Biphasic changes in the Ser-9 phosphorylation of glycogen synthase kinase-3beta after electroconvulsive shock in the rat brain.
BACKGROUND
Glycogen synthase kinase-3beta (GSK-3beta) plays important roles in intracellular signaling pathways. Phosphorylation at Ser-9 reduces the activity of GSK-3beta, while phosphorylation at Tyr-216 enhances its activity. Mood stabilizing agents increase the phosphorylation of GSK-3beta at Ser-9, and hence inhibit its activity. This property has been considered to be related to the therapeutic action of these drugs. The effect of electroconvulsive shock (ECS), an effective mood stabilizing treatment, on the phosphorylation of GSK-3beta is not known yet.


METHODS
In this study, the effect of ECS on the phosphorylation of GSK-3beta was examined in the rat frontal cortex, hippocampus, and cerebellum by Western blot analysis using antibodies specific for Ser-9 or Tyr-216 phosphorylated GSK-3beta.


RESULTS
In all regions, the phosphorylation of GSK-3beta at Ser-9 was decreased immediately after ECS, but then increased above basal level within 10 min and maintained at an increased level for more than 30 min. Meanwhile, the phosphorylation at Tyr-216 of GSK-3beta did not show any significant changes after ECS.


CONCLUSIONS
These results showed that ECS could induce biphasic changes in the Ser-9 phosphorylation of GSK-3beta in the rat brain, suggesting some similarities, as well as differences, in the actions of mood stabilizers and ECS in the signal transduction mechanisms of the brain.
Roh
Myoung-Sun
MS
Department of Neuropsychiatry, College of Medicine, Kangwon National University, Chunchon, South Korea.
Kang
Ung Gu
UG
Shin
Soon Young
SY
Lee
Young Han
YH
Jung
Hee Yeon
HY
Juhnn
Yong-Sung
YS
Kim
Yong Sik
YS
D000818:Animals; D015153:Blotting, Western; D001921:Brain / Q000201:enzymology*; D004565:Electroconvulsive Therapy; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism*; D000071679:Glycogen Synthase Kinase 3 beta; D008297:Male; D010766:Phosphorylation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012694:Serine / Q000737:chemistry; D015398:Signal Transduction
D012694:Serine; D000071679:Glycogen Synthase Kinase 3 beta; C000605508:Gsk3b protein, rat; D038362:Glycogen Synthase Kinase 3