TY - JOUR
T1 - 14-3-3γ is upregulated by in vitro ischemia and binds to protein kinase Raf in primary cultures of astrocytes
AU - Chen, Xiao Qian
AU - Chen, Jian Guo
AU - Zhang, Yun Z.
AU - Hsiao, Wendy Wen Luan
AU - Yu, Albert Cheung Hoi
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2003/6/1
Y1 - 2003/6/1
N2 - The 14-3-3 protein family comprises critical regulatory molecules involved in signaling during cell division, proliferation, and apoptosis. Despite extensive study, the functions of the 14-3-3 proteins in brain remain unclear. 14-3-3γ, a subtype of the 14-3-3 family of proteins, was thought to be brain- and neuron-specific. Using RNA arbitrarily primed PCR, we identified an upregulated cDNA fragment of the 14-3-3γ gene in primary cultures of astrocytes. Using Northern blot analysis, we confirmed this fragment was brain-specific. In cultures of astrocytes, 14-3-3γ genes and proteins were differentially expressed at different ages and the proteins were distributed only in the cytoplasm. These results indicated that 14-3-3γ was not neuron-specific but also expressed in astrocytes. The function of this protein in brain is unclear. Northern and Western blot analyses demonstrated that 14-3-3γ mRNA and protein were upregulated in cultured astrocytes in an anaerobic chamber-induced ischemia model. The induction of 14-3-3γ proteins was neither suppressed by an MAP kinase inhibitor (U0126) nor a PI-3 kinase inhibitor (LY294002). These data indicated that induction of 14-3-3γ might not involve PI-3 and MAP kinase-dependent pathways. Using coimmunoprecipitation, we demonstrated that endogenous 14-3-3γ bound to c-Raf-1 and p-Raf 259. As Raf is one of the critical serine/threonine kinases controlling cell growth, differentiation, and death, the binding of 14-3-3γ to Raf indicates the critical role of this protein in ischemia-induced apoptosis and the changes in signal transduction in astrocytes in culture.
AB - The 14-3-3 protein family comprises critical regulatory molecules involved in signaling during cell division, proliferation, and apoptosis. Despite extensive study, the functions of the 14-3-3 proteins in brain remain unclear. 14-3-3γ, a subtype of the 14-3-3 family of proteins, was thought to be brain- and neuron-specific. Using RNA arbitrarily primed PCR, we identified an upregulated cDNA fragment of the 14-3-3γ gene in primary cultures of astrocytes. Using Northern blot analysis, we confirmed this fragment was brain-specific. In cultures of astrocytes, 14-3-3γ genes and proteins were differentially expressed at different ages and the proteins were distributed only in the cytoplasm. These results indicated that 14-3-3γ was not neuron-specific but also expressed in astrocytes. The function of this protein in brain is unclear. Northern and Western blot analyses demonstrated that 14-3-3γ mRNA and protein were upregulated in cultured astrocytes in an anaerobic chamber-induced ischemia model. The induction of 14-3-3γ proteins was neither suppressed by an MAP kinase inhibitor (U0126) nor a PI-3 kinase inhibitor (LY294002). These data indicated that induction of 14-3-3γ might not involve PI-3 and MAP kinase-dependent pathways. Using coimmunoprecipitation, we demonstrated that endogenous 14-3-3γ bound to c-Raf-1 and p-Raf 259. As Raf is one of the critical serine/threonine kinases controlling cell growth, differentiation, and death, the binding of 14-3-3γ to Raf indicates the critical role of this protein in ischemia-induced apoptosis and the changes in signal transduction in astrocytes in culture.
KW - Differential gene expression
KW - Injury
KW - LY294002
KW - RNA arbitrarily primed PCR
KW - U0126
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U2 - 10.1002/glia.10185
DO - 10.1002/glia.10185
M3 - Article
C2 - 12730952
AN - SCOPUS:0038119829
SN - 0894-1491
VL - 42
SP - 315
EP - 324
JO - Glia
JF - Glia
IS - 4
ER -