MOLECULAR-CLONING AND EXPRESSION PATTERN OF RPR-1, A RESINIFERATOXIN-BINDING, PHOSPHOTRIESTERASE-RELATED PROTEIN, EXPRESSED IN RAT-KIDNEY TUBULES

Bacterial phosphotriesterases are enzymes that hydrolyse phosphotriest er-containing organophosphate pesticides, Resiniferatoxin is a vanillo id that desensitises nociceptive neurons, By screening a rat cDNA libr ary with labelled resiniferatoxin, we unexpectedly isolated a novel ra t phosphotriesterase homologue, here named rpr-1, that encodes a 349 a mino acid, 39 kDa protein (confirmed by in vitro translation), Norther n blotting and in situ hybridisation show expression primarily in prox imal tubules of the kidney, in which rpr-1 distribution correlates wit h resiniferatoxin-binding activity. These results suggest an unsuspect ed link between the phosphotriesterase enzyme family and resiniferatox in toxicity and pharmacology. (C) 1997 Federation of European Biochemi cal Societies.