STRUCTURAL CHARACTERIZATION AND MAPPING OF THE NORMAL EPITHELIAL CELL-SPECIFIC-1 GENE

The normal epithelial cell-specific 1 (NES1) gene is a recently identi fied novel serine protease-like gene which is down-regulated during br east cancer progression. The gene product has 34-42% identity with the members of three distinct serine protease families: the trypsin-like family, activators of kringle domain-containing growth factors, and th e kallikrein family (X. L. Liu et al., (1996) Cancer Res 56, 3371-3379 ), Although the cDNA of this gene has been cloned, its genomic structu re and chromosomal position are not as yet known, Here, we report the genomic characterization and mapping of the NES1 gene. By subcloning a nd sequencing a PAC clone containing the complete NES1 gene, we were a ble to characterize the structure of this gene. The NES1 gene spans 5. 5 kb and is composed of five coding exons and one untranslated exon, T he positions of the introns were similar to trypsinogen, prostate spec ific antigen (PSA), and tissue plasminogen activator (TPA). NES1 gene was also localized with somatic cell mapping, radiation hybrid mapping , and fluorescence in situ hybridization techniques to chromosome 19q1 3.3-q13.4, the same region where the human kallikrein gene family resi des. Taken together, our results suggest that the NES1 gene originates from the same ancestor as trpsinogen, PSA, and TPA, but remains in cl ose proximity to PSA. (C) 1998 Academic Press.