Dynamics of the dATP pool in cultured mammalian cells.
Exp Cell Res
; 199(1): 120-8, 1992 Mar.
Article
en En
| MEDLINE
| ID: mdl-1735453
ABSTRACT
Conditions for labeling the dATP pool of V79 and 3T3 cells from [3H]deoxyadenosine (salvage) or [3H]adenine (via ribonucleotide reduction) were established. With deoxyadenosine the specific radioactivity of dATP reached a constant value after 60 min. In resting 3T3 cells this value was 30 times higher than in S-phase cells. Turnover of dATP and absolute rates of DNA synthesis and excretion of breakdown products of dATP were determined from the accumulation of isotope in various compartments and the specific activity of dATP. In S-phase cells the dATP pool had a half-life of 4 min, identical to that of dTTP determined earlier. Deoxyadenosine was the major breakdown product of dATP in the presence of an inhibitor of adenosine deaminase. The rate of deoxyadenosine excretion of V79 cells amounted to 4% of the rate of dATP incorporation into DNA. Inhibition of DNA replication increased deoxyadenosine excretion 5- to 10-fold, demonstrating a continued de novo synthesis of dATP, albeit at a slightly reduced rate. Our results fit a model involving a substrate cycle between dAMP and deoxyadenosine regulating the dATP pool, similar to the model of substrate cycles involved in the regulation of pyrimidine deoxyribonucleotide pools developed earlier.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
ADN
/
Nucleótidos de Desoxiadenina
Límite:
Animals
Idioma:
En
Revista:
Exp Cell Res
Año:
1992
Tipo del documento:
Article
País de afiliación:
Suecia