Activating mutations in MET in HPRCC. (a) In normal cells, hepatocyte growth
factor (HGF) binds to MET receptor to induce MET dimerization and release
autoinhibition. This permits, through several phosphorilation steps, the
activation of second-messenger molecules (such as GRB2, GAB1, or PI3K) leading
to morphogenic, motogenic, and mitogenic programmes. (b) Renal cells from patients with HPRCC
can harbour germline mutations in the tyrosine kinase domain of MET. These
mutations release the autoinhibition by the MET carboxyl terminus, allowing the transition of the receptor
to the active kinase form in absence of ligand stimulation.
