HMGA1 recruits CTIP2-repressed P-TEFb to the HIV-1 and cellular target promoters.
Nucleic Acids Res
; 42(8): 4962-71, 2014 Apr.
Article
en En
| MEDLINE
| ID: mdl-24623795
ABSTRACT
Active positive transcription elongation factor b (P-TEFb) is essential for cellular and human immunodeficiency virus type 1 (HIV-1) transcription elongation. CTIP2 represses P-TEFb activity in a complex containing 7SK RNA and HEXIM1. Recently, the inactive 7SK/P-TEFb small nuclear RNP (snRNP) has been detected at the HIV-1 core promoter as well as at the promoters of cellular genes, but a recruiting mechanism still remains unknown to date. Here we show global synergy between CTIP2 and the 7SK-binding chromatin master-regulator HMGA1 in terms of P-TEFb-dependent endogenous and HIV-1 gene expression regulation. While CTIP2 and HMGA1 concordingly repress the expression of cellular 7SK-dependent P-TEFb targets, the simultaneous knock-down of CTIP2 and HMGA1 also results in a boost in Tat-dependent and independent HIV-1 promoter activity. Chromatin immunoprecipitation experiments reveal a significant loss of CTIP2/7SK/P-TEFb snRNP recruitment to cellular gene promoters and the HIV-1 promoter on HMGA1 knock-down. Our findings not only provide insights into a recruiting mechanism for the inactive 7SK/P-TEFb snRNP, but may also contribute to a better understanding of viral latency.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Proteínas Represoras
/
VIH-1
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Regiones Promotoras Genéticas
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Proteína HMGA1a
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Proteínas Supresoras de Tumor
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Factor B de Elongación Transcripcional Positiva
Límite:
Humans
Idioma:
En
Revista:
Nucleic Acids Res
Año:
2014
Tipo del documento:
Article
País de afiliación:
Francia