title: Variations on a nucleosome theme: The structural basis of centromere function.
abstract: The centromere is a specialized chromosomal structure that dictates kinetochore assembly and, thus, is essential for accurate chromosome segregation. Centromere identity is determined epigenetically by the presence of a centromere-specific histone H3 variant, CENP-A, that replaces canonical H3 in centromeric chromatin. Here, we discuss recent work by Roulland et al. that identifies structural elements of the nucleosome as essential determinants of centromere function. In particular, CENP-A nucleosomes have flexible DNA ends due to the short αN helix of CENP-A. The higher flexibility of the DNA ends of centromeric nucleosomes impairs binding of linker histones H1, while it facilitates binding of other essential centromeric proteins, such as CENP-C, and is required for mitotic fidelity. This work extends previous observations indicating that the differential structural properties of CENP-A nucleosomes are on the basis of its contribution to centromere identity and function. Here, we discuss the implications of this work and the questions arising from it.
authors.affiliation: Institute of Molecular Biology of Barcelona, CSIC, Barcelona, Spain.|Institute for Research in Biomedicine, IRB Barcelona, The Barcelona Institute for Science and Technology, Barcelona, Spain.
authors.forename: Olga
authors.initials: O
authors.lastname: Moreno-Moreno
authors.affiliation: Institute of Molecular Biology of Barcelona, CSIC, Barcelona, Spain.|Institute for Research in Biomedicine, IRB Barcelona, The Barcelona Institute for Science and Technology, Barcelona, Spain.
authors.forename: Mònica
authors.initials: M
authors.lastname: Torras-Llort
authors.affiliation: Institute of Molecular Biology of Barcelona, CSIC, Barcelona, Spain.|Institute for Research in Biomedicine, IRB Barcelona, The Barcelona Institute for Science and Technology, Barcelona, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Azorín
mesh_terms: D000818:Animals; D002503:Centromere / Q000378:metabolism*; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism; D020090:Chromosome Segregation; D006657:Histones / Q000378:metabolism; D006801:Humans; D009707:Nucleosomes / Q000378:metabolism*; D015003:Yeasts / Q000235:genetics / Q000378:metabolism
chemical_list: D002868:Chromosomal Proteins, Non-Histone; D006657:Histones; D009707:Nucleosomes
keywords: CCAN; CENP-A; centromere; chromatin; histone H1; kinetochore; nucleosome structure