Proteolytical histone processing during human stem cell differentiation

Epigenetic modifications of chromatin are essential in the regulation of many biological
processes. The evolutionary conserved histone proteins that are intimately associated with
DNA to form the chromatin are pivotal epigenetic substrates herein. The amino-terminal tail
of these histones protrudes from the nucleosome and can become modified by many different
posttranslational modifications on at least 60 different residues. However, one kind of PTM
has received only little attention in epigenetics until now: proteolytical histone clipping. Here we present a pioneering project to elucidate the role and impact of histone processing in differentiating human embryonic stem cells (hESC) as well as its role in induced pluripotency. All experiments on hESC will be conducted on the G1 cell line that was generated by the Department for Reproductive Medicine (Ghent University Hospital). First, enzyme translocation and activity in the nucleus as well as chromatin-wide distribution of the clipping events will be monitored by fluorescent microscopy. Second, the impact of inhibiting this epigenetic event will be monitored at the transcriptome level. Third, ChIPseq analysis will define the genes that are targeted by this histone clipping. Finally, histone clipping in induced pluripotent stem cells will be monitored.