Gene Symbol: SSB2
Description: Hsp70 family ATPase SSB2
Alias: YG103, Hsp70 family ATPase SSB2
Species: Saccharomyces cerevisiae S288c

Top Publications

  1. Yan W, Schilke B, Pfund C, Walter W, Kim S, Craig E. Zuotin, a ribosome-associated DnaJ molecular chaperone. EMBO J. 1998;17:4809-17 pubmed
    ..We propose that Zuo1 binds to ribosomes, in part, by interaction with ribosomal RNA and that Zuo1 functions with Ssb as a chaperone on the ribosome. ..
  2. Kim S, Craig E. Broad sensitivity of Saccharomyces cerevisiae lacking ribosome-associated chaperone ssb or zuo1 to cations, including aminoglycosides. Eukaryot Cell. 2005;4:82-9 pubmed
    ..We conclude that, in vivo, the major cause of the aminoglycoside sensitivity of cells lacking ribosome-associated molecular chaperones is a general increase in cation influx, perhaps due to altered maturation of membrane proteins. ..
  3. Pfund C, Lopez Hoyo N, Ziegelhoffer T, Schilke B, Lopez Buesa P, Walter W, et al. The molecular chaperone Ssb from Saccharomyces cerevisiae is a component of the ribosome-nascent chain complex. EMBO J. 1998;17:3981-9 pubmed
    ..These interactions allow Ssb to function as a chaperone on the ribosome, preventing the misfolding of newly synthesized proteins. ..
  4. Bobula J, Tomala K, Jez E, Wloch D, Borts R, Korona R. Why molecular chaperones buffer mutational damage: a case study with a yeast Hsp40/70 system. Genetics. 2006;174:937-44 pubmed
    ..A plausible role of chaperones is to stabilize genetic networks, thus making them more tolerant to malfunctioning of their constituents. ..
  5. Muldoon Jacobs K, Dinman J. Specific effects of ribosome-tethered molecular chaperones on programmed -1 ribosomal frameshifting. Eukaryot Cell. 2006;5:762-70 pubmed
    ..Analysis of published DNA microarray experiments reveals conditions under which Ssb1, Ssb2, Ssz1, and Zuo1 transcript levels are regulated independently of those of genes encoding ribosomal proteins...
  6. Shaner L, Wegele H, Buchner J, Morano K. The yeast Hsp110 Sse1 functionally interacts with the Hsp70 chaperones Ssa and Ssb. J Biol Chem. 2005;280:41262-9 pubmed
    ..These data suggest that the Hsp110 chaperone operates in concert with Hsp70 in yeast and that this collaboration is required for cellular Hsp70 functions. ..
  7. Yam A, Albanèse V, Lin H, Frydman J. Hsp110 cooperates with different cytosolic HSP70 systems in a pathway for de novo folding. J Biol Chem. 2005;280:41252-61 pubmed
    ..It, thus, appears that Hsp110 is an important regulator of Hsp70-substrate interactions. Based on our data, we propose that Hsp110 cooperates with the SSB and SSA Hsp70 subfamilies, which act sequentially during de novo folding. ..
  8. von Plehwe U, Berndt U, Conz C, Chiabudini M, Fitzke E, Sickmann A, et al. The Hsp70 homolog Ssb is essential for glucose sensing via the SNF1 kinase network. Genes Dev. 2009;23:2102-15 pubmed publisher
    ..The data are consistent with a model in which Ssb is crucial for efficient regulation within the SNF1 signaling network, thereby allowing an appropriate response to changing glucose levels. ..
  9. Albanèse V, Reissmann S, Frydman J. A ribosome-anchored chaperone network that facilitates eukaryotic ribosome biogenesis. J Cell Biol. 2010;189:69-81 pubmed publisher
    ..Our results demonstrate that, in addition to their known cytoplasmic roles in de novo protein folding, some ribosome-anchored CLIPS chaperones play a critical role in nuclear steps of ribosome biogenesis. ..

More Information


  1. Allen K, Chernova T, Tennant E, Wilkinson K, Chernoff Y. Effects of ubiquitin system alterations on the formation and loss of a yeast prion. J Biol Chem. 2007;282:3004-13 pubmed
    ..We propose that UPS alterations induce an adaptive response, resulting in accumulation of the large "aggresome"-like aggregates that promote de novo prion generation and prion recovery from the chaperone treatment. ..
  2. Albanèse V, Yam A, Baughman J, Parnot C, Frydman J. Systems analyses reveal two chaperone networks with distinct functions in eukaryotic cells. Cell. 2006;124:75-88 pubmed
    ..The emergence of a translation-linked chaperone network likely underlies the elaborate cotranslational folding process necessary for the evolution of larger multidomain proteins characteristic of eukaryotic cells. ..
