title: Histone H2B ubiquitylation disrupts local and higher-order chromatin compaction.
abstract: Regulation of chromatin structure involves histone posttranslational modifications that can modulate intrinsic properties of the chromatin fiber to change the chromatin state. We used chemically defined nucleosome arrays to demonstrate that H2B ubiquitylation (uH2B), a modification associated with transcription, interferes with chromatin compaction and leads to an open and biochemically accessible fiber conformation. Notably, these effects were specific for ubiquitin, as compaction of chromatin modified with a similar ubiquitin-sized protein, Hub1, was only weakly affected. Applying a fluorescence-based method, we found that uH2B acts through a mechanism distinct from H4 tail acetylation, a modification known to disrupt chromatin folding. Finally, incorporation of both uH2B and acetylated H4 resulted in synergistic inhibition of higher-order chromatin structure formation, possibly a result of their distinct modes of action.
authors.affiliation: Laboratory of Synthetic Protein Chemistry, The Rockefeller University, New York, New York, USA.
authors.forename: Beat
authors.initials: B
authors.lastname: Fierz
authors.forename: Champak
authors.initials: C
authors.lastname: Chatterjee
authors.forename: Robert K
authors.initials: RK
authors.lastname: McGinty
authors.forename: Maya
authors.initials: M
authors.lastname: Bar-Dagan
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Raleigh
authors.forename: Tom W
authors.initials: TW
authors.lastname: Muir
mesh_terms: D002843:Chromatin / Q000378:metabolism*; D031541:Fluorescence Resonance Energy Transfer; D006657:Histones / Q000378:metabolism*; D011487:Protein Conformation; D054875:Ubiquitination
chemical_list: D002843:Chromatin; D006657:Histones