Negative regulation of Sp1 trans-activation is correlated with the binding of cellular proteins to the amino terminus of the Sp1 trans-activation domain.
Sp1 is a well characterized and ubiquitously expressed transcription factor that regulates the constitutive and induced expression of a variety of mammalian genes. It is unclear whether Sp1 activity is regulated in vivo; the mechanism by which Sp1 interacts with the basal transcription complex has not been firmly established. We report the identification of a ubiquitously expressed and evolutionarily conserved nuclear protein, p74, that specifically binds Sp1 in vivo and in vitro. p74 interacts with several portions of the Sp1 trans-activation domain in vitro, and we correlate the binding of p74 to the amino-terminal serine/threonine-rich subdomain of Sp1 with the inhibition of Sp1-mediated transcription in vivo.
Murata
Y
Y
Department of Molecular Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710.
Kim
H G
HG
Rogers
K T
KT
Udvadia
A J
AJ
Horowitz
J M
JM
D001665:Binding Sites; D002478:Cells, Cultured; D004268:DNA-Binding Proteins; D005656:Fungal Proteins / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D016329:Sp1 Transcription Factor / Q000235:genetics* / Q000378:metabolism; D014157:Transcription Factors; D014158:Transcription, Genetic; D015533:Transcriptional Activation
D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C052130:GAL4 protein, S cerevisiae; D009687:Nuclear Proteins; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D016329:Sp1 Transcription Factor; D014157:Transcription Factors