Calcium ion impedes translation initiation at the synapse.
Stimulation of synaptoneurosome suspensions by the neurotransmitter glutamate gives rise to rapid loading of ribosomes onto mRNA and increased incorporation of amino acids into trichloroacetic acid-precipitable polypeptides. Metabotropic glutamate receptors (mGluRs) are responsible for this effect. Although simultaneous Ca2+ entry and mGluR stimulation do not change the response, entry of Ca2+ 30 s or 3 min before mGluR stimulation markedly depresses the polyribosomal loading. Either NMDA or ionophore (A23187) produces the depression. A calmodulin antagonist, W7, alleviates the effect, suggesting that inactivation of phospholipase A2 by calcium-calmodulin-dependent kinase II is partially responsible for the phenomenon. Thus, interaction between different classes of glutamate receptors affects the control of protein translation at the synapse. This effect may partially explain recent observations of negative interactions between receptor classes in induction of long-term potentiation.
Department of Psychology, Beckman Institute, University of Illinois at Urbana-Champaign.
I J
IJ
Weiler
W S
WS
Childers
W T
WT
Greenough
D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000494:pharmacology; D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology*; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000502:physiology; D002147:Calmodulin / Q000037:antagonists & inhibitors; D002540:Cerebral Cortex / Q000166:cytology; D003515:Cycloleucine / Q000031:analogs & derivatives / Q000494:pharmacology; D003864:Depression, Chemical; D005786:Gene Expression Regulation / Q000187:drug effects*; D007476:Ionophores / Q000494:pharmacology; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology*; D016202:N-Methylaspartate / Q000494:pharmacology; D009419:Nerve Tissue Proteins / Q000096:biosynthesis* / Q000235:genetics; D015240:Phorbol 12,13-Dibutyrate / Q000494:pharmacology; D010741:Phospholipases A / Q000502:physiology; D054467:Phospholipases A2; D014176:Protein Biosynthesis / Q000187:drug effects*; D016318:Quisqualic Acid / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D018094:Receptors, Metabotropic Glutamate / Q000502:physiology*; D012270:Ribosomes / Q000378:metabolism; D013449:Sulfonamides / Q000494:pharmacology; D013569:Synapses / Q000187:drug effects* / Q000378:metabolism
D002147:Calmodulin; D007476:Ionophores; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; D018094:Receptors, Metabotropic Glutamate; D013449:Sulfonamides; D003515:Cycloleucine; C036361:1-amino-1,3-dicarboxycyclopentane; D015240:Phorbol 12,13-Dibutyrate; D000001:Calcimycin; D016202:N-Methylaspartate; C017967:W 7; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D016318:Quisqualic Acid; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D010741:Phospholipases A; D054467:Phospholipases A2; D002118:Calcium