title: Regulation of Aerobic Energy Metabolism in Podospora anserina by Two Paralogous Genes Encoding Structurally Different c-Subunits of ATP Synthase.
abstract: Most of the ATP in living cells is produced by an F-type ATP synthase. This enzyme uses the energy of a transmembrane electrochemical proton gradient to synthesize ATP from ADP and inorganic phosphate. Proton movements across the membrane domain (FO) of the ATP synthase drive the rotation of a ring of 8-15 c-subunits, which induces conformational changes in the catalytic part (F1) of the enzyme that ultimately promote ATP synthesis. Two paralogous nuclear genes, called Atp9-5 and Atp9-7, encode structurally different c-subunits in the filamentous fungus Podospora anserina. We have in this study identified differences in the expression pattern for the two genes that correlate with the mitotic activity of cells in vegetative mycelia: Atp9-7 is transcriptionally active in non-proliferating (stationary) cells while Atp9-5 is expressed in the cells at the extremity (apex) of filaments that divide and are responsible for mycelium growth. When active, the Atp9-5 gene sustains a much higher rate of c-subunit synthesis than Atp9-7. We further show that the ATP9-7 and ATP9-5 proteins have antagonist effects on the longevity of P. anserina. Finally, we provide evidence that the ATP9-5 protein sustains a higher rate of mitochondrial ATP synthesis and yield in ATP molecules per electron transferred to oxygen than the c-subunit encoded by Atp9-7. These findings reveal that the c-subunit genes play a key role in the modulation of ATP synthase production and activity along the life cycle of P. anserina. Such a degree of sophistication for regulating aerobic energy metabolism has not been described before.
authors.affiliation: Institute for Integrative Biology of the Cell (I2BC), CEA-CNRS-Université Paris-Sud, Gif sur Yvette, France.
authors.forename: Carole H
authors.initials: CH
authors.lastname: Sellem
authors.affiliation: CNRS, Institut de Biochimie et Génétique Cellulaires, UMR 5095, Bordeaux, France.|Université Victor Segalen-Bordeaux 2, IBGC, UMR 5095, Bordeaux, France.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: di Rago
authors.affiliation: CNRS, Institut de Biochimie et Génétique Cellulaires, UMR 5095, Bordeaux, France.|Université Victor Segalen-Bordeaux 2, IBGC, UMR 5095, Bordeaux, France.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Lasserre
authors.affiliation: Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, Detroit, Michigan, United States of America.
authors.forename: Sharon H
authors.initials: SH
authors.lastname: Ackerman
authors.affiliation: Institute for Integrative Biology of the Cell (I2BC), CEA-CNRS-Université Paris-Sud, Gif sur Yvette, France.
authors.forename: Annie
authors.initials: A
authors.lastname: Sainsard-Chanet
mesh_terms: D000332:Aerobiosis; D004734:Energy Metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005656:Fungal Proteins / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D015966:Gene Expression Regulation, Fungal; D025261:Mitochondrial Proton-Translocating ATPases / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D009840:Oligomycins / Q000494:pharmacology; D048468:Podospora / Q000201:enzymology / Q000235:genetics*; D021122:Protein Subunits / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism
chemical_list: D004791:Enzyme Inhibitors; D005656:Fungal Proteins; D009840:Oligomycins; D021122:Protein Subunits; D025261:Mitochondrial Proton-Translocating ATPases