Figure 3. Matriptase-2 cleaves membrane HJV.

(A) HeLa cells were transfected with HJV in the presence of the empty vector (mock), matriptase-2^wt (MT2^wt), MT2^R774C and MT2^MASK. Whole cell extracts, concentrated media and PI-PLC supernatants were loaded onto a 10% SDS-PAGE and processed for western blot analysis. Anti-FLAG and anti-HJV were used to detect MT2 and HJV respectively. β-ME: beta-mercaptoethanol. (B) Binding assay was used to measure m-HJV in the presence of increasing concentrations of wild type and mutants MT2 expressing vectors and was performed essentially as described in Fig. 1B. Experiments were made in triplicate and performed three times. Error bars indicate SD. Exact P-values refer to MT2^wt versus MT2^R774C. (C) HeLa cells were transfected with MT2^wt and MT2^MASK, in the presence of HJV^wt, HJV^W191C and HJV^R335Q. Whole cell extracts, concentrated media and PI-PLC supernatants were loaded onto a 10% SDS-PAGE and processed for western blot analyses.

s-HJV: soluble HJV; m-HJV: membrane associated HJV. CL: cellular lysates; CM: conditioned medium; PI-PLC: supernatant after PI-PLC cleavage. The equal loading was verified by α-tubulin.