Regulation of eukaryotic initiation factor 4E phosphorylation in the nervous system of Aplysia californica.
We have used an antibody that specifically recognizes eukaryotic initiation factor 4E (eIF4E) when it is phosphorylated at Ser(207) to characterize eIF4E phosphorylation in the nervous system of APLYSIA: The level of phosphorylated eIF4E, but not the level of total eIF4E, was significantly correlated with the basal rate of translation measured from different animals. Serotonin (5-HT), a transmitter that regulates the rate of translation in APLYSIA: neurons, had mixed effects on eIF4E phosphorylation. 5-HT decreased eIF4E phosphorylation in sensory cell clusters through activation of protein kinase C. 5-HT increased eIF4E phosphorylation in the whole pleural ganglia. In the APLYSIA: nervous system, eIF4E phosphorylation correlated with phosphorylation of the p38 MAP kinase, but not the p42 MAP kinase (ERK). Furthermore, an inhibitor of the p38 MAP kinase significantly decreased basal eIF4E phosphorylation, but an inhibitor of the MAP or ERK kinase (MEK) did not. Despite the correlation of eIF4E phosphorylation with the basal rate of translation, inhibition of eIF4E phosphorylation by an inhibitor of the p38 MAP kinase did not significantly decrease the rate of translation.
Dyer
J R
JR
Department of Neurology and Neurosurgery, McGill University, Montreal Neurological Institute, Montreal, Quebec, Canada.
Sossin
W S
WS
D000470:Alkaloids; D000818:Animals; D001048:Aplysia; D053119:Benzophenanthridines; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000031:analogs & derivatives / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D039561:Eukaryotic Initiation Factor-4E; D017952:Ganglia, Invertebrate / Q000502:physiology*; D066298:In Vitro Techniques; D007700:Kinetics; D008715:Methionine / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D010448:Peptide Initiation Factors / Q000378:metabolism*; D010617:Phenanthridines / Q000494:pharmacology; D015240:Phorbol 12,13-Dibutyrate / Q000494:pharmacology; D010766:Phosphorylation; D014176:Protein Biosynthesis; D012701:Serotonin / Q000494:pharmacology; D013873:Thionucleotides / Q000494:pharmacology; D048051:p38 Mitogen-Activated Protein Kinases
D000470:Alkaloids; D053119:Benzophenanthridines; D004791:Enzyme Inhibitors; D039561:Eukaryotic Initiation Factor-4E; D010448:Peptide Initiation Factors; D010617:Phenanthridines; D013873:Thionucleotides; D005576:Colforsin; C016957:adenosine-3',5'-cyclic phosphorothioate; D012701:Serotonin; D015240:Phorbol 12,13-Dibutyrate; D008715:Methionine; D000242:Cyclic AMP; C016299:chelerythrine; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases