Fig. 5: TRPV1 R557 is a crucial residue for coupling between the S1–S4 and pore domains.
From: Evidence that the TRPV1 S1-S4 membrane domain contributes to thermosensing
a, b Whole-cell patch-clamp electrophysiology data from HEK293 cells show that the wild-type hTRPV1 is heat activated, while the hTRPV1-R557A mutant is not. Error bars in panel (b) are s.e.m. c 15N-edited NOESY-TROSY data of the R557-water resonance cross-peak is missing at low temperature but present at elevated temperature, suggesting that R557 amide backbone moves from a membrane embedded to a solvent-accessible position in a temperature-dependent manner. d NMR temperature titration of hV1-S1S4-R557A. G548 in hV1-S1S4-R557A resonance intensity as a function of temperature shows two-state behavior analogous to the wild-type hV1-S1S4 domain (compare Fig. 2d). e A histogram and a Gaussian distribution fit of ΔH identify a mean ΔH = 19.7 ± 0.1 kcal mol−1 for the mutant hV1-S1S4-R557A (n = 70 residues). The data are suggestive of a temperature-dependent conformational change in hV1-S1S4-R557A. f Comparison of 1H-15N TROSY-HSQC spectra show that the R557A mutation causes perturbation at Y554 supporting that the R557A mutation disrupts the cation–π interaction. Source data are provided as a Source Data file.
