%0 Journal Article %A Miller, Myrna M. %A Jarosinski, Keith W. %A Schat, Karel A. %T Negative modulation of the chicken infectious anemia virus promoter by COUP-TF1 and an E box-like element at the transcription start site binding δEF1 %D 2008 %J Journal of General Virology, %V 89 %N 12 %P 2998-3003 %@ 1465-2099 %R https://doi.org/10.1099/vir.0.2008/003103-0 %I Microbiology Society, %X Expression of enhanced green fluorescent protein (EGFP) under control of the promoter-enhancer of chicken infectious anemia virus (CAV) is increased in an oestrogen receptor-enhanced cell line when treated with oestrogen and the promoter-enhancer binds unidentified proteins that recognize a consensus oestrogen response element (ERE). Co-transfection assays with the CAV promoter and the nuclear receptor chicken ovalbumin upstream promoter transcription factor 1 (COUP-TF1) showed that expression of EGFP was decreased by 50 to 60 % in DF-1 and LMH cells. The CAV promoter that included sequences at and downstream of the transcription start point had less expression than a short promoter construct. Mutation of a putative E box at this site restored expression levels. Electromobility shift assays showed that the transcription regulator delta-EF1 (δEF1) binds to this E box region. These findings indicate that the CAV promoter activity can be affected directly or indirectly by COUP-TF1 and δEF1. %U https://www.microbiologyresearch.org/content/journal/jgv/10.1099/vir.0.2008/003103-0