Engineering Chromatin States Towards Understanding Epigenetic Regulation

Chromatin serves as the physiologically relevant form of eukaryotic genomes. Modifications to both the DNA and the histone-packaging proteins allow chromatin to act as a dynamic signaling platform to regulate genomic DNA access and ultimately establish and maintain cellular phenotypes, so-called epigenetic regulation. Aberrant chromatin signaling, as a consequence of abnormal inputs and outputs, is associated with many diseases, especially cancer. A full understanding of individual chromatin signaling processes, and their interconnectivity, is a prerequisite to the design of next-generation therapeutic agents that act to ameliorate epigenetic dysregulation. However, it is extremely challenging to explore specific epigenetic mechanisms in the complex milieu of the cell nucleus. We developed a method that brings the precision and flexibility of synthetic chemistry to a native chromatin context using newly identified ultra-fast split inteins. Expanding and utilizing this advance protein-engineering tool we characterize novel histone modifications and their effect on cellular transcription.