cAMP inhibits translation by inducing Ca2+/calmodulin-independent elongation factor 2 kinase activity in IPC-81 cells.
Treatment of IPC-81 cells led to inhibition of protein synthesis, which was accompanied by an increase in the average size of polysomes and a decreased rate of elongation, indicating that it involved inhibition of peptide chain elongation. This inhibition was also associated with increased phosphorylation of elongation factor eEF2 (which inhibits its activity) and enhanced Ca2+/calmodulin-independent activity of eEF2 kinase. Previous work has shown that phosphorylation of eEF2 kinase by cAMP-dependent protein kinase (cAPK) in vitro induces such activator-independent activity, and the present data show that such a mechanism can occur in intact cells to link physiological levels of cAPK activation with inhibition of protein synthesis.
Department of Anatomy and Cell Biology, University of Bergen, Norway.
R
R
Hovland
T S
TS
Eikhom
C G
CG
Proud
L I
LI
Cressey
M
M
Lanotte
S O
SO
Døskeland
G
G
Houge
D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000818:Animals; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D002147:Calmodulin / Q000502:physiology*; D002460:Cell Line; D000242:Cyclic AMP / Q000031:analogs & derivatives / Q000494:pharmacology*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D054736:Elongation Factor 2 Kinase; D004789:Enzyme Activation / Q000187:drug effects; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D008715:Methionine / Q000378:metabolism; D009154:Mutation; D010441:Peptide Chain Elongation, Translational / Q000187:drug effects; D020652:Peptide Elongation Factor 2; D010445:Peptide Elongation Factors / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D011132:Polyribosomes / Q000378:metabolism; D014176:Protein Biosynthesis / Q000187:drug effects*; D051381:Rats; D013873:Thionucleotides / Q000494:pharmacology
D002147:Calmodulin; D007527:Isoenzymes; D020652:Peptide Elongation Factor 2; D010445:Peptide Elongation Factors; D013873:Thionucleotides; D015124:8-Bromo Cyclic Adenosine Monophosphate; C015929:8-((4-chlorophenyl)thio)cyclic-3',5'-AMP; D008715:Methionine; D000242:Cyclic AMP; C517691:Eef2k protein, rat; D017868:Cyclic AMP-Dependent Protein Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D054736:Elongation Factor 2 Kinase