The function of GLS (glutaminase, ENSG00000115419) is as follows. Catalyzes the first reaction in the primary pathway for the renal catabolism of glutamine. Plays a role in maintaining acid-base homeostasis. Regulates the levels of the neurotransmitter glutamate, the main excitatory neurotransmitter in the brain (PubMed:30239721, PubMed:30575854, PubMed:30970188). {ECO:0000269|PubMed:30239721, ECO:0000269|PubMed:30575854, ECO:0000269|PubMed:30970188}. [Isoform 2]: Lacks catalytic activity. .