The receptor of Hepatocyte Growth Factor-Scatter Factor (HGF) is a tyr
osine kinase which regulates cell motility and growth. After ligand-in
duced tyrosine phosphorylation, the HGF receptor associates with the S
hc adaptor, via the SH2 domain. Site-directed mutagenesis of the HGF r
eceptor indicates that phosphotyrosines y(1349)VHV and (YVNV)-V-1356 c
an work as docking sites for Shc. The K-d of this interaction, measure
d in real time using synthetic phosphopeptides and recombinant She on
a BIAcore biosensor, is 150 nm for both sites. After stimulation of th
e HGF receptor, Shc is phosphorylated on (YVNV)-V-317, generating an h
igh affinity binding site for Gr62 (K-d = 15 nM). This duplicates the
high affinity binding site for Grb2 present on the HGF receptor ((YVNV
)-V-1356). Thus HGF stimulation can trigger the Ras pathway by recruit
ing Gr62 both directly through the receptor, and indirectly, through S
ite. Overexpression of wild-type She, but not of the Y-317 --> F mutan
t, enhances cell migration and growth in response to HGF. These data s
how that Shc is a relevant substrate of the HGF receptor, and works as
an 'amplifier' of the motogenic as well as of the mitogenic response.