PMID- 10441131
OWN - NLM
STAT- MEDLINE
DCOM- 19990908
LR  - 20131121
IS  - 0006-2960 (Print)
IS  - 0006-2960 (Linking)
VI  - 38
IP  - 32
DP  - 1999 Aug 10
TI  - Mutation of Tyr307 and Leu309 in the protein phosphatase 2A catalytic subunit
      favors association with the alpha 4 subunit which promotes dephosphorylation of
      elongation factor-2.
PG  - 10371-6
AB  - The cellular location and substrate specificity of the catalytic subunit (C) of
      protein phosphatase 2A (PP2A) depend on its interaction with A and B subunits.
      The distribution of epitope-tagged wild-type or mutated C subunits was studied by
      transient expression in COS-7 cells. Wild-type tagged C expressed at low levels
      formed ABC trimer and AC dimer like the endogenous C. Single mutations of C at
      the site of phosphorylation (Y307F) or carboxymethylation (L309Q) resulted in
      recovery of only AC dimer. Double mutation of both residues resulted in
      association of C with alpha 4 protein (alpha 4), a novel subunit of PP2A, instead
      of with A and B subunits. Thus, the distribution of C between ABC trimer, AC
      dimer, and alpha 4C complexes can be affected by modifications of the C-terminal 
      residues. The alpha 4 protein is a homologue of the yeast Tap42 protein that
      functions downstream of the TOR protein to regulate protein synthesis. Transient 
      overexpression of FLAG-alpha 4 resulted in increased dephosphorylation of
      elongation factor 2, but had no effect on phosphorylation of either p70S6 kinase 
      or PHAS-I (eIF4E-BP). Signals that affect phosphorylation or methylation of the C
      subunit of PP2A may promote subunit exchange and direct phosphatase activity to
      specific intracellular substrates.
FAU - Chung, H
AU  - Chung H
AD  - Center for Cell Signaling, The University of Virginia, Charlottesville 22908,
      USA.
FAU - Nairn, A C
AU  - Nairn AC
FAU - Murata, K
AU  - Murata K
FAU - Brautigan, D L
AU  - Brautigan DL
LA  - eng
GR  - CA77584/CA/NCI NIH HHS/United States
GR  - GM50402/GM/NIGMS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - Biochemistry
JT  - Biochemistry
JID - 0370623
RN  - 0 (Anion Exchange Resins)
RN  - 0 (Bacterial Proteins)
RN  - 0 (Hemagglutinins)
RN  - 0 (Lectins)
RN  - 0 (Oligopeptides)
RN  - 0 (Peptide Elongation Factor 2)
RN  - 0 (Peptide Elongation Factors)
RN  - 0 (Peptides)
RN  - 0 (Phosphoproteins)
RN  - 0 (Resins, Synthetic)
RN  - 0 (hemagglutinin A, Porphyromonas gingivalis)
RN  - 42HK56048U (Tyrosine)
RN  - 83453-40-1 (Mono Q)
RN  - 98849-88-8 (FLAG peptide)
RN  - EC 3.1.3.16 (Phosphoprotein Phosphatases)
RN  - EC 3.1.3.16 (Protein Phosphatase 2)
RN  - GMW67QNF9C (Leucine)
SB  - IM
MH  - Animals
MH  - Anion Exchange Resins
MH  - *Bacterial Proteins
MH  - COS Cells
MH  - Catalytic Domain/*genetics
MH  - Chromatography, Ion Exchange
MH  - Hemagglutinins/genetics/isolation & purification/metabolism
MH  - Lectins
MH  - Leucine/*genetics/metabolism
MH  - Mutagenesis, Site-Directed
MH  - Oligopeptides/biosynthesis/genetics/metabolism
MH  - Peptide Elongation Factor 2
MH  - Peptide Elongation Factors/*metabolism
MH  - Peptides/genetics/metabolism
MH  - Phosphoprotein Phosphatases/*genetics/isolation & purification/metabolism
MH  - Phosphoproteins/*metabolism
MH  - Phosphorylation
MH  - Precipitin Tests
MH  - Protein Phosphatase 2
MH  - Resins, Synthetic
MH  - Transfection
MH  - Tyrosine/*genetics/metabolism
EDAT- 1999/08/11 00:00
MHDA- 1999/08/11 00:01
CRDT- 1999/08/11 00:00
PHST- 1999/08/11 00:00 [pubmed]
PHST- 1999/08/11 00:01 [medline]
PHST- 1999/08/11 00:00 [entrez]
AID - 10.1021/bi990902g [doi]
AID - bi990902g [pii]
PST - ppublish
SO  - Biochemistry. 1999 Aug 10;38(32):10371-6. doi: 10.1021/bi990902g.