Impact of flanking residue modifications on binding specificity of H3K9 methylation reader; Dppa3

Abstract

Somatic cells can be converted to an embryonic stem cell-like state by transcription factor-mediated reprogramming. These induced pluripotent stem cells (iPSCs), like ESCs, have the ability to divide indefinitely and differentiate into any tissue under the correct stimuli. This property makes them valuable for regenerative therapy. Chromatin modification is thought to play a role in maintaining the plasticity of pluripotency. Notably, histone modifications that can be recognized by specific reader proteins are crucial to chromatin regulation. Recent work has found that modifications to flanking residues of key histone modification sites can play a regulatory role in the binding of reader proteins. Furthermore, proteins that recognize H3K9 methylation have been implicated as having significant impacts on late stage reprogramming. We are therefore interested in assessing the impact of flanking residues on the binding of Dppa3, which has been implicated as important for reprogramming, to the H3K9 methylation site. To this end we are purifying recombinant versions of this protein and determining the impact of flanking residue modifications to its binding specificity using an in vitro histone peptide array