C/EBP proteins activate transcription from the human immunodeficiency virus type 1 long terminal repeat in macrophages/monocytes.
J Virol
; 69(9): 5337-44, 1995 Sep.
Article
en En
| MEDLINE
| ID: mdl-7636977
Three binding sites for C/EBP proteins are found in the human immunodeficiency virus type 1 (HIV-1) long terminal repeat (LTR) (V. M. Tesmer, A. Rajadhyaksha, J. Babin, and M. Bina, Proc. Natl. Acad. Sci. USA 90:7298-7302, 1993). We have determined the functional role of C/EBP proteins and C/EBP sites in regulating transcription from the HIV-1 LTR in monocytes/macrophages. Inhibition of endogenous C/EBP proteins, using either an excess of C/EBP binding sites or a trans-dominant negative inhibitor, demonstrated that C/EBP proteins are required for basal and activated levels of HIV-1 LTR transcription in the promonocytic cell line U937. Northern (RNA) blots and binding assays showed that NF-IL6 is the only known C/EBP family member which is increased when U937 cells are activated. Mutational analyses of the HIV-1 LTR showed that one C/EBP site is required for normal LTR transcription both before and after cellular activation and that the two 3' C/EBP sites are functionally equivalent. However, transcription from crippled HIV-1 LTRs lacking C/EBP sites can still be induced following activation of U937 cells. Several models are suggested for how elevated NF-IL6 may participate in an autostimulatory loop involving HIV infection, macrophage activation, cytokine expression, and HIV replication.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Proteínas Nucleares
/
Regulación Viral de la Expresión Génica
/
Duplicado del Terminal Largo de VIH
/
VIH-1
/
Proteínas de Unión al ADN
Tipo de estudio:
Prognostic_studies
Límite:
Humans
Idioma:
En
Revista:
J Virol
Año:
1995
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Estados Unidos