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Identification of molecular determinants of channel gating in the transient receptor potential box of vanilloid receptor I
Author(s) -
Valente Pierluigi,
GarcíaSanz Nuria,
Gomis Ana,
FernándezCarvajal Asia,
FernándezBallester Gregorio,
Viana Félix,
Belmonte Carlos,
FerrerMontiel Antonio
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fj.08-107425
Subject(s) - trpv , transient receptor potential channel , trpv1 , gating , chemistry , alanine scanning , ion channel , alanine , biophysics , receptor , mutant , allosteric regulation , mutagenesis , microbiology and biotechnology , biochemistry , biology , amino acid , gene
Transient receptor potential vanilloid receptor subtype I (TRPV1) is an ion channel gated by physical and chemical stimuli that belongs to the TRPV protein family. TRPV receptors contain a highly conserved, 6‐mer segment near the channel gate, known as the TRP box, whose function remains unknown. Here, we performed an alanine scanning mutagenesis of the TRP box of TRPV1 (IWKLQR) and found that mutation of this motif affected channel gating by raising the free energy of channel activation. Functional characterization of TRPV1 mutants showed that substitution of I696, W697, and R701 by alanine severely affected voltage‐ and heat‐dependent activation and notably reduced the capsaicin responsiveness and tachyphylaxia, while mutation of K698, L699, and Q700 had minor effects. In addition, mutation of I696 to alanine promoted a strong outward rectification at negative membrane potentials, and slowed the kinetics of channel activation. Taken together, our findings suggest that modification of I696, W697, and R701 to alanine altered channel function by affecting events downstream of the initial stimuli‐sensing step and imply that inter‐subunit interactions within the TRP box play an important role in TRPV1 gating.—Valente, P., García‐Sanz, N., Gomis, A., Fernández‐Carvajal, A., Fernández‐Ballester, G., Viana, F., Belmonte, C., and Ferrer‐Montiel, A. Identification of molecular determinants of channel gating in the transient receptor potential box of vanilloid receptor I. FASEB J. 22, 3298–3309 (2008)