title: Phosphorylation and activation of p70s6k by PDK1.
abstract: Activation of the protein p70s6k by mitogens leads to increased translation of a family of messenger RNAs that encode essential components of the protein synthetic apparatus. Activation of the kinase requires hierarchical phosphorylation at multiple sites, culminating in the phosphorylation of the threonine in position 229 (Thr229), in the catalytic domain. The homologous site in protein kinase B (PKB), Thr308, has been shown to be phosphorylated by the phosphoinositide-dependent protein kinase PDK1. A regulatory link between p70s6k and PKB was demonstrated, as PDK1 was found to selectively phosphorylate p70s6k at Thr229. More importantly, PDK1 activated p70s6k in vitro and in vivo, whereas the catalytically inactive PDK1 blocked insulin-induced activation of p70s6k.
authors.affiliation: Friedrich Miescher Institute, Maulbeerstrasse 66, CH-4058, Basel, Switzerland.
authors.forename: N
authors.initials: N
authors.lastname: Pullen
authors.forename: P B
authors.initials: PB
authors.lastname: Dennis
authors.forename: M
authors.initials: M
authors.lastname: Andjelkovic
authors.forename: A
authors.initials: A
authors.lastname: Dufner
authors.forename: S C
authors.initials: SC
authors.lastname: Kozma
authors.forename: B A
authors.initials: BA
authors.lastname: Hemmings
authors.forename: G
authors.initials: G
authors.lastname: Thomas
mesh_terms: D064413:3-Phosphoinositide-Dependent Protein Kinases; D000595:Amino Acid Sequence; D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D001665:Binding Sites; D054734:Calcium-Calmodulin-Dependent Protein Kinase Type 4; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D002384:Catalysis; D002460:Cell Line; D004789:Enzyme Activation; D007328:Insulin / Q000494:pharmacology; D007329:Insulin Antagonists / Q000494:pharmacology; D008969:Molecular Sequence Data; D010766:Phosphorylation; D010769:Phosphothreonine / Q000378:metabolism; D011090:Polyenes / Q000494:pharmacology; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D011994:Recombinant Proteins / Q000378:metabolism; D019893:Ribosomal Protein S6 Kinases / Q000378:metabolism*; D020123:Sirolimus; D000077191:Wortmannin
chemical_list: D000730:Androstadienes; D007328:Insulin; D007329:Insulin Antagonists; D011090:Polyenes; D011518:Proto-Oncogene Proteins; D011994:Recombinant Proteins; D010769:Phosphothreonine; D064413:3-Phosphoinositide-Dependent Protein Kinases; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D019893:Ribosomal Protein S6 Kinases; D054734:Calcium-Calmodulin-Dependent Protein Kinase Type 4; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D020123:Sirolimus; D000077191:Wortmannin