title: Sir2-dependent daughter-to-mother transport of the damaged proteins in yeast is required to prevent high stress sensitivity of the daughters.
abstract: The budding yeast Saccharomyces cerevisiae actively transports adverse factors (e.g. oxidized proteins) from the daughter to mother cells. The transport is believed to ensure that the daughters are born "young", thus preventing clonal senescence. Is this the only reason for the existence of such transport? We subjected yeast cells to various stress conditions and compared survival of mother and daughter cells. It was found that replicative age-dependent mortality under our experimental stress conditions was U-shaped: the resistance of both virgin daughters and old mother cells (more than three bud scars) was lower compared to the young mothers. SIR2 mutants were shown to fail to maintain the mother-daughter asymmetry. We showed that sir2 knockout affects the relative stress resistance in favor of the mothers. Thus, daughter cells are more vulnerable to a variety of stresses than the young mothers, and Sir2-dependent transport of the adverse factors acts to equalize the resistance.
authors.affiliation: Belozersky Institute of Physico-Chemical Biology and Institute of Mitoegineering, Moscow State University, Russia. knorre@belozersky.msu.ru
authors.forename: Dmitry A
authors.initials: DA
authors.lastname: Knorre
authors.forename: Irina A
authors.initials: IA
authors.lastname: Kulemzina
authors.forename: Maxim I
authors.initials: MI
authors.lastname: Sorokin
authors.forename: Sergey A
authors.initials: SA
authors.lastname: Kochmak
authors.forename: Natalya A
authors.initials: NA
authors.lastname: Bocharova
authors.forename: Sviatoslav S
authors.initials: SS
authors.lastname: Sokolov
authors.forename: Fedor F
authors.initials: FF
authors.lastname: Severin
mesh_terms: D016922:Cellular Senescence; D010455:Peptides / Q000378:metabolism; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D038281:Silent Information Regulator Proteins, Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D056565:Sirtuin 2 / Q000235:genetics / Q000378:metabolism*; D013312:Stress, Physiological; D013696:Temperature
chemical_list: D010455:Peptides; D029701:Saccharomyces cerevisiae Proteins; D038281:Silent Information Regulator Proteins, Saccharomyces cerevisiae; C097188:polyglutamine; C087778:SIR2 protein, S cerevisiae; D056565:Sirtuin 2