Relative current amplitudes and EC50 values of chimeras between GluR6(Q) and GluR7(Q)
| Clone | KA current [%] | Glu current [%] | n | Ratio Glu/KA | EC50 KA [μm] | EC50Glu [μm] | n |
|---|---|---|---|---|---|---|---|
| GluR6(Q) | 100.0 ± 17.9 | 100.0 ± 21.6 | 34 | 0.9 ± 0.1 | 1.7 ± 0.7 | 45.6 ± 15.2 | 3 |
| GluR7(Q) | 0.0 ± 0.0 | 0.0 ± 0.0 | 3 | 0.0 ± 0.0 | |||
| GluR6N–GluR7PC | 0.09 ± 0.04 | 0.6 ± 0.1 | 3 | 9.1 ± 2.8 | ctl | 20.0 ± 3.5 | 3 |
| GluR6NP–GluR7C | 0.4 ± 0.1 | 5.5 ± 1.6 | 8 | 13.1 ± 0.9 | 3.7 ± 1.0 | 47.2 ± 4.2 | 3 |
| GluR7N–GluR6PC | 155.0 ± 76.1 | 137.0 ± 64.4 | 7 | 1.0 ± 0.4 | 1.7 ± 0.2 | 223.0 ± 65.8 | 3 |
| GluR7NP–GluR6C | 235.0 ± 40.6 | 228.0 ± 38.2 | 4 | 0.8 ± 0.1 | 1.7 ± 0.3 | 103.0 ± 12.5 | 3 |
| GluR6–GluR7FC | 83.7 ± 5.1 | 68.6 ± 4.2 | 3 | 1.10 ± 0.01 | 1.5 ± 0.1 | 45.3 ± 9.0 | 4 |
| GluR7–GluR6FC | 0.02 ± 0.02 | 0.1 ± 0.1 | 4 | 5.5 ± 1.3 | ctl | ctl | |
| GluR6–GluR7L3 | 0.07 ± 0.01 | 0.003 ± 0.002 | 6 | 6.7 ± 0.4 | ctl | ctl | |
| GluR7–GluR6L3 | 207.0 ± 39.3 | 166.3 ± 34.8 | 4 | 0.79 ± 0.05 | 2.4 ± 0.6 | 314.0 ± 92.5 | 3 |
| GluR7–GluR6L3C/FC | 7.9 ± 0.5 | 7.0 ± 0.7 | 9 | 1.07 ± 0.06 | 2.5 ± 0.1 | 129.1 ± 5.0 | 3 |
| GluR7–GluR6L3N | 0.01 ± 0.01 | 0.10 ± 0.03 | 5 | 12.5 ± 0.6 | ctl | 307.3 ± 16.1 | 3 |
Receptors expressed in Xenopus oocytes were probed with 300 μm glutamate and 300 μm kainate as agonists. All currents were measured after 8 min of pretreatment of oocytes with ConA to minimize desensitization. Relative currents were calculated by taking GluR6 currents of the same batch as 100%. EC50 values were determined using 11 different concentrations (0.03, 0.1, 0.3, 1, 3, 10, 30, 100, 300, 1000, and 3000 μm) of either kainate or glutamate. Data are shown as means ± SEM. For an explanation of the constructs, see Figure 1and Materials and Methods. ctl, Currents too low for EC50values to be calculated. Absolute currents for wild-type GluR6 are 28615 ± 2078 nA (KA) and 27593 ± 2134 nA (Glu).