Figure 3.

Distinct proteolytic processing of the secreted serine protease KLK14 by plasma membrane anchored serine proteases hepsin and TMPRSS2. A. Anti-HA Western blot analysis for KLK14-HA of conditioned media and lysates from cells co-transfected with wild type or active-site mutated KLK14-HA (KLK14; KLK14^m) and wild type or active-site mutated hepsin-Flag (hepsin; hepsin^m) or wild type or active-site mutated TMPRSS2-Myc (TMPRSS2; TMPRSS2^m). Arrowhead indicates hepsin generated KLK14 fragment of the predicted molecular mass of the KLK14 SPD. B. Anti-Flag and anti-Myc Western blot analysis for hepsin-Flag and TMPRSS2-Myc of lysates from cells co-expressing KLK14 or KLK14^m with hepsin or hepsin^m, or KLK14 or KLK14^m with TMPRSS2 or TMPRSS2^m.