... activity of the Sp1/ Sp3 interaction or the Sp1/ Sp3 /Ets-1 interaction by approximately 90% and 80%, respectively. Mutation of the Ets-1 binding site (mut5) also blocked the effect of Ets-1 in the presence ... studies in Drosophila Schneider cells confirmed that the constitutiveexpression of this gene is controlled by Ets-1 and requires the presence both of the Sp1 and Sp3 transcription factors. The presence ... cells is controlled by Ets-1 and Oct-1 and requires the presence of both Sp1 and Sp3 Mingfeng Liu1, Julian L. Leibowitz2, David A. Clark1,4, Michael Mendicino1, Qin Ning1, Jin Wen Ding1,Cheryl...