Protein tyrosine kinases and phosphatases control apoptosis induced by extracellular adenosine 5′-triphosphate

Vincenzo Bronte, Beatrice Macino, Annalisa Zambon, Antonio Rosato, Susanna Mandruzzato, Paola Zanovello, Dino Collavo

Research output: Contribution to journalArticle

Abstract

Institute of Oncology, Chair of Immunology, Inter-University Center for Cancer Research, Via Gattamelata 64, Padova 35128, Italy Extracellular ATP (ATPo) induces apoptosis and osmotic lysis in several cell lines. We investigated the role of protein tyrosine kinases (PTKs) and phosphatases (PTPases) in ATPo-induced apoptosis. The PTK inhibitor genistein prevented DNA fragmentation due to ATPo without affecting cell lysis. Comparison of western blot analysis and in vitro kinase assays of anti-phosphotyrosine immunoprecipitates indicated that ATPo activated PTKs whose activity was tightly regulated by PTPases. In fact, an early increase in tyrosine kinase activity was observed after ATPo-treatment and was prevented by specific PTPase inhibitors. In addition, a rapid dephosphorylation of phosphotyrosyl residues on several proteins was detected in ATPo-treated cells. Accordingly, inhibitors of PTPases, but not of serine/threonine phosphatases, were as effective as PTK-inhibitors in blocking ATPo-mediated DNA fragmentation. We describe the early events occurring in ATPo-induced apoptosis and suggest a role for PTPases in cell death.

Original languageEnglish
Pages (from-to)344-351
Number of pages8
JournalBiochemical and Biophysical Research Communications
Volume218
Issue number1
DOIs
Publication statusPublished - Jan 5 1996

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ASJC Scopus subject areas

  • Biochemistry
  • Biophysics
  • Molecular Biology

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