Antigen activation of murine T cells induces tyrosine phosphorylation of a polypeptide associated with the T cell antigen receptor

Cell. 1986 Sep 26;46(7):1083-90. doi: 10.1016/0092-8674(86)90708-7.


The antigen receptor complex on murine MHC class II-restricted T cells consists of disulfide-linked alpha and beta chains noncovalently associated with four additional polypeptides, two that are endoglycosaminidase F-sensitive, gp26 and gp21, and two that are endoglycosaminidase F-resistant, p25 and p16. We demonstrate here that treatment of murine T cell hybridomas with phorbol 12-myristate 13-acetate results in phosphorylation of p25 and gp21 on serine residues. However, activation of cells by antigen results in the phosphorylation of the gp21 chain and a heretofore unidentified 21 kd protein. This newly defined polypeptide, p21, is specifically immunoprecipitated with the antigen receptor complex, is endoglycosaminidase F-resistant, and is itself part of a disulfide-linked molecule. Unlike antigen-induced phosphorylation of gp21, which occurs on serine residues, phosphorylation of p21 occurs uniquely on tyrosine residues.

MeSH terms

  • Animals
  • Antigens
  • Isoelectric Point
  • Lymphocyte Activation
  • Macromolecular Substances
  • Membrane Proteins / metabolism
  • Mice
  • Molecular Weight
  • Phosphoproteins / metabolism*
  • Phosphorylation
  • Phosphoserine / metabolism
  • Phosphotyrosine
  • Receptors, Antigen, T-Cell / physiology*
  • T-Lymphocytes / physiology*
  • Tetradecanoylphorbol Acetate / pharmacology
  • Tyrosine / analogs & derivatives
  • Tyrosine / metabolism


  • Antigens
  • Macromolecular Substances
  • Membrane Proteins
  • Phosphoproteins
  • Receptors, Antigen, T-Cell
  • Phosphoserine
  • Phosphotyrosine
  • Tyrosine
  • Tetradecanoylphorbol Acetate