Utilizing a Fusion Protein for Sequence Specific Nucleosome Shifting in Chromatin

Presenter(s): William Reed-dustin − Biology, Human Physiology

Faculty Mentor(s): Jeffrey McKnight

Poster 81

Research Area: Natural/Physical Science (Molecular Biology)

Chromatin refers to the organization of DNA in eukaryotic organisms. Chromatin is organized such that DNA wraps around protein groups called histones. The units of histones wrapped in DNA are called nucleosomes, nucleosomes are connected by short stretches of linker DNA. DNA in nucleosomes is relatively inaccessible to RNA polymerase and transcription factors and thus, is effectively turned off. The goal of this research was to move nucleosomes onto specific DNA sequences by producing a fusion protein that would combine the binding domain from a specific transcription factor, XBP1, and the active domain from a known chromatin remodeler protein, CHD1. A procedure originally developed by Dr. Jeffrey McKnight was used to produce a plasmid that coded for a protein with the binding domain of XBP1 and the active domain of CHD1. This plasmid was then transformed into yeast. The cells’ DNA was then digested into mono-nucleosomes which were sequenced and compared to yeast without the plasmid inserted. This was done to see if the fusion protein had altered the nucleosomes’ locations.
The goal of this research is to show that the strategy for fusion protein production can be applied to diverse transcription factors across the yeast genome. Ultimately, this strategy could be useful in cancer treatment, silencing oncogenes by moving nucleosomes onto their binding sites.