title: H2O2 induces rapid biophysical and permeability changes in the plasma membrane of Saccharomyces cerevisiae.
abstract: In Saccharomyces cerevisiae, the diffusion rate of hydrogen peroxide (H2O2) through the plasma membrane decreases during adaptation to H2O2 by means of a mechanism that is still unknown. Here, evidence is presented that during adaptation to H2O2 the anisotropy of the plasma membrane increases. Adaptation to H2O2 was studied at several times (15min up to 90min) by applying the steady-state H2O2 delivery model. For wild-type cells, the steady-state fluorescence anisotropy increased after 30min, or 60min, when using 2-(9-anthroyloxy) stearic acid (2-AS), or diphenylhexatriene (DPH) membrane probe, respectively. Moreover, a 40% decrease in plasma membrane permeability to H2O2 was observed at 15min with a concomitant two-fold increase in catalase activity. Disruption of the ergosterol pathway, by knocking out either ERG3 or ERG6, prevents the changes in anisotropy during H2O2 adaptation. H2O2 diffusion through the plasma membrane in S. cerevisiae cells is not mediated by aquaporins since the H2O2 permeability constant is not altered in the presence of the aquaporin inhibitor mercuric chloride. Altogether, these results indicate that the regulation of the plasma membrane permeability towards H2O2 is mediated by modulation of the biophysical properties of the plasma membrane.
authors.affiliation: Centro de Química e Bioquímica da Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisboa, Portugal.
authors.forename: Vanderlei
authors.initials: V
authors.lastname: Folmer
authors.forename: Nuno
authors.initials: N
authors.lastname: Pedroso
authors.forename: Ana C
authors.initials: AC
authors.lastname: Matias
authors.forename: Sílvia C D N
authors.initials: SC
authors.lastname: Lopes
authors.forename: Fernando
authors.initials: F
authors.lastname: Antunes
authors.forename: Luísa
authors.initials: L
authors.lastname: Cyrne
authors.forename: H Susana
authors.initials: HS
authors.lastname: Marinho
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects; D016880:Anisotropy; D020346:Aquaporins / Q000378:metabolism; D001692:Biological Transport / Q000187:drug effects; D055592:Biophysical Phenomena; D001703:Biophysics; D002463:Cell Membrane Permeability / Q000187:drug effects*; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D008560:Membrane Fluidity / Q000187:drug effects; D009154:Mutation / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000187:drug effects*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism
chemical_list: D020346:Aquaporins; D029701:Saccharomyces cerevisiae Proteins; D006861:Hydrogen Peroxide