Control of interferon-tau gene expression by Ets-2.
Expression of the multiple interferon-tau (IFN-tau) genes is restricted to embryonic trophectoderm of ruminant ungulate species for a few days in early pregnancy. The promoter regions of these genes are highly conserved. A proximal (bp -91 to -69) sequence has been implicated in controlling trophoblast-specific expression. Here it was used as a target for yeast one-hybrid screening of a day 13 conceptus cDNA library. Two transcription factors of the Ets family, Ets-2 and GABPalpha, were identified, consistent with the observation that active ovine IFN-tau genes contain a single 10-bp Ets motif (core: GGAA) in the proximal segment, whereas three known inactive ovine genes contain a mutated core motif (TGAA). Cotransfection of a promoter- (-126 to +50) luciferase reporter construct from an active gene (bovineIFN-tau1; boIFNT1) and an Ets-2 expression plasmid in human JAr cells provided up to a 30-fold increase in reporter expression, whereas promoters from inactive genes were not transactivated. GABPalpha alone was ineffective and had only a approximately 2-fold positive effect when coexpressed with its partner GABPbeta. Other Ets-related transcription factors, which were not detected in the genetic screen, also provided a range of lesser transactivation effects. Coexpression of Ets-2 and activated Ras failed to transactivate the IFNT promoter greater than Ets-2 alone in JAr cells. The presence of Ets-2 in nuclei of embryonic trophectoderm was confirmed immunocytochemically. Together, these data suggest that Ets-2 plays a role in the transient expression of the nonvirally inducible IFNT genes.
Ezashi
T
T
Department of Animal Sciences, University of Missouri, Columbia, MO 65211, USA.
Ealy
A D
AD
Ostrowski
M C
MC
Roberts
R M
RM
D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D018076:DNA, Complementary / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics*; D005260:Female; D051268:GA-Binding Protein Transcription Factor; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D007370:Interferon Type I / Q000235:genetics*; D008969:Molecular Sequence Data; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000235:genetics*; D050787:Proto-Oncogene Protein c-ets-2; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D012097:Repressor Proteins; D012441:Saccharomyces cerevisiae; D016415:Sequence Alignment; D012756:Sheep; D015534:Trans-Activators / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics*; D014162:Transfection
D018076:DNA, Complementary; D004268:DNA-Binding Proteins; C107465:ERF protein, human; C494069:ETS2 protein, human; D051268:GA-Binding Protein Transcription Factor; D007370:Interferon Type I; D011257:Pregnancy Proteins; D050787:Proto-Oncogene Protein c-ets-2; D011518:Proto-Oncogene Proteins; D012097:Repressor Proteins; D015534:Trans-Activators; D014157:Transcription Factors; C020947:interferon tau