphosphate Solute carrier organic anion transporter family member 2A1 Protein Humans UnknownInhibitorDetails D-glyceraldehyde 3-phosphate Solute carrier organic anion transporter family member 2A1 Protein Humans UnknownInhibitorDetails Glucose-6-Phosphate Solute carrier organic anion transporter family member 2A1 Protein Humans UnknownInhibitorDetails Lactic acid Solute carrier organic anion transporter family member 2A1 Protein Humans UnknownInhibitorDetails Phosphoenolpyruvate Solute carrier organic anion transporter family member 2A1 Protein Humans UnknownInhibitorDetails Pyruvic acid Solute carrier organic anion transporter family member 2A1 Protein Humans UnknownInhibitorDetails - Binding Properties
Drug Target Property Measurement pH Temperature (°C) D-glyceraldehyde 3-phosphate Solute carrier organic anion transporter family member 2A1 Ki (nM) 15000000 N/A N/A Details Lactic acid Solute carrier organic anion transporter family member 2A1 Ki (nM) 48000000 N/A N/A Details Phosphoenolpyruvate Solute carrier organic anion transporter family member 2A1 Ki (nM) 13000000 N/A N/A Details Pyruvic acid Solute carrier organic anion transporter family member 2A1 Ki (nM) 26000000 N/A N/A Details