title: Growth yield homeostasis in respiring yeast is due to a strict mitochondrial content adjustment.
abstract: In living cells, growth is the result of coupling between substrate catabolism and multiple metabolic processes taking place during net biomass formation and cell property maintenance. A crucial parameter for growth description is its yield, i.e. the efficiency of the transformation from substrate consumption to biomass formation. Using numerous yeast strains growing on different respiratory media, we have shown that the growth yield is identical regardless of the strain, growth phase, and respiratory substrate used. This homeostasis is the consequence of a strict linear relationship between growth and respiratory rates. Moreover, in all conditions tested, the oxygen consumption rate was strictly controlled by the cellular content of respiratory chain compounds in such a way that, in vivo, the steady state of oxidative phosphorylation was kept constant. Thus, the growth yield homeostasis depends on the tight adjustment of the cellular content of respiratory chain compounds to the growth rate. Any process leading to a defect in this adjustment allows an energy waste and consequently an energy yield decrease.
authors.affiliation: Institute of Biochemistry and Genetics of the Cell, CNRS Unité Mixte de Recherche 5095-Université Bordeaux 2, 1 Rue Camille Saint Saëns, 33077 Bordeaux Cedex, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Devin
authors.forename: Laurent
authors.initials: L
authors.lastname: Dejean
authors.forename: Bertrand
authors.initials: B
authors.lastname: Beauvoit
authors.forename: Cyrille
authors.initials: C
authors.lastname: Chevtzoff
authors.forename: Nicole
authors.initials: N
authors.lastname: Avéret
authors.forename: Odile
authors.initials: O
authors.lastname: Bunoust
authors.forename: Michel
authors.initials: M
authors.lastname: Rigoulet
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D003580:Cytochromes / Q000378:metabolism; D006706:Homeostasis; D008928:Mitochondria / Q000378:metabolism*; D009154:Mutation; D010100:Oxygen / Q000378:metabolism; D010101:Oxygen Consumption; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D013816:Thermodynamics
chemical_list: D003580:Cytochromes; D000255:Adenosine Triphosphate; D000242:Cyclic AMP; D010100:Oxygen