Gal4 protein binding is required but not sufficient for derepression and induction of GAL2 expression.
The Saccharomyces cerevisiae GAL2 gene upstream activator sequence (UAS) region was examined for protein bound in vivo by chromatin footprinting at high resolution. Gal4 transcriptional activator protein binds to the two consensus UAS sites whether GAL2 expression is induced, uninduced, or repressed by growth with different carbon sources. Although wild type strains show loss of the Gal4 protein-specific footprint in repressing media containing glucose, constitutive high level expression of Gal4 protein restores the GAL2 UAS footprints without fully derepressing GAL2 transcription. Thus binding of the Gal4 activator to target sites in the DNA is required but not sufficient for GAL2 derepression and induction. Gal4-independent protein-DNA complexes were also detected in the region, including one over the previously noted centromere-binding protein (CP1) site upstream of the Gal4 complexes.
Huibregtse
J M
JM
Department of Biological Chemistry, University of Michigan, Ann Arbor 48109-0606.
Good
P D
PD
Marczynski
G T
GT
Jaehning
J A
JA
Engelke
D R
DR
D001483:Base Sequence; D002843:Chromatin / Q000378:metabolism; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005656:Fungal Proteins / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D026901:Membrane Transport Proteins / Q000096:biosynthesis / Q000235:genetics*; D008969:Molecular Sequence Data; D009004:Monosaccharide Transport Proteins; D016133:Polymerase Chain Reaction / Q000379:methods; D011401:Promoter Regions, Genetic; D012331:RNA, Fungal / Q000302:isolation & purification / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors
D002843:Chromatin; D017931:DNA Primers; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C052130:GAL4 protein, S cerevisiae; D026901:Membrane Transport Proteins; D009004:Monosaccharide Transport Proteins; D012331:RNA, Fungal; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; C043910:galactose permease