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Protein phosphatases and DNA tumor viruses: transformation through the back door?

M C Mumby1, G Walter

  • 1Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas 75235-9041.

Cell Regulation
|August 1, 1991
PubMed

Insights

Small DNA tumor viruses hijack cellular pathways by altering protein phosphatase activity. This viral oncogene mechanism leads to uncontrolled cell growth and transformation through modified phosphorylation levels.

Area of Science:

  • Oncology
  • Virology
  • Molecular Biology

Background:

  • Cellular transformation by oncogenic viruses often involves dysregulated signal transduction pathways controlling cell growth.
  • Protein phosphorylation, regulated by kinases and phosphatases, is a key mechanism in these pathways.
  • While viral protein kinases are known oncogenes, altered phosphatase activity's role in transformation was previously unestablished.

Purpose of the Study:

  • To review the novel mechanism by which small DNA tumor viruses induce cellular transformation.
  • To highlight the role of viral oncogenes in regulating cellular protein phosphatases.
  • To emphasize the significance of altered phosphatase activity in viral oncogenesis.

Main Methods:

  • Review of existing literature on viral oncogenes and cellular signaling pathways.
  • Analysis of studies investigating the interaction between viral oncogenes and protein phosphatases.
  • Examination of evidence linking altered phosphorylation levels to viral transformation.

Main Results:

  • Small DNA tumor viruses utilize viral oncogenes to bind and regulate cellular protein serine/threonine phosphatases.
  • This interaction leads to altered phosphatase activity and subsequent changes in protein phosphorylation.
  • Evidence supports altered phosphatase activity as a critical step in viral-mediated cellular transformation.

Conclusions:

  • Viral oncogenes can directly manipulate cellular phosphatase activity to promote transformation.
  • Altered protein phosphorylation due to viral interference with phosphatases is a key oncogenic mechanism.
  • This mechanism represents a significant pathway for cellular transformation induced by small DNA tumor viruses.

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