Department of Biochemistry and Molecular Biology; Program in Molecular Medicine
Binding Sites; Chromosomal Proteins, Non-Histone; DNA Footprinting; DNA, Fungal; DNA-Binding Proteins; Fungal Proteins; Galactose; Gene Expression Regulation, Fungal; Genes, Fungal; *Nuclear Proteins; Nucleosomes; Promoter Regions (Genetics); Saccharomyces cerevisiae; *Saccharomyces cerevisiae Proteins; Trans-Activation (Genetics); Trans-Activators; Transcription Factors
Life Sciences | Medicine and Health Sciences
The Saccharomyces cerevisiae SWI-SNF complex is a 2-MDa protein assembly that is required for the function of many transcriptional activators. Here we describe experiments on the role of the SWI-SNF complex in activation of transcription by the yeast activator GAL4. We find that while SWI-SNF activity is not required for the GAL4 activator to bind to and activate transcription from nucleosome-free binding sites, the complex is required for GAL4 to bind to and function at low-affinity, nucleosomal binding sites in vivo. This SWI-SNF dependence can be overcome by (i) replacing the low-affinity sites with higher-affinity, consensus GAL4 binding sequences or (ii) placing the low-affinity sites into a nucleosome-free region. These results define the criteria for the SWI-SNF dependence of gene expression and provide the first in vivo evidence that the SWI-SNF complex can regulate gene expression by modulating the DNA binding of an upstream activator protein.
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Citation: Mol Cell Biol. 1997 Aug;17(8):4811-9.
Molecular and cellular biology
Burns, Loree Griffin and Peterson, Craig L., "The yeast SWI-SNF complex facilitates binding of a transcriptional activator to nucleosomal sites in vivo" (1997). Open Access Articles. 1449.