title: Mass spectrometry analysis of Arabidopsis histone H3 reveals distinct combinations of post-translational modifications.
abstract: Chromatin is regulated at many different levels, from higher-order packing to individual nucleosome placement. Recent studies have shown that individual histone modifications, and combinations thereof, play a key role in modulating chromatin structure and gene activity. Reported here is an analysis of Arabidopsis histone H3 modifications by nanoflow-HPLC coupled to electrospray ionization on a hybrid linear ion trap-Fourier transform mass spectrometer (LTQ/FTMS). We find that the sites of acetylation and methylation, in general, correlate well with other plants and animals. Two well-studied modifications, dimethylation of Lys-9 (correlated with silencing) and acetylation of Lys-14 (correlated with active chromatin) while abundant by themselves were rarely found on the same histone H3 tail. In contrast, dimethylation at Lys-27 and monomethylation at Lys-36 were commonly found together. Interestingly, acetylation at Lys-9 was found only in a low percentage of histones while acetylation of Lys-14 was very abundant. The two histone H3 variants, H3.1 and H3.2, also differ in the abundance of silencing and activating marks confirming other studies showing that the replication-independent histone H3 is enriched in active chromatin.
authors.affiliation: Life Science Core Curriculum, Department and Molecular Biology Institute, University of California, Los Angeles, CA 90095, USA.
authors.forename: Lianna
authors.initials: L
authors.lastname: Johnson
authors.forename: Sahana
authors.initials: S
authors.lastname: Mollah
authors.forename: Benjamin A
authors.initials: BA
authors.lastname: Garcia
authors.forename: Tara L
authors.initials: TL
authors.lastname: Muratore
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Shabanowitz
authors.forename: Donald F
authors.initials: DF
authors.lastname: Hunt
authors.forename: Steven E
authors.initials: SE
authors.lastname: Jacobsen
mesh_terms: D000107:Acetylation; D029681:Arabidopsis Proteins / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism*; D015153:Blotting, Western; D006657:Histones / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism*; D008745:Methylation; D011499:Protein Processing, Post-Translational; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D029681:Arabidopsis Proteins; D006657:Histones