title: A mechanism for asymmetric segregation of age during yeast budding.
abstract: Ageing and the mortality that ensues are sustainable for the species only if age is reset in newborns. In budding yeast, buds are made young whereas ageing factors, such as carbonylated proteins and DNA circles, remain confined to the ageing mother cell. The mechanisms of this confinement and their relevance are poorly understood. Here we show that a septin-dependent, lateral diffusion barrier forms in the nuclear envelope and limits the translocation of pre-existing nuclear pores into the bud. The retention of DNA circles within the mother cell depends on the presence of the diffusion barrier and on the anchorage of the circles to pores mediated by the nuclear basket. In accordance with the diffusion barrier ensuring the asymmetric segregation of nuclear age-determinants, the barrier mutant bud6Delta fails to properly reset age in buds. Our data involve septin-dependent diffusion barriers in the confinement of ageing factors to one daughter cell during asymmetric cell division.
authors.affiliation: Institute of Biochemistry, Biology Department, ETH Zurich, Schafmattstrasse 18, 8093 Zurich, Switzerland.
authors.forename: Zhanna
authors.initials: Z
authors.lastname: Shcheprova
authors.forename: Sandro
authors.initials: S
authors.lastname: Baldi
authors.forename: Stephanie Buvelot
authors.initials: SB
authors.lastname: Frei
authors.forename: Gaston
authors.initials: G
authors.lastname: Gonnet
authors.forename: Yves
authors.initials: Y
authors.lastname: Barral
mesh_terms: D000705:Anaphase; D002455:Cell Division; D016764:Cell Polarity / Q000502:physiology*; D016922:Cellular Senescence / Q000502:physiology*; D020090:Chromosome Segregation; D015825:Chromosomes, Fungal / Q000235:genetics / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000378:metabolism; D004271:DNA, Fungal / Q000235:genetics / Q000378:metabolism; D004058:Diffusion; D036681:Fluorescence Recovery After Photobleaching; D008840:Microfilament Proteins / Q000378:metabolism; D008938:Mitosis; D009685:Nuclear Envelope / Q000378:metabolism; D010957:Plasmids / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism
chemical_list: C107727:BUD6 protein, S cerevisiae; D003598:Cytoskeletal Proteins; D004271:DNA, Fungal; D008840:Microfilament Proteins; D029701:Saccharomyces cerevisiae Proteins