TY - JOUR
T1 - Membrane depolarization induces the undulating phosphorylation/ dephosphorylation of glycogen synthase kinase 3β, and this dephosphorylation involves protein phosphatases 2A and 2B in SH-SY5Y human neuroblastoma cells
AU - Lee, Yun Il
AU - Seo, Mi Ran
AU - Kim, Yeni
AU - Kim, So Young
AU - Kang, Ung Gu
AU - Kim, Yong Sik
AU - Juhnn, Yong Sung
PY - 2005/6/10
Y1 - 2005/6/10
N2 - Changes in plasma membrane electrical potential evoke signals that regulate the expressions of various genes in the nervous system. However, the role of glycogen synthase kinase 3β (GSK-3β) in this process has not been elucidated. Thus, this study was performed to examine whether membrane depolarization can regulate the phosphorylation of GSK-3β and to identify the molecular mechanisms involved in this regulation. The depolarization by treating with 100 mM KCl for 5 min resulted in the undulating phosphorylation of GSK-3β at Ser-9 in SH-SY5Y human neuroblastoma cells, in H19-7/ IGF-IR rat embryonic hippocampal cells, and in PC12 rat pheochromocytoma cells, but not in A172 human glioblastoma cells. Cellular β-catenin contents showed a temporal pattern similar to that of the Ser-9 phosphorylation of GSK-3β. Treatment with wortmannin or calphostin C or the expression of dominant negative Akt inhibited phosphorylation of GSK-3β at Ser-9 following the KCl-induced depolarization of SH-SY5Y cells. Moreover, pretreatment with okadaic acid or cyclosporin A blocked the dephosphorylation of GSK-3β at Ser-9 at 0, 15, and 30 min after KCl-induced depolarization, and the activity of protein phosphatases (PP) 2A and 2B increased at these times. Treatment with nifedipine or calcium-free medium inhibited GSK-3β dephosphorylation following membrane depolarization, and the amounts of co-immunoprecipitated GSK-3β and PP2A changed in parallel with GSK-3β dephosphorylation. Our study demonstrated that KCl-induced depolarization caused undulating GSK-3β phosphorylation/dephosphorylation, which was regulated for the most part by phosphatidylinositol 3-kinase and Akt (phosphorylation) and PP2A and PP2B (dephosphorylation), respectively.
AB - Changes in plasma membrane electrical potential evoke signals that regulate the expressions of various genes in the nervous system. However, the role of glycogen synthase kinase 3β (GSK-3β) in this process has not been elucidated. Thus, this study was performed to examine whether membrane depolarization can regulate the phosphorylation of GSK-3β and to identify the molecular mechanisms involved in this regulation. The depolarization by treating with 100 mM KCl for 5 min resulted in the undulating phosphorylation of GSK-3β at Ser-9 in SH-SY5Y human neuroblastoma cells, in H19-7/ IGF-IR rat embryonic hippocampal cells, and in PC12 rat pheochromocytoma cells, but not in A172 human glioblastoma cells. Cellular β-catenin contents showed a temporal pattern similar to that of the Ser-9 phosphorylation of GSK-3β. Treatment with wortmannin or calphostin C or the expression of dominant negative Akt inhibited phosphorylation of GSK-3β at Ser-9 following the KCl-induced depolarization of SH-SY5Y cells. Moreover, pretreatment with okadaic acid or cyclosporin A blocked the dephosphorylation of GSK-3β at Ser-9 at 0, 15, and 30 min after KCl-induced depolarization, and the activity of protein phosphatases (PP) 2A and 2B increased at these times. Treatment with nifedipine or calcium-free medium inhibited GSK-3β dephosphorylation following membrane depolarization, and the amounts of co-immunoprecipitated GSK-3β and PP2A changed in parallel with GSK-3β dephosphorylation. Our study demonstrated that KCl-induced depolarization caused undulating GSK-3β phosphorylation/dephosphorylation, which was regulated for the most part by phosphatidylinositol 3-kinase and Akt (phosphorylation) and PP2A and PP2B (dephosphorylation), respectively.
UR - http://www.scopus.com/inward/record.url?scp=20444464441&partnerID=8YFLogxK
U2 - 10.1074/jbc.M413987200
DO - 10.1074/jbc.M413987200
M3 - Article
C2 - 15799972
AN - SCOPUS:20444464441
SN - 0021-9258
VL - 280
SP - 22044
EP - 22052
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 23
ER -