Cloning and expression of novel mosaic serine proteases with and without atransmembrane domain from human lung

Two cDNAs encoding novel mosaic proteins with a serine protease domain and potential regulatory modules, consisting of a protein kinase substrate and a low-density lipoprotein receptor, were cloned from a human lung cDNA libr ary by PCR. One with a transmembrane domain (MSPL) and the other without on e (MSPS) comprise 581 and 537 amino acids, respectively. Except for the C-t erminal ends, the two isoforms had an identical serine protease domain exhi biting 42, 39 and 43% identity with those of plasma kallikrein, hepsin and transmembrane protease serine 2, respectively. Both genes were predominantl y expressed in human lung, placenta, pancreas and prostate. (C) 2001 Elsevi er Science B.V. All rights reserved.