Expansion of the mast cell chymase locus over the past 200 million years of mammalian evolution

摘要: The acidic granules of natural killer (NK) cells, T mast and neutrophils store large amounts serine proteases. Functionally, these proteases are involved, e.g., in the induction apoptosis, recruitment inflammatory remodeling extra-cellular matrix. Among granule phylogenetically related cell chymases, neutrophil cathepsin G, T-cell granzymes (Gzm B to H Gzm N), which share characteristic absence a Cys191–Cys220 bridge. genes clustered one locus, chymase all previously investigated mammals. In this paper, we present detailed analysis locus cattle (Bos taurus) opossum (Monodelphis domestica). gained information delineates evolution over more than 200 million years. Surprisingly, contains two α-chymase G where other studied loci have single genes. Moreover, holds at least four for duodenases, not found loci. Interestingly, duodenases seem digestive rather immune functions. opossum, on hand, only locus-related been identified. These arranged but appear separated by marsupial-specific chromosomal rearrangement. Phylogenetic analyses place firmly with α-chymases, indicates that had already evolved as separate, clearly identifiable gene before separation marsupials placental contrast, second is positioned between granzymes, duodenases. genes, therefore, probably separate subfamilies after mammals from marsupials. platypus, locus-like sequence could be This published “granzyme” does cluster any families, shares bridge findings indicate derived ancestor was years ago.