Visualization of SHP-1-target interaction

Christoph Biskup, Annette Böhmer, Rico Pusch, Laimonas Kelbauskas, Alexander Gorshokov, Irina Majoul, Jörg Lindenau, Klaus Benndorf, Frank D. Böhmer*

*Korrespondierende/r Autor/-in für diese Arbeit
20 Zitate (Scopus)


Signaling of receptor tyrosine kinases (RTKs) is regulated by protein-tyrosine phosphatases (PTPs). We previously discovered the efficient downregulation of Ros RTK signaling by the SH2 domain PTP SHP-1, which involves a direct interaction of both molecules. Here, we studied the mechanism of this interaction in detail. Phosphopeptides representing the SHP-1 candidate binding sites in the Ros cytoplasmic domain, pY2267 and pY2327, display high affinity binding to the SHP-1 N-terminal SH2 domain (Kd=217 nM and 171 nM, respectively). Y2327 is, however, a poor substrate of Ros kinase and, therefore, contributes little to SHP-1 binding in vitro. To explore the mechanism of association in intact cells, functional fluorescent fusion proteins of Ros and SHP-1 were generated. Complexes of both molecules could be detected by Förster resonance energy transfer (FRET) in intact HEK293 and COS7 cells. As expected, the association required the functional SHP-1 N-terminal SH2 domain. Unexpectedly, pY2267 and pY2327 both contributed to the association. Mutation of Y2327 reduced constitutive association in COS7 cells. Ligand-dependent association was abrogated upon mutation of Y2267 but remained intact when Y2327 was mutated. A phosphopeptide representing the binding site pY2267 was a poor substrate for SHP-1, whereas Ros activation loop phosphotyrosines were effectively dephosphorylated. We propose a model for SHP-1-Ros interaction in which ligand-stimulated phosphorylation of Ros Y2267 by Ros, phosphorylation of Y2327 by a heterologous kinase, and inactivation of Ros by SHP-1-mediated dephosphorylation play a role in the regulation of complex stability.

ZeitschriftJournal of Cell Science
Seiten (von - bis)5165-5178
PublikationsstatusVeröffentlicht - 01.10.2004

Strategische Forschungsbereiche und Zentren

  • Forschungsschwerpunkt: Infektion und Entzündung - Zentrum für Infektions- und Entzündungsforschung Lübeck (ZIEL)


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