Nucleosomes, the fundamental units of chromatin structure, are regulators and barriers to transcription, replication and repair. Post-translational modifications (PTMs) of the histone proteins within nucleosomes regulate these DNA processes. Histone H3(T118) is a site of phosphorylation [H3(T118ph)] and is implicated in regulation of transcription and DNA repair. We prepared H3(T118ph) by expressed protein ligation and determined its influence on nucleosome dynamics. We find H3(T118ph) reduces DNA-histone binding by 2 kcal/mol, increases nucleosome mobility by 28-fold and increases DNA accessibility near the dyad region by 6-fold. Moreover, H3(T118ph) increases the rate of hMSH2-hMSH6 nucleosome disassembly and enables nucleosome disassembly by the SWI/SNF chromatin remodeler. These studies suggest that H3(T118ph) directly enhances and may reprogram chromatin remodeling reactions.
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http://dx.doi.org/10.1093/nar/gkr304 | DOI Listing |
Nucleic Acids Res
April 2014
Department of Physics, The Ohio State University, Columbus, OH 43210, USA, Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA, Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA and Huygens-Kamerlingh Onnes Laboratory, Leiden University, The Netherlands.
Nucleosomes contain ∼146 bp of DNA wrapped around a histone protein octamer that controls DNA accessibility to transcription and repair complexes. Posttranslational modification (PTM) of histone proteins regulates nucleosome function. To date, only modest changes in nucleosome structure have been directly attributed to histone PTMs.
View Article and Find Full Text PDFJ Struct Biol
October 2012
Structural and Computational Biology Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Road, New Delhi 110067, India.
Nucleosome assembly proteins (Nap) are histone chaperones with vital roles in chromatin assembly and disassembly. Decoding of histone post-translational modifications by histone chaperones is central in regulation of gene expression. We probed binding interfaces in Nap-histone complexes using histone peptide interaction arrays and chemical shift perturbation techniques.
View Article and Find Full Text PDFNucleic Acids Res
August 2011
Department of Physics, The Ohio State University and The Ohio State University Medical Center, Columbus, OH 43210, USA.
Nucleosomes, the fundamental units of chromatin structure, are regulators and barriers to transcription, replication and repair. Post-translational modifications (PTMs) of the histone proteins within nucleosomes regulate these DNA processes. Histone H3(T118) is a site of phosphorylation [H3(T118ph)] and is implicated in regulation of transcription and DNA repair.
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