Son of Sevenless Binds to the SH3 Domain of Src-Type Tyrosine Kinase

Changwon Park, Youngbong Choi, Yungdae Yun

Research output: Contribution to journalArticlepeer-review


To identify molecules which bind to the SH3 domains of p56lck, we screened a mouse T-cell lymphoma cDNA library using the yeast two-hybrid system. As a result, we obtained several positive clones including the Son of Sevenless gene which encodes a mammalian homolog of Drosophila Ras GDP/GTP exchange factor. In a subsequent analysis with the yeast two-hybrid system, Sos associated only with the constitutively active form of p56lck (F505) but not with wild type P56lck (Y505), indicating the requirement for an active conformation of p56lck for binding to Sos. Subsequently, we have demonstrated in vitro that the SH3 domain of p56lck as well as the proline-rich sequences of Sos are responsible for this association. In addition, the proline-rich domain of Sos also bound to the SH3 domains of other src-type tyrosine kinases, src and fyn, but not to that of PLC-γ. More importantly, the p56lck SH3-Sos interaction was enhanced by serum stimulation, suggesting the possibility that the direct interaction between p56lck SH3 and Sos may contribute to the regulation of the Ras pathway.

Original languageEnglish (US)
Pages (from-to)518-523
Number of pages6
JournalMolecules and cells
Issue number5
StatePublished - Oct 31 1998
Externally publishedYes


  • SH3 Domain
  • Son of Sevenless
  • Yeast Two-Hybrid/Ras
  • p56

ASJC Scopus subject areas

  • Molecular Biology
  • Cell Biology


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