Desensitization properties of wild-type and mutant AMPAR and KAR channels
| Subunit | τdes (msec) | %des | Plateau/peak | τrec (msec) |
|---|---|---|---|---|
| Ai, wt | 3.2 ± 0.2 | 97.9 ± 0.6 | 0.021 ± 0.006 | 155 ± 11 |
| Al (R624E) | 5.8 ± 0.3 | 57.6 ± 4.0 | 0.424 ± 0.040 | 127 ± 6 |
| Bi, wt | 5.6 ± 0.3 | 96.5 ± 0.8 | 0.035 ± 0.008 | 21.8 ± 2.0 |
| Bi (R628E) | 10.8 ± 1.1 | 14.5 ± 1.5 | 0.855 ± 0.015 | ND |
| Bo, wt | 1.8 ± 0.2 | 98.4 ± 0.5 | 0.016 ± 0.005 | 24.3 ± 1.9 |
| Bo (R628E) | 3.3 ± 0.2 | 58.0 ± 3.4 | 0.420 ± 0.034 | 23.9 ± 2.2 |
| 6, wt | 3.4 ± 0.1 | 99.6 ± 0.2 | 0.004 ± 0.002 | 1920 ± 110 |
| 6 (R632E) | 6.8 ± 0.7 | 90.5 ± 2.1 | 0.095 ± 0.021 | 1070 ± 120 |
| 6 (E631R) | 1.9 ± 0.1 | 99.9 ± 0.1 | 0.001 ± 0.001 | 1050 ± 40 |
| 6 (E634R) | 3.5 ± 0.3 | 99.8 ± 0.1 | 0.002 ± 0.001 | 1620 ± 110 |
The time constants of desensitization (τdes) and recovery from it (τrec) were obtained from single exponential fits (for details, see Materials and Methods). %des and plateau/peak ratio are based on peak and steady-state current amplitudes. Values shown are the mean ± SEM (n = 4-10). We could not determine (ND) the recovery from desensitization for GluR-Bi (R628E) because of the small desensitizating current component. wt, Wild type.