The KLK7 (PRSS6) gene, encoding for the stratum corneum chymotryptic enzyme is a new member of the human kallikrein gene family - genomic characterization, mapping, tissue expression and hormonal regulation

The human stratum corneum chymotryptic enzyme (HSCCE; PRSS6, KLK7 gene) has been purified from human stratum corneum and is known to participate in th e cell shedding process. The cDNA of the gene has previously been reported. Here, we describe the identification of 5' and 3' extensions of the publis hed mRNA, and the complete genomic organization of the gene. KLK7 is compos ed of five coding exons which have similar lengths to exons of other kallik rein-like genes. The intron phases are completely conserved between this ge ne and other members of the kallikrein-like gene family. Precise mapping of KLK7 has indicated that it is located at chromosomal locus 19q13.3-q13.4 b etween the already known genes zyme (KLK6) (centromere) and neuropsin (KLK8 ) (telomere). Until recently, it was thought that this gene is expressed on ly in the skin. We here provide evidence that KLK7 is also expressed at rel atively high levels in the central nervous system, kidney, mammary and sali vary glands. Its expression is up-regulated by estrogens and glucocorticoid s in the breast carcinoma cell line BT-474. The cDNA and protein of this ge ne an homologous to sequences of other kallikrein-like genes. The gene enco des for a secreted protein. Phylogenetic analysis, the close structural sim ilarities, and its co-localization in the same chromosomal region, suggest that the gene encoding for the stratum corneum chymotryptic enzyme is a new member of the expanded human kallikrein gene family. (C) 2000 Elsevier Sci ence B.V. All rights reserved.