(335g) Engineer a Protein-Based Sensor for Quantifying Histone Epigenetic Modifications

Epigenetic modifications are heritable changes in chromatin that affect gene expression and contribute to determining cellular phenotype. Post-translational modifications (PTMs) of histone proteins are an important category of epigenetic modifications. Aberrant changes in histone acetylation levels, one of the most common histone PTM, have been associated with early-stage tumor genesis; and are emerging as promising biomarkers for cancer detection and monitoring. Current detection approaches of histone acetylation are either tedious to perform or require expensive instrumentation, which hinders their transition to clinics. To address this challenge, we have developed a sensitive histone acetylation probe by combining protein engineering, nanomaterial and fluorescence spectroscopy. The protein sensor is developed by engineering the bromodomain of human polybromo-1 (PB1). The developed probe can recognize acetylation of H3K14 with high specificity. The acetylation level is quantified by using fluorescence correlation spectroscopy (FCS). The performance of our sensor was characterized using histone proteins with defined levels of acetylation as well as extracts from human cells lines. Our sensor offers a simple and sensitive quantification of total acetylation levels of H3K14.