Table 1.
Comparison of site-specific phosphorylation of PKD1 in rat pancreatic acinii.
| PKD1 serine phosphorylation | |||
|---|---|---|---|
| Variable | pS916 | pS744/748 | p |
| Stimulation by pancreatic secretagoguesii | |||
| Yes | CCK, carbachol, bombesin | CCK, carbachol, bombesin | |
| No | Secretin, VIP, endothelin | Secretin, VIP, endothelin | |
| Stimulation by pancreatic growth factorsiii | |||
| Yes | - | - | |
| No | Insulin, EGF, PDGF, VEGF, bFGF, IGF1, TGFβ, HGF | Insulin, EGF, PDGF, VEGF, bFGF, IGF1, TGFβ, HGF | |
| Stimulation by post-receptor activators | |||
| Yes | TPA | TPA | |
| No | Ionophore, 8-Br-cAMP | Ionophore, 8-Br-cAMP | |
| t1/2 of CCKiv (s) | 28.9 ± 3.1 | 103 ± 7.4 | 0.0031 |
| tmax of CCKiv (s) | 525 ± 75 | 900 ± 122 | NSv |
| EC50 of CCKvi (nM) | 0.14 ± 0.02 | 0.19 ± 0.05 | NS |
| EC50 of CCK-JMVv(nM)i | 1070 ± 725 | 119 ± 60 | NS |
| Fold increase with CCK (100nM)vi | 53.4 ± 7.2 | 11.2 ± 1.3 | 0.013 |
| Fold increase with CCK-JMV(10 μM)vi | 4.4 ± 0.9 | 2.5 ± 0.4 | NS |
| CCK stimulation with GF109203X(5 μM) (% CCK alone) | 38.0 ± 3.2 | 13.0 ± 0.8 | 0.026 |
| CCK stimulation with Thapsigargin (1 μM) (% CCK alone) | 4.2 ± 0.8 | 14.4 ± 1.4 | 0.032 |
| CCK stimulation with Go6976(10 μM) (% CCK alone) | 57.5 ± 20.0 | 86.9 ± 17.3 | NS |
| CCK stimulation with Go6983(10 μM) (% CCK alone) | 51.5 ± 9.1 | 17.6 ± 2.1 | 0.011 |
i
Results are calculated from the data shown in Figures 2–8. For CCK stimulation after pre-incubation with GF109203X, thapsigargin, Go6976 and Go6983, results are expressed as the percentages of the stimulation seen with CCK (10 nM) after pre-incubation in incubation buffer without any additions.
ii
Concentrations and incubation times are reported in Figure 2.
iii
Concentrations and incubation times are reported in Figure 2.
iv
Stimulation with 10 nM CCK as described in Fig. 4.
v
NS: p value not significant (≥0.05).
vi
Stimulation with CCK for 5 min as described in Fig. 5.