Related Experiment Video
Updated: Oct 20, 2026

Light-mediated Reversible Modulation of the Mitogen-activated Protein Kinase Pathway during Cell Differentiation and Xenopus Embryonic Development
Published on: June 15, 2017
[Modulation of the adenylate cyclase-cAMP pathway by protein kinase C in chick retinal pigment epithelium]
1Department of Ophthalmology, Hiroshima University School of Medicine, Japan.
Abstract:
I investigated stimulation of cyclic adenosine 3':5'-monophosphate (cAMP) production by isoproterenol and forskolin in cultured chick embryo retinal pigment epithelium. In addition, in order to study the interaction between signal transduction systems, I studied the effects of phorbol 12-myristate, 13-acetate (PMA), a protein kinase C (PKC) activator, on isoproterenol- or forskolin-stimulated cAMP production. After stimulation with 10(-9)-10(-5) M isoproterenol and forskolin, a marked and concentration-dependent increase in cAMP level was observed. However, addition of 10(-10)-10(-5) M PMA had no effect on the cAMP level. Preincubation of isoproterenol and forskolin with 100 nM PMA suppressed the increase of cAMP. The suppressive effect of PMA was stronger on isoproterenol-stimulated production than on forskolin-stimulated production. 4 alpha-phorbol 12, 13, didecanoate, a weak activator of PKC, had a weak suppressive effect on cAMP-production stimulated by isoproterenol. Both staurosporin and H-7, 1-(5-isoquinolinylsulfonyl)-methylpiperazine, inhibitors of PKC, decreased the suppression of cAMP production by PMA. It is speculated that in chick retinal pigment epithelium PKC stimulators, such as PMA, may inhibit the adenylate cyclase pathway.
Related Concept Videos
Intracellular Signaling Cascades
Interactions Between Signaling Pathways
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
Amplifying Signals via Second Messengers
GPCRs Regulate Adenylyl Cylase Activity
Two...
cAMP-dependent Protein Kinase Pathways
Calmodulin-dependent Signaling
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...

