Nucleosomal regulation of chromatin composition and nuclear assembly revealed by histone depletion

Nat Struct Mol Biol. 2014 Jul;21(7):617-25. doi: 10.1038/nsmb.2845. Epub 2014 Jun 22.


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.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism
  • Cell Cycle Proteins / physiology
  • Chromatin Assembly and Disassembly
  • DNA / metabolism
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • DNA-Binding Proteins / physiology
  • Guanine Nucleotide Exchange Factors / genetics
  • Guanine Nucleotide Exchange Factors / metabolism
  • Guanine Nucleotide Exchange Factors / physiology
  • Histones / metabolism*
  • Models, Genetic
  • Nuclear Envelope / metabolism
  • Nuclear Pore / metabolism
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism
  • Nuclear Proteins / physiology
  • Nucleosomes / metabolism*
  • Nucleosomes / physiology
  • Proteomics
  • Spindle Apparatus / metabolism
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Transcription Factors / physiology
  • Xenopus Proteins / genetics
  • Xenopus Proteins / metabolism
  • Xenopus Proteins / physiology
  • Xenopus laevis


  • AHCTF1 protein, Xenopus
  • Cell Cycle Proteins
  • DNA-Binding Proteins
  • Guanine Nucleotide Exchange Factors
  • Histones
  • Nuclear Proteins
  • Nucleosomes
  • RCC1 protein, Xenopus
  • Transcription Factors
  • Xenopus Proteins
  • DNA