title: Evidence for a dual role of actin in regulating chromosome organization and dynamics in yeast.
abstract: Eukaryotic chromosomes undergo movements that are involved in the regulation of functional processes such as DNA repair. To better understand the origin of these movements, we used fluorescence microscopy, image analysis and chromosome conformation capture to quantify the actin contribution to chromosome movements and interactions in budding yeast. We show that both the cytoskeletal and nuclear actin drive local chromosome movements, independently of Csm4, a putative LINC protein. Inhibition of actin polymerization reduces subtelomere dynamics, resulting in more confined territories and enrichment in subtelomeric contacts. Artificial tethering of actin to nuclear pores increased both nuclear pore complex (NPC) and subtelomere motion. Chromosome loci that were positioned away from telomeres exhibited reduced motion in the presence of an actin polymerization inhibitor but were unaffected by the lack of Csm4. We further show that actin was required for locus mobility that was induced by targeting the chromatin-remodeling protein Ino80. Correlated with this, DNA repair by homologous recombination was less efficient. Overall, interphase chromosome dynamics are modulated by the additive effects of cytoskeletal actin through forces mediated by the nuclear envelope and nuclear actin, probably through the function of actin in chromatin-remodeling complexes.
authors.affiliation: INSERM UMR 944, Equipe Biologie et Dynamique des Chromosomes, Institut Universitaire d'Hématologie, Hôpital St. Louis 1, Avenue Claude Vellefaux, Paris 75010, France CNRS, UMR 7212, Paris 75010, France Université Paris Diderot, Sorbonne Paris Cité, Paris 75010, France Institut Pasteur, Groupe Régulation Spatiale des Génomes, Paris 75015, France CNRS, UMR 3525, Paris 75015, France Sorbonne Universités, UPMC Université Paris 6, Paris 75005, France.
authors.forename: Maya
authors.initials: M
authors.lastname: Spichal
authors.affiliation: INSERM UMR 944, Equipe Biologie et Dynamique des Chromosomes, Institut Universitaire d'Hématologie, Hôpital St. Louis 1, Avenue Claude Vellefaux, Paris 75010, France CNRS, UMR 7212, Paris 75010, France Université Paris Diderot, Sorbonne Paris Cité, Paris 75010, France.
authors.forename: Alice
authors.initials: A
authors.lastname: Brion
authors.affiliation: Institut Pasteur, Unité Imagerie et Modélisation, Paris 75015, France CNRS, URA 2582, Paris 75015, France.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Herbert
authors.affiliation: Institut Pasteur, Groupe Régulation Spatiale des Génomes, Paris 75015, France CNRS, UMR 3525, Paris 75015, France.
authors.forename: Axel
authors.initials: A
authors.lastname: Cournac
authors.affiliation: Institut Pasteur, Groupe Régulation Spatiale des Génomes, Paris 75015, France CNRS, UMR 3525, Paris 75015, France.
authors.forename: Martial
authors.initials: M
authors.lastname: Marbouty
authors.affiliation: Institut Pasteur, Unité Imagerie et Modélisation, Paris 75015, France CNRS, URA 2582, Paris 75015, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Zimmer
authors.affiliation: Institut Pasteur, Groupe Régulation Spatiale des Génomes, Paris 75015, France CNRS, UMR 3525, Paris 75015, France romain.koszul@pasteur.fr emmanuelle-g.fabre@inserm.fr.
authors.forename: Romain
authors.initials: R
authors.lastname: Koszul
authors.affiliation: INSERM UMR 944, Equipe Biologie et Dynamique des Chromosomes, Institut Universitaire d'Hématologie, Hôpital St. Louis 1, Avenue Claude Vellefaux, Paris 75010, France CNRS, UMR 7212, Paris 75010, France Université Paris Diderot, Sorbonne Paris Cité, Paris 75010, France Institut Pasteur, Groupe Régulation Spatiale des Génomes, Paris 75015, France CNRS, UMR 3525, Paris 75015, France romain.koszul@pasteur.fr emmanuelle-g.fabre@inserm.fr.
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Fabre
mesh_terms: D000199:Actins / Q000502:physiology*; D002843:Chromatin / Q000235:genetics / Q000378:metabolism; D015825:Chromosomes, Fungal / Q000502:physiology*; D008565:Membrane Proteins / Q000502:physiology; D022022:Nuclear Pore / Q000378:metabolism; D055503:Protein Multimerization; D021381:Protein Transport; D059767:Recombinational DNA Repair; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000502:physiology; D016615:Telomere / Q000235:genetics / Q000378:metabolism
chemical_list: D000199:Actins; C530079:CSM4 protein, S cerevisiae; D002843:Chromatin; D008565:Membrane Proteins; D029701:Saccharomyces cerevisiae Proteins
keywords: Actin; Chromosome; Dynamics