Human foamy virus Bel 1 transactivator/estrogen receptor fusion proteins allow inducible transactivation of both human foamy virus promoters.
Recombinant plasmids that express human foamy virus (HFV) Bel 1 transactivator and human estrogen receptor (ER) fusion proteins were constructed. The HFV bel 1 gene was inserted up- and downstream of the ER gene. Recombinant Bel 1-ER and ER-Bel 1 fusion proteins were expressed in eukaryotic cells. In the absence of estrogen, the ER moiety of the fusion proteins suppressed Bel 1-mediated transactivation as measured in CAT reporter gene-based transactivation assays. However, transactivation of the HFV LTR and the HFV internal promoter by Bel 1-ER and ER-Bel 1 fusion proteins was recovered in the presence of estrogen. Thus, the transactivation function of the Bel 1 moiety of the chimeric Bel 1-ER fusion proteins can be efficiently, specifically, and intentionally activated and inactivated by simply adding the low-molecular weight effector estrogen.
Yang
P
P
Institute of Virology, College of Life Science, Wuhan University, Hubei, PR China.
Flügel
R M
RM
Li
W
W
Löchelt
M
M
D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D006801:Humans; D011401:Promoter Regions, Genetic; D011960:Receptors, Estrogen / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012191:Retroviridae Proteins / Q000235:genetics / Q000378:metabolism*; D016092:Spumavirus / Q000235:genetics*; D020079:Terminal Repeat Sequences; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D015533:Transcriptional Activation
D004268:DNA-Binding Proteins; D011960:Receptors, Estrogen; D011993:Recombinant Fusion Proteins; D012191:Retroviridae Proteins; D015534:Trans-Activators; C074061:bel1 protein, Human foamy virus