Identification of a nuclear gene (FMC1) required for the assembly/stability of yeast mitochondrial F(1)-ATPase in heat stress conditions.
We have identified a yeast nuclear gene (FMC1) that is required at elevated temperatures (37 degrees C) for the formation/stability of the F(1) sector of the mitochondrial ATP synthase. Western blot analysis showed that Fmc1p is a soluble protein located in the mitochondrial matrix. At elevated temperatures in yeast cells lacking Fmc1p, the alpha-F(1) and beta-F(1) proteins are synthesized, transported, and processed to their mature size. However, instead of being incorporated into a functional F(1) oligomer, they form large aggregates in the mitochondrial matrix. Identical perturbations were reported previously for yeast cells lacking either Atp12p or Atp11p, two specific assembly factors of the F(1) sector (Ackerman, S. H., and Tzagoloff, A. (1990) Proc. Natl. Acad. Sci. U. S. A. 87, 4986--4990), and we show that the absence of Fmc1p can be efficiently compensated for by increasing the expression of Atp12p. However, unlike Atp12p and Atp11p, Fmc1p is not required in normal growth conditions (28--30 degrees C). We propose that Fmc1p is required for the proper folding/stability or functioning of Atp12p in heat stress conditions.
Lefebvre-Legendre
L
L
Institut de Biochimie et Génétique Cellulaires du CNRS, Université Victor Ségalen, Bordeaux 2, 33077 Bordeaux cedex, France.
Vaillier
J
J
Benabdelhak
H
H
Velours
J
J
Slonimski
P P
PP
di Rago
J P
JP
D018833:Chaperonins; D005656:Fungal Proteins / Q000502:physiology; D005800:Genes, Fungal; D006358:Hot Temperature; D008928:Mitochondria / Q000201:enzymology*; D024101:Mitochondrial Proteins; D025261:Mitochondrial Proton-Translocating ATPases; D018832:Molecular Chaperones; D010101:Oxygen Consumption; D017510:Protein Folding; D006180:Proton-Translocating ATPases / Q000737:chemistry* / Q000502:physiology; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins
C110382:ATP12 protein, S cerevisiae; C434343:Atp11 protein, S pombe; D005656:Fungal Proteins; D024101:Mitochondrial Proteins; D018832:Molecular Chaperones; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; D018833:Chaperonins; C098664:ATP11 protein, S cerevisiae; D025261:Mitochondrial Proton-Translocating ATPases; D006180:Proton-Translocating ATPases