The Syk/ZAP-70 protein tyrosine kinase connection to antigen receptor signalling processes

Semin Immunol. 1995 Aug;7(4):227-36. doi: 10.1006/smim.1995.0027.


The T- and B-cell receptor (TCR and BCR) signal transduction processes involve a coordinated interplay between two classes of non-receptor protein tyrosine kinases (PTKs), the Src-family and the Syk/ZAP-70 family of PTKs. Following antigen-receptor stimulation, the Src-family of PTKs mediate the phosphorylation of tyrosine residues contained in a signalling motif localized in the TCR and BCR subunits. The phosphorylation of this signalling motif recruits the Syk/ZAP-70 family of PTKs into the antigen receptor complex. This mechanism requires the tandem SH2 domains in ZAP-70 complexing to two critically spaced phosphotyrosine residues within the signalling motif. The clustering of Syk/ZAP-70 and cross-talk between this family and the Src-PTKs regulates subsequent signalling events that lead to a variety of cellular responses, such as antibody secretion, lymphokine production, cytolytic activity, proliferation, differentiation and cell survival.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.
  • Review

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Enzyme Precursors / physiology*
  • Humans
  • Intracellular Signaling Peptides and Proteins
  • Molecular Sequence Data
  • Protein-Tyrosine Kinases / physiology*
  • Receptors, Antigen, B-Cell / physiology*
  • Receptors, Antigen, T-Cell / physiology*
  • Signal Transduction / immunology*
  • Syk Kinase
  • ZAP-70 Protein-Tyrosine Kinase


  • Enzyme Precursors
  • Intracellular Signaling Peptides and Proteins
  • Receptors, Antigen, B-Cell
  • Receptors, Antigen, T-Cell
  • Protein-Tyrosine Kinases
  • SYK protein, human
  • Syk Kinase
  • ZAP-70 Protein-Tyrosine Kinase
  • ZAP70 protein, human