Redox regulation of a src family protein tyrosine kinase p56lck in T cells

Oncogene. 1993 Nov;8(11):3133-9.


Protein tyrosine phosphorylation was examined after T cells were exposed to oxidative stress in vitro to investigate the possible involvement of redox regulation in T-cell signaling. Oxidative reagents such as hydrogen peroxide (H2O2) and diamide, which oxidize the free sulfhydryl groups in the cells, markedly induced tyrosine phosphorylation of multiple cellular proteins, especially a 55-kDa protein, of cultured peripheral blood T lymphocytes (PBL blasts). The 55-kDa molecule phosphorylated by diamide turned out to be a src family protein tyrosine kinase, p56lck. The immune complex kinase assay showed that the kinase activity of p56lck of diamide-treated PBL blasts was enhanced. The tryptic peptide mapping of p56lck demonstrated that diamide induced the phosphorylation both at Tyr-394 (autophosphorylation site) and at Tyr-505 (negative regulatory site). Taken together, the tyrosine phosphorylation and presumably kinase activity of p56lck were swiftly enhanced by oxidative stress, indicating that T cells have a redox-sensitive signaling mechanism, which is partly mediated by the lymphocyte-specific protein tyrosine kinase p56lck.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cells, Cultured
  • Humans
  • Lymphocyte Specific Protein Tyrosine Kinase p56(lck)
  • Oxidation-Reduction
  • Phosphorylation
  • Protein-Tyrosine Kinases / metabolism*
  • Sulfhydryl Compounds / metabolism
  • T-Lymphocytes / enzymology*
  • Tyrosine / metabolism


  • Sulfhydryl Compounds
  • Tyrosine
  • Protein-Tyrosine Kinases
  • Lymphocyte Specific Protein Tyrosine Kinase p56(lck)