scholarly journals Thiolation of Low-Mr Phosphotyrosine Protein Phosphatase by Thiol-Disulfides

IUBMB Life ◽  
1999 ◽  
Vol 48 (5) ◽  
pp. 505-511 ◽  
Author(s):  
Donatella Degl'Innocenti ◽  
Anna Caselli ◽  
Fabiana Rosati ◽  
Riccardo Marzocchini ◽  
Giampaolo Manao ◽  
...  
Keyword(s):  
Protein Phosphatase ◽  
Phosphotyrosine Protein Phosphatase

Differential role of four cysteines on the activity of a low M r phosphotyrosine protein phosphatase

FEBS Letters ◽  
1992 ◽  
Vol 310 (1) ◽  
pp. 9-12 ◽  
Author(s):  
Paola Chiarugi ◽  
Riccardo Marzocchini ◽  
Giovanni Raugei ◽  
Claudia Pazzagli ◽  
Andrea Berti ◽  
...  
Keyword(s):  
Protein Phosphatase ◽  
Phosphotyrosine Protein Phosphatase

scholarly journals Inhibition of cellular response to platelet-derived growth factor by low M r phosphotyrosine protein phosphatase overexpression

FEBS Letters ◽  
1994 ◽  
Vol 349 (1) ◽  
pp. 7-12 ◽  
Author(s):  
Andrea Berti ◽  
Stefania Rigacci ◽  
Giovanni Raugei ◽  
Donatella Degl'Innocenti ◽  
Giampietro Ramponi
Keyword(s):  
Growth Factor ◽  
Protein Phosphatase ◽  
Cellular Response ◽  
Platelet Derived Growth Factor ◽  
Phosphotyrosine Protein Phosphatase

scholarly journals Abundance of Low Molecular Weight Phosphotyrosine Protein Phosphatase in the Nerve-Ending Fraction in the Brain.

1999 ◽  
Vol 22 (8) ◽  
pp. 794-798 ◽  
Author(s):  
Hiroko TANINO ◽  
Jun-ichi YOSHIDA ◽  
Ryoji YAMAMOTO ◽  
Yumi KOBAYASHI ◽  
Shun SHIMOHAMA ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Nerve Ending ◽  
Protein Phosphatase ◽  
Low Molecular Weight ◽  
Phosphotyrosine Protein Phosphatase ◽  
The Brain

scholarly journals Involvement of a phosphotyrosine protein phosphatase in the suppression of platelet-derived growth factor receptor autophosphorylation in ras-transformed cells

1993 ◽  
Vol 293 (1) ◽  
pp. 215-221 ◽  
Author(s):  
L Tomáska ◽  
R J Resnick
Keyword(s):  
Growth Factor ◽  
Phosphatase Activity ◽  
Receptor Tyrosine Kinase ◽  
Protein Phosphatase ◽  
Kinase Activity ◽  
Platelet Derived Growth Factor ◽  
Transformed Cells ◽  
Pdgf Receptor ◽  
Tyrosine Kinase Activity ◽  
Phosphotyrosine Protein Phosphatase

The nature of the suppression of platelet-derived growth factor (PDGF) receptor autophosphorylation in ras-transformed NIH 3T3 fibroblasts was investigated. The PDGF receptor from ras-transformed cells that had been purified by wheatgerm-lectin affinity chromatography displayed normal PDGF-induced autophosphorylation, indicating that the receptor is not irreversibly modified. Various phosphotyrosine-protein-phosphatase inhibitors did not reverse the inhibition of PDGF-receptor kinase in crude membrane preparations from ras-transformed cells. However, treatment of intact ras-transformed cells both with 2 mM sodium orthovanadate and with 20 microM phenylarsine oxide restored PDGF-receptor tyrosine-kinase activity to a level similar to that observed in normal cells. Direct measurement of the phosphatase activities in crude cellular fractions revealed a 2.5-fold higher membrane-associated phosphotyrosine-protein-phosphatase activity in ras-transformed cells, whereas phosphoserine-protein-phosphatase activity remained unchanged between the cell lines. These data suggest that the suppression of the PDGF-receptor tyrosine-kinase activity in ras-transformed cells is mediated via an inhibitory component, distinct from the receptor, that may be positively regulated by the dephosphorylation of tyrosine residue(s).

scholarly journals [Phosphotyrosine]protein phosphatase in rat brain. A major [phosphotyrosine]protein phosphatase is a 23 kDa protein distinct from acid phosphatase

1986 ◽  
Vol 239 (1) ◽  
pp. 155-162 ◽  
Author(s):  
M Okada ◽  
K Owada ◽  
H Nakagawa
Keyword(s):  
Acid Phosphatase ◽  
Molecular Mass ◽  
Rat Brain ◽  
Column Chromatography ◽  
Protein Phosphatase ◽  
Specific Activity ◽  
Deae Cellulose ◽  
Sodium Vanadate ◽  
Nitrophenyl Phosphate ◽  
Phosphotyrosine Protein Phosphatase

A [phosphotyrosine]protein phosphatase (PTPPase) was purified almost to homogeneity from rat brain, with [32P]p130gag-fps, an oncogene product of Fujinami sarcoma virus, as substrate. The characteristics of the purified preparation of PTPPase were as follows: the enzyme was a monomer with a molecular mass of 23 kDa; its optimum pH was 5.0-5.5; its activity was not dependent on bivalent cations; its activity was strongly inhibited by sodium vanadate, but was not inhibited by ZnCl2, L(+)-tartrate or NaF; it catalysed the dephosphorylation of [32P]p130gag-fps, [[32P]Tyr]casein, p-nitrophenyl phosphate and L-phosphotyrosine, but did not hydrolyse [[32P]Ser]tubulin, L-phosphoserine, DL-phosphothreonine, 5′-AMP, 2′-AMP or beta-glycerophosphate significantly. During the purification, most of the PTPPase activity was recovered in distinct fractions from those of conventional low-molecular-mass acid phosphatase (APase), which was reported to be a major PTPPase [Chernoff & Li (1985) Arch. Biochem. Biophys. 240, 135-145], from DE-52 DEAE-cellulose column chromatography, and those two enzymes could be completely separated by Sephadex G-75 column chromatography. APase also showed PTPPase activity with [32P]p130gag-fps, but the specific activity was lower than that of PTPPase with molecular mass of 23 kDa, and it was not sensitive to sodium vanadate. These findings suggested that PTPPase (23 kDa) was the major and specific PTPPase in the cell.

Cloning, expression and characterisation of a new human low M r phosphotyrosine protein phosphatase originating by alternative splicing

FEBS Letters ◽  
1998 ◽  
Vol 431 (1) ◽  
pp. 111-115 ◽  
Author(s):  
A Modesti ◽  
R Marzocchini ◽  
G Raugei ◽  
F Chiti ◽  
A Sereni ◽  
...  
Keyword(s):  
Alternative Splicing ◽  
Protein Phosphatase ◽  
Phosphotyrosine Protein Phosphatase
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