title: PKA modulates GSK-3beta- and cdk5-catalyzed phosphorylation of tau in site- and kinase-specific manners.
abstract: Phosphorylation of tau protein is regulated by several kinases, especially glycogen synthase kinase 3beta (GSK-3beta), cyclin-dependent protein kinase 5 (cdk5) and cAMP-dependent protein kinase (PKA). Phosphorylation of tau by PKA primes it for phosphorylation by GSK-3beta, but the site-specific modulation of GSK-3beta-catalyzed tau phosphorylation by the prephosphorylation has not been well investigated. Here, we found that prephosphorylation by PKA promotes GSK-3beta-catalyzed tau phosphorylation at Thr181, Ser199, Ser202, Thr205, Thr217, Thr231, Ser396 and Ser422, but inhibits its phosphorylation at Thr212 and Ser404. In contrast, the prephosphorylation had no significant effect on its subsequent phosphorylation by cdk5 at Thr181, Ser199, Thr205, Thr231 and Ser422; inhibited it at Ser202, Thr212, Thr217 and Ser404; and slightly promoted it at Ser396. These studies reveal the nature of the inter-regulation of tau phosphorylation by the three major tau kinases.
authors.affiliation: Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, NY 10314, USA. feiliu63@hotmail.com
authors.forename: Fei
authors.initials: F
authors.lastname: Liu
authors.forename: Zhihou
authors.initials: Z
authors.lastname: Liang
authors.forename: Jianhua
authors.initials: J
authors.lastname: Shi
authors.forename: Dongmei
authors.initials: D
authors.lastname: Yin
authors.forename: Ezzat
authors.initials: E
authors.lastname: El-Akkad
authors.forename: Inge
authors.initials: I
authors.lastname: Grundke-Iqbal
authors.forename: Khalid
authors.initials: K
authors.lastname: Iqbal
authors.forename: Cheng-Xin
authors.initials: CX
authors.lastname: Gong
mesh_terms: D000596:Amino Acids; D002384:Catalysis; D017868:Cyclic AMP-Dependent Protein Kinases / Q000502:physiology*; D051360:Cyclin-Dependent Kinase 5 / Q000378:metabolism*; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism*; D000071679:Glycogen Synthase Kinase 3 beta; D006801:Humans; D010766:Phosphorylation; D016875:tau Proteins / Q000378:metabolism*
chemical_list: D000596:Amino Acids; D016875:tau Proteins; D051360:Cyclin-Dependent Kinase 5; C000605506:GSK3B protein, human; D000071679:Glycogen Synthase Kinase 3 beta; D017868:Cyclic AMP-Dependent Protein Kinases; D038362:Glycogen Synthase Kinase 3