Expression of c-met proto-oncogene in COS cells induces the signal transducing high-affinity receptor for hepatocyte growth factor

By transfection of the expression plasmid containing a human c-met cDNA into COS-7 cells, high-affinity binding sites specific for HGF with a K_d value of 30 pM were newly detected. Furthermore, only in the c-met transfected COS-7 cells, but not in the control COS-7 cells, DNA synthesis was markedly induced in response to HGF. Thus, transient expression of exogenous c-met cDNA resulted in the appearance of high-affinity receptor for HGF and conversion of the normally non-responsive COS-7 cells into the HGF-responsive cells. These results provide evidence for identifying the c-met product as a signal transducing high-affinity receptor for HGF.