title: Biphasic modulation of fatty acid synthase by hydrogen peroxide in Saccharomyces cerevisiae.
abstract: Taking into account published contradictory results concerning the regulation of fatty acid synthase (Fas) by H(2)O(2), we carried out a systematic study where two methods of H(2)O(2) delivery (steady-state and bolus addition) and the effect of a wide range of H(2)O(2) concentrations were investigated. A decrease in Fas activity was observed for cells exposed to 100 and 150μM H(2)O(2) in a steady-state, while a bolus addition of the same H(2)O(2) concentrations did not alter Fas activity. Similar results were observed for the mRNA levels of FAS1, the gene that encodes Fas subunit β. However, the exposure to a steady-state 50μM H(2)O(2) dose lead to an increase in FAS1 mRNA levels, showing a biphasic modulation of Fas by H(2)O(2). The results obtained emphasize that cellular effects of H(2)O(2) can vary over a narrow range of concentrations. Therefore, a tight control of H(2)O(2) exposure, which can be achieved by exposing H(2)O(2) in a steady-state, is important for cellular studies of H(2)O(2)-dependent redox regulation.
authors: Centro de Química e Bioquímica and Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal.
authors: Ana C
authors: AC
authors: Matias
authors: H Susana
authors: HS
authors: Marinho
authors: Luísa
authors: L
authors: Cyrne
authors: Enrique
authors: E
authors: Herrero
authors: Fernando
authors: F
authors: Antunes
mesh_terms: D064429:Fatty Acid Synthases / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000378:metabolism
chemical_list: D006861:Hydrogen Peroxide; D064429:Fatty Acid Synthases