title: Dynamical remodeling of the transcriptome during short-term anaerobiosis in Saccharomyces cerevisiae: differential response and role of Msn2 and/or Msn4 and other factors in galactose and glucose media.
abstract: In contrast to previous steady-state analyses of the O(2)-responsive transcriptome, here we examined the dynamics of the response to short-term anaerobiosis (2 generations) in both catabolite-repressed (glucose) and derepressed (galactose) cells, assessed the specific role that Msn2 and Msn4 play in mediating the response, and identified gene networks using a novel clustering approach. Upon shifting cells to anaerobic conditions in galactose medium, there was an acute ( approximately 10 min) yet transient (<45 min) induction of Msn2- and/or Msn4-regulated genes associated with the remodeling of reserve energy and catabolic pathways during the switch from mixed respiro-fermentative to strictly fermentative growth. Concomitantly, MCB- and SCB-regulated networks associated with the G(1)/S transition of the cell cycle were transiently down-regulated along with rRNA processing genes containing PAC and RRPE motifs. Remarkably, none of these gene networks were differentially expressed when cells were shifted in glucose, suggesting that a metabolically derived signal arising from the abrupt cessation of respiration, rather than O(2) deprivation per se, elicits this "stress response." By approximately 0.2 generation of anaerobiosis in both media, more chronic, heme-dependent effects were observed, including the down-regulation of Hap1-regulated networks, derepression of Rox1-regulated networks, and activation of Upc2-regulated ones. Changes in these networks result in the functional remodeling of the cell wall, sterol and sphingolipid metabolism, and dissimilatory pathways required for long-term anaerobiosis. Overall, this study reveals that the acute withdrawal of oxygen can invoke a metabolic state-dependent "stress response" but that acclimatization to oxygen deprivation is a relatively slow process involving complex changes primarily in heme-regulated gene networks.
authors.affiliation: Department of Molecular and Integrative Physiology, University of Illinois, Urbana, Illinois 61801, USA.
authors.forename: Liang-Chuan
authors.initials: LC
authors.lastname: Lai
authors.forename: Alexander L
authors.initials: AL
authors.lastname: Kosorukoff
authors.forename: Patricia V
authors.initials: PV
authors.lastname: Burke
authors.forename: Kurt E
authors.initials: KE
authors.lastname: Kwast
mesh_terms: D000465:Algorithms; D020816:Amino Acid Motifs; D000693:Anaerobiosis / Q000187:drug effects / Q000235:genetics*; D002453:Cell Cycle / Q000187:drug effects / Q000235:genetics; D019295:Computational Biology; D003470:Culture Media / Q000737:chemistry / Q000494:pharmacology; D004247:DNA / Q000096:biosynthesis / Q000235:genetics; D004260:DNA Repair / Q000187:drug effects / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004734:Energy Metabolism / Q000187:drug effects / Q000235:genetics; D005690:Galactose / Q000494:pharmacology*; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects*; D005800:Genes, Fungal / Q000235:genetics; D005947:Glucose / Q000494:pharmacology*; D010100:Oxygen / Q000378:metabolism; D012331:RNA, Fungal / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic / Q000187:drug effects*
chemical_list: D003470:Culture Media; D004268:DNA-Binding Proteins; C081935:MSN2 protein, S cerevisiae; C081937:MSN4 protein, S cerevisiae; D012331:RNA, Fungal; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D004247:DNA; D005947:Glucose; D010100:Oxygen; D005690:Galactose