title: Phosphorylation of tau at Ser214 mediates its interaction with 14-3-3 protein: implications for the mechanism of tau aggregation.
abstract: The microtubule associated protein tau is a major component of neurofibrillary tangles in Alzheimer disease brain, however the neuropathological processes behind the formation of neurofibrillary tangles are still unclear. Previously, 14-3-3 proteins were reported to bind with tau. 14-3-3 Proteins usually bind their targets through specific serine/threonine -phosphorylated motifs. Therefore, the interaction of tau with 14-3-3 mediated by phosphorylation was investigated. In this study, we show that the phosphorylation of tau by either protein kinase A (PKA) or protein kinase B (PKB) enhances the binding of tau with 14-3-3 in vitro. The affinity between tau and 14-3-3 is increased 12- to 14-fold by phosphorylation as determined by real time surface plasmon resonance studies. Mutational analyses revealed that Ser214 is critical for the phosphorylation-mediated interaction of tau with 14-3-3. Finally, in vitro aggregation assays demonstrated that phosphorylation by PKA/PKB inhibits the formation of aggregates/filaments of tau induced by 14-3-3. As the phosphorylation at Ser214 is up-regulated in fetal brain, tau's interaction with 14-3-3 may have a significant role in the organization of the microtubule cytoskeleton in development. Also as the phosphorylation at Ser214 is up-regulated in Alzheimer's disease brain, tau's interaction with 14-3-3 might be involved in the pathology of this disease.
authors.affiliation: Department of Psychiatry, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Golam
authors.initials: G
authors.lastname: Sadik
authors.forename: Toshihisa
authors.initials: T
authors.lastname: Tanaka
authors.forename: Kiyoko
authors.initials: K
authors.lastname: Kato
authors.forename: Hidenaga
authors.initials: H
authors.lastname: Yamamori
authors.forename: Begum Nurun
authors.initials: BN
authors.lastname: Nessa
authors.forename: Takashi
authors.initials: T
authors.lastname: Morihara
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Takeda
mesh_terms: D048948:14-3-3 Proteins / Q000276:immunology / Q000378:metabolism*; D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism; D000071679:Glycogen Synthase Kinase 3 beta; D047468:Immunoprecipitation / Q000379:methods; D010766:Phosphorylation / Q000187:drug effects; D011485:Protein Binding / Q000187:drug effects / Q000502:physiology; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D051381:Rats; D012694:Serine / Q000378:metabolism*; D020349:Surface Plasmon Resonance / Q000379:methods; D013997:Time Factors; D016875:tau Proteins / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D048948:14-3-3 Proteins; D000906:Antibodies; D016875:tau Proteins; D012694:Serine; D000071679:Glycogen Synthase Kinase 3 beta; D051057:Proto-Oncogene Proteins c-akt; D017868:Cyclic AMP-Dependent Protein Kinases; D038362:Glycogen Synthase Kinase 3