Abstract
The core CoREST complex (LHC) contains histone deacetylase HDAC1 and histone demethylase LSD1 held together by the scaffold protein CoREST. Here, we analyze the purified LHC with modified peptide and reconstituted semisynthetic mononucleosome substrates. LHC demethylase activity toward methyl-Lys4 in histone H3 is strongly inhibited by H3 Lys14 acetylation, and this appears to be an intrinsic property of the LSD1 subunit. Moreover, the deacetylase selectivity of LHC unexpectedly shows a marked preference for H3 acetyl-Lys9 versus acetyl-Lys14 in nucleosome substrates but this selectivity is lost with isolated acetyl-Lys H3 protein. This diminished activity of LHC to Lys-14 deacetylation in nucleosomes is not merely due to steric accessibility based on the pattern of sensitivity of the LHC enzymatic complex to hydroxamic acid-mediated inhibition. Overall, these studies have revealed how a single Lys modification can confer a composite of resistance in chromatin to a key epigenetic enzyme complex involved in gene silencing.
Highlights
Chromatin remodeling and histone modifications contribute to epigenetic regulation of gene expression in physiologic and disease processes
Using the unacetylated H3K4me2 tail peptide, we observed a bi-phasic demethylase activity with LHC that was not observed with purified GST-LSD1 as the catalyst (Figure 2B)
Since the HDAC1 in LHC was in principle capable of deacetylating these substrates contemporaneously with demethylation, we examined the demethylation in the presence of 10 mM SAHA (Vorinostat), a broad spectrum histone deacetylases (HDACs) inhibitor (Grant et al, 2007; Richon et al, 1998)
Summary
Chromatin remodeling and histone modifications contribute to epigenetic regulation of gene expression in physiologic and disease processes. Enzymes that reversibly modify Lys residues in histones and other proteins are emerging therapeutic targets in cancer and other diseases. Such enzymes include the ’writers’, Lys acetyltransferases (KATs) and Lys methyltransferases (KMTs) and ’erasers’ histone deacetylases (HDACs) and lysine demethylases (KDMs) (Cole, 2008; Helin and Dhanak, 2013; Shortt et al, 2017). HDAC1 is a Class I HDAC Zn hydrolase and has a broad range of targeted acetyl-lysine (Kac) sites in histones and non-histone proteins (Cole, 2008; Falkenberg and Johnstone, 2014; Taunton et al, 1996).
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
