Scientific background: |
ARG1(arginase, live) is a cytosolic enzyme and expressed predominantly in the liver as a component
of the urea cycle. The isoform encoded by ARG1, referred to as the liver, or A-I, isoform, contributes
98% of the arginase activity in liver but is also present in red cells. Using a rat liver ARG1 cDNA clone
to probe a human liver cDNA library, Haraguchi et al. (1987) isolated and characterized a cDNA
corresponding to the ARG1 gene. The ARG1 gene is mapped on 6q23.2 and the arginase gene
contains 8 exons. By immunologic studies, 90% of the arginase in red blood cell and liver was
precipitated by the antibody, whereas only 50% of the arginase in kidney, brain, and the gastrointestinal
tract reacted with it. 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. |
References: |
1. Cardoso, M. L., Martins, E., Vasconcelos, R., Vilarinho, L., Rocha, J. Identification of a novel R21X
mutation in the liver-type arginase gene (ARG1) in four Portuguese patients with argininemia. Hum.
Mutat. 14: 355-356, 1999.
2. Grody, W. W., Dodson, A., Klein, D., Kern, R. M., Bassand, P., Cederbaum, S. D. Molecular genetic
study of human arginase deficiency. (Abstract) Am. J. Hum. Genet. 45 (suppl.): A191 only, 1989.
3. Haraguchi, Y., Takiguchi, M., Amaya, Y., Kawamoto, S., Matsuda, I., Mori, M. Molecular cloning and
nucleotide sequence of cDNA for human liver arginase. Proc. Nat. Acad. Sci. 84: 412-415, 1987. |