title: A quantitative analysis of histone methylation and acetylation isoforms from their deuteroacetylated derivatives: application to a series of knockout mutants.
abstract: The core histones, H2A, H2B, H3 and H4, undergo post-translational modifications (PTMs) including lysine acetylation, methylation and ubiquitylation, arginine methylation and serine phosphorylation. Lysine residues may be mono-, di- and trimethylated, the latter resulting in an addition of mass to the protein that differs from acetylation by only 0.03639 Da, but that can be distinguished either on high-performance mass spectrometers with sufficient mass accuracy and mass resolution or via retention times. Here we describe the use of chemical derivatization to quantify methylated and acetylated histone isoforms by forming deuteroacetylated histone derivatives prior to tryptic digestion and bottom-up liquid chromatography-mass spectrometric analysis. The deuteroacetylation of unmodified or mono-methylated lysine residues produces a chemically identical set of tryptic peptides when comparing the unmodified and modified versions of a protein, making it possible to directly quantify lysine acetylation. In this work, the deuteroacetylation technique is used to examine a single histone H3 peptide with methyl and acetyl modifications at different lysine residues and to quantify the relative abundance of each modification in different deacetylase and methylase knockout yeast strains. This application demonstrates the use of the deuteroacetylation technique to characterize modification 'cross-talk' by correlating different PTMs on the same histone tail.
authors.affiliation: Middle Atlantic Mass Spectrometry Laboratory, Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA. kstampe2@live.johnshopkins.edu
authors.forename: Katherine L
authors.initials: KL
authors.lastname: Fiedler
authors.forename: Poonam
authors.initials: P
authors.lastname: Bheda
authors.forename: Junbiao
authors.initials: J
authors.lastname: Dai
authors.forename: Jef D
authors.initials: JD
authors.lastname: Boeke
authors.forename: Cynthia
authors.initials: C
authors.lastname: Wolberger
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Cotter
mesh_terms: D000107:Acetylation; D000595:Amino Acid Sequence; D003903:Deuterium / Q000737:chemistry; D055786:Gene Knockout Techniques / Q000379:methods*; D006657:Histones / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008745:Methylation; D008969:Molecular Sequence Data; D009154:Mutation; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D020033:Protein Isoforms; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000502:physiology; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D014357:Trypsin / Q000737:chemistry / Q000378:metabolism
chemical_list: D006657:Histones; D010446:Peptide Fragments; D020033:Protein Isoforms; D029701:Saccharomyces cerevisiae Proteins; D003903:Deuterium; D014357:Trypsin