Which of the Following Correctly Accounts for the Regulation of Carbamoyl

Question

Which of the following correctly accounts for the regulation of carbamoyl phosphate synthetase I?
A)inhibited by N-acetylglutamate,activated by acetylation of a lysine residue
B)inhibited by N-acetylglutamate,activated by phosphorylation of a tyrosine residue
C)activated by N-acetylglutamate,inhibited by acetylation of a lysine residue
D)activated by N-acetylglutamate,activated by phosphorylation of a tyrosine residue
E)none of the above

Accepted Answer

Carbamoyl phosphate synthetase I (CPS1) is activated by N-acetylglutamate. This enzyme does not get activated by phosphorylation or acetylation; instead, its activity is modulated by the presence of N-acetylglutamate, which serves as an essential allosteric activator in the urea cycle.