Quantitative analysis of purine nucleotides indicates that purinosomes increase de novo purine biosynthesis.
J Biol Chem
; 290(11): 6705-13, 2015 Mar 13.
Article
en En
| MEDLINE
| ID: mdl-25605736
ABSTRACT
Enzymes in the de novo purine biosynthesis pathway are recruited to form a dynamic metabolic complex referred to as the purinosome. Previous studies have demonstrated that purinosome assembly responds to purine levels in culture medium. Purine-depleted medium or 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole (DMAT) treatment stimulates the purinosome assembly in HeLa cells. Here, several metabolomic technologies were applied to quantify the static cellular levels of purine nucleotides and measure the de novo biosynthesis rate of IMP, AMP, and GMP. Direct comparison of purinosome-rich cells (cultured in purine-depleted medium) and normal cells showed a 3-fold increase in IMP concentration in purinosome-rich cells and similar levels of AMP, GMP, and ratios of AMP/GMP and ATP/ADP for both. In addition, a higher level of IMP was also observed in HeLa cells treated with DMAT. Furthermore, increases in the de novo IMP/AMP/GMP biosynthetic flux rate under purine-depleted condition were observed. The synthetic enzymes, adenylosuccinate synthase (ADSS) and inosine monophosphate dehydrogenase (IMPDH), downstream of IMP were also shown to be part of the purinosome. Collectively, these results provide further evidence that purinosome assembly is directly related to activated de novo purine biosynthesis, consistent with the functionality of the purinosome.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Nucleótidos de Purina
/
Purinas
/
Metabolómica
/
Complejos Multienzimáticos
Límite:
Humans
Idioma:
En
Revista:
J Biol Chem
Año:
2015
Tipo del documento:
Article