Acetyl-methyllysine marks chromatin at active transcription start sites
Ontology highlight
ABSTRACT: Lysine residues in histones and other proteins can be modified by post-translational modifications (PTMs) that encode regulatory information. Lysine acetylation and methylation are especially important for regulating chromatin and gene expression. Pathways involving these PTMs are targets for clinically approved therapeutics to treat human diseases. Lysine methylation and acetylation are generally assumed to be mutually exclusive at the same residue. Here, we report the discovery of cellular lysine residues that are both methylated and acetylated on the same sidechain to form acetyl-methyllysine (Kacme). We show that Kacme is found on histone H4 across a range of species and across mammalian tissues. Kacme is associated with marks of active chromatin, increased transcriptional initiation, and is regulated in response to biological signals. H4Kacme can be installed by enzymatic acetylation of monomethyllysine peptides and is resistant to deacetylation by some HDACs in vitro. Further, Kacme can be bound by chromatin proteins that recognize modified lysine residues, as we demonstrate with the crystal structure of acetyllysine-binding protein BRD2 bound to a histone H4Kacme peptide. These results establish Kacme as a new cellular PTM with the potential to encode information distinct from methylation and acetylation alone and demonstrate that Kacme has all the hallmarks of a PTM with fundamental importance to chromatin biology.
INSTRUMENT(S): Orbitrap Q Exactive, Orbitrap Exploris
ORGANISM(S): Drosophila Melanogaster (ncbitaxon:7227) Homo Sapiens (ncbitaxon:9606) Mus Musculus (ncbitaxon:10090)
SUBMITTER: Matthew D. Simon
PROVIDER: MSV000087982 | MassIVE | Fri Aug 13 07:04:00 BST 2021
REPOSITORIES: MassIVE
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