Calcineurin dephosphorylates glycogen synthase kinase-3 beta at serine-9 in neuroblast-derived cells.
This study examined the role of calcineurin, a major calcium-dependent protein phosphatase, in dephosphorylating Ser-9 and activating glycogen synthase kinase-3beta (GSK-3beta). Treatment with calcineurin inhibitors increased phosphorylation of GSK-3beta at Ser-9 in SH-SY5Y human neuroblastoma cells. The over-expression of a constitutively active calcineurin mutant, calcineurin A beta (1-401), led to a significant decrease in phosphorylation at Ser-9, an increase in the activity of GSK-3beta, and an increase in the phosphorylation of tau. K(m) of calcineurin for a GSK-3beta phosphopeptide was 469.3 microM, and specific activity of calcineurin was 15.2 nmol/min/mg. In addition, calcineurin and GSK-3beta were co-immunoprecipitated in neuron-derived cells and brain tissues, and calcineurin formed a complex only with dephosphorylated GSK-3beta. We conclude that in vitro, calcineurin can dephosphorylate GSK-3beta at Ser-9 and form a stable complex with GSK-3beta, suggesting the possibility that calcineurin regulates the dephosphorylation and activation of GSK-3betain vivo.
Kim
Yeni
Y
Department of Biochemistry and Molecular Biology, Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea.
Lee
Yun-Il
YI
Seo
Miran
M
Kim
So-Young
SY
Lee
Ji-Eun
JE
Youn
Hong-Duk
HD
Kim
Yong-Sik
YS
Juhnn
Yong-Sung
YS
D000818:Animals; D019703:Calcineurin / Q000235:genetics* / Q000378:metabolism*; D065095:Calcineurin Inhibitors; D045744:Cell Line, Tumor; D016572:Cyclosporine / Q000494:pharmacology; D004789:Enzyme Activation / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005910:Glioma; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism*; D000071679:Glycogen Synthase Kinase 3 beta; D006801:Humans; D008297:Male; D051379:Mice; D009154:Mutation; D009447:Neuroblastoma; D009474:Neurons / Q000166:cytology / Q000201:enzymology*; D010766:Phosphorylation / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012694:Serine / Q000378:metabolism; D016559:Tacrolimus / Q000494:pharmacology; D014162:Transfection
D065095:Calcineurin Inhibitors; D004791:Enzyme Inhibitors; D011994:Recombinant Proteins; D012694:Serine; D016572:Cyclosporine; C000605506:GSK3B protein, human; D000071679:Glycogen Synthase Kinase 3 beta; C000605507:Gsk3b protein, mouse; C000605508:Gsk3b protein, rat; D038362:Glycogen Synthase Kinase 3; D019703:Calcineurin; C525674:PPP3CB protein, human; D016559:Tacrolimus