The expanded human kallikrein gene family: locus characterization and molecular cloning of a new member, KLK-L3 (KLK9).

In rodents, kallikreins are encoded by a large multigene family but in humans, only three kallikrein genes were thought to exist. Based on the homology between the human and the rodent kallikrein loci, we defined a 300-kb human kallikrein gene region on chromosome 19q13. 3-q13.4. By using linear sequence information, restriction analysis, PCR, and blotting techniques, we were able to construct the first detailed map of the human kallikrein gene locus. Comparative analysis of genes located in this area enabled us to expand the human kallikrein multigene family with some recently identified serine proteases and establish common structural features. We further identified a new kallikrein-like gene, named kallikrein-like gene 3 (KLK-L3; HGMW-approved symbol KLK9). We describe the structural characterization of the KLK-L3 gene, together with its precise chromosomal localization in relation to other kallikreins and its tissue expression pattern and hormonal regulation.