What question did this study set out to answer?

Investigate the molecular mechanisms by which the insulinomimetic agents hydrogen peroxide and vanadate stimulate protein tyrosine phosphorylation and regulate tyrosine phosphatase activity in intact cells.

February 1, 1990Journal of Biological ChemistryOpen Access

The insulinomimetic agents H2O2 and vanadate stimulate protein tyrosine phosphorylation in intact cells.

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Authors

DHD HeffetzWeizmann Institute of Science IBIlana BushkinWeizmann Institute of Science RDRon O. DrorLeiden University

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Implication

In vitro study demonstrates that hydrogen peroxide and vanadate synergistically stimulate protein tyrosine phosphorylation in Fao cells, indicating shared signaling pathways with insulin.

Key Points

Investigate the molecular mechanisms by which the insulinomimetic agents hydrogen peroxide and vanadate stimulate protein tyrosine phosphorylation and regulate tyrosine phosphatase activity in intact cells.
Treated cultured Fao hepatoma cells with 3 mM hydrogen peroxide, sodium orthovanadate (up to 1 mM), or insulin (10^-7 M), alone and in combination.
Profiled protein tyrosine phosphorylation by Western blotting using anti-phosphotyrosine antibodies.
Assayed cytosolic protein tyrosine phosphatase activity in cell lysates following exposure to the test agents.
Treatment with 3 mM H2O2 rapidly increased tyrosine phosphorylation across four key proteins (pp180, 150, 114, and 100), and adding 100 µM sodium orthovanadate potentiated phosphorylation 6- to 10-fold.
Cytosolic protein tyrosine phosphatase activity was inhibited by 50% with 3 mM H2O2 alone and further suppressed by vanadate (half-maximal inhibition at 15 µM; maximal at 1 mM), whereas vanadate alone produced negligible inhibition.
Pretreatment with H2O2 followed by a 45-second insulin challenge (10^-7 M) replicated the phosphorylation-potentiating effects of vanadate without altering protein tyrosine phosphatase activity.

Cite This Study

Heffetz et al. (1990) studied this question.

synapsesocial.com/papers/6a11cb9a37ecc83ca3fd3e47 https://doi.org/10.1016/s0021-9258(19)39885-0

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Implication

In vitro study demonstrates that hydrogen peroxide and vanadate synergistically stimulate protein tyrosine phosphorylation in Fao cells, indicating shared signaling pathways with insulin.

The insulinomimetic agents H2O2 and vanadate stimulate protein tyrosine phosphorylation in intact cells.

Discussion

Member takes

Implication

Key Points

Cite This Study

The insulinomimetic agents H2O2 and vanadate stimulate protein tyrosine phosphorylation in intact cells.

Discussion

Member takes

Implication

Key Points

Cite This Study

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