title: Glycogen synthase kinase-3 beta-mediated tau phosphorylation in cultured cell lines.
abstract: To study further the role of glycogen synthase kinase-3beta on tau phosphorylation, glycogen synthase kinase-3beta and tau expression vectors were co-transfected into CHO-K1, COS-7 and SH-SY5Y cell. Tau phosphorylation was assessed by phosphorylation-dependent antibodies AT-8, AT-180, AT-270 and PHF-1. The AT-270 and AT-8 epitopes were consistently phosphorylated by glycogen synthase kinase-3beta in the three cell lines. Phosphorylation on AT-180 epitope was significant in CHO-K1 and SH-SY5Y cells while PHF-1 epitope was hyper-phosphorylated only in SH-SY5Y cells. We also found that lithium induces phosphorylation of the serine 9 residue of glycogen synthase kinase-3beta together with inhibition of tau phosphorylation on PHF-1 epitope in all the three cell lines. This suggests a novel mechanism whereby lithium-mediated inhibition of GSK-3beta activity influences tau phosphorylation.
authors.affiliation: Department of Biochemistry, The Chinese University of Hong Kong, Shatin, China.
authors.forename: Chris Wing-Cheung
authors.initials: CW
authors.lastname: Lee
authors.forename: Kwok-Fai
authors.initials: KF
authors.lastname: Lau
authors.forename: Christopher C J
authors.initials: CC
authors.lastname: Miller
authors.forename: Pang-Chui
authors.initials: PC
authors.lastname: Shaw
mesh_terms: D000818:Animals; D016466:CHO Cells; D019556:COS Cells; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D006224:Cricetinae; D038362:Glycogen Synthase Kinase 3 / Q000502:physiology*; D000071679:Glycogen Synthase Kinase 3 beta; D006801:Humans; D010766:Phosphorylation; D014162:Transfection / Q000379:methods; D014407:Tumor Cells, Cultured; D016875:tau Proteins / Q000378:metabolism*
chemical_list: D016875:tau Proteins; C000605506:GSK3B protein, human; D000071679:Glycogen Synthase Kinase 3 beta; D038362:Glycogen Synthase Kinase 3