Figure 2. The R970C mutation promotes generation of a p45 MET fragment.

(A) Vectors expressing WT, N930S, P991S, T992I, or R970C human MET and (B) vectors expressing WT MET or R970C MET were used to transiently transfect MDCK or MCF-7 cells, respectively. (C) Genomic DNA of MDA-MB231 and NCI-H1437 cells was extracted and sequences corresponding to the MET juxtamembrane region were amplified by PCR and sequenced. (D) NCI-H1437 cells were seeded at 8, 4, 2, and 1 × 10⁵ cells/well in a 12-well plate and cultured for three days. (A, B, D) Cell lysates were analyzed by western blotting with an antibody directed against the C-terminal region of human MET and ERK2. (E) Sparse and confluent NCI-H1437 cells were cultured 48h. Cell lysates were analyzed by western blotting successively with an antibody directed against the C-terminal region of human MET (MET C-term), the kinase domain of MET (MET kinase) and the extracellular region of human MET (MET N-term). (F) NCI-H1437 cells were transfected with a control siRNA (ctl) or a pool of three siRNAs targeting MET. Cell lysates were analyzed by western blotting with an antibody directed against the C-terminal region of human MET and ERK2. Arrowheads indicate full-length MET and p45 MET.