Related Experiment Videos
Nucleosome disruption by transcription factor binding in yeast
1Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892.
Science (New York, N.Y.)
|December 3, 1993
Summary
Yeast's GAL4 protein can bind DNA within repressive chromatin structures. This occurs in vivo, demonstrating transcription factors can access DNA even when packaged into nucleosomes, impacting gene regulation.
Area of Science:
- Molecular Biology
- Genetics
- Epigenetics
Background:
- DNA packaging into chromatin influences gene expression.
- The yeast transcriptional activator GAL4 binds to specific DNA sequences.
Purpose of the Study:
- To investigate the in vivo binding of the yeast transcriptional activator GAL4 to DNA within chromatin.
- To determine if GAL4 can bind to its DNA site when chromatin structure is repressive.
Main Methods:
- Utilized a yeast episome for in vivo studies.
- Analyzed GAL4 binding to a positioned nucleosome containing a GAL4 binding site.
- Investigated binding with GAL80 masking or absence of the GAL4 activation domain.
Main Results:
- GAL4 binding disrupts a positioned nucleosome in vivo.
- GAL4 successfully binds DNA in chromatin even when its activation domain is masked or absent.
- Demonstrated that transcription factor binding can occur within seemingly repressive chromatin.
Conclusions:
- Transcription factors can bind to DNA sites embedded within repressive chromatin structures in vivo.
- Chromatin packaging does not always prevent transcription factor access.
- This has implications for understanding gene regulation in eukaryotes.