Constitutive association of EGF receptor with the CrkII-23 mutant that inhibits transformation of NRK cells by EGF and TGF-β

Satoshi Ota, Shinae Kizaka-Kondoh, Yuko Hashimoto, Hiroshi Nishihara, Kazuo Nagashima, Takeshi Kurata, Hiroto Okayama, Michiyuki Matsuda

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

Crk belongs to the adapter proteins that participate in many signalling pathways from cell surface receptors. We have characterised the CrkII-23 mutant that inhibits the transformation of NRK cells induced by epidermal growth factor (EGF) and transforming growth factor (TGF)-β. To study the biochemical difference, cDNAs of the wild-type CrkII and the CrkII-23 mutant were introduced stably into NIH 3T3 cells expressing EGF receptor (EGFR). Both CrkII and CrkII-23 were phosphorylated on tyrosine upon EGF simulation with similar time course and dose dependency. Whereas the wild-type CrkII bound to EGRF only after EGF stimulation, CrkII-23 bound to EGFR from before stimulation. Mutation in the Src homology (SH) 2 or amino-terminal SH3 domain did not abolish the binding of CrkII-23 to EGFR in the quiescent cells, suggesting that the binding is mediated by a novel mechanism. These CrkII-23-derived mutants, however, did not suppress transformation of NRK cells by EGF and TGF-β Hence, both the SH2 and amino-terminal SH3 domains are required to inhibit transformation of NRK cells. These results suggest that persistent signalling from CrkII-23 bound to EGFR suppresses transformation by EGF and TGF-β in NRK23 cells.

Original languageEnglish
Pages (from-to)283-290
Number of pages8
JournalCellular Signalling
Volume10
Issue number4
DOIs
Publication statusPublished - 1998 Apr
Externally publishedYes

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Keywords

  • Crk
  • EGF
  • EGF receptor
  • NRK cell

ASJC Scopus subject areas

  • Cell Biology

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