ITAMs: immunoregulatory scaffolds that link immunoreceptors to their intracellular signaling pathways

Receptors Channels. 1998;5(5):243-53.


Antigen receptors on the surface of T and B lymphocytes and various immunoglobulin Fc receptors are complexed multi-subunit structures that possess unique cytoplasmic modules, termed immunoreceptor tyrosine-based activation motif (ITAM). These modules consist of two repeats of the conserved sequence Tyr-X-X-Leu/lle spaced by six-to-eight residues and they function as 'on and off' switches that link the receptors to their intracellular signaling machinery. Thus, engagement of ITAM-containing receptors results in a rapid and transient phosphorylation of the ITAMs' tyrosine residues that function as temporal scaffolds for Src homology 2 (SH2) domains of downstream effector molecules. Recruitment and binding of these molecules to phospho-ITAMs initiate a cascade of biochemical events that lead to cell proliferation, differentiation, and acquisition of unique effector functions.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • B-Lymphocytes / immunology*
  • Humans
  • Molecular Sequence Data
  • Receptors, Cytoplasmic and Nuclear / genetics
  • Receptors, Cytoplasmic and Nuclear / immunology*
  • Receptors, Immunologic / immunology*
  • Signal Transduction / immunology*
  • T-Lymphocytes / immunology*


  • Receptors, Cytoplasmic and Nuclear
  • Receptors, Immunologic