Cyclic AMP stimulates the phosphorylation and activation of p42 and p44 mitogen-activated protein kinases in 3T3-F442A preadipocytes.
The effects of cyclic AMP on mitogen-activated protein (MAP) kinase activation were investigated in 3T3-F442A preadipocytes. Several agents, which raise intracellular cyclic AMP levels by distinct mechanisms, induced a transient activation of the p42 and p44 isoforms of MAP kinase and of a MAP kinase kinase. Activation of MAP kinase by cyclic AMP was prevented by two distinct inhibitors of cyclic AMP-dependent protein kinase and by PD 098059, a specific inhibitor of the activation of the MAP kinase kinase MEK 1. Therefore, in contrast to most cell types studied, cyclic AMP exerts a positive influence on the MAP kinase pathway in 3T3-F442A preadipocytes at a level upstream of the activation of MAP kinase kinase.
Yarwood
S J
SJ
Hannah Research Institute, Scotland, United Kingdom.
Kilgour
E
E
Anderson
N G
NG
D016475:3T3 Cells; D017667:Adipocytes / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D000818:Animals; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D002454:Cell Differentiation / Q000187:drug effects; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000494:pharmacology*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004815:Epidermal Growth Factor / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D051379:Mice; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*
D004791:Enzyme Inhibitors; D005419:Flavonoids; D005576:Colforsin; D004815:Epidermal Growth Factor; D000242:Cyclic AMP; D011505:Protein-Tyrosine Kinases; D017868:Cyclic AMP-Dependent Protein Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one