Degree of Increase in KCNQ1 Current Amplitude by KCNE1 WT and Mutants
. | Q1 alone . | + E1-WT . | + E1-G40C . | + E1-K41C . | + E1-L42C . | + E1-E43C . | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Q1-WT | ||||||||||||
| Mean | 1.00 | 2.67 | 2.77 | 2.39 | 1.25 | 0.38a | ||||||
| SEM | 0.19 | 0.32 | 0.21 | 0.42 | 0.27 | 0.11 | ||||||
| n | 14 | 11 | 8 | 9 | 9 | 6 | ||||||
| Q1(-Cys)-WT | ||||||||||||
| Mean | 1.00 | 8.45 | 2.43 | 6.45 | 1.95 | 2.05 | ||||||
| SEM | 0.13 | 1.67 | 0.53 | 0.93 | 0.13 | 0.34 | ||||||
| n | 21 | 9 | 7 | 5 | 11 | 5 | ||||||
| Q1(-Cys)-I145C | ||||||||||||
| Mean | 1.00 | 4.51 | 11.00 | 3.39 | 4.19 | 3.52 | ||||||
| SEM | 0.32 | 0.49 | 2.13 | 0.52 | 0.80 | 0.69 | ||||||
| n | 14 | 11 | 8 | 8 | 11 | 9 | ||||||
. | Q1 alone . | + E1-WT . | + E1-G40C . | + E1-K41C . | + E1-L42C . | + E1-E43C . | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Q1-WT | ||||||||||||
| Mean | 1.00 | 2.67 | 2.77 | 2.39 | 1.25 | 0.38a | ||||||
| SEM | 0.19 | 0.32 | 0.21 | 0.42 | 0.27 | 0.11 | ||||||
| n | 14 | 11 | 8 | 9 | 9 | 6 | ||||||
| Q1(-Cys)-WT | ||||||||||||
| Mean | 1.00 | 8.45 | 2.43 | 6.45 | 1.95 | 2.05 | ||||||
| SEM | 0.13 | 1.67 | 0.53 | 0.93 | 0.13 | 0.34 | ||||||
| n | 21 | 9 | 7 | 5 | 11 | 5 | ||||||
| Q1(-Cys)-I145C | ||||||||||||
| Mean | 1.00 | 4.51 | 11.00 | 3.39 | 4.19 | 3.52 | ||||||
| SEM | 0.32 | 0.49 | 2.13 | 0.52 | 0.80 | 0.69 | ||||||
| n | 14 | 11 | 8 | 8 | 11 | 9 | ||||||
Total current amplitudes in oocytes coexpressing E1 with Q1 are corrected for interference by Xenopus endogenous Q1 (estimated by the mean current amplitude from oocytes expressing E1-WT alone, n =14–21 per batch of oocytes). These current amplitudes, and the current amplitudes from oocytes expressing Q1 alone, are then corrected for differences in the degrees of activation at the test voltage when current amplitudes are measured (based on the average 2-s isochronal activation curves), and then normalized by the mean current from oocytes expressing Q1 alone.
In multiple experiments, most oocytes expressing E1-E43C with Q1-WT die 2 d after cRNA injection. Therefore, the current amplitudes of Q1-WT/E1-E43C are limited to data obtained ∼1 d after cRNA injection, earlier than data from the other groups of oocytes.