TABLE 1.
Comparision of ZnPy, KCNE1, and KCNE3 effects on KCNQ1 G is the channel conductance in the presence of either ZnPy or auxiliary subunits, whereas G0 is the conductance of KCNQ1 without ZnPy or any auxiliary subunits (KCNE1 or KCNE3). Both ZnPy and KCNE increase the conductance ∼4-fold; ZnPy and KCNE1 slow the activation and deactivation, whereas KCNE3 accelerates the deactivation. In addition, ZnPy inhibits KCNQ1 inactivation, whereas KCNE completely abolishes the inactivation. Significance was estimated by using a paired t-test; n > 4. NA, not applicable.
| KCNQ1a | ZnPy (5 μm)a | KCNQ1-KCNE1a | KCNQ1-KCNE3b | |
|---|---|---|---|---|
| G/G0 | 1.0 | 4.2 ± 0.8c | 4.3 ± 0.9c | 4.4 ± 1.5c |
| τ activation (ms) | 23.4 ± 4.9 | 73.7 ± 12.5c | τ1, 1297.6 ± 432.5c; τ2, 218.0 ± 46.8 | 25.9 ± 2.8 |
| τ deactivation (ms) | 60.6 ± 6.2 | 113.20 ± 15.41c | 243.8 ± 47.9c | 21.6 ± 3.4c |
| Inactivation (%) | 67.2 ± 3.7 | 14.2 ± 12.5c | NA | NA |
a
The KCNQ1 and KCNQ1-KCNE1 currents were elicited by depolarization to +50 mV
b
The KCNQ1-KCNE3 currents were elicited by depolarization to +40 mV
c
*, p < 0.05 compared with KCNQ1