ZFX transactivation of the HIV-1 LTR is cell specific and depends on core enhancer and TATA box sequences.
The ZFX gene is ubiquitously transcribed and highly conserved among vertebrates. The integrity of Zfx, its murine homologue, has been shown to be important for growth during embryogenesis and sustained gamete production. Alternative splicing was shown to result in production of mRNAs coding for either ZFX804or a shorter isoform initiated downstream, ZFX575. ZFX575was previously shown to be a potent transactivator of the HLA-A11 promoter. Here, the HIV-1 LTR is also shown to be potently transactivated by ZFX575in several cell types, while ZFX804activity is found to be similar to that of ZFX575, null or intermediary according to the cell type. In all cell types, the HIV-1 TATA box sequence is a key element of transactivation, while the Sp1 or NFkappaB sites are variably required, according to the cell type. Overall, the results suggest that ZFX575and ZFX804could play a role in HIV-1 LTR induction as co-activators enhancing productive interactions between upstream transactivators and the basal transcription complexes recruited by the TATA box.
Gazin
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INSERM U462, Laboratoire associé du Comité de Paris de la Ligue Nationale Contre le Cancer, Centre Hayem, Institut Universitaire d'Hématologie, Hôpital Saint-Louis, 1 avenue Claude Vellefaux, 75475 Paris cedex 10, France. c.gazin@jupiter.chu-stlouis.fZ
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D015342:DNA Probes / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics*; D004742:Enhancer Elements, Genetic; D015696:Gene Products, tat / Q000235:genetics; D017930:Genes, Reporter; D005822:Genetic Vectors; D016325:HIV Long Terminal Repeat; D015497:HIV-1 / Q000235:genetics*; D006801:Humans; D051741:Kruppel-Like Transcription Factors; D051379:Mice; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D016328:NF-kappa B / Q000235:genetics; D016329:Sp1 Transcription Factor / Q000235:genetics; D016385:TATA Box; D014157:Transcription Factors; D015533:Transcriptional Activation; D016335:Zinc Fingers / Q000235:genetics; D054322:tat Gene Products, Human Immunodeficiency Virus
D015342:DNA Probes; D004268:DNA-Binding Proteins; D015696:Gene Products, tat; D051741:Kruppel-Like Transcription Factors; D016328:NF-kappa B; D016329:Sp1 Transcription Factor; D014157:Transcription Factors; D054322:tat Gene Products, Human Immunodeficiency Virus; C062076:zinc finger protein, X-linked