  3. Dombek K, Kacherovsky N, Young E. The Reg1-interacting proteins, Bmh1, Bmh2, Ssb1, and Ssb2, have roles in maintaining glucose repression in Saccharomyces cerevisiae. J Biol Chem. 2004;279:39165-74 pubmed
    ..Here we show that the Reg1-interacting proteins Bmh1, Bmh2, Ssb1, and Ssb2 have roles in glucose repression...
  4. Mandal A, Gibney P, Nillegoda N, Theodoraki M, Caplan A, Morano K. Hsp110 chaperones control client fate determination in the hsp70-Hsp90 chaperone system. Mol Biol Cell. 2010;21:1439-48 pubmed publisher
    ..These findings support a model in which Hsp110 chaperones contribute significantly to the decision made by Hsp70 to fold or degrade a client protein. ..
  5. Moriel Carretero M, Tous C, Aguilera A. Control of the function of the transcription and repair factor TFIIH by the action of the cochaperone Ydj1. Proc Natl Acad Sci U S A. 2011;108:15300-5 pubmed publisher
    ..Our results provide evidence for a role of chaperones in NER and transcription, with implications in cancer and TFIIH-associated syndromes. ..
  6. Heinen R, Diniz Mendes L, Silva J, Paschoalin V. Identification of the divergent calmodulin binding motif in yeast Ssb1/Hsp75 protein and in other HSP70 family members. Braz J Med Biol Res. 2006;39:1399-408 pubmed
    ..A model in which calmodulin displaces Bag-1 and modulates Ssb1/Hsp75 chaperone activity is discussed. ..
  7. Abrams J, Verghese J, Gibney P, Morano K. Hierarchical functional specificity of cytosolic heat shock protein 70 (Hsp70) nucleotide exchange factors in yeast. J Biol Chem. 2014;289:13155-67 pubmed publisher
  8. Reineke L, Cao Y, Baus D, Hossain N, Merrick W. Insights into the role of yeast eIF2A in IRES-mediated translation. PLoS ONE. 2011;6:e24492 pubmed publisher
    ..These data suggest that eIF2A acts as a switch to regulate IRES-mediated translation, and eEF1A may be an important mediator of translational activation during ethanol stress. ..
  9. Keefer K, True H. Prion-Associated Toxicity is Rescued by Elimination of Cotranslational Chaperones. PLoS Genet. 2016;12:e1006431 pubmed publisher
    ..This toxicity rescue demonstrates that chaperone modification can block key steps of the prion life cycle and has exciting implications for potential treatment of many human protein conformational disorders. ..
  10. Ma C, Wu S, Li N, Chen Y, Yan K, Li Z, et al. Structural snapshot of cytoplasmic pre-60S ribosomal particles bound by Nmd3, Lsg1, Tif6 and Reh1. Nat Struct Mol Biol. 2017;24:214-220 pubmed publisher
    ..These findings pinpoint a structural checkpoint role for Nmd3 in PTC assembly, and provide information about functional and mechanistic roles of these assembly factors in the maturation of the 60S ribosomal subunit. ..
  11. Mudholkar K, Fitzke E, Prinz C, Mayer M, Rospert S. The Hsp70 homolog Ssb affects ribosome biogenesis via the TORC1-Sch9 signaling pathway. Nat Commun. 2017;8:937 pubmed publisher
    ..Here the authors find that the ribosome biogenesis defect associated with the loss of Ssb is attributable to a specific disruption in TORC1 signaling rather than defects in ribosomal protein folding. ..
  12. Michimoto T, Aoki T, Toh e A, Kikuchi Y. Yeast Pdr13p and Zuo1p molecular chaperones are new functional Hsp70 and Hsp40 partners. Gene. 2000;257:131-7 pubmed
    ..Taken together, we propose that Pdr13p and Zuo1p are a new pair of Hsp70:Hsp40 molecular chaperones. In addition, Pdr13p co-sedimented with translating ribosomes and this association was independent of the presence of Zuo1p. ..
  13. Rakwalska M, Rospert S. The ribosome-bound chaperones RAC and Ssb1/2p are required for accurate translation in Saccharomyces cerevisiae. Mol Cell Biol. 2004;24:9186-97 pubmed
    ..Based on the combined data we conclude that RAC and Ssb1/2p are crucial in maintaining translational fidelity beyond their postulated role as chaperones for nascent polypeptides. ..
