Summary of the biophysical properties of jellyfish andDrosophila Shal currents
| Parameter | dShal | jShal1 | jShal1 + jShalγ1 | jShal1 + jShalγ1 (T) |
|---|---|---|---|---|
| Activation | ||||
| V50(mV) | −3.8 ± 0.1 (8) | −39.3 ± 0.1 (11) | −11.8 ± 0.9 (8) | −17.7 ± 0.7 (7) |
| Slope (mV/e-fold) | 15.38 ± 0.07 (8) | 22.4 ± 0.1 (11) | 17.4 ± 0.1 (8) | 17.5 ± 0.07 (7) |
| Inactivation | ||||
| V50(mV) | −60.6 ± 0.1 (8) | −106.1 ± 0.2 (11) | −71.5 ± 0.2 (8) | −64.4 ± 0.7 (7) |
| Slope (mV/e-fold) | 6.3 ± 0.1 (8) | 6.1 ± 0.15 (11) | 4.9 ± 0.2 (8) | 7.9 ± 0.2 (7) |
| τFAST (msec) | 40.1 ± 2.1 (8) | 137 ± 6.7 (4) | 2.69 ± 0.04 (13) | 24.3 ± 0.8 (8) |
| τSLOW (msec) | 165 ± 8.4 (8) | 889 ± 61 (4) | 275 ± 12 (8) | |
| % Fast | 57 ± 3 (8) | 41 ± 2 (4) | 43 ± 2 (8) | |
| Recovery | ||||
| τR-F (msec) | 505 ± 12.9 (9) | 375 ± 25.4 (4)* | 170 ± 5.7 (5) | 9.76 ± 2.5 (7) |
| τR-S (msec) | 3824 ± 813 (5)2-160 | 155 ± 17.2 (7)2-160 |
V50 and slope (in mV/e-fold change in conductance) of activation and steady-state inactivation are derived from the Boltzmann fits of the conductance/voltage and steady-state inactivation data shown in Figures 3, 4, 5. τFAST and τSLOW are the fast and slow time constants of inactivation and were determined at +50 mV. The percent of the current inactivating with τFAST is also given. τR-Fand τR-S are time constants of fast and slow components of recovery from inactivation determined at −100 mV for dShal and the heteromultimeric currents and at −120 mV for jShal1. If a single component to recovery was identified, it is given as τR-F. Error values (±) are for SEs of curve fits and data points, and sample sizes are indicated in parentheses.
↵* A small (≤15%), virtually instantaneous component to jShal1 recovery fit is not listed, because it is probably caused by channels that did not inactivate during the test pulse and did not close during the shortest recovery periods.
↵F2-160 These are the major recovery components for jShal1 + jShalγ1 and jShal1 + jShalγ1 (T) heteromultimers, at 87 and 64%, respectively.