| First Author | Schaeper U | Year | 2000 |
| Journal | J Cell Biol | Volume | 149 |
| Issue | 7 | Pages | 1419-32 |
| PubMed ID | 10871282 | Mgi Jnum | J:200336 |
| Mgi Id | MGI:5508295 | Doi | 10.1083/jcb.149.7.1419 |
| Citation | Schaeper U, et al. (2000) Coupling of Gab1 to c-Met, Grb2, and Shp2 mediates biological responses. J Cell Biol 149(7):1419-32 |
| abstractText | Gab1 is a substrate of the receptor tyrosine kinase c-Met and involved in c-Met-specific branching morphogenesis. It associates directly with c-Met via the c-Met-binding domain, which is not related to known phosphotyrosine-binding domains. In addition, Gab1 is engaged in a constitutive complex with the adaptor protein Grb2. We have now mapped the c-Met and Grb2 interaction sites using reverse yeast two-hybrid technology. The c-Met-binding site is localized to a 13-amino acid region unique to Gab1. Insertion of this site into the Gab1-related protein p97/Gab2 was sufficient to confer c-Met-binding activity. Association with Grb2 was mapped to two sites: a classical SH3-binding site (PXXP) and a novel Grb2 SH3 consensus-binding motif (PX(V/I)(D/N)RXXKP). To detect phosphorylation-dependent interactions of Gab1 with downstream substrates, we developed a modified yeast two-hybrid assay and identified PI(3)K, Shc, Shp2, and CRKL as interaction partners of Gab1. In a trk-met-Gab1-specific branching morphogenesis assay, association of Gab1 with Shp2, but not PI(3)K, CRKL, or Shc was essential to induce a biological response in MDCK cells. Overexpression of a Gab1 mutant deficient in Shp2 interaction could also block HGF/SF-induced activation of the MAPK pathway, suggesting that Shp2 is critical for c-Met/Gab1-specific signaling. |
