Glutamine synthetase that catalyzes the ATP-dependent conversion of glutamate and ammonia to glutamine (PubMed:30158707, PubMed:16267323). Its role depends on tissue localization: in the brain, it regulates the levels of toxic ammonia and converts neurotoxic glutamate to harmless glutamine, whereas in the liver, it is one of the enzymes responsible for the removal of ammonia (By similarity). Essential for proliferation of fetal skin fibroblasts (PubMed:18662667). Independently of its glutamine synthetase activity, required for endothelial cell migration during vascular development: acts by regulating membrane localization and activation of the GTPase RHOJ, possibly by promoting RHOJ palmitoylation (PubMed:30158707). May act as a palmitoyltransferase for RHOJ: able to autopalmitoylate and then transfer the palmitoyl group to RHOJ (PubMed:30158707). Plays a role in ribosomal 40S subunit biogenesis (PubMed:26711351). ATP + L-glutamate + NH4(+) = ADP + H(+) + L-glutamine + phosphate hexadecanoyl-CoA + L-cysteinyl-[protein] = CoA + S-hexadecanoyl-L-cysteinyl-[protein] Glutamine synthetase activity is inhibited by methionine sulfoximine (MSO). Decamer; composed of two pentamers (PubMed:18005987). Interacts with PALMD (By similarity). Interacts with RHOJ (PubMed:30158707). Mainly localizes in the cytosol, with a fraction associated with the cell membrane. Expressed in endothelial cells. Expressed during early fetal stages. By glucocorticoids. Vitamin D and the Wnt signaling pathway inhibit its expression and activity. Palmitoylated; undergoes autopalmitoylation. Ubiquitinated by ZNRF1. The disease is caused by variants affecting the gene represented in this entry. Belongs to the glutamine synthetase family. Glutamine synthetase entry