PMID- 10373555
OWN - NLM
STAT- MEDLINE
DCOM- 19990722
LR  - 20190508
IS  - 0270-7306 (Print)
IS  - 0270-7306 (Linking)
VI  - 19
IP  - 7
DP  - 1999 Jul
TI  - Domain swapping used to investigate the mechanism of protein kinase B regulation 
      by 3-phosphoinositide-dependent protein kinase 1 and Ser473 kinase.
PG  - 5061-72
AB  - Protein kinase B (PKB or Akt), a downstream effector of phosphoinositide 3-kinase
      (PI 3-kinase), has been implicated in insulin signaling and cell survival. PKB is
      regulated by phosphorylation on Thr308 by 3-phosphoinositide-dependent protein
      kinase 1 (PDK1) and on Ser473 by an unidentified kinase. We have used chimeric
      molecules of PKB to define different steps in the activation mechanism. A chimera
      which allows inducible membrane translocation by lipid second messengers that
      activate in vivo protein kinase C and not PKB was created. Following membrane
      attachment, the PKB fusion protein was rapidly activated and phosphorylated at
      the two key regulatory sites, Ser473 and Thr308, in the absence of further cell
      stimulation. This finding indicated that both PDK1 and the Ser473 kinase may be
      localized at the membrane of unstimulated cells, which was confirmed for PDK1 by 
      immunofluorescence studies. Significantly, PI 3-kinase inhibitors prevent the
      phosphorylation of both regulatory sites of the membrane-targeted PKB chimera.
      Furthermore, we show that PKB activated at the membrane was rapidly
      dephosphorylated following inhibition of PI 3-kinase, with Ser473 being a better 
      substrate for protein phosphatase. Overall, the results demonstrate that PKB is
      stringently regulated by signaling pathways that control both
      phosphorylation/activation and dephosphorylation/inactivation of this pivotal
      protein kinase.
FAU - Andjelkovic, M
AU  - Andjelkovic M
AD  - Friedrich Miescher-Institut, CH-4058 Basel, Switzerland.
FAU - Maira, S M
AU  - Maira SM
FAU - Cron, P
AU  - Cron P
FAU - Parker, P J
AU  - Parker PJ
FAU - Hemmings, B A
AU  - Hemmings BA
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Mol Cell Biol
JT  - Molecular and cellular biology
JID - 8109087
RN  - 0 (Mitogens)
RN  - 0 (Proto-Oncogene Proteins)
RN  - 0 (Recombinant Fusion Proteins)
RN  - 2ZD004190S (Threonine)
RN  - 452VLY9402 (Serine)
RN  - EC 2.7.- (Protein Kinases)
RN  - EC 2.7.1.- (Phosphatidylinositol 3-Kinases)
RN  - EC 2.7.11.1 (3-Phosphoinositide-Dependent Protein Kinases)
RN  - EC 2.7.11.1 (AKT1 protein, human)
RN  - EC 2.7.11.1 (PDPK1 protein, human)
RN  - EC 2.7.11.1 (Protein-Serine-Threonine Kinases)
RN  - EC 2.7.11.1 (Proto-Oncogene Proteins c-akt)
RN  - NI40JAQ945 (Tetradecanoylphorbol Acetate)
SB  - IM
MH  - 3-Phosphoinositide-Dependent Protein Kinases
MH  - Animals
MH  - Binding Sites
MH  - Biological Transport
MH  - Cattle
MH  - Cell Line
MH  - Cell Membrane/metabolism
MH  - Enzyme Activation
MH  - Humans
MH  - Mitogens/pharmacology
MH  - Phosphatidylinositol 3-Kinases/metabolism
MH  - Phosphorylation
MH  - Protein Kinases/*metabolism
MH  - Protein-Serine-Threonine Kinases/*metabolism
MH  - Proto-Oncogene Proteins/genetics/*metabolism
MH  - Proto-Oncogene Proteins c-akt
MH  - Recombinant Fusion Proteins/genetics/metabolism
MH  - Serine/*metabolism
MH  - Tetradecanoylphorbol Acetate/pharmacology
MH  - Threonine/metabolism
MH  - Time Factors
PMC - PMC84347
EDAT- 1999/06/22 00:00
MHDA- 1999/06/22 00:01
CRDT- 1999/06/22 00:00
PHST- 1999/06/22 00:00 [pubmed]
PHST- 1999/06/22 00:01 [medline]
PHST- 1999/06/22 00:00 [entrez]
AID - 10.1128/mcb.19.7.5061 [doi]
PST - ppublish
SO  - Mol Cell Biol. 1999 Jul;19(7):5061-72. doi: 10.1128/mcb.19.7.5061.