One of the enzymes of the urea cycle, the metabolic pathway transforming neurotoxic amonia produced by protein catabolism into inocuous urea in the liver of ureotelic animals (Probable). Catalyzes the formation of arginosuccinate from aspartate, citrulline and ATP and together with ASL it is responsible for the biosynthesis of arginine in most body tissues (Probable). Indirectly, may be involved in the control of blood pressure (PubMed:19491403). ATP + L-aspartate + L-citrulline = 2-(N(omega)-L-arginino)succinate + AMP + diphosphate + H(+) Amino-acid biosynthesis; L-arginine biosynthesis; L-arginine from L-ornithine and carbamoyl phosphate: step 2/3. Nitrogen metabolism; urea cycle; (N(omega)-L-arginino)succinate from L-aspartate and L-citrulline: step 1/1. Homotetramer. Interacts with NMRAL1. Interacts with CLOCK; in a circadian manner (By similarity). Forms tissue-specific complexes with ASL, SLC7A1, HSP90AA1 and nitric oxide synthase NOS1, NOS2 or NOS3; the complex regulates cell-autonomous L-arginine synthesis and citrulline recycling while channeling extracellular L-arginine to nitric oxide synthesis pathway (By similarity). Acetylated by CLOCK in a circadian manner which negatively regulates its enzyme activity. Deacetylated by histone deacetylases. Binds and is activated by Bj-BPP-10c, a bioactive anti-hypertensive proline-rich decapeptide, part of the C-type natriuretic peptide precursor. Belongs to the argininosuccinate synthase family. Type 1 subfamily.