The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)



Gene Review

SSC1  -  Hsp70 family ATPase SSC1

Saccharomyces cerevisiae S288c

Synonyms: ENS1, Endo.SceI 75 kDa subunit, Endonuclease SceI 75 kDa subunit, Heat shock protein SSC1, mitochondrial, J1639, ...
Welcome! If you are familiar with the subject of this article, you can contribute to this open access knowledge base by deleting incorrect information, restructuring or completely rewriting any text. Read more.

Disease relevance of SSC1

  • Overexpression of Yge1p in the temperature-sensitive mutant strains of mitochondrial hsp70, Ssc1p, caused hypersensitivity to temperature for cell growth, suggesting a genetic interaction between the YGE1 and SSC1 genes [1].
  • Analysis of the SSC1 DNA sequence revealed that it could encode a 70,627-dalton protein that is more similar to DnaK, an Escherichia coli hsp70 protein, than other yeast hsp70s whose sequences have been determined [2].

High impact information on SSC1

  • PMR1 is identical to SSC1, a gene previously identified by its effect on secretion of some foreign proteins from yeast [3].
  • Unlike SSC1 mutants, an SSH1 mutant showed no detectable defects in import of several proteins from the cytosol to the matrix compared to wild type [4].
  • SSC1, a member of the 70-kDa heat shock protein multigene family of Saccharomyces cerevisiae, is essential for growth [5].
  • Mutations in two of these yeast genes (SSC1 and SSD1), whose expression is increased a few fold after temperature upshift, were constructed in vitro and substituted into the yeast genome in place of the wild-type alleles [5].
  • The larger subunit (75 kDa) of Endo.SceI, encoded by a nuclear gene (ENS1), is transported from the cytosol into the mitochondria [6].

Biological context of SSC1

  • We report that deletion of the HSP78 gene in yeast strains with point mutations in the SSC1 gene (encoding matrix Hsp70) led to loss of mitochondrial DNA, indicating that at least one of the heat shock proteins Hsp78 and mt-Hsp70 is needed to maintain a rho+ state of the mitochondrial genome [7].
  • One H. polymorpha 70 kDa protein was strongly induced during growth at elevated temperatures, whereas a second 70 kDa protein as well as a 60 kDa protein showed strong protein sequence homology to mitochondrial SSC1 and hsp60, respectively, from S. cerevisiae [8].
  • Ecm10p was initially identified as a cell wall synthesis-related gene product [Genetics 147 (1997) 435] and also reported as a mitochondrial protein which was partially capable of compensating the phenotypic defect by SSC1 gene mutation [FEBS Lett. 487 (2000) 307] [9].
  • Molecular genetic analysis of ENS1 demonstrated its indispensability for growth and the requirement of a high level of its expression at the sporulation and germination stages [10].
  • The amino acid sequence of Cp-mtHSP70 shares common domains with mitochondrial and proteobacterial homologues, including 34 amino acids of an NH2-terminal mitochondrion-like targeting presequence [11].

Anatomical context of SSC1


Associations of SSC1 with chemical compounds

  • The arginine tRNA gene, named HSX1, is essential for growth on a nonfermentable carbon source at high temperatures and for synthesis of the SSC1 heat shock protein [13].
  • Both fluorescein- and immunogold-labeled anti-Cp-mtHSP70 localize to a single mitochondrial compartment in close apposition to the nucleus [11].

Other interactions of SSC1


Analytical, diagnostic and therapeutic context of SSC1


  1. Yge1p, a eukaryotic Grp-E homolog, is localized in the mitochondrial matrix and interacts with mitochondrial Hsp70. Nakai, M., Kato, Y., Ikeda, E., Toh-e, A., Endo, T. Biochem. Biophys. Res. Commun. (1994) [Pubmed]
  2. SSC1, an essential member of the yeast HSP70 multigene family, encodes a mitochondrial protein. Craig, E.A., Kramer, J., Shilling, J., Werner-Washburne, M., Holmes, S., Kosic-Smithers, J., Nicolet, C.M. Mol. Cell. Biol. (1989) [Pubmed]
  3. The yeast secretory pathway is perturbed by mutations in PMR1, a member of a Ca2+ ATPase family. Rudolph, H.K., Antebi, A., Fink, G.R., Buckley, C.M., Dorman, T.E., LeVitre, J., Davidow, L.S., Mao, J.I., Moir, D.T. Cell (1989) [Pubmed]
  4. The cold sensitivity of a mutant of Saccharomyces cerevisiae lacking a mitochondrial heat shock protein 70 is suppressed by loss of mitochondrial DNA. Schilke, B., Forster, J., Davis, J., James, P., Walter, W., Laloraya, S., Johnson, J., Miao, B., Craig, E. J. Cell Biol. (1996) [Pubmed]
  5. SSC1, a member of the 70-kDa heat shock protein multigene family of Saccharomyces cerevisiae, is essential for growth. Craig, E.A., Kramer, J., Kosic-Smithers, J. Proc. Natl. Acad. Sci. U.S.A. (1987) [Pubmed]
  6. A maturase-like subunit of the sequence-specific endonuclease endo.SceI from yeast mitochondria. Nakagawa, K., Morishima, N., Shibata, T. J. Biol. Chem. (1991) [Pubmed]
  7. The mitochondrial ClpB homolog Hsp78 cooperates with matrix Hsp70 in maintenance of mitochondrial function. Moczko, M., Schönfisch, B., Voos, W., Pfanner, N., Rassow, J. J. Mol. Biol. (1995) [Pubmed]
  8. Affinity purification of molecular chaperones of the yeast Hansenula polymorpha using immobilized denatured alcohol oxidase. Evers, M.E., Huhse, B., Titorenko, V.I., Kunau, W.H., Hartl, F.U., Harder, W., Veenhuis, M. FEBS Lett. (1993) [Pubmed]
  9. Ecm10p localizes in yeast mitochondrial nucleoids and its overexpression induces extensive mitochondrial DNA aggregations. Sakasegawa, Y., Hachiya, N.S., Tsukita, S., Kaneko, K. Biochem. Biophys. Res. Commun. (2003) [Pubmed]
  10. A subunit of yeast site-specific endonuclease SceI is a mitochondrial version of the 70-kDa heat shock protein. Morishima, N., Nakagawa, K., Yamamoto, E., Shibata, T. J. Biol. Chem. (1990) [Pubmed]
  11. Cryptosporidium parvum mitochondrial-type HSP70 targets homologous and heterologous mitochondria. Slapeta, J., Keithly, J.S. Eukaryotic Cell (2004) [Pubmed]
  12. Isolation of a gene encoding a mitochondrial HSP70 protein from Schizosaccharomyces pombe. Powell, M.J., Watts, F.Z. Gene (1990) [Pubmed]
  13. Ty element-induced temperature-sensitive mutations of Saccharomyces cerevisiae. Kawakami, K., Shafer, B.K., Garfinkel, D.J., Strathern, J.N., Nakamura, Y. Genetics (1992) [Pubmed]
  14. Dual modes of transcriptional and translational initiation of SSP1, the gene for a mitochondrial HSP70, responding to heat-shock in Schizosaccharomyces pombe. Kasai, H., Isono, K. Nucleic Acids Res. (1991) [Pubmed]
  15. cDNA cloning and efficient mitochondrial import of pre-mtHSP70 from rat liver. Webster, T.J., Naylor, D.J., Hartman, D.J., Høj, P.B., Hoogenraad, N.J. DNA Cell Biol. (1994) [Pubmed]
WikiGenes - Universities