Quantitative phosphoproteomics reveals SLP-76 dependent regulation of PAG and Src family kinases in T cells

PLoS One. 2012;7(10):e46725. doi: 10.1371/journal.pone.0046725. Epub 2012 Oct 11.


The SH2-domain-containing leukocyte protein of 76 kDa (SLP-76) plays a critical scaffolding role in T cell receptor (TCR) signaling. As an adaptor protein that contains multiple protein-binding domains, SLP-76 interacts with many signaling molecules and links proximal receptor stimulation to downstream effectors. The function of SLP-76 in TCR signaling has been widely studied using the Jurkat human leukaemic T cell line through protein disruption or site-directed mutagenesis. However, a wide-scale characterization of SLP-76-dependant phosphorylation events is still lacking. Quantitative profiling of over a hundred tyrosine phosphorylation sites revealed new modes of regulation of phosphorylation of PAG, PI3K, and WASP while reconfirming previously established regulation of Itk, PLCγ, and Erk phosphorylation by SLP-76. The absence of SLP-76 also perturbed the phosphorylation of Src family kinases (SFKs) Lck and Fyn, and subsequently a large number of SFK-regulated signaling molecules. Altogether our data suggests unique modes of regulation of positive and negative feedback pathways in T cells by SLP-76, reconfirming its central role in the pathway.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adaptor Proteins, Signal Transducing / genetics
  • Adaptor Proteins, Signal Transducing / metabolism*
  • Amino Acid Motifs
  • Cell Line
  • Humans
  • Intracellular Signaling Peptides and Proteins / metabolism
  • Kinetics
  • Membrane Proteins / metabolism*
  • Phosphoproteins / genetics
  • Phosphoproteins / metabolism*
  • Phosphorylation
  • Protein Processing, Post-Translational
  • Proteomics
  • Receptors, Antigen, T-Cell / metabolism
  • Signal Transduction
  • T-Lymphocytes / metabolism*
  • src-Family Kinases / metabolism*


  • Adaptor Proteins, Signal Transducing
  • Intracellular Signaling Peptides and Proteins
  • Membrane Proteins
  • PAG1 protein, human
  • Phosphoproteins
  • Receptors, Antigen, T-Cell
  • SLP-76 signal Transducing adaptor proteins
  • src-Family Kinases