Factors Affecting Histone Deacetylase 1 Activity and Selectivity

Abstract

Acetylation is an important post‐translational modification (PTM). Aberrant acetylation, or deacetylation, has been linked to cancer, diabetes, neurodegeneration and auto‐immune disorders. Lysine acetylation is a reversible PTM, where deacetylation is catalyzed by histone deacetylases. Histone deacetylase function is crucial for a properly functioning cell, yet information about the specific biological pathways regulated by each isozyme is limited. HDAC1 is especially intriguing due to its known involvement in multiple stable nuclear complexes. However, the role of these complexes in regulating the deacetylase activity of HDAC1 is unclear. We have measured changes in activity and selectivity of HDAC1 upon addition of the following known protein binding partners; retinoblastoma protein 1 (Rb1), DNA methyltransferase 1 (DNMT1), rest corepressor 1 (CoREST), and lysine demethylase 1 (LSD1). We have reconstituted the HDAC1‐containing complexes with these proteins in vitro, as indicated by immunoprecipitation and size‐exclusion chromatography. Using substrate peptide analogs, we have measured the effect of binding partners on HDAC1 activity, demonstrating that these binding partners activate and increase HDAC1 activity to varying extents. Measurement of the reactivity of HDAC1 and HDAC1‐containing complexes with acetylated peptide substrates and full‐length protein substrates (i.e. histones) will provide insight into the role of binding partners in determining HDAC1 substrate selectivity. Support or Funding Information National Institutes of Health R01‐GM‐040602