The cDNA for the zyme/protease M/neurosin gene (HGMW-approved symbol PRSS9)
has recently been identified. Zyme appears to play a role in Alzheimer dis
ease as well as in breast cancer. In this paper, we describe the complete g
enomic organization of the zyme gene. Zyme spans 10.5 kb of genomic sequenc
e on chromosome 19q13.3-q13.4. The gene consists of seven exons, the first
two of which are untranslated. All splice junctions follow the GT/AG rule,
and the intron phases are identical to those of many other genes belonging
to the same family, i.e., the kallikreins, NES1, and neuropsin. Fine-mappin
g of the genomic locus indicates that zyme lies upstream of the NES1 gene a
nd downstream from the PSA and KLK2 genes. Tissue expression studies indica
te that zyme is expressed mainly in brain tissue, including spinal cord and
cerebellum, in mammary gland, and in kidney and uterus. Zyme is regulated
by steroid hormones in the breast carcinoma cell line BT-474. Estrogens and
progestins, and to a lesser extent androgens, up-regulate the zyme gene in
a dose-dependent manner. (C) 1999 Academic Press.