Exploring the role and implications of a Histone Deacetylase III (HDAC3) and NCOR/SMRT in cancer and embryonic stem cell differentiation

Histone deacetylase (HDAC) enzymes regulate global chromatin accessibility by removing the acetyl moiety from Lys residues in histone tails, restoring their positive charge and tightening chromatin to prevent gene transcription. The highly related class-I HDACs and their associated co-repressor complexes (Sin3, NuRD, CoREST, MiDAC and NCoR) have roles in many biological processes including, but not limited to, embryonic development, cell cycle regulation and apoptosis. The primary aim of this research is to create a HDAC3 with a degradation TAG (dTAG) to elucidate its role in embryonic development and cancer progression. The system uses CRISPR/Cas9 technology to incorporate a mutant FKBP12F36V tag into the gene of the protein of interest (POI), such that the resulting fusion protein (HDAC3-dTAG) can be targeted with a PROTAC molecule. Protein targeting chimeras (PROTACs) are hetero-bifunctional molecules that incorporate highly-selective E3 ligase and FKBP12F36V ligands to exploit a cells degradation system to remove the POI. The rapid degradation of HDAC3 (~2 hours) will allow us to examine its role within the same time-frame as gene regulation and DNA synthesis, something not previously possible with knockout models. We expect to extend our understanding of class-I HDAC function in cell proliferation and homeostasis that will inform their use as drug targets in numerous disease types.