Activation of Ras cascade increases the mitochondrial enzyme content of respiratory competent yeast.
We investigated the effects of genetic and physiological modulations of the cAMP-protein kinase A pathway on mitochondrial biogenesis of yeast cells grown on lactate. Yeast mutants with over-activated Ras/adenylate cyclase pathway (i.e., Ras2(val19), ira1Delta(ira2)Delta) or with a constitutive downstream activation of protein kinases A (i.e., bcyDelta) showed an increase in the mitochondrial enzyme content. In contrast, loss of Ras activity (i.e., Ras2 mutant) resulted in a slight decrease. The treatment by cAMP of a responsive mutant increased the oxidative phosphorylation capacity of cells and increased the transcript level of nuclear genes encoding for mitochondrial proteins. In contrast, the transcript level of mitochondrial DNA genes was unchanged. It is concluded that the Ras/cAMP/protein kinase A pathway is part of the regulatory circuit controlling biogenesis of the oxidative phosphorylation complexes in yeast cells.
Dejean
Laurent
L
Institut de Biochimie et Génétique Cellulaires, UMR 5095 CNRS/Université Victor Segalen, 1 rue Camille Saint-Saëns, Bordeaux cedex 33077, France.
Beauvoit
Bertrand
B
Bunoust
Odile
O
Guérin
Bernard
B
Rigoulet
Michel
M
D015152:Blotting, Northern; D000242:Cyclic AMP / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D003580:Cytochromes / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D004272:DNA, Mitochondrial / Q000378:metabolism; D019344:Lactic Acid / Q000378:metabolism; D008928:Mitochondria / Q000201:enzymology*; D009154:Mutation; D010100:Oxygen / Q000378:metabolism; D010101:Oxygen Consumption; D011485:Protein Binding; D012313:RNA / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D015398:Signal Transduction; D018631:ras Proteins / Q000378:metabolism*
D003580:Cytochromes; D004272:DNA, Mitochondrial; D019344:Lactic Acid; D012313:RNA; D004247:DNA; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases; D018631:ras Proteins; D010100:Oxygen