Increased expression of metalloprotease meprin β is associated with fibrotic syndromes and Alzheimer's disease (AD). Hence, regulation of meprin activity might be a suitable strategy for the treatment of these conditions. Meprin β is a type 1 transmembrane protein, but can be released from the cell surface by ectodomain shedding. The protease is expressed as an inactive zymogen and requires proteolytic maturation by tryptic serine proteases. In the present study, we demonstrate, for the first time, the differences in the activation of soluble and membrane bound meprin β and suggest transmembrane serine protease 6 [TMPRSS6 or matriptase-2 (MT2)] as a new potent activator, cleaving off the propeptide of meprin β between Arg61 and Asn62 as determined by MS. We show that MT2, but not TMPRSS4 or pancreatic trypsin, is capable of activating full-length meprin β at the cell surface, analysed by specific fluorogenic peptide cleavage assay, Western blotting and confocal laser scanning microscopy (CLSM). Maturation of full-length meprin β is required for its activity as a cell surface sheddase, releasing the ectodomains of transmembrane proteins, as previously shown for the amyloid precursor protein (APP).
Metalloprotease meprin β is activated by transmembrane serine protease matriptase-2 at the cell surface thereby enhancing APP shedding
- Views Icon Views
- Share Icon Share
Felix Jäckle, Frederike Schmidt, Rielana Wichert, Philipp Arnold, Johannes Prox, Martin Mangold, Anke Ohler, Claus U. Pietrzik, Tomas Koudelka, Andreas Tholey, Michael Gütschow, Marit Stirnberg, Christoph Becker-Pauly; Metalloprotease meprin β is activated by transmembrane serine protease matriptase-2 at the cell surface thereby enhancing APP shedding. Biochem J 15 August 2015; 470 (1): 91–103. doi: https://doi.org/10.1042/BJ20141417
Download citation file: