title: Chemical Synthesis of Phosphorylated Histone H2A at Tyr57 Reveals Insight into the Inhibition Mode of the SAGA Deubiquitinating Module.
abstract: Monoubiquitination of histone H2B plays a central role in transcription activation and is required for downstream histone-methylation events. Deubiquitination of H2B by the Spt-Ada-Gcn5 acetyltransferase (SAGA) coactivator complex is regulated by a recently discovered histone mark, phosphorylated H2AY57 (H2AY57p), which inhibits deubiquitination of H2B by the SAGA complex as well as restricting demethylation of H3 and increasing its acetylation. Evidence for the effect of H2AY57p, however, was indirect and was investigated in vivo by monitoring the effects of chemical inhibition of Tyr kinase CK2 or by mutating the phosphorylation site. We applied the total chemical synthesis of proteins to prepare H2AY57p efficiently and study the molecular details of this regulation. This analogue, together with semisynthetically prepared ubiquitinated H2B, enabled us to provide direct evidence for the cross-talk between those two marks and the inhibition of SAGA activity by H2AY57p.
authors.affiliation: Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa, 3200008, Israel.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Jbara
authors.affiliation: Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa, 3200008, Israel.
authors.forename: Suman Kumar
authors.initials: SK
authors.lastname: Maity
authors.affiliation: Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD, 21205-2185, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Morgan
authors.affiliation: Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD, 21205-2185, USA. cwolberg@jhmi.edu.
authors.forename: Cynthia
authors.initials: C
authors.lastname: Wolberger
authors.affiliation: Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa, 3200008, Israel. abrik@technion.ac.il.
authors.forename: Ashraf
authors.initials: A
authors.lastname: Brik
mesh_terms: D000107:Acetylation; D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid; D006657:Histones / Q000737:chemistry*; D013058:Mass Spectrometry; D010766:Phosphorylation; D014443:Tyrosine / Q000737:chemistry*; D025801:Ubiquitin / Q000737:chemistry*
chemical_list: D006657:Histones; D025801:Ubiquitin; D014443:Tyrosine
keywords: chemical protein synthesis; deubiquitination; phosphorylation; proteins; total synthesis