Genomic organization and chromosomal localization of mouse proteinase 3 (Myeloblastin)

Proteinase 3 (PR3), is a matrix-degrading serine proteinase expressed in di fferent hematopoietic cell lineages. The PR3 protein appears to regulate th e myeloid differentiation and was found to be the autoantigen associated wi th Wegener granulomatosis. We have isolated and characterized the gene for mouse PR3 (mPR3) and determined its chromosomal location. The gene has been localized to Chromosome (Chr) 10. Comparison of mouse PR3 genomic structur e with that of its human counterpart indicates that: 1) the mPR3 gene spans 7 kb organized in 5 exons and 4 introns, 2) the codons of His-Asp-Ser of t he catalytic site are conserved and spread out over different exons, simila r to the human gene, and 3) the gene product encodes a pre-preform of the p rotein. Knowledge of the structure and chromosomal location of the mPR3 gen e may help better the understanding of the temporal and cell-specific expre ssion of mouse PR3.