The Syk family of protein tyrosine kinases in T-cell activation and development

Immunol Rev. 1998 Oct;165:167-80. doi: 10.1111/j.1600-065x.1998.tb01238.x.


The processes of T-cell development and activation employ similar immature and mature receptors as well as similar signal transduction pathways to achieve different outcomes. Many signaling molecules are shared between the receptor signaling pathways, including two families of cytoplasmic protein tyrosine kinases, the Src family and the Syk family. The two Syk family members expressed in T cells, Syk and ZAP-70, are structurally similar but are expressed at different times during thymic development and during T-cell activation. These two kinases, although they share many physical features, differ in terms of biochemical activity and regulation. We discuss the overlapping and distinct characteristics of Syk and ZAP-70 in T-cell signaling and the potential biological importance of their differences.

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
  • Cell Differentiation
  • Evolution, Molecular
  • Humans
  • Lymphocyte Activation
  • Molecular Sequence Data
  • Protein-Tyrosine Kinases / chemistry
  • Protein-Tyrosine Kinases / physiology
  • Receptor Protein-Tyrosine Kinases / chemistry
  • Receptor Protein-Tyrosine Kinases / physiology*
  • Receptors, Antigen, T-Cell, gamma-delta
  • Signal Transduction
  • T-Lymphocytes / cytology*
  • T-Lymphocytes / immunology*
  • Thymus Gland / cytology
  • ZAP-70 Protein-Tyrosine Kinase


  • Receptors, Antigen, T-Cell, gamma-delta
  • Protein-Tyrosine Kinases
  • Receptor Protein-Tyrosine Kinases
  • TYRO3 protein, human
  • ZAP-70 Protein-Tyrosine Kinase
  • ZAP70 protein, human