Sp1 and Sp3 regulate basal transcription of the human APOBEC3G gene

Autor: Heide Muckenfuss, Erika Krebil, Christina Schwer, Julia K. Kaiser, Carsten Münk, Egbert Flory, Marion Battenberg, Klaus Cichutek
Jazyk: angličtina
Rok vydání: 2007
Předmět:
Zdroj: Nucleic Acids Research
ISSN: 1362-4962
0305-1048
Popis: APOBEC3G (A3G), a member of the recently discovered family of human cytidine deaminases, is expressed in peripheral blood lymphocytes and has been shown to be active against HIV-1 and other retroviruses. To gain new insights into the transcriptional regulation of this restriction factor, we cloned and characterized the promoter region of A3G. Transcriptional start sites were identified by 5 0 -rapid amplification of cDNA ends analysis. Luciferase reporter assays demonstrated that a 1025bp A3G promoter sequence (from � 959 to þ66 relative to the major transcriptional start site) displayed constitutive promoter activity. In T cells, the A3G promoter was not inducible by mitogenic stimulation, interferon treatment or expression of HIV-1 proteins. Using a series of 5 0 deletion promoter constructs in luciferase reporter assays, we identified a 180bp region that was sufficient for full promoter activity. Transcriptional activity of this A3G core promoter was dependent on a GC-box (located at position � 87/� 78 relative to the major transcriptional start site) and was abolished after mutation of this DNA element. Electrophoretic mobility shift assays and chromatin immunoprecipitation assays demonstrated that the identified GC-box represented a binding site for the ubiquitous transcription factors specificity protein (Sp) 1 and Sp3.
Databáze: OpenAIRE