TABLE 1.
Effects of SNAP on the voltage-dependent activation and inactivation of N-type Ca2+ channels in HEK293 cells cotransfected with wild-type Cav2.2 (or Cav2.2 mutants), α2δ1, and Cavβ1, Cavβ3, or Cavβ4 subunits
| Specific subunit combination | V0.5 | Slope factor | n |
|---|---|---|---|
| Voltage-dependent activation | |||
| Cav2.2 + β1 + α2δ1 | −13.23 ± 2.04 | 3.03 ± 0.91 | 9 |
| Cav2.2 + β1 + α2δ1 (+SNAP) | −3.68 ± 4.68a | 5.58 ± 1.54a | 8 |
| Cav2.2 + β3 + α2δ1 | −12.13 ± 2.53 | 3.69 ± 1.16 | 8 |
| Cav2.2 + β3 + α2δ1 (+SNAP) | −2.48 ± 1.72a | 6.85 ± 0.80a | 8 |
| Cav2.2 + β4 + α2δ1 | −15.44 ± 2.06 | 5.23 ± 0.71 | 8 |
| Cav2.2 + β4 + α2δ1 (+SNAP) | −13.20 ± 1.48 | 6.84 ± 0.79 | 9 |
| Cav2.2 C805A + β3 + α2δ1 | −8.89 ± 2.42 | 5.29 ± 0.50 | 8 |
| Cav2.2 C805A + β3 + α2δ1 (+SNAP) | −9.49 ± 4.21 | 7.06 ± 0.64 | 8 |
| Cav2.2 C930A + β3 + α2δ1 | −1.07 ± 2.32 | 3.55 ± 0.57 | 7 |
| Cav2.2 C930A + β3 + α2δ1 (+SNAP) | −1.40 ± 3.84 | 5.74 ± 0.44 | 7 |
| Voltage-dependent inactivation | |||
| Cav2.2 + β1 + α2δ1 | −48.94 ± 1.16 | 7.27 ± 0.52 | 8 |
| Cav2.2 + β1 + α2δ1 (+SNAP) | −49.19 ± 1.04 | 8.63 ± 0.53 | 9 |
| Cav2.2 + β3 + α2δ1 | −47.45 ± 1.05 | 7.23 ± 0.45 | 8 |
| Cav2.2 + β3 + α2δ1 (+SNAP) | −51.42 ± 0.89 | 6.68 ± 0.59 | 7 |
| Cav2.2 + β4 + α2δ1 | −47.73 ± 1.04 | 10.69 ± 0.86 | 8 |
| Cav2.2 + β4 + α2δ1 (+SNAP) | −46.84 ± 1.77 | 8.72 ± 1.55 | 8 |
| Cav2.2 C805A + β3 + α2δ1 | −55.21 ± 0.60 | 11.30 ± 0.54 | 8 |
| Cav2.2 C805A + β3 + α2δ1 (+SNAP) | −56.15 ± 0.76 | 11.16 ± 0.62 | 8 |
| Cav2.2 C930A + β3 + α2δ1 | −47.78 ± 1.53 | 9.89 ± 1.17 | 7 |
| Cav2.2 C930A + β3 + α2δ1 (+SNAP) | −48.93 ± 1.07 | 11.83 ± 0.92 | 7 |
a p < 0.05, compared with the corresponding control (before SNAP application).