Hepatic glutamine synthetase controls N5-methylglutamine in homeostasis and cancer.
Nat Chem Biol
; 19(3): 292-300, 2023 03.
Article
em En
| MEDLINE
| ID: mdl-36280791
ABSTRACT
Glutamine synthetase (GS) activity is conserved from prokaryotes to humans, where the ATP-dependent production of glutamine from glutamate and ammonia is essential for neurotransmission and ammonia detoxification. Here, we show that mammalian GS uses glutamate and methylamine to produce a methylated glutamine analog, N5-methylglutamine. Untargeted metabolomics revealed that liver-specific GS deletion and its pharmacological inhibition in mice suppress hepatic and circulating levels of N5-methylglutamine. This alternative activity of GS was confirmed in human recombinant enzyme and cells, where a pathogenic mutation in the active site (R324C) promoted the synthesis of N5-methylglutamine over glutamine. N5-methylglutamine is detected in the circulation, and its levels are sustained by the microbiome, as demonstrated by using germ-free mice. Finally, we show that urine levels of N5-methylglutamine correlate with tumor burden and GS expression in a ß-catenin-driven model of liver cancer, highlighting the translational potential of this uncharacterized metabolite.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Glutamina
/
Neoplasias
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Nat Chem Biol
Assunto da revista:
BIOLOGIA
/
QUIMICA
Ano de publicação:
2023
Tipo de documento:
Article
País de afiliação:
Reino Unido