CLONING AND CHARACTERIZATION OF THE HUMAN TYPE-II ARGINASE GENE

There are two forms of arginase in humans, both catalyzing the hydroly sis of arginine to ornithine and urea, Recent studies in animal models and in Type I arginase-deficient patients suggest that Type II argina se is inducible and may play an important role in the regulation of ex tra-urea cycle arginine metabolism by modulating cellular arginine con centrations. We PCR amplified and cloned the human Type II arginase ge ne, the first nonliver arginase gene reported in mammals. While sequen ce homology to Type I arginase, arginase activity data, and immunoprec ipitation with an anti-AII antibody confirm the identity of this gene, Northern blot analysis demonstrates its differential expression in th e brain, prostate, and kidney. Type II arginase may be an important pa rt of the arginine regulatory system affecting nitric oxide synthase, arginine decarboxylase, kyotorphin synthase,and arginine-glycine trans aminase activities and polyamine and proline biosynthesis. (C) 1996 Ac ademic Press, Inc.