title: A Cul4 E3 ubiquitin ligase regulates histone hand-off during nucleosome assembly.
abstract: Nucleosome assembly following DNA replication and gene transcription is important to maintain genome stability and epigenetic information. Newly synthesized histones H3-H4 first bind histone chaperone Asf1 and are then transferred to other chaperones for nucleosome assembly. However, it is unknown how H3-H4 is transferred from the Asf1-H3-H4 complex to other chaperones because Asf1 binds H3-H4 with high affinity. Here, we show that yeast Rtt101(Mms1) E3 ubiquitin ligase preferentially binds and ubiquitylates new histone H3 acetylated at lysine 56. Inactivation of Rtt101 or mutating H3 lysine residues ubiquitylated by the Rtt101(Mms1) ligase impairs nucleosome assembly and promotes Asf1-H3 interactions. Similar phenotypes occur in human cells in which the ortholog of Rtt101(Mms1), Cul4A(DDB1), is depleted. These results indicate that the transfer of H3-H4 from the Asf1-H3-H4 complex to other histone chaperones is regulated by a conserved E3 ligase and provide evidence for crosstalk between histone acetylation and ubiquitylation in nucleosome assembly.
authors.affiliation: Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55905, USA.
authors.forename: Junhong
authors.initials: J
authors.lastname: Han
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.forename: Honglian
authors.initials: H
authors.lastname: Zhang
authors.forename: Zhiquan
authors.initials: Z
authors.lastname: Wang
authors.forename: Hui
authors.initials: H
authors.lastname: Zhou
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D000107:Acetylation; D018797:Cell Cycle Proteins / Q000378:metabolism; D044842:Cullin Proteins / Q000737:chemistry / Q000378:metabolism*; D006657:Histones / Q000378:metabolism*; D006801:Humans; D008958:Models, Molecular; D018832:Molecular Chaperones / Q000378:metabolism; D009707:Nucleosomes / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism*; D004718:Saccharomycetales / Q000378:metabolism*; D054875:Ubiquitination
chemical_list: C109731:ASF1 protein, S cerevisiae; C114234:CUL4A protein, human; D018797:Cell Cycle Proteins; D044842:Cullin Proteins; D006657:Histones; D018832:Molecular Chaperones; D009707:Nucleosomes; C476451:RTT101 protein, S cerevisiae; C505157:Rtt106 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins