N-methyl-D-aspartate receptor dependent transcriptional regulation of two calcium/calmodulin-dependent protein kinase type II isoforms in rodent cerebral cortex.
Alpha Calcium/calmodulin-dependent protein kinase type II (CaMKII-alpha) expression is regulated in an activity-dependent manner, but it is not known whether other CaMKII isoforms (beta, delta, and gamma) are similarly regulated. We examined the activity-dependent regulation of these CaMKII isoforms in vivo, using a model of generalized seizures caused by i.p. injection of kainic acid. Following seizure induction, CaMKII-alpha expression was downregulated and CaMKII-delta expression upregulated while CaMKII-beta and CaMKII-gamma expression was unaffected. A transient downregulation in CaMKII-alpha and a transient increase in CaMKII-delta occurred throughout neocortex in the same temporal order. Although CaMKII-alpha mRNA was decreased by seizure activity, the less abundant, alternatively spliced, CaMKII-alpha33 mRNA was unaffected. Organotypic cortical slice cultures treated with bicuculline and 4-aminopyridine to induce seizure activity also showed a downregulation of CaMKII-alpha mRNA and an upregulation of CaMKII-delta mRNA. Prior exposure to tetrodotoxin prevented the changes in CaMKII-alpha and CaMKII-delta mRNA regulation and this was mimicked by D-L-2-amino-5-phosphonovaleric acid, but not by 6-cyano-2,3-dihydroxy-7-nitro-quinoxaline, suggesting that CaMKII-alpha and CaMKII-delta mRNA expression is regulated in an N-methyl-D-aspartate receptor-dependent manner. Regulation was also transcription dependent. Blocking transcription with actinomycin-D prevented activity-dependent changes in CaMKII-alpha and CaMKII-delta mRNA, but produced opposite effects on basal transcription, resulting in more stabilized CaMKII-alpha mRNA and less stabilized CaMKII-delta mRNA. These results reveal unique patterns of seizure-induced alterations in CaMKII mRNAs. Activity-dependent changes in subunit composition could, therefore, differentially influence the functional attributes of the CaMKII holoenzyme.
Murray
K D
KD
Center for Neuroscience, University of California, Davis, 1544 Newton Court, Davis, CA 95616, USA.
Isackson
P J
PJ
Jones
E G
EG
D000818:Animals; D054737:Calcium-Calmodulin-Dependent Protein Kinase Kinase; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics; D002540:Cerebral Cortex / Q000737:chemistry / Q000378:metabolism*; D007527:Isoenzymes / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics; D008297:Male; D017346:Protein Serine-Threonine Kinases / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D012640:Seizures / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000502:physiology*
D007527:Isoenzymes; D012333:RNA, Messenger; D016194:Receptors, N-Methyl-D-Aspartate; D017346:Protein Serine-Threonine Kinases; D054737:Calcium-Calmodulin-Dependent Protein Kinase Kinase; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases