Table 1.
Electrophysiological properties of WT and mutant Cav3.2 channels
| Constructions | Mutations | Activation V1/2 (mV) and K (mV) | Inactivation V1/2 (mV) and K (mV) | Kinetics at −45 mV τact (ms) and τinact (ms) |
| WT | — | −45.07 ± 0.34 (65) | −69.02 ± 0.27 (68) | 9.476 ± 0.33 (62) |
| 5.26 ± 0.07 (65) | 4.06 ± 0.06 (68) | 29 ± 0.7 (62) | ||
| N-ter Ala | S29A, S32A, S49A, S51A, S53A | −45.97 ± 1.0 (8) | −69.97 ± 1.02 (8) | 9.036 ± 1.07 (7) |
| 4.963 ± 0.15 (8) | 4.199 ± 0.2 (8) | 26.14 ± 2.75 (8) | ||
| LI-IIA Ala | S442A, S4445A, T446A, S532A, S535A, S558A, S561A | −54.71 ± 1.59(7)* | −76.59 ± 0.914(7)* | 4.347 ± 0.43 (5)* |
| 5.354 ± 0.41(7) | 3.609 ± 0.07(7) | 17.96 ± 1.67(5)* | ||
| LI-IIB Ala | S650A, S653A, S687A, S715A, S717A, S749A, T751A, S758A | −44.24 ± 0.6 (6) | −67.84 ± 0.25 (7) | 12.14 ± 0.42 (5) |
| 5.029 ± 0.16 (6) | 4.021 ± 0.09 (7) | 32.75 ± 3.5 (5) | ||
| LII-III Ala | T1034A, S1035A, T1061A, S1071A, S1073A, S1091A, S1090A, S1099A, S1103A, S1107A, S1127A, S1144A, S1174A, S1175A, S1198A, S1246A | −45.6 ± 1.52 (5) | −68.97 ± 0.87 (5) | 8.235 ± 0.94 (4) |
| 5.264 ± 0.16 (5) | 4.102 ± 0.05 (5) | 25.83 ± 3.6 (4) | ||
| LIII-IV Ala | S1587A, T1588A, S1591A | −46.03 ± 1.62 (8) | −70.35 ± 0.78 (10) | 8.203 ± 0.64 (11) |
| 5.604 ± 0.18 (8) | 3.873 ± 0.08 (10) | 29.76 ± 2.1 (11) | ||
| C-terΔ | Q1886Stop | −47.79 ± 1.4 (7) | −69.09 ± 0.97 (8) | 8.558 ± 1.08 (5) |
| 4.961 ± 0.34 (7) | 4.087 ± 0.1 (8) | 26.02 ± 2.16 (5) | ||
| LI-II A1 | S442A, S4445A, T446A | −54.05 ± 0.7 (11)* | −76.17 ± 0.7 (11)* | 4.561 ± 0.24 (11)* |
| 5.297 ± 0.1 (11) | 3.509 ± 0.11 (11)† | 23.49 ± 1.06 (11)‡ | ||
| LI-II A2 | S532A, S535A | −45.69 ± 1.03 (5) | −69.09 ± 0.4 (5) | 7.927 ± 0.48 (5) |
| 5.326 ± 0.35 (5) | 4.189 ± 0.18 (5) | 27.34 ± 2.17 (5) | ||
| LI-II A3 | S558A, S561A | −44.04 ± 1.69 (6) | −66.4 ± 0.866 (6) | 11.28 ± 1.20 (7) |
| 5.356 ± 0.36 (6) | 4.045 ± 0.25 (6) | 27.2 ± 2.8 (7) | ||
| WT AP | — | −61.6 ± 1.04 (12)* | −89.53 ± 2.2 (11)* | 2.919 ± 0.26 (11)* |
| 6.124 ± 0.14 (12) | 4.224 ± 0.04 (11) | 15.82 ± 1.5 (11)* | ||
| LI-II A1 AP | S442A, S4445A, T446A | −64.58 ± 1.08 (8)* | −89.3 ± 1.3 (9)* | 2.584 ± 0.211 (8)* |
| 5.572 ± 0.32 (8) | 3.763 ± 0.06 (9) | 21.33 ± 2.3 (8)† |
V1/2 represents the half-activation and half-inactivation potentials, respectively; K is the slope factor; and τact and τinact are the activation and inactivation kinetics, respectively. The kinetics values were obtained by fitting the current traces obtained using the I-V curve protocol with a double-exponential function. The number of cells is indicated in parentheses.
*
P < 0.001 compared with the WT channels.
†
P < 0.01 compared with the WT channels.
‡
P < 0.05 compared with the WT channels.