Abundant non-canonical dUTP found in primary human macrophages drives its frequent incorporation by HIV-1 reverse transcriptase.
J Biol Chem
; 286(28): 25047-55, 2011 Jul 15.
Article
en En
| MEDLINE
| ID: mdl-21454906
ABSTRACT
Terminally differentiated/non-dividing macrophages contain extremely low cellular dNTP concentrations (20-40 nm), compared with activated CD4(+) T cells (2-5 µm). However, our LC-MS/MS study revealed that the non-canonical dUTP concentration (2.9 µm) is â¼60 times higher than TTP in macrophages, whereas the concentrations of dUTP and TTP in dividing human primary lymphocytes are very similar. Specifically, we evaluated the contribution of HIV-1 reverse transcriptase to proviral DNA uracilation under the physiological conditions found in HIV-1 target cells. Indeed, biochemical simulation of HIV-1 reverse transcription demonstrates that HIV-1 RT efficiently incorporates dUTP in the macrophage nucleotide pools but not in the T cell nucleotide pools. Measurement of both pre-steady state and steady state kinetic parameters of dUTP incorporation reveals minimal selectivity of HIV-1 RT for TTP over dUTP, implying that the cellular dUTP/TTP ratio determines the frequency of HIV-1 RT-mediated dUTP incorporation. The RT of another lentivirus, simian immunodeficiency virus, also displays efficient dUTP incorporation in the dNTP/dUTP pools found in macrophages but not in T cells. Finally, 2',3'-dideoxyuridine was inhibitory to HIV-1 proviral DNA synthesis in macrophages but not in T cells. The data presented demonstrates that the non-canonical dUTP was abundant relative to TTP, and efficiently incorporated during HIV-1 reverse transcription, particularly in non-dividing macrophages.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Uridina Trifosfato
/
ADN Viral
/
VIH-1
/
Provirus
/
Transcripción Reversa
/
Transcriptasa Inversa del VIH
/
Macrófagos
Límite:
Humans
Idioma:
En
Revista:
J Biol Chem
Año:
2011
Tipo del documento:
Article
País de afiliación:
Estados Unidos