Jac1, a mitochondrial J-type chaperone, is involved in the biogenesis of Fe/S clusters in Saccharomyces cerevisiae.
A minor Hsp70 chaperone of the mitochondrial matrix of Saccharomyces cerevisiae, Ssq1, is involved in the formation or repair of Fe/S clusters and/or mitochondrial iron metabolism. Here, we report evidence that Jac1, a J-type chaperone of the mitochondrial matrix, is the partner of Ssq1 in this process. Reduced activity of Jac1 results in a decrease in activity of Fe/S containing mitochondrial proteins and an accumulation of iron in mitochondria. Fe/S enzyme activities remain low in both jac1 and ssq1 mutant mitochondria even if normal mitochondrial iron levels are maintained. Therefore, the low activities observed are not solely due to oxidative damage caused by excess iron. Rather, these molecular chaperones likely play a direct role in the normal assembly process of Fe/S clusters.
Voisine
C
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Department of Biomolecular Chemistry, University of Wisconsin, Madison, WI 53706, USA.
Cheng
Y C
YC
Ohlson
M
M
Schilke
B
B
Hoff
K
K
Beinert
H
H
Marszalek
J
J
Craig
E A
EA
D000154:Aconitate Hydratase / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D005656:Fungal Proteins / Q000235:genetics / Q000502:physiology; D018840:HSP70 Heat-Shock Proteins; D007501:Iron / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism*; D024101:Mitochondrial Proteins; D018832:Molecular Chaperones / Q000235:genetics / Q000502:physiology*; D016297:Mutagenesis, Site-Directed; D011817:Rabbits; D012441:Saccharomyces cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D013385:Succinate Dehydrogenase / Q000378:metabolism
D005656:Fungal Proteins; D018840:HSP70 Heat-Shock Proteins; C121520:ISU1 protein, S cerevisiae; C115914:JAC1 protein, S cerevisiae; D024101:Mitochondrial Proteins; D018832:Molecular Chaperones; C121524:NFU1 protein, S cerevisiae; C115913:SSQ1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D007501:Iron; D013385:Succinate Dehydrogenase; D000154:Aconitate Hydratase