A molecular switch for translational control in taste memory consolidation.
In a variety of species memory consolidation following different learning paradigms has been shown to be dependent on protein synthesis. However, it is not known whether modulation of protein synthesis is a critical component of the consolidation process, nor is the identity of any protein(s) subject to translational regulation, known. We report here that phosphorylation of eukaryotic elongation factor-2 (eEF2), an indicator for translational elongation attenuation, is correlated with input that produces taste memory consolidation in the relevant cortex of rat. The temporal pattern of eEF2 phosphorylation is similar to extra-cellular regulated kinase 2 (ERK2) activation and S6K1 phosphorylation, which are known to stimulate translation initiation. In addition, increased eEF2 phosphorylation and increased alphaCaMKII expression is detected in a synaptoneurosomal fraction made from taste cortex following memory consolidation. These results suggest that increased initiation rate together with decreased elongation rate, during memory consolidation, shift the rate-limiting step of protein synthesis, to produce a local switch-like effect in the expression of neuronal proteins.
Belelovsky
K
K
Center for Brain and Behaviour, Department of Neurobiology and Ethology, Faculty of Sciences, University of Haifa, Haifa 30905, Israel.
Elkobi
A
A
Kaphzan
H
H
Nairn
A C
AC
Rosenblum
K
K
D000818:Animals; D002540:Cerebral Cortex / Q000378:metabolism / Q000502:physiology; D003216:Conditioning, Operant / Q000187:drug effects; D003600:Cytosol / Q000201:enzymology / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D006624:Hippocampus / Q000378:metabolism / Q000502:physiology; D008297:Male; D008568:Memory / Q000502:physiology*; D016202:N-Methylaspartate / Q000494:pharmacology; D020652:Peptide Elongation Factor 2 / Q000235:genetics / Q000502:physiology; D010766:Phosphorylation; D051381:Rats; D017208:Rats, Wistar; D038762:Ribosomal Protein S6 Kinases, 70-kDa / Q000235:genetics / Q000502:physiology; D013574:Synaptosomes / Q000201:enzymology / Q000502:physiology; D013649:Taste / Q000502:physiology*
D020652:Peptide Elongation Factor 2; D016202:N-Methylaspartate; D038762:Ribosomal Protein S6 Kinases, 70-kDa; C448901:ribosomal protein S6 kinase, 70kD, polypeptide 1