Molecular Determinants of Vanilloid Sensitivity in TRPV1

Narender R. Gavva, Lana Klionsky, Yusheng Qu, Licheng Shi, Rami Tamir, Steve Edenson, T. J. Zhang, Vellarkad N. Viswanadhan, Attila Toth, Larry V. Pearce, Todd W. Vanderah, Frank Porreca, Peter M. Blumberg, Jack Lile, Yax Sun, Ken Wild, Jean Claude Louis, James J.S. Treanor

Research output: Contribution to journalArticlepeer-review

289 Scopus citations

Abstract

Vanilloid receptor 1 (TRPV1), a membrane-associated cation channel, is activated by the pungent vanilloid from chili peppers, capsaicin, and the ultra potent vanilloid from Euphorbia resinifera, resiniferatoxin (RTX), as well as by physical stimuli (heat and protons) and proposed endogenous ligands (anandamide, N-arachidonyldopamine, N-oleoyldopamine, and products of lipoxygenase). Only limited information is available in TRPV1 on the residues that contribute to vanilloid activation. Interestingly, rabbits have been suggested to be insensitive to capsaicin and have been shown to lack detectable [3H]RTX binding in membranes prepared from their dorsal root ganglia. We have cloned rabbit TRPV1 (oTRPV1) and report that it exhibits high homology to rat and human TRPV1. Like its mammalian orthologs, oTRPV1 is selectively expressed in sensory neurons and is sensitive to protons and heat activation but is 100-fold less sensitive to vanilloid activation than either rat or human. Here we identify key residues (Met547 and Thr550) in transmembrane regions 3 and 4 (TM3/4) of rat and human TRPV1 that confer vanilloid sensitivity, [3H]RTX binding and competitive antagonist binding to rabbit TRPV1. We also show that these residues differentially affect ligand recognition as well as the assays of functional response versus ligand binding. Furthermore, these residues account for the reported pharmacological differences of RTX, PPAHV (phorbol 12-phenyl-acetate 13-acetate 20-homovanillate) and capsazepine between human and rat TRPVI. Based on our data we propose a model of the TM3/4 region of TRPV1 bound to capsaicin or RTX that may aid in the development of potent TRPV1 antagonists with utility in the treatment of sensory disorders.

Original languageEnglish (US)
Pages (from-to)20283-20295
Number of pages13
JournalJournal of Biological Chemistry
Volume279
Issue number19
DOIs
StatePublished - May 7 2004

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Fingerprint Dive into the research topics of 'Molecular Determinants of Vanilloid Sensitivity in TRPV1'. Together they form a unique fingerprint.

Cite this