THE GENES OF THE LYSOSOMAL CYSTEINE PROTEINASES CATHEPSIN-B, CATHEPSIN-H, CATHEPSIN-L, AND CATHEPSIN-S MAP TO DIFFERENT MOUSE CHROMOSOMES

The mouse genes for the lysosomal cysteine proteinases cathepsin B, H, L, and S were mapped to Chromosomes (Chrs) 14, 9, 13, and 3, respecti vely. Two of the DNA probes used in this study detected an additional, independently segregating locus. The cathepsin B-specific probe hybri dized to a locus on Chr 2, and the cathepsin H probe to a locus on the X Chr. These loci either correspond to pseudogenes or to cathepsin B- and cathepsin H-related genes. The four cysteine proteinases mapped i n this study lie within known regions of conserved synteny between mou se and human chromosomes, when compared with the corresponding positio ns of their human homologs. Assuming that the genes of the cysteine pr oteinase gene family arose from a common ancestral gene, our results s uggest that these four cysteine proteinases had been dispersed over di fferent chromosomes before separation of mouse and human in evolution.