Stimulation by 5-HT of [35S]GTPγS (0.2 nM) binding to membranes of Sf9 cells coexpressing the h5-ht5Areceptor and G protein subunits of the Gi/o, Gs, Gq/11, and G12/13 family
| Proteins Expressed | Maximum Stimulation | pEC50 | n |
|---|---|---|---|
| % | −logM | ||
| h5-ht5A-HEK 2933-a | 135 ± 3 | 7.0 ± 0.1 | 3 |
| h5-ht5A-Sf9 | 38 ± 16 | 6.9 ± 0.4 | 5 |
| h5-ht5A + Gαi/o-Sf93-b | 326 ± 653-c | 6.5 ± 0.2 | 2 |
| h5-ht5A + Gαi1-Sf9 | 297 ± 1203-c | 6.6 ± 0.1 | 3 |
| h5-ht5A + Gαi2-Sf9 | 340 ± 1313-c | 6.6 ± 0.2 | 4 |
| h5-ht5A + Gαi3-Sf9 | 260 ± 553-c | 6.9 ± 0.1 | 4 |
| h5-ht5A + Gαo-Sf9 | 263 ± 603-c | 7.0 ± 0.1 | 4 |
| h5-ht5A + Gαz-Sf9 | 20 ± 3 | 6.8 ± 0.6 | 3 |
| h5-ht5A + Gαs-Sf9 | 9 ± 3 | 6.6 ± 0.0 | 2 |
| h5-ht5A + Gαq-Sf9 | 25 ± 13 | 6.5 ± 0.4 | 3 |
| h5-ht5A + Gα11-Sf9 | 54 ± 9 | 6.9 ± 0.2 | 3 |
| h5-ht5A + Gα16-Sf9 | 50 ± 11 | 6.6 ± 0.3 | 3 |
| h5-ht5A + Gα12-Sf9 | —3-e | —3-e | 2 |
| h5-ht5A + Gα13-Sf9 | —3-e | —3-e | 3 |
| h5-ht5A + Gβ1γ2-Sf9 | 113 ± 233-d | 6.9 ± 0.3 | 5 |
| h5-ht5A + Gαi/o + Gβ1γ2-Sf93-b | 573 ± 184 | 6.6 ± 0.1 | 2 |
| h5-ht5A + Gαi1 + Gβ1γ2-Sf9 | 629 ± 1533-d | 6.9 ± 0.1 | 7 |
| h5-ht5A + Gαi2 + Gβ1γ2-Sf9 | 490 ± 149 | 6.8 ± 0.2 | 7 |
| h5-ht5A + Gαi3 + Gβ1γ2-Sf9 | 489 ± 563-d | 7.1 ± 0.1 | 5 |
| h5-ht5A + Gαo + Gβ1γ2-Sf9 | 172 ± 27 | 7.4 ± 0.1 | 4 |
| h5-ht5A + Gαz + Gβ1γ2-Sf9 | 61 ± 123-d | 7.0 ± 0.3 | 3 |
| h5-ht5A + Gαs + Gβ1γ2-Sf9 | 36 ± 93-d | 6.6 ± 0.1 | 3 |
| h5-ht5A + Gαq + Gβ1γ2-Sf9 | 135 ± 93-d | 6.8 ± 0.4 | 3 |
| h5-ht5A + Gα11 + Gβ1γ2-Sf9 | 81 ± 50 | 6.9 ± 0.6 | 4 |
| h5-ht5A + Gα16 + Gβ1γ2-Sf9 | 64 ± 18 | 6.4 ± 0.4 | 3 |
| h5-ht5A + Gα12 + Gβ1γ2-Sf9 | —3-e | —3-e | 2 |
| h5-ht5A + Gα13 + Gβ1γ2-Sf9 | —3-e | —3-e | 3 |
[35S]GTPγS binding studies were performed as described inExperimental Procedures. The maximum stimulation and pEC50 values were derived from the curves. The results are mean ± S.D. values from n independent experiments.
↵3-a Data for h5-ht5A-HEK 293 were taken fromFrancken et al., 1998.
↵3-b Gαi/o represents the combination of Gαi1, Gαi2, Gαi3, and Gαosubunits.
↵3-c Maximum stimulation value for h5-ht5A+Gα-Sf9 that is significantly (Student's ttest, P < .05) higher than that for h5-ht5A-Sf9.
↵3-d Maximum stimulation value for h5-ht5A(+Gα) + Gβ1γ2-Sf9 that is significantly (Student's t test, P < .05) higher than that for h5-ht5A(+Gα)-Sf9.
↵3-e —, no 5-HT-induced stimulation of [35S]GTPγS binding was observed for coexpressions with Gα12 or Gα13 subunits.