Precision Mapping of Coexisting Modifications in Histone H3 Tails from Embryonic Stem Cells by ETD-MS/MS

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• 作者：Hye Ryung Jung ; Simone Sidoli ; Simon Haldbo ; Richard R. Sprenger ; Veit Schw盲mmle ; Diego Pasini ; Kristian Helin ; Ole N. Jensen
• 刊名：Analytical Chemistry
• 出版年：2013
• 出版时间：September 3, 2013
• 年：2013
• 卷：85
• 期：17
• 页码：8232-8239
• 全文大小：373K
• 年卷期：v.85,no.17(September 3, 2013)
• ISSN：1520-6882

文摘

Post-translational modifications (PTMs) of histones play a major role in regulating chromatin dynamics and influence processes such as transcription and DNA replication. Here, we report 114 distinct combinations of coexisting PTMs of histone H3 obtained from mouse embryonic stem (ES) cells. Histone H3 N-terminal tail peptides (amino acids 1鈥?0, 5鈥? kDa) were separated by optimized weak cation exchange/hydrophilic interaction liquid chromatography (WCX/HILIC) and sequenced online by electron transfer dissociation (ETD) tandem mass spectrometry (MS/MS). High mass accuracy and near complete sequence coverage allowed unambiguous mapping of the major histone marks and discrimination between isobaric and nearly isobaric PTMs such as trimethylation and acetylation. Hierarchical data analysis identified H3K27me2-H3K36me2 as the most frequently observed PTMs in H3. Modifications at H3 residues K27 and K36 often coexist with the abundant mark K23ac, and we identified two frequently occurring quadruplet marks 鈥楰9me1K23acK27me2K36me2鈥?and 鈥楰9me3K23acK27me2K36me鈥? which might indicate a role in crosstalk. Co-occurrence frequency analysis revealed also an interplay between methylations of K9, K27, and K36, suggesting interdependence between histone methylation marks. We hypothesize that the most abundant coexisting PTMs may provide a signature for the permissive state of mouse ES cells.