Investigation of the CECR2 bromodomain binding interactions with H2A.Z histone variants using a new AlphaScreen assay

Abstract

A subset of epigenetic regulatory proteins modulate gene expression through structural domains called bromodomains which bind to N-ε-acetylations on histone protein lysine residues. Dysregulation of this process can have major impacts on gene expression and has been implicated in a number of cancers, inflammation, and neurological diseases. The histone variant H2A.Z isoforms are abundant in gene promoter regions and involved in transcriptional regulation. One bromodomain-containing protein that was recently shown to act at acetylated H2A.Z isoform sites is CECR2. Full characterization of CECR2’s binding interactions with H2A.Z isoforms has yet to be determined but is crucial for understanding its role in transcriptional regulation and in disease. While prior studies used protein-observed 19F NMR, the AlphaScreen assay is a more efficient characterization method. Therefore, the AlphaScreen assay’s potential for characterizing these types of interactions was evaluated for characterizing the interactions of the CECR2 bromodomain and diacetylated H2A.Z peptide isoforms. Overall, this allows for both the better understanding of native CECR2 binding interactions and the optimization of a more efficient characterization method.