Table 1.
JNK activity (fold induction)a | cAMP level | IP level | |||||
---|---|---|---|---|---|---|---|
GPCR | GPCR agonists | Agonist | EGF | Agonist + EGF | % increaseb | % decreasec | % increased |
Gs-coupled | |||||||
D1R | Dopamine (10 μM) | 1.4±0.2 | 1.7±0.3 | 2.1±0.5 | 1156±78** | NA | 10±12 |
LHR | Chorionic | 1.5±0.1 | 1.8±0.2 | 2.2±0.4 | 367±63** | NA | 14±19 |
Gonadotropin (1 μg ml−1) | |||||||
SecR | Secretin (1 μM) | 4.6±0.6 | 1.6±0.1 | 4.9±0.6 | 2897±121** | NA | 712±63** |
V2R | Vasopressin (100 nM) | 2.3±0.2 | 1.8±0.2 | 2.8±0.4 | 1342±119** | NA | 246±59** |
Gi-coupled | |||||||
ORL1R | OFQ (100 nM) | 2.5±0.4 | 2.0±0.3 | 6.3±1.1* | NA | 29±11*** | 14±15 |
D2R | Dopamine (10 μM) | 2.3±0.3 | 2.0±0.1 | 6.0±1.0* | NA | 26±8*** | 19±22 |
SSTR1 | Somatostatin (100 nM) | 2.5±0.6 | 1.9±0.2 | 5.9±0.5* | NA | 28±7*** | 16±39 |
mt1R | Melatonin (100 nM) | 2.2±0.2 | 2.1±0.4 | 5.6±0.6* | NA | 30±8*** | 23±21 |
Gq-coupled | |||||||
GRPR | Bombesin (100 nM) | 6.7±0.7 | 1.7±0.1 | 7.1±0.6 | 6±18 | NA | 1209±128** |
BK2R | Bradykinin (100 nM) | 6.8±0.9 | 2.0±0.4 | 7.7±1.2 | 4±29 | NA | 468±77** |
M1R | Carbachol (200 μM) | 5.9±0.9 | 1.6±0.1 | 6.6±1.0 | 523±74** | NA | 833±67** |
H1R | Histamine (100 μM) | 6.2±0.5 | 1.8±0.1 | 7.0±0.7 | 356±52** | NA | 642±87** |
Cos-7 cells were transfected with the cDNAs encoding different GPCRs in the absence (for cAMP and IP assays) or presence (for JNK assay) of JNK-HA. Assays were performed as described in Methods. The JNK activities were determined at 30 min after individual or co-treatment with specific GPCR agonists (as indicated) and EGF (100 ng ml−1). For cAMP assays, transfected cells were stimulated with the corresponding agonists in the absence (for Gs- and Gq-coupled receptors) or presence (for Gi-coupled receptors) of forskolin (10 μM) co-treatment for 30 min. For IP assays, agonists were administered to the transfected cells for 30 min.
Values shown represent the mean±s.e. from at least three separate experiments, with the basal JNK activity (in the absence of GPCR agonists) defined as one-fold induction.
Data represent the mean±s.e. of three separate experiments, with the basal level defined as 100%.
Data represent the mean±s.e. of three separate experiments, with the forskolin-enhanced cAMP level defined as 100%. Data analysis was performed by Bonferroni's corrected t-test.
Co-administration of GPCR agonists and EGF triggered the JNK activations synergistically as compared to their individual responses (two-way ANOVA, P<0.05).
Agonist treatment significantly increased cAMP or IP formation as compared to the basal levels (one-way ANOVA, P<0.05).
Agonist treatment significantly suppressed the forskolin-induced cAMP formation (one-way ANOVA, P<0.05). NA, not applicable.