Nucleic Acids Research Advance Access originally published online on June 8, 2009
Nucleic Acids Research 2009 37(14):4684-4695; doi:10.1093/nar/gkp473
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Nucleic Acids Research, 2009, Vol. 37, No. 14 4684-4695
© 2009 The Author(s)
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/2.0/uk/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Gene Regulation, Chromatin and Epigenetics |
The incorporation of the novel histone variant H2AL2 confers unusual structural and functional properties of the nucleosome
1Université Joseph Fourier – Grenoble 1, INSERM Institut Albert Bonniot, U823, Site Santé-BP 170, 38042 Grenoble Cedex 9, 2Université de Lyon, Laboratoire de Biologie Moléculaire de la Cellule, CNRS-UMR 5239/INRA 1237/IFR128 Biosciences, Ecole Normale Supérieure de Lyon, 46 Allée d'Italie, 69364 Lyon cedex 07, France, 3MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, UK, 4CNRS/UJF, Laboratoire de Spectrométrie Physique, UMR 5588, BP87, 140 Av. de la Physique, 38402 St. Martin d'Hères Cedex, France, 5Charles University in Prague, Institute of Cellular Biology and Pathology, First Faculty of Medicine and Department of Cell Biology, Institute of Physiology, Academy of Sciences of the Czech Republic, Albertov 4, 128 01 Prague 2, Czech Republic and 6Université de Lyon, Laboratoire de Physique, CNRS UMR 5672, Ecole Normale Supérieure de Lyon, 46 Allée d'Italie, 69364 Lyon cedex 07, France
*To whom correspondence should be addressed. Tel: +33 4 72 72 88 98; Fax: +33 4 72 72 80 80; Email: dimitar.anguelov{at}ens-lyon.fr
Correspondence may also be addressed to Stefan Dimitrov. +33 4 76 54 94 73; +33 4 76 54 95 95; Email: stefan.dimitrov{at}ujf-grenoble.fr
Received January 9, 2009. Revised May 7, 2009. Accepted May 18, 2009.
In this work we have studied the properties of the novel mouse histone variant H2AL2. H2AL2 was used to reconstitute nucleosomes and the structural and functional properties of these particles were studied by a combination of biochemical approaches, atomic force microscopy (AFM) and electron cryo-microscopy. DNase I and hydroxyl radical footprinting as well as micrococcal and exonuclease III digestion demonstrated an altered structure of the H2AL2 nucleosomes all over the nucleosomal DNA length. Restriction nuclease accessibility experiments revealed that the interactions of the H2AL2 histone octamer with the ends of the nucleosomal DNA are highly perturbed. AFM imaging showed that the H2AL2 histone octamer was complexed with only
130 bp of DNA. H2AL2 reconstituted trinucleosomes exhibited a type of a beads on a string structure, which was quite different from the equilateral triangle 3D organization of conventional H2A trinucleosomes. The presence of H2AL2 affected both the RSC and SWI/SNF remodeling and mobilization of the variant particles. These unusual properties of the H2AL2 nucleosomes suggest a specific role of H2AL2 during mouse spermiogenesis.