Arginase-1 is a protein which in humans is encoded by the ARG1 gene. This is the final enzyme in the urea cycle which converts nitrogen-waste like ammonia into less toxic urea for excretion in urine.
Arginase catalyzes the hydrolysis of arginine to ornithine and urea. In addition to arginase-1, there also exists a second type arginase-2, which differs in its tissue distribution, subcellular localization, immunologic crossreactivity and physiologic function. The type I isoform encoded by this gene, is a cytosolic enzyme and expressed predominantly in the liver as a component of the urea cycle. Inherited deficiency of this enzyme results in argininemia, an autosomal recessive disorder characterized by hyperammonemia. Two transcript variants encoding different isoforms have been found for this gene.
This article incorporates text from the United States National Library of Medicine, which is in the public domain.