Tyrosine phosphorylation-dependent activation of NF-kappa B. Requirement for p56 LCK and ZAP-70 protein tyrosine kinases

Eur J Biochem. 2001 Mar;268(5):1508-15. doi: 10.1046/j.1432-1327.2001.02028.x.


Phosphorylation of the N-terminal domain of I kappa B inhibitory subunits induces activation of the transcription factor NF-kappa B. Although serine phosphorylation has been shown to induce ubiquitination and subsequent proteasome-mediated degradation of I kappa B-alpha, little is known about the mechanisms that lead to release of active NF-kappa B in T cells as a consequence of tyrosine phosphorylation of I kappa B-alpha [Imbert, V., Rupec, R.A., Livolsi, A., Pahl, H.L., Traenckner, B.M., Mueller-Dieckmann, C., Farahifar, D., Rossi, B., Auberger, P., Baeuerle, P. & Peyron, J.F. (1996) Cell 86, 787--798]. The involvement of the tyrosine kinases p56(lck) and ZAP-70 in this reaction is demonstrated here using specific pharmacological inhibitors and Jurkat mutants unable to express these kinases. Although the inhibitors prevented both pervanadate-induced phosphorylation of I kappa B-alpha on Tyr42 and NF-kappa B activation, we observed that, in p56(lck)-deficient Jurkat mutants, NF-kappa B could still associate with I kappa B-alpha despite phosphorylation on Tyr42. Furthermore, the SH2 domain of p56(lck) appeared to be required for pervanadate-induced NF-kappa B activation but not for Tyr42 phosphorylation. These results show that p56(lck) and ZAP-70 are key components of the signaling pathway that leads to phosphotyrosine-dependent NF-kappa B activation in T cells and confirm that tyrosine kinases must control at least two different steps to induce activation of NF-kappa B. Finally, we show that H(2)O(2), which stimulates p56(lck) and ZAP-70 in T cells, is an activator of NF-kappa B through tyrosine phosphorylation of I kappa B-alpha.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • DNA / genetics
  • DNA / metabolism
  • DNA-Binding Proteins / chemistry
  • DNA-Binding Proteins / metabolism
  • Enzyme Activation / drug effects
  • Humans
  • Hydrogen Peroxide / pharmacology
  • I-kappa B Proteins*
  • Jurkat Cells
  • Lymphocyte Specific Protein Tyrosine Kinase p56(lck) / antagonists & inhibitors
  • Lymphocyte Specific Protein Tyrosine Kinase p56(lck) / chemistry
  • Lymphocyte Specific Protein Tyrosine Kinase p56(lck) / genetics
  • Lymphocyte Specific Protein Tyrosine Kinase p56(lck) / metabolism*
  • Mutation / genetics
  • NF-KappaB Inhibitor alpha
  • NF-kappa B / metabolism*
  • Phosphorylation / drug effects
  • Phosphotyrosine / metabolism*
  • Protein Binding / drug effects
  • Protein Tyrosine Phosphatases / antagonists & inhibitors
  • Protein-Tyrosine Kinases / antagonists & inhibitors
  • Protein-Tyrosine Kinases / genetics
  • Protein-Tyrosine Kinases / metabolism*
  • Pyrazoles / pharmacology
  • Pyrimidines / pharmacology
  • Signal Transduction / drug effects
  • Stilbenes / pharmacology
  • T-Lymphocytes / drug effects
  • T-Lymphocytes / enzymology
  • T-Lymphocytes / metabolism
  • Transcriptional Activation* / drug effects
  • Vanadates / pharmacology
  • ZAP-70 Protein-Tyrosine Kinase
  • src Homology Domains


  • 4-amino-5-(4-methylphenyl)-7-(tert-butyl)pyrazolo(3,4-d)pyrimidine
  • DNA-Binding Proteins
  • I-kappa B Proteins
  • NF-kappa B
  • NFKBIA protein, human
  • Pyrazoles
  • Pyrimidines
  • Stilbenes
  • pervanadate
  • NF-KappaB Inhibitor alpha
  • Phosphotyrosine
  • Vanadates
  • 3,3',4,5'-tetrahydroxystilbene
  • DNA
  • Hydrogen Peroxide
  • Protein-Tyrosine Kinases
  • Lymphocyte Specific Protein Tyrosine Kinase p56(lck)
  • ZAP-70 Protein-Tyrosine Kinase
  • ZAP70 protein, human
  • Protein Tyrosine Phosphatases