title: Biphasic changes in the Ser-9 phosphorylation of glycogen synthase kinase-3beta after electroconvulsive shock in the rat brain.
abstract: 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.
authors.affiliation: Department of Neuropsychiatry, College of Medicine, Kangwon National University, Chunchon, South Korea.
authors.forename: Myoung-Sun
authors.initials: MS
authors.lastname: Roh
authors.forename: Ung Gu
authors.initials: UG
authors.lastname: Kang
authors.forename: Soon Young
authors.initials: SY
authors.lastname: Shin
authors.forename: Young Han
authors.initials: YH
authors.lastname: Lee
authors.forename: Hee Yeon
authors.initials: HY
authors.lastname: Jung
authors.forename: Yong-Sung
authors.initials: YS
authors.lastname: Juhnn
authors.forename: Yong Sik
authors.initials: YS
authors.lastname: Kim
mesh_terms: 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
chemical_list: D012694:Serine; D000071679:Glycogen Synthase Kinase 3 beta; C000605508:Gsk3b protein, rat; D038362:Glycogen Synthase Kinase 3