title: Human centromeric CENP-A chromatin is a homotypic, octameric nucleosome at all cell cycle points.
abstract: Chromatin assembled with centromere protein A (CENP-A) is the epigenetic mark of centromere identity. Using new reference models, we now identify sites of CENP-A and histone H3.1 binding within the megabase, α-satellite repeat-containing centromeres of 23 human chromosomes. The overwhelming majority (97%) of α-satellite DNA is found to be assembled with histone H3.1-containing nucleosomes with wrapped DNA termini. In both G1 and G2 cell cycle phases, the 2-4% of α-satellite assembled with CENP-A protects DNA lengths centered on 133 bp, consistent with octameric nucleosomes with DNA unwrapping at entry and exit. CENP-A chromatin is shown to contain equimolar amounts of CENP-A and histones H2A, H2B, and H4, with no H3. Solid-state nanopore analyses show it to be nucleosomal in size. Thus, in contrast to models for hemisomes that briefly transition to octameric nucleosomes at specific cell cycle points or heterotypic nucleosomes containing both CENP-A and histone H3, human CENP-A chromatin complexes are octameric nucleosomes with two molecules of CENP-A at all cell cycle phases.
authors.affiliation: Ludwig Institute for Cancer Research and Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093.
authors.forename: Yael
authors.identifier: 0000-0001-5753-5485
authors.initials: Y
authors.lastname: Nechemia-Arbely
authors.affiliation: Ludwig Institute for Cancer Research and Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093.
authors.forename: Daniele
authors.identifier: 0000-0002-8795-6771
authors.initials: D
authors.lastname: Fachinetti
authors.affiliation: Center for Biomolecular Science and Engineering, University of California, Santa Cruz, Santa Cruz, CA 95064.
authors.forename: Karen H
authors.initials: KH
authors.lastname: Miga
authors.affiliation: Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104.
authors.forename: Nikolina
authors.initials: N
authors.lastname: Sekulic
authors.affiliation: Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, Netherlands.
authors.forename: Gautam V
authors.initials: GV
authors.lastname: Soni
authors.affiliation: Ludwig Institute for Cancer Research and Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093.
authors.forename: Dong Hyun
authors.initials: DH
authors.lastname: Kim
authors.affiliation: Ludwig Institute for Cancer Research and Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093.
authors.forename: Adeline K
authors.initials: AK
authors.lastname: Wong
authors.affiliation: Ludwig Institute for Cancer Research and Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093.
authors.forename: Ah Young
authors.initials: AY
authors.lastname: Lee
authors.affiliation: Ludwig Institute for Cancer Research and Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093.
authors.forename: Kristen
authors.initials: K
authors.lastname: Nguyen
authors.affiliation: Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, Netherlands.
authors.forename: Cees
authors.initials: C
authors.lastname: Dekker
authors.affiliation: Ludwig Institute for Cancer Research and Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093.
authors.forename: Bing
authors.initials: B
authors.lastname: Ren
authors.affiliation: Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104.
authors.forename: Ben E
authors.initials: BE
authors.lastname: Black
authors.affiliation: Ludwig Institute for Cancer Research and Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093 dcleveland@ucsd.edu.
authors.forename: Don W
authors.identifier: 0000-0002-1934-3682
authors.initials: DW
authors.lastname: Cleveland
mesh_terms: D001324:Autoantigens / Q000235:genetics*; D002453:Cell Cycle / Q000235:genetics*; D045744:Cell Line, Tumor; D002503:Centromere / Q000235:genetics*; D000076247:Centromere Protein A; D002843:Chromatin / Q000235:genetics*; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics*; D004247:DNA / Q000235:genetics; D004276:DNA, Satellite / Q000235:genetics; D006367:HeLa Cells; D006657:Histones / Q000235:genetics; D006801:Humans; D009707:Nucleosomes / Q000235:genetics*
chemical_list: D001324:Autoantigens; C000619700:CENPA protein, human; D000076247:Centromere Protein A; D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D004276:DNA, Satellite; D006657:Histones; D009707:Nucleosomes; D004247:DNA