title: Nucleosomal regulation of chromatin composition and nuclear assembly revealed by histone depletion.
abstract: Nucleosomes are the fundamental unit of chromatin, but analysis of transcription-independent nucleosome functions has been complicated by the gene-expression changes resulting from histone manipulation. Here we solve this dilemma by developing Xenopus laevis egg extracts deficient for nucleosome formation and by analyzing the proteomic landscape and behavior of nucleosomal chromatin and nucleosome-free DNA. We show that although nucleosome-free DNA can recruit nuclear-envelope membranes, nucleosomes are required for spindle assembly and for formation of the lamina and of nuclear pore complexes (NPCs). We show that, in addition to the Ran G-nucleotide exchange factor RCC1, ELYS, the initiator of NPC formation, fails to associate with naked DNA but directly binds histone H2A-H2B dimers and nucleosomes. Tethering ELYS and RCC1 to DNA bypasses the requirement for nucleosomes in NPC formation in a synergistic manner. Thus, the minimal essential function of nucleosomes in NPC formation is to recruit RCC1 and ELYS.
authors: Laboratory of Chromosome and Cell Biology, Rockefeller University, New York, New York, USA.
authors: Christian
authors: C
authors: Zierhut
authors: Laboratory of Chromosome and Cell Biology, Rockefeller University, New York, New York, USA.
authors: Christopher
authors: C
authors: Jenness
authors: 1] Graduate School of Frontier Biosciences, Osaka University, Suita, Japan. [2] Japan Science and Technology Agency, Core Research for Evolutional Science and Technology, Suita, Japan.
authors: Hiroshi
authors: H
authors: Kimura
authors: Laboratory of Chromosome and Cell Biology, Rockefeller University, New York, New York, USA.
authors: Hironori
authors: H
authors: Funabiki
mesh_terms: D000818:Animals; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D042002:Chromatin Assembly and Disassembly; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D006657:Histones / Q000378:metabolism*; D008957:Models, Genetic; D009685:Nuclear Envelope / Q000378:metabolism; D022022:Nuclear Pore / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D009707:Nucleosomes / Q000378:metabolism* / Q000502:physiology; D040901:Proteomics; D008941:Spindle Apparatus / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D029867:Xenopus Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D014982:Xenopus laevis
chemical_list: C525081:AHCTF1 protein, Xenopus; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D020662:Guanine Nucleotide Exchange Factors; D006657:Histones; D009687:Nuclear Proteins; D009707:Nucleosomes; C499304:RCC1 protein, Xenopus; D014157:Transcription Factors; D029867:Xenopus Proteins; D004247:DNA