Competitive binding of postsynaptic density 95 and Ca2+-calmodulin dependent protein kinase II to N-methyl-D-aspartate receptor subunit 2B in rat brain.
OBJECTIVE
To investigate the interactions among postsynaptic density 95 (PSD-95), Ca2+-calmodulin dependent protein kinase IIalpha (CaMKIIalpha), and N-methyl-D-aspartate receptor subunit 2B (NR2B) during ischemia and reperfusion in hippocampus of rats.


METHODS
Brain ischemia was induced by four-vessel occlusion procedure in rats. Immunoprecipitation and immunoblotting were performed to study the interactions and phosphorylation of proteins. The association-dissociation of PSD-95 and CaMKIIalpha to and from N-methyl-D-aspartate (NMDA) receptor induced by ischemia and reperfusion and the effects of 1-[N,O-bis-(5-isoquinolinesulfonyl)-N-methyl-L-tyrosyl]-4-phenyl-piperazine (KN-62, a selective inhibitor of CaMKII) on these protein interactions were investigated. Coimmunoprecipitation and immunoblotting were performed for the studies of interactions among proteins.


RESULTS
The alternations of the binding level of PSD-95 and CaMKIIalpha to NR2B during ischemia and reperfusion demonstrated the negative correlation to each other. Pre-administration of KN62 through both cerebral ventricles inhibited the 10 min ischemia-induced increase of the binding of PSD-95 to NR2B and, on the contrary, promoted the binding of CaMKIIalpha to NR2B.


CONCLUSIONS
PSD-95 competes with CaMKII to bind to NR2B during ischemia and reperfusion in rat hippocampus.
Meng
Fan-jie
FJ
Research Center of Biochemistry and Molecular Biology, Xuzhou Medical College, Xuzhou 221002, China.
Guo
Jun
J
Song
Bo
B
Yan
Xue-bo
XB
Zhang
Guang-yi
GY
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D000818:Animals; D001667:Binding, Competitive; D002545:Brain Ischemia / Q000150:complications; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000076122:Disks Large Homolog 4 Protein; D006624:Hippocampus / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*; D015427:Reperfusion Injury / Q000209:etiology / Q000378:metabolism*
D000076122:Disks Large Homolog 4 Protein; C501449:Dlg4 protein, rat; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D016194:Receptors, N-Methyl-D-Aspartate; C033652:postsynaptic density proteins; C063302:KN 62; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases; C517675:Camk2a protein, rat