Docking-based substrate recognition by the catalytic domain of a protein tyrosine kinase, C-terminal Src kinase (Csk)

J Biol Chem. 2006 Mar 24;281(12):8183-9. doi: 10.1074/jbc.M508120200. Epub 2006 Jan 26.


Protein tyrosine kinases are key enzymes of mammalian signal transduction. Substrate specificity is a fundamental property that determines the specificity and fidelity of signaling by protein tyrosine kinases. However, how protein tyrosine kinases recognize the protein substrates is not well understood. C-terminal Src kinase (Csk) specifically phosphorylates Src family kinases on a C-terminal Tyr residue, which down-regulates their activities. We have previously determined that Csk recognizes Src using a substrate-docking site away from the active site. In the current study, we identified the docking determinants in Src recognized by the Csk substrate-docking site and demonstrated an interaction between the docking determinants of Src and the Csk substrate-docking site for this recognition. A similar mechanism was confirmed for Csk recognition of another Src family kinase, Yes. Although both Csk and MAP kinases used docking sites for substrate recognition, their docking sites consisted of different substructures in the catalytic domain. These results helped establish a docking-based substrate recognition mechanism for Csk. This model may provide a framework for understanding substrate recognition and specificity of other protein tyrosine kinases.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Binding Sites
  • CSK Tyrosine-Protein Kinase
  • Catalysis
  • Catalytic Domain
  • Cell Line, Tumor
  • Dose-Response Relationship, Drug
  • Humans
  • Kinetics
  • MAP Kinase Signaling System
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed
  • Mutation
  • Phosphorylation
  • Protein Binding
  • Protein Structure, Tertiary
  • Protein-Tyrosine Kinases / chemistry*
  • Protein-Tyrosine Kinases / metabolism
  • Proto-Oncogene Proteins c-yes / metabolism
  • RNA, Small Interfering / metabolism
  • Recombinant Proteins / chemistry
  • Sequence Homology, Amino Acid
  • Substrate Specificity*
  • Time Factors
  • src Homology Domains
  • src-Family Kinases


  • RNA, Small Interfering
  • Recombinant Proteins
  • Protein-Tyrosine Kinases
  • CSK Tyrosine-Protein Kinase
  • Proto-Oncogene Proteins c-yes
  • YES1 protein, human
  • src-Family Kinases
  • CSK protein, human