TABLE 2.
Inositol phosphate signaling of the ghrelin receptor wild type and mutant forms with substitutions in positions PheV:13,TrpVI:13, and HisVI:17
The constructs were expressed in transiently transfected COS-7 cells. The efficacy data on basal activity and maximal response (Emax) are expressed as a percentage of the basal activity on the wild-type ghrelin receptor. Values are shown ± S.E. Values for n are shown in parentheses.
| Basal activity | Emax | EC50 | |
|---|---|---|---|
| % | % | nm | |
| Wild-type ghrelin | 100 (57) | 250 ± 23 (57) | 0.34 ± 0.04 (57) |
| FV:13A | 2.6 ± 2.4 (6) | 170 ± 20 (6) | 1.40 ± 0.3 (6) |
| FV:13H | 4.2 ± 2.0 (4) | 87 ± 4 (3) | 2.00 ± 0.7 (4) |
| FV:13Y | 16 ± 3 (3) | 140 ± 30 (3) | 0.27 ± 0.05 (3) |
| FV:13C | 15 ± 7 (3) | 160 ± 30 (3) | 1.40 ± 0.7 (5) |
| WVI:13A | 0 (4) | 24 ± 3 (4) | 3.20 ± 0.8 (3) |
| WVI:13H | 0 (4) | 49 ± 5 (3) | 1.30 ± 0.4 (4) |
| HVI:17A | 39 ± 9 (3) | 290 ± 20 (3) | 0.60 ± 0.03 (3) |
| FV:13H/WVI:13H | 0 (3) | 0 (3) | >10.000 (3) |
| FV:13C/WVI:13H | 0 (3) | 0 (3) | >10.000 (3) |