Effects of NHERF1 on PTH1R desensitization
ROS-T6-N4 cells were exposed to a first challenge for 15 min in the absence of IBMX. After ligand washout, cells were incubated a second time with 10 nM PTH (15 min) in the presence of IBMX. Cells were treated with Tet (10 ng/ml) to induce maximal NHERF1 expression, where indicated. Receptor desensitization was assayed as described under Materials and Methods. Data are summarized as the mean ± S.E. n = 4 independent experiments.
First Incubation | Second Incubation | cAMP | ||
|---|---|---|---|---|
| −NHERF | +NHERF | |||
| nM | ||||
| 0.1% BSA | 10 nM PTH(1-34) | 220 ± 30 | 243 ± 40 | |
| 3 nM PTH(1-34) | 10 nM PTH(1-34) | 160 ± 2 | 206 ± 1.8 | |
| 10 nM PTH(1-34) | 10 nM PTH(1-34) | 133 ± 16 | 192 ± 2 | |
| 30 nM PTH(1-34) | 10 nM PTH(1-34) | 101 ± 11 | 156 ± 12 | |
| 100 nM PTH(1-34) | 10 nM PTH(1-34) | 75 ± 6 | 134 ± 12 | |
| 300 nM PTH(1-34) | 10 nM PTH(1-34) | 40 ± 4 | 90 ± 9 | |
| 1000 nM PTH(1-34) | 10 nM PTH(1-34) | 21 ± 11 | 53 ± 14 | |