TABLE 1

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