Table 1. Effects of i3 Loop Deletions on the Sensitivity of M3R to Gβ5-RGS7a.
M3R |
M3R with Gβ5-RGS7 |
|||||
---|---|---|---|---|---|---|
nb | Emaxc,d | –log EC50d,e | nb | Emaxc,d | –log EC50d,e | |
WT | 80 | 100 ± 3.94 | 6.35 ± 0.13 | 86 | 64 ± 3.15 | 6.00 ± 0.16 |
M3RΔ304–325 | 60 | 101 ± 3.66 | 6.57 ± 0.14 | 67 | 82 ± 3.11 | 6.56 ± 0.13 |
M3RΔ325–345 | 63 | 70 ± 2.78 | 6.82 ± 0.13 | 67 | 73 ± 2.37 | 6.24 ± 0.11 |
M3RΔ370–390 | 64 | 106 ± 2.62 | 6.95 ± 0.08 | 67 | 56 ± 1.60 | 6.66 ± 0.10 |
M3RΔ304–390 | 36 | 61 ± 4.05 | 5.61 ± 0.23 | 36 | 68 ± 10.33 | 4.90 ± 0.43 |
CCh-induced Ca2+ signaling was measured by FLIPR in cells transfected with different M3R i3 loop deletion mutants as described in the legend of Figure 1 and Experimental Procedures.
n is the number of points analyzed (two independent experiments).
Emax is the maximal change in well fluorescence expressed as a percentage of that of WT M3R (=100%).
Mean ± the standard error of the mean.
–Log EC50 (in molar) is the negative logarithm of the agonist concentration that produces the half-maximal effect.