  14. Panni S, Montecchi Palazzi L, Kiemer L, Cabibbo A, Paoluzi S, Santonico E, et al. Combining peptide recognition specificity and context information for the prediction of the 14-3-3-mediated interactome in S. cerevisiae and H. sapiens. Proteomics. 2011;11:128-43 pubmed publisher
    ..Our approach provides an orthogonal reliability assessment and maps with high confidence the 14-3-3 peptide target on the partner proteins. ..
  15. Nelson R, Ziegelhoffer T, Nicolet C, Werner Washburne M, Craig E. The translation machinery and 70 kd heat shock protein cooperate in protein synthesis. Cell. 1992;71:97-105 pubmed
    ..Mutant ssb1 ssb2 strains grow slowly, contain a low number of translating ribosomes, and are hypersensitive to several inhibitors of ..
  16. Chiabudini M, Tais A, Zhang Y, Hayashi S, Wölfle T, Fitzke E, et al. Release factor eRF3 mediates premature translation termination on polylysine-stalled ribosomes in Saccharomyces cerevisiae. Mol Cell Biol. 2014;34:4062-76 pubmed publisher
    ..increased in the absence of the ribosome-bound chaperones ribosome-associated complex (RAC) and Ssb (Ssb1 and Ssb2)...
  17. Staresincic L, Walker J, Dirac Svejstrup A, Mitter R, Svejstrup J. GTP-dependent binding and nuclear transport of RNA polymerase II by Npa3 protein. J Biol Chem. 2011;286:35553-61 pubmed publisher
    ..Together, our data suggest that Npa3 defines an unconventional pathway for nuclear import of RNAPII, which involves GTP-dependent binding of Npa3 to the polymerase. ..
  18. Lee R, Brunette S, Puente L, Megeney L. Metacaspase Yca1 is required for clearance of insoluble protein aggregates. Proc Natl Acad Sci U S A. 2010;107:13348-53 pubmed publisher
    ..Together, our results show that Yca1 contributes to the fitness and adaptability of growing yeast through an aggregate remodeling activity. ..
  19. Zhang H, Richardson D, Roberts D, Utley R, Erdjument Bromage H, Tempst P, et al. The Yaf9 component of the SWR1 and NuA4 complexes is required for proper gene expression, histone H4 acetylation, and Htz1 replacement near telomeres. Mol Cell Biol. 2004;24:9424-36 pubmed
    ..Taken together, these data indicate that Yaf9 may function in NuA4 and SWR1 complexes to help antagonize silencing near telomeres. ..
  20. Gautschi M, Just S, Mun A, Ross S, Rücknagel P, Dubaquie Y, et al. The yeast N(alpha)-acetyltransferase NatA is quantitatively anchored to the ribosome and interacts with nascent polypeptides. Mol Cell Biol. 2003;23:7403-14 pubmed
    ..The combination of data suggests that Nat1p presents the N termini of nascent polypeptides for acetylation and might serve additional roles during protein synthesis. ..
  21. Tomala K, Korona R. Alleviation of deleterious effects of protein mutation through inactivation of molecular chaperones. Mol Genet Genomics. 2008;280:409-17 pubmed publisher
    ..We suggest that under non-stressful conditions, molecular chaperones are tuned to support folding of native proteins, but not that of mutated ones. ..
  22. Lopez Buesa P, Pfund C, Craig E. The biochemical properties of the ATPase activity of a 70-kDa heat shock protein (Hsp70) are governed by the C-terminal domains. Proc Natl Acad Sci U S A. 1998;95:15253-8 pubmed
    ..The differential influence of the peptide-binding domain on the ATPase domain may, in part, explain the functional uniqueness of these two classes of Hsp70s. ..
  23. Koplin A, Preissler S, Ilina Y, Koch M, Scior A, Erhardt M, et al. A dual function for chaperones SSB-RAC and the NAC nascent polypeptide-associated complex on ribosomes. J Cell Biol. 2010;189:57-68 pubmed publisher
    ..These findings emphasize the concept that ribosome production is coordinated with the protein-folding capacity of ribosome-associated chaperones. ..
  24. Dragovic Z, Shomura Y, Tzvetkov N, Hartl F, Bracher A. Fes1p acts as a nucleotide exchange factor for the ribosome-associated molecular chaperone Ssb1p. Biol Chem. 2006;387:1593-600 pubmed
    ..Interestingly, Fes1p inhibits the stimulation of Ssb1p ATPase by RAC, suggesting a complex regulatory role of Fes1p in modulating the function of Ssb Hsp70s in co-translational protein folding. ..
  25. Döring K, Ahmed N, Riemer T, Suresh H, Vainshtein Y, Habich M, et al. Profiling Ssb-Nascent Chain Interactions Reveals Principles of Hsp70-Assisted Folding. Cell. 2017;170:298-311.e20 pubmed publisher
    ..Ssb thus employs substrate-tailored dynamic nascent chain associations to coordinate co-translational protein folding, facilitate accelerated translation, and support membrane targeting of organellar proteins. ..
