title: Influence of immobilization stress on the expression and phosphatase activity of protein phosphatase 2A in the rat brain.
abstract: BACKGROUND
  Protein phosphatase 2A (PP2A) is a major kinase phosphatase that plays an important role in regulating the activities of protein kinase cascades. It has been revealed that stress changes neuronal gene expression by activating these cascades. We examined the expression of the catalytic subunit C and serine and threonine phosphatase activity of PP2A in the rat frontal cortex and hippocampus following various immobilization stress paradigms.
  
  
  METHODS
  Immunoblot and immunohistochemical analyses were performed to examine the expression of PP2A. The level of phosphatase activity of PP2A was determined as the amount of free phosphate generated from a synthetic phosphopeptide.
  
  
  RESULTS
  Immunoblot analysis revealed no significant change in the level of PP2A immunoreactivity in response to either a single or repeated stress. Immunohistochemical analysis revealed that neither a single nor repeated stress changed PP2A immunoreactivity in the hippocampus; however, the levels of serine and threonine phosphatase activity in the frontal cortex and hippocampus were significantly upregulated in response to a single or repeated stress.
  
  
  CONCLUSIONS
  These results demonstrated that both a single and repeated immobilization stress upregulated the activity of PP2A in the rat brain, suggesting that PP2A may be involved, at least in part, in the downregulation of protein kinase activation induced by stress.
authors: Department of Psychiatry and Neurosciences, Hiroshima University School of Medicine, Hiroshima, Japan.
authors: Shigeru
authors: S
authors: Morinobu
authors: Koichiro
authors: K
authors: Fujimaki
authors: Ki-ichiro
authors: K
authors: Kawano
authors: Kazuhide
authors: K
authors: Tanaka
authors: Jun
authors: J
authors: Takahashi
authors: Masako
authors: M
authors: Ohkawa
authors: Shigeto
authors: S
authors: Yamawaki
authors: Nobumasa
authors: N
authors: Kato
mesh_terms: D000818:Animals; D020134:Catalytic Domain / Q000502:physiology; D005625:Frontal Lobe / Q000201:enzymology*; D006624:Hippocampus / Q000201:enzymology*; D007103:Immobilization; D015151:Immunoblotting / Q000379:methods; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D010768:Phosphoserine / Q000378:metabolism; D010769:Phosphothreonine / Q000378:metabolism; D054648:Protein Phosphatase 2; D051381:Rats; D017207:Rats, Sprague-Dawley; D013312:Stress, Physiological / Q000201:enzymology* / Q000378:metabolism; D013997:Time Factors
chemical_list: D010769:Phosphothreonine; D010768:Phosphoserine; D010749:Phosphoprotein Phosphatases; D054648:Protein Phosphatase 2