Anti-CPS1 Antibody Picoband® Fluoro488 Conjugated

Carbamoyl phosphate synthetase I is a ligase enzyme located in the mitochondria involved in the production of urea. The mitochondrial enzyme encoded by this gene catalyzes synthesis of carbamoyl phosphate from ammonia and bicarbonate. This reaction is the first committed step of the urea cycle, which is important in the removal of excess urea from cells. The encoded protein may also represent a core mitochondrial nucleoid protein. Three transcript variants encoding different isoforms have been found for this gene. The shortest isoform may not be localized to the mitochondrion. Mutations in this gene have been associated with carbamoyl phosphate synthetase deficiency, susceptibility to persistent pulmonary hypertension, and susceptibility to venoocclusive disease after bone marrow transplantation.

Predominantly expressed in T-cells. Also detected in proliferating intestinal epithelial cells and in the basal epithelial cells of mammary gland epithelium.

Acts as a negative regulator of entry into mitosis (G2 to M transition) by protecting the nucleus from cytoplasmically activated cyclin B1-complexed CDK1 before the onset of mitosis by mediating phosphorylation of CDK1 on 'Tyr-15'. Specifically phosphorylates and inactivates cyclin B1-complexed CDK1 reaching a maximum during G2 phase and a minimum as cells enter M phase. Phosphorylation of cyclin B1-CDK1 occurs exclusively on 'Tyr-15' and phosphorylation of monomeric CDK1 does not occur. Its activity increases during S and G2 phases and decreases at M phase when it is hyperphosphorylated. A correlated decrease in protein level occurs at M/G1 phase, probably due to its degradation.

1. Adcock, M. W., Ledbetter, D. H., O'Brien, W. E. Analysis of mammalian carbamyl phosphate synthetase I utilizing cDNA clones from human and rat liver. (Abstract) Fed. Proc. 43: 1726, 1984. 2. Adcock, M. W., O'Brien, W. E. Molecular cloning of cDNA for rat and human carbamyl phosphate synthetase I. J. Biol. Chem. 259: 13471-13476, 1984. 3. Aoshima, T., Kajita, M., Sekido, Y., Kikuchi, S., Yasuda, I., Saheki, T., Watanabe, K., Shimokata, K., Niwa, T. Novel mutations (H337R and 238-362del) in the CPS1 gene cause carbamoyl phosphate synthetase I deficiency. Hum. Hered. 52: 99-101, 2001.