Cloning, genomic organization, chromosomal assignment and expression of a novel mosaic serine proteinase: epitheliasin

We report the isolation of a cDNA encoding a novel murine serine proteinase , epitheliasin. The cDNA spans 1753 hp and encodes a mosaic protein with a calculated molecular mass of 53529 Da, Its domains include a cytoplasmic ta il, a type II transmembrane domain, a low-density lipoprotein receptor clas s A domain, a cysteine rich scavenger receptor-like domain and a serine pro teinase domain. The proteinase portion domain shows 46-53% identity with mo use neurotrypsin, acrosin, hepsin and enteropeptidase, The gene, located in the telomeric region in the long arm of mouse chromosome 16, consists of 1 4 exons and 13 introns and spans approximately 18 kb, Epitheliasin is expre ssed primarily in the apical surfaces of renal tubular and airway epithelia l cells. (C) 2000 Federation of European Biochemical Societies.