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UVA inactivates protein tyrosine phosphatases by calpain-mediated degradation

Pawan Gulati1, Boyka Markova, Martin Göttlicher

  • 1Forschungszentrum Karlsruhe, Institute of Toxicology and Genetics, Herrmann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.

EMBO Reports
|July 13, 2004
PubMed

Insights

Ultraviolet (UV) irradiation triggers irreversible degradation of protein tyrosine phosphatases (PTPs) via calpain activation. This novel mechanism contributes to UV-induced cellular responses, impacting skin health.

Area of Science:

  • Dermatology
  • Molecular Biology
  • Cellular Biology

Background:

  • UV irradiation induces inflammatory and proliferative cellular responses.
  • These responses are partly mediated by receptor tyrosine kinase activation.
  • Protein tyrosine phosphatases (PTPs) normally inhibit receptor tyrosine kinases.

Purpose of the Study:

  • To investigate the mechanism of PTP inactivation following UV irradiation.
  • To identify novel pathways involved in UV-induced cellular signaling.

Main Methods:

  • Examined PTP inactivation mechanisms after UV exposure.
  • Investigated the role of calpain activation and oxidative modification in PTP degradation.

Main Results:

  • UV irradiation causes reversible PTP oxidation.
  • UV also triggers irreversible PTP degradation mediated by calpain.
  • Calpain activation and PTP oxidative modification are required for this degradation.
  • This effect is prominent with UVA/UVB at physiological doses.

Conclusions:

  • UV-induced PTP degradation by calpain is a novel, irreversible mechanism.
  • This pathway contributes significantly to UV-induced cellular responses in the skin.

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