title: EphB1 recruits c-Src and p52Shc to activate MAPK/ERK and promote chemotaxis.
abstract: Eph receptors and their ligands (ephrins) play an important role in axonal guidance, topographic mapping, and angiogenesis. The signaling pathways mediating these activities are starting to emerge and are highly cell- and receptor-type specific. Here we demonstrate that activated EphB1 recruits the adaptor proteins Grb2 and p52Shc and promotes p52Shc and c-Src tyrosine phosphorylation as well as MAPK/extracellular signal-regulated kinase (ERK) activation. EphB1-mediated increase of cell migration was abrogated by the MEK inhibitor PD98059 and Src inhibitor PP2. In contrast, cell adhesion, which we previously showed to be c-jun NH2-terminal kinase (JNK) dependent, was unaffected by ERK1/2 and Src inhibition. Expression of dominant-negative c-Src significantly reduced EphB1-dependent ERK1/2 activation and chemotaxis. Site-directed mutagenesis experiments demonstrate that tyrosines 600 and 778 of EphB1 are required for its interaction with c-Src and p52Shc. Furthermore, phosphorylation of p52Shc by c-Src is essential for its recruitment to EphB1 signaling complexes through its phosphotyrosine binding domain. Together these findings highlight a new aspect of EphB1 signaling, whereby the concerted action of c-Src and p52Shc activates MAPK/ERK and regulates events involved in cell motility.
authors.affiliation: Division of Nephrology and Department of Clinical Research, University of Bern, CH-3010 Bern, Switzerland.
authors.forename: Cecile
authors.initials: C
authors.lastname: Vindis
authors.forename: Douglas Pat
authors.initials: DP
authors.lastname: Cerretti
authors.forename: Thomas O
authors.initials: TO
authors.lastname: Daniel
authors.forename: Uyen
authors.initials: U
authors.lastname: Huynh-Do
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D000818:Animals; D000081247:CSK Tyrosine-Protein Kinase; D002465:Cell Movement; D002633:Chemotaxis / Q000502:physiology*; D051380:GRB2 Adaptor Protein; D006801:Humans; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D036225:Receptor, EphB1 / Q000378:metabolism*; D055765:Shc Signaling Adaptor Proteins; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D014443:Tyrosine / Q000378:metabolism; D019061:src-Family Kinases
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D051380:GRB2 Adaptor Protein; C495948:GRB2 protein, human; D011506:Proteins; C528024:SHC1 protein, human; D055765:Shc Signaling Adaptor Proteins; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D014443:Tyrosine; D011505:Protein-Tyrosine Kinases; D036225:Receptor, EphB1; D000081247:CSK Tyrosine-Protein Kinase; D019061:src-Family Kinases; C000631346:CSK protein, human; D020928:Mitogen-Activated Protein Kinases