NAG can be used in the production of ornithine and arginine, two important amino acids, or as an allosteric cofactor for carbamoyl phosphate synthase (CPS1).

In mammals, NAGS is expressed primarily in the liver and small intestine, and is localized to the mitochondrial matrix.

[7][8] The currently accepted role of NAG in vertebrates is as an essential allosteric cofactor for CPS1, and therefore it acts as the primary controller of flux through the urea cycle.

As it stands, the evolutionary journey of NAGS from essential synthetic enzyme to primary urea cycle controller is yet to be fully understood.

[15] In many vertebrates, N-acetylglutamate is an essential allosteric cofactor of CPS1, the enzyme that catalyzes the first step of the urea cycle.