First Author | Mallen-St Clair J | Year | 2006 |
Journal | Biol Chem | Volume | 387 |
Issue | 8 | Pages | 1143-6 |
PubMed ID | 16895486 | Mgi Jnum | J:135860 |
Mgi Id | MGI:3794687 | Doi | 10.1515/BC.2006.141 |
Citation | Mallen-St Clair J, et al. (2006) Cathepsins L and S are not required for activation of dipeptidyl peptidase I (cathepsin C) in mice. Biol Chem 387(8):1143-6 |
abstractText | The cysteine protease dipeptidyl peptidase I (DPPI) activates granule-associated immune-cell serine proteases. The in vivo activator of DPPI itself is unknown; however, cathepsins L and S are candidates because they activate pro-DPPI in vitro. In this study, we tested whether cathepsins L and S activate pro-DPPI in vivo by characterizing DPPI activity and processing in cells lacking cathepsins L and S. DPPI activity, and the relative size and amounts of DPPI heavy and light chains, were identical in mast cells from wild-type and cathepsin L/S double-null mice. Furthermore, the activity of DPPI-dependent chymase was preserved in tissues of cathepsin L/S double-null mice. These results show that neither cathepsin L nor S is required for activation of DPPI and suggest that one or more additional proteases is responsible. |