title: Spatial reorganization of telomeres in long-lived quiescent cells.
abstract: BACKGROUND
  The spatiotemporal behavior of chromatin is an important control mechanism of genomic function. Studies in Saccharomyces cerevisiae have broadly contributed to demonstrate the functional importance of nuclear organization. Although in the wild yeast survival depends on their ability to withstand adverse conditions, most of these studies were conducted on cells undergoing exponential growth. In these conditions, as in most eukaryotic cells, silent chromatin that is mainly found at the 32 telomeres accumulates at the nuclear envelope, forming three to five foci.
  
  
  RESULTS
  Here, combining live microscopy, DNA FISH and chromosome conformation capture (HiC) techniques, we report that chromosomes adopt distinct organizations according to the metabolic status of the cell. In particular, following carbon source exhaustion the genome of long-lived quiescent cells undergoes a major spatial re-organization driven by the grouping of telomeres into a unique focus or hypercluster localized in the center of the nucleus. This change in genome conformation is specific to quiescent cells able to sustain long-term viability. We further show that reactive oxygen species produced by mitochondrial activity during respiration commit the cell to form a hypercluster upon starvation. Importantly, deleting the gene encoding telomere associated silencing factor SIR3 abolishes telomere grouping and decreases longevity, a defect that is rescued by expressing a silencing defective SIR3 allele competent for hypercluster formation.
  
  
  CONCLUSIONS
  Our data show that mitochondrial activity primes cells to group their telomeres into a hypercluster upon starvation, reshaping the genome architecture into a conformation that may contribute to maintain longevity of quiescent cells.
authors.affiliation: Institut Curie, PSL Research University, Paris, F-75248, France.|CNRS, UMR 3664, Paris, F-75248, France.|Sorbonne Universités, UPMC Univ, Paris 06, France.
authors.forename: Micol
authors.initials: M
authors.lastname: Guidi
authors.affiliation: Institut Curie, PSL Research University, Paris, F-75248, France.|CNRS, UMR 3664, Paris, F-75248, France.|Sorbonne Universités, UPMC Univ, Paris 06, France.
authors.forename: Myriam
authors.initials: M
authors.lastname: Ruault
authors.affiliation: Institut Pasteur, Department Genomes and Genetics, Groupe Régulation Spatiale des Génomes, 75015, Paris, France.|CNRS, UMR 3525, 75015, Paris, France.
authors.forename: Martial
authors.initials: M
authors.lastname: Marbouty
authors.affiliation: Institut Curie, PSL Research University, Paris, F-75248, France.|CNRS, UMR 3664, Paris, F-75248, France.|Sorbonne Universités, UPMC Univ, Paris 06, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Loïodice
authors.affiliation: Institut Pasteur, Department Genomes and Genetics, Groupe Régulation Spatiale des Génomes, 75015, Paris, France.|CNRS, UMR 3525, 75015, Paris, France.
authors.forename: Axel
authors.initials: A
authors.lastname: Cournac
authors.affiliation: Institut Curie, PSL Research University, Paris, F-75248, France.|CNRS, UMR 3664, Paris, F-75248, France.|Sorbonne Universités, UPMC Univ, Paris 06, France.
authors.forename: Cyrille
authors.initials: C
authors.lastname: Billaudeau
authors.affiliation: Institut Curie, PSL Research University, Paris, F-75248, France.|CNRS, UMR 3664, Paris, F-75248, France.|Sorbonne Universités, UPMC Univ, Paris 06, France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Hocher
authors.affiliation: LPTMC, Université Pierre et Marie Curie, UMR 7600, Sorbonne Universités, 4 Place Jussieu, 75005, Paris, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Mozziconacci
authors.affiliation: Institut Pasteur, Department Genomes and Genetics, Groupe Régulation Spatiale des Génomes, 75015, Paris, France.|CNRS, UMR 3525, 75015, Paris, France.
authors.forename: Romain
authors.initials: R
authors.lastname: Koszul
authors.affiliation: Institut Curie, PSL Research University, Paris, F-75248, France. angela.taddei@curie.fr.|CNRS, UMR 3664, Paris, F-75248, France. angela.taddei@curie.fr.|Sorbonne Universités, UPMC Univ, Paris 06, France. angela.taddei@curie.fr.
authors.forename: Angela
authors.initials: A
authors.lastname: Taddei
mesh_terms: D002244:Carbon / Q000378:metabolism; D002503:Centromere; D015825:Chromosomes, Fungal; D017382:Reactive Oxygen Species / Q000378:metabolism; D016192:Resting Phase, Cell Cycle / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D038281:Silent Information Regulator Proteins, Saccharomyces cerevisiae / Q000235:genetics; D016615:Telomere / Q000648:ultrastructure*
chemical_list: D017382:Reactive Oxygen Species; C084122:SIR3 protein, S cerevisiae; D038281:Silent Information Regulator Proteins, Saccharomyces cerevisiae; D002244:Carbon