Protein tyrosine kinases Src and Csk: a tail's tale

Curr Opin Chem Biol. 2003 Oct;7(5):580-5. doi: 10.1016/j.cbpa.2003.08.009.


Csk and Src are two protein tyrosine kinases with similar amino acid sequences but very different structures and functions. Csk catalyzes a tail phosphorylation reaction on Src and thereby restrains Src's activity and oncogenic potential. Comparative analysis of the domain interactions in these enzymes provides a lesson in signalling diversity and mechanisms of enzyme regulation. The molecular basis of the specificity of Csk targeting the Src tail appears to involve both local and long-range interactions and illustrates the complexity of selective targeting in post-translational modification.

Publication types

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

MeSH terms

  • Animals
  • CSK Tyrosine-Protein Kinase
  • Humans
  • Protein Structure, Tertiary
  • Protein-Tyrosine Kinases / chemistry
  • Protein-Tyrosine Kinases / metabolism*
  • Proto-Oncogene Proteins pp60(c-src) / genetics
  • Proto-Oncogene Proteins pp60(c-src) / metabolism*
  • Substrate Specificity
  • src-Family Kinases


  • Protein-Tyrosine Kinases
  • CSK Tyrosine-Protein Kinase
  • Proto-Oncogene Proteins pp60(c-src)
  • src-Family Kinases
  • CSK protein, human