Sequestration of hm1, hm3 and hm5 receptors coexpressed with GRKs in COS-7 cells
| Proportions of sequestered receptors | |||
|---|---|---|---|
| hm1 receptors | hm3 receptors | hm5 receptors | |
| % | |||
| Control | 10 ± 5 (7) | 22 ± 6 (3) | 24 ± 3 (3) |
| GRK2 | 31 ± 5 (7)2-b | 34 ± 2 (3)2-a | 51 ± 5 (3)2-b |
| DN-GRK2 | 25 ± 2 (5)2-b | 13 ± 7 (4) | 23 ± 7 (5) |
| GRK4δ | 8 ± 5 (3) | 8 ± 6 (3)2-a | 21 ± 2 (3) |
| GRK5 | 2 ± 3 (3)2-a | 20 ± 3 (3) | 24 ± 5 (3) |
| GRK6 | 8 ± 5 (3) | 20 ± 4 (3) | 22 ± 2 (3) |
COS-7 cells expressing hm1, hm3 or hm5 receptors with or without GRKs were incubated with varying concentrations of carbamylcholine for 120 min. Proportions of sequestered receptors were determined as decrease of [3H]NMS binding activity on cells treated with 10−4m carbamylcholine. Results are shown as mean ± standard deviation from three to seven independent experiments. The number of experiments is indicated in parentheses.