Immunoreceptor tyrosine-based activation motif (ITAM), a unique module linking antigen and Fc receptors to their signaling cascades

J Leukoc Biol. 1997 Jan;61(1):6-16. doi: 10.1002/jlb.61.1.6.


Signal transduction by the T cell and B cell antigen receptors and by receptors for a variety of immunoglobulins' Fc region is strictly dependent on a receptor subunit cytoplasmic module termed immunoreceptor tyrosine-based activation motif (ITAM). This module exists in one or more copies in each of the receptor-associated signal-transducing molecules and it possesses two repeats of the consensus sequence Tyr-X-X-Leu/Ile spaced by six to eight amino acids. Receptor engagement is followed by a rapid and transient phosphorylation of tyrosine residues within their ITAMs, thereby creating temporary binding sites for Src homology 2 (SH2)-containing signaling molecules operating downstream of the activated receptor. The purpose of this review is to discuss recent findings on the functional role of ITAMs in antigen and Fc receptor-mediated signal transduction, with a particular emphasis on kinases operating upstream and downstream of the ITAMs.

Publication types

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

MeSH terms

  • Phosphorylation
  • Receptors, Amino Acid / immunology
  • Receptors, Amino Acid / metabolism*
  • Receptors, Antigen, B-Cell / chemistry
  • Receptors, Antigen, B-Cell / immunology
  • Receptors, Antigen, B-Cell / physiology*
  • Receptors, Antigen, T-Cell / chemistry
  • Receptors, Antigen, T-Cell / immunology
  • Receptors, Antigen, T-Cell / physiology*
  • Receptors, Fc / chemistry
  • Receptors, Fc / immunology
  • Receptors, Fc / physiology*
  • Signal Transduction / immunology
  • Signal Transduction / physiology*
  • src-Family Kinases / immunology
  • src-Family Kinases / physiology*


  • Receptors, Amino Acid
  • Receptors, Antigen, B-Cell
  • Receptors, Antigen, T-Cell
  • Receptors, Fc
  • tyrosine receptor
  • src-Family Kinases