title: Histone variant macroH2A1.2 is mono-ubiquitinated at its histone domain.
abstract: Histone macroH2A1.2 (macroH2A) is an unusual histone H2A variant with a large non-histone macrodomain at its carboxyl terminal. MacroH2A1.2 is enriched in facultative heterochromatin, including inactivated X chromosomes in mammalian females and senescence-associated heterochromatin foci. We show here that a small population of macroH2A1.2 is mono-ubiquitinated in human HeLa cells. Mass spectrometry analysis revealed that the specific targeting sites for the mono-ubiquitination are Lys115 and Lys116 of the histone domain. A corresponding Lys119 conserved in histone H2A is also mono-ubiquitinated by Ring protein in the polycomb group complex. We suggest that the mono-ubiquitination of macroH2A1.2 and histone H2A has similar or synergistic implications, but that the multiple ubiquitination sites in macroH2A1.2 might confer a variety of functions upon macroH2A1.2 to modulate chromatin states.
authors.affiliation: Department of Integrated Genetics, National Institute of Genetics, Mishima 411-8540, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Ogawa
authors.forename: T
authors.initials: T
authors.lastname: Ono
authors.forename: Y
authors.initials: Y
authors.lastname: Wakata
authors.forename: K
authors.initials: K
authors.lastname: Okawa
authors.forename: H
authors.initials: H
authors.lastname: Tagami
authors.forename: K-i
authors.initials: KI
authors.lastname: Shibahara
mesh_terms: D000595:Amino Acid Sequence; D015153:Blotting, Western; D002846:Chromatography, Affinity; D004591:Electrophoresis, Polyacrylamide Gel; D006367:HeLa Cells; D006657:Histones / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D009707:Nucleosomes / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D025801:Ubiquitin / Q000378:metabolism*
chemical_list: D006657:Histones; D009707:Nucleosomes; D025801:Ubiquitin; C120756:macroH2A histone