Fig. 7
From: TRPV1 SUMOylation regulates nociceptive signaling in models of inflammatory pain
SUMOylation lowered temperature coefficient (Q10) and temperature threshold (Tthreshold) of TRPV1 activation. a–d Representative responses to a family of temperature jumps ranging from 33 to 54 °C (see inset in a for an example) for CHO-K1 cells that expressed Flag-TRPV1 (a), Flag-TRPV1+GFP-SUMO1+Ubc9 (b), Flag-TRPV1-K822R (c), and Flag-TRPV1-K822R+GFP-SUMO1+Ubc9 (d). Temperature was calibrated offline from the pipette current using the temperature dependence of electrolyte conductivity. The red traces indicate the response at 42 °C. e Arrhenius plot of steady-state currents shown in a–d. The major component of the reflection that represents the strong temperature dependence was fitted to a linear equation. Error bars indicate standard deviations (s.d.). f, g Comparison of Q10 derived from the linear fits in e and Tthreshold changes. Q10 = 21.0 ± 3.3 (n = 5) and Tthreshold = 41.4 ± 0.9 (n = 8) for TRPV1, Q10 = 7.8 ± 1.0 (n = 5) and Tthreshold = 35.6 ± 2.6 (n = 8) for TRPV1+SUMO1+Ubc9, Q10 = 20.5 ± 1.2 (n = 5) and Tthreshold = 42.4 ± 0.7 (n = 7) for TRPV1-K822R, Q10 = 20.7 ± 2.3 (n = 6) and Tthreshold = 40.7 ± 0.4 (n = 6) for TRPV1-K822R+SUMO1+Ubc9. Colored symbols in g indicate individual data points. Data are means ± s.e.m. P = 0.0004 for Q10 TRPV1 vs. TRPV1+SUMO1+Ubc9; P = 0.00004 for Tthreshold TRPV1 vs. TRPV1+SUMO1+Ubc9 by Student’s t test. h Temperature response curves for TRPV1 (black), TRPV1+SUMO1+Ubc9 (blue), TRPV1-K822R (olive), and TRPV1-K822R+SUMO1+Ubc9 (pink), measured from the maximal currents at the end of temperature steps. Each curve represents measurements from an individual cell and the responses were normalized to its maximum responses at 54 °C. i, j Representative whole-cell current traces evoked by a family of temperature jumps in DRG neurons isolated from control and SENP1 cKO mice. Holding potential was −60 mV. k Arrhenius plots for cells shown in i, j. Heat-evoked responses were fitted by linear regression and yielded Q10 = 21.8 for control (black, n = 6) and Q10 = 10.0 for SENP1 cKO (red, n = 5). l Comparison of temperature response curves of control (black) and SENP1 cKO (red) DRG neurons
