Gene Symbol: SSQ1
Description: Hsp70 family ATPase SSQ1
Alias: SSC2, SSH1, Hsp70 family ATPase SSQ1
Species: Saccharomyces cerevisiae S288c

Top Publications

  1. Rodriguez Manzaneque M, Tamarit J, Belli G, Ros J, Herrero E. Grx5 is a mitochondrial glutaredoxin required for the activity of iron/sulfur enzymes. Mol Biol Cell. 2002;13:1109-21 pubmed
    ..Phenotypic defects associated with the absence of Grx5 are suppressed by overexpression of SSQ1 and ISA2, two genes involved in the synthesis and assembly of iron/sulfur clusters into proteins...
  2. Andrew A, Dutkiewicz R, Knieszner H, Craig E, Marszalek J. Characterization of the interaction between the J-protein Jac1p and the scaffold for Fe-S cluster biogenesis, Isu1p. J Biol Chem. 2006;281:14580-7 pubmed
    ..However, when present in combination with a mutation in SSQ1 that causes an alteration in the substrate binding cleft, growth was significantly compromised...
  3. Voisine C, Schilke B, Ohlson M, Beinert H, Marszalek J, Craig E. Role of the mitochondrial Hsp70s, Ssc1 and Ssq1, in the maturation of Yfh1. Mol Cell Biol. 2000;20:3677-84 pubmed
    ..matrix of the yeast Saccharomyces cerevisiae contains two molecular chaperones of the Hsp70 class, Ssc1 and Ssq1. We report that Ssc1 and Ssq1 play sequential roles in the import and maturation of the yeast frataxin homologue (..
  4. Ciesielski S, Schilke B, Osipiuk J, Bigelow L, Mulligan R, Majewska J, et al. Interaction of J-protein co-chaperone Jac1 with Fe-S scaffold Isu is indispensable in vivo and conserved in evolution. J Mol Biol. 2012;417:1-12 pubmed publisher
    ..Thus, we conclude that the Jac1:Isu1 interaction plays an indispensable role in the essential process of mitochondrial Fe-S cluster biogenesis. ..
  5. Schilke B, Forster J, Davis J, James P, Walter W, Laloraya S, et al. The cold sensitivity of a mutant of Saccharomyces cerevisiae lacking a mitochondrial heat shock protein 70 is suppressed by loss of mitochondrial DNA. J Cell Biol. 1996;134:603-13 pubmed
    b>SSH1, a newly identified member of the heat shock protein (hsp70) multigene family of the budding yeast Saccharomyces cerevisiae, encodes a protein localized to the mitochondrial matrix...
  6. Knieszner H, Schilke B, Dutkiewicz R, D Silva P, Cheng S, Ohlson M, et al. Compensation for a defective interaction of the hsp70 ssq1 with the mitochondrial Fe-S cluster scaffold isu. J Biol Chem. 2005;280:28966-72 pubmed
    b>Ssq1, a specialized yeast mitochondrial Hsp70, plays a critical role in the biogenesis of proteins containing Fe-S clusters through its interaction with Isu, the scaffold on which clusters are built...
  7. Dutkiewicz R, Marszalek J, Schilke B, Craig E, Lill R, Muhlenhoff U. The Hsp70 chaperone Ssq1p is dispensable for iron-sulfur cluster formation on the scaffold protein Isu1p. J Biol Chem. 2006;281:7801-8 pubmed
    ..Hence, consistent with previous in vivo data, these chaperones likely function in steps subsequent to the de novo synthesis of the Fe/S cluster on Isu1p. ..
  8. Li L, Miao R, Bertram S, Jia X, Ward D, Kaplan J. A role for iron-sulfur clusters in the regulation of transcription factor Yap5-dependent high iron transcriptional responses in yeast. J Biol Chem. 2012;287:35709-21 pubmed publisher
    ..Using a genetic screen to identify genes involved in Yap5 iron sensing, we discovered that a mutation in SSQ1, which encodes a mitochondrial chaperone involved in iron-sulfur cluster synthesis, prevented expression of Yap5 ..
  9. Schmidt S, Strub A, Rottgers K, Zufall N, Voos W. The two mitochondrial heat shock proteins 70, Ssc1 and Ssq1, compete for the cochaperone Mge1. J Mol Biol. 2001;313:13-26 pubmed
    Two members of the heat shock protein 70 kDa (Hsp70) family, Ssc1 and Ssq1, perform important functions in the mitochondrial matrix...