  26. Kosodo Y, Imai K, Hirata A, Noda Y, Takatsuki A, Adachi H, et al. Multicopy suppressors of the sly1 temperature-sensitive mutation in the ER-Golgi vesicular transport in Saccharomyces cerevisiae. Yeast. 2001;18:1003-14 pubmed
    ..were classified as: (1) those that encode a multifunctional suppressor, SSD1; (2) heat shock proteins, SSB1 and SSB2; (3) cell surface proteins, WSC1, WSC2 and MID2; (4) ER-Golgi transport proteins, USO1 and BET1; and (5) an as-yet-..
  27. Chiabudini M, Conz C, Reckmann F, Rospert S. Ribosome-associated complex and Ssb are required for translational repression induced by polylysine segments within nascent chains. Mol Cell Biol. 2012;32:4769-79 pubmed publisher
    ..This active role of RAC/Ssb in the quality control of polylysine proteins significantly contributed to the low level of expression of nonstop transcripts in vivo. ..
  28. Willmund F, del Alamo M, Pechmann S, Chen T, Albanèse V, Dammer E, et al. The cotranslational function of ribosome-associated Hsp70 in eukaryotic protein homeostasis. Cell. 2013;152:196-209 pubmed publisher
    ..Thus, cotranslationally acting Hsp70 meets the challenge of folding the eukaryotic proteome by stabilizing its longer, more slowly translated, and aggregation-prone nascent polypeptides. ..
  29. Bonner J, Carlson T, Fackenthal D, Paddock D, Storey K, Lea K. Complex regulation of the yeast heat shock transcription factor. Mol Biol Cell. 2000;11:1739-51 pubmed
  30. Deplazes A, Möckli N, Luke B, Auerbach D, Peter M. Yeast Uri1p promotes translation initiation and may provide a link to cotranslational quality control. EMBO J. 2009;28:1429-41 pubmed publisher
    ..Together with genetic data, these interactions indicate that Uri1p may coordinate translation initiation and cotranslational quality control. ..
  31. Jao D, Chen K. Tandem affinity purification revealed the hypusine-dependent binding of eukaryotic initiation factor 5A to the translating 80S ribosomal complex. J Cell Biochem. 2006;97:583-98 pubmed
  32. Elbing K, McCartney R, Schmidt M. Purification and characterization of the three Snf1-activating kinases of Saccharomyces cerevisiae. Biochem J. 2006;393:797-805 pubmed
    ..Finally, we showed that the Snf1 kinase domain isolated from bacteria as a GST fusion protein can be activated in vitro and shows substrate specificity in the absence of its beta and gamma subunits. ..
  33. Smith R, Wellman K, Smith M. Trans-species activity of a nonself recognition domain. BMC Microbiol. 2013;13:63 pubmed publisher
    ..Finally, our results suggest that variations on the PA incompatibility domain may serve as novel and specific antimicrobial peptides. ..
  34. Conz C, Otto H, Peisker K, Gautschi M, Wölfle T, Mayer M, et al. Functional characterization of the atypical Hsp70 subunit of yeast ribosome-associated complex. J Biol Chem. 2007;282:33977-84 pubmed
    ..The two domains of this protein thus cooperate in a way that allows for severe interference in either but not in both of them. ..
  35. Mirzaei H, Rogers R, Grimes B, Eng J, Aderem A, Aebersold R. Characterizing the connectivity of poly-ubiquitin chains by selected reaction monitoring mass spectrometry. Mol Biosyst. 2010;6:2004-14 pubmed publisher
    ..cerevisiae. We then applied the method to detect toxin induced changes in the poly-ubiquitination profile in complex and enriched protein samples. ..
  36. Kaplan Y, Kupiec M. A role for the yeast cell cycle/splicing factor Cdc40 in the G1/S transition. Curr Genet. 2007;51:123-40 pubmed
    ..Finally, we discuss possible mechanisms of suppression by the cDNAs that imply cell cycle regulation by apparently unrelated processes, such as splicing, translation initiation and glycolysis. ..
  37. Honey S, Schneider B, Schieltz D, Yates J, Futcher B. A novel multiple affinity purification tag and its use in identification of proteins associated with a cyclin-CDK complex. Nucleic Acids Res. 2001;29:E24 pubmed
    ..Associated proteins were identified using mass spectrometry. These included the known associated proteins Cdc28, Sic1 and Cks1. Several other proteins were found including the 70 kDa chaperone, Ssa1. ..