PMID- 10421574
OWN - NLM
STAT- MEDLINE
DCOM- 19991117
LR  - 20131121
IS  - 0960-9822 (Print)
IS  - 0960-9822 (Linking)
VI  - 9
IP  - 14
DP  - 1999 Jul 15
TI  - The hydrophobic phosphorylation motif of conventional protein kinase C is
      regulated by autophosphorylation.
PG  - 728-37
AB  - BACKGROUND: A growing number of kinases are now known to be controlled by two
      phosphorylation switches, one on a loop near the entrance to the active site and 
      a second on the carboxyl terminus. For the protein kinase C (PKC) family of
      enzymes, phosphorylation at the activation loop is mediated by another kinase but
      the mechanism for carboxy-terminal phosphorylation is still unclear. The latter
      switch contains two phosphorylation sites - one on a 'turn' motif and the second 
      on a conserved hydrophobic phosphorylation motif - that are found separately or
      together in a number of other kinases. RESULTS: Here, we investigated whether the
      carboxy-terminal phosphorylation sites of a conventional PKC are controlled by
      autophosphorylation or by another kinase. First, kinetic analyses revealed that a
      purified construct of the kinase domain of PKC betaII autophosphorylated on the
      Ser660 residue of the hydrophobic phosphorylation motif in an apparently
      concentration-independent manner. Second, kinase-inactive mutants of PKC did not 
      incorporate phosphate at either of the carboxy-terminal sites, Thr641 or Ser660, 
      when expressed in COS-7 cells. The inability to incorporate phosphate on the
      hydrophobic site was unrelated to the phosphorylation state of the other key
      phosphorylation sites: kinase-inactive mutants with negative charge at Thr641
      and/or the activation-loop position were also not phosphorylated in vivo.
      CONCLUSIONS: PKC betaII autophosphorylates at its conserved carboxy-terminal
      hydrophobic phosphorylation site by an apparently intramolecular mechanism.
      Expression studies with kinase-inactive mutants revealed that this mechanism is
      the only one responsible for phosphorylating this motif in vivo. Thus,
      conventional PKC autoregulates the carboxy-terminal phosphorylation switch
      following phosphorylation by another kinase at the activation loop switch.
FAU - Behn-Krappa, A
AU  - Behn-Krappa A
AD  - Department of Pharmacology, University of California at San Diego, La Jolla,
      California 92093-0640, USA.
FAU - Newton, A C
AU  - Newton AC
LA  - eng
GR  - GM 43154/GM/NIGMS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - England
TA  - Curr Biol
JT  - Current biology : CB
JID - 9107782
RN  - 2ZD004190S (Threonine)
RN  - 452VLY9402 (Serine)
RN  - EC 2.7.11.13 (Protein Kinase C)
SB  - IM
MH  - Amino Acid Sequence
MH  - Animals
MH  - COS Cells
MH  - Kinetics
MH  - Models, Biological
MH  - Molecular Sequence Data
MH  - Phosphorylation
MH  - Protein Kinase C/chemistry/*metabolism
MH  - Serine/chemistry
MH  - Threonine/chemistry
MH  - Time Factors
EDAT- 1999/07/27 00:00
MHDA- 1999/07/27 00:01
CRDT- 1999/07/27 00:00
PHST- 1999/07/27 00:00 [pubmed]
PHST- 1999/07/27 00:01 [medline]
PHST- 1999/07/27 00:00 [entrez]
AID - S0960-9822(99)80332-7 [pii]
PST - ppublish
SO  - Curr Biol. 1999 Jul 15;9(14):728-37.