More Information


  1. Andrew A, Song J, Schilke B, Craig E. Posttranslational regulation of the scaffold for Fe-S cluster biogenesis, Isu. Mol Biol Cell. 2008;19:5259-66 pubmed publisher
    ..reduction in the activity of several components of the cluster biogenesis system, including the specialized Hsp70 Ssq1, causes a 15-20-fold up-regulation of Isu...
  2. Jensen L, Sanchez R, Srinivasan C, Valentine J, Culotta V. Mutations in Saccharomyces cerevisiae iron-sulfur cluster assembly genes and oxidative stress relevant to Cu,Zn superoxide dismutase. J Biol Chem. 2004;279:29938-43 pubmed
    ..By comparison, the sod1Delta lysine auxotrophy appears to be reversed in the seo mutants by increased expression of genes in the lysine biosynthetic pathway, perhaps through sensing of mitochondrial damage by the retrograde response. ..
  3. Manicki M, Majewska J, Ciesielski S, Schilke B, Blenska A, Kominek J, et al. Overlapping binding sites of the frataxin homologue assembly factor and the heat shock protein 70 transfer factor on the Isu iron-sulfur cluster scaffold protein. J Biol Chem. 2014;289:30268-78 pubmed publisher
    ..apoprotein is known to require the interaction of Isu with the J-protein/Hsp70 molecular chaperone pair, Jac1 and Ssq1. Here we show that the Yfh1 interaction with Isu involves the PVK sequence motif, which is also the site key for ..
  4. Lewrenz I, Rietzschel N, Guiard B, Lill R, van der Laan M, Voos W. The functional interaction of mitochondrial Hsp70s with the escort protein Zim17 is critical for Fe/S biogenesis and substrate interaction at the inner membrane preprotein translocase. J Biol Chem. 2013;288:30931-43 pubmed publisher
    ..mutant cells were prone to acquire respiratory deficits and showed a strong aggregation of the mitochondrial Hsp70 Ssq1 together with a concomitant defect in Fe/S protein biogenesis...
  5. Uzarska M, Dutkiewicz R, Freibert S, Lill R, Muhlenhoff U. The mitochondrial Hsp70 chaperone Ssq1 facilitates Fe/S cluster transfer from Isu1 to Grx5 by complex formation. Mol Biol Cell. 2013;24:1830-41 pubmed publisher
    The mitochondrial Hsp70 chaperone Ssq1 plays a dedicated role in the maturation of iron-sulfur (Fe/S) proteins, an essential process of mitochondria...
  6. Strain J, Lorenz C, Bode J, Garland S, Smolen G, Ta D, et al. Suppressors of superoxide dismutase (SOD1) deficiency in Saccharomyces cerevisiae. Identification of proteins predicted to mediate iron-sulfur cluster assembly. J Biol Chem. 1998;273:31138-44 pubmed
    ..One sod1Delta suppressor represents SSQ1 which encodes a hsp70-type molecular chaperone found in the mitochondria...
  7. Kim R, Saxena S, Gordon D, Pain D, Dancis A. J-domain protein, Jac1p, of yeast mitochondria required for iron homeostasis and activity of Fe-S cluster proteins. J Biol Chem. 2001;276:17524-32 pubmed
    ..proteins (lacking 70 or 152 amino acids) were associated with phenotypes strikingly similar to the phenotypes of ssq1 mutants...
  8. Lutz T, Westermann B, Neupert W, Herrmann J. The mitochondrial proteins Ssq1 and Jac1 are required for the assembly of iron sulfur clusters in mitochondria. J Mol Biol. 2001;307:815-25 pubmed
    Mitochondria of the yeast Saccharomyces cerevisiae contain three different Hsp70 chaperones, Ssc1, Ecm10 and Ssq1. Ssc1 is an essential protein that mediates the import of nuclear-encoded proteins into the organelle and their subsequent ..
  9. Schilke B, Voisine C, Beinert H, Craig E. Evidence for a conserved system for iron metabolism in the mitochondria of Saccharomyces cerevisiae. Proc Natl Acad Sci U S A. 1999;96:10206-11 pubmed
    ..In a synthetic lethal screen with the mitochondrial heat shock protein (HSP)70, SSQ1, we identified a gene of Saccharomyces cerevisiae, NFU1, which encodes a protein with sequence identity to the C-..
  10. Knight S, Sepuri N, Pain D, Dancis A. Mt-Hsp70 homolog, Ssc2p, required for maturation of yeast frataxin and mitochondrial iron homeostasis. J Biol Chem. 1998;273:18389-93 pubmed
    ..Yeast with ssc2-1 mutations were identified by a screen for altered iron-dependent gene regulation and mitochondrial dysfunction...