Gene Symbol: MGE1
Description: Mge1p
Alias: YGE1, Mge1p
Species: Saccharomyces cerevisiae S288c

Top Publications

  1. Truscott K, Voos W, Frazier A, Lind M, Li Y, Geissler A, et al. A J-protein is an essential subunit of the presequence translocase-associated protein import motor of mitochondria. J Cell Biol. 2003;163:707-13 pubmed
    ..are known: mitochondrial Hsp70 (mtHsp70); the peripheral membrane protein Tim44; and the nucleotide exchange factor Mge1. We have identified the fourth essential subunit of the PAM, an essential inner membrane protein of 18 kD with a J-..
  2. 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
    ..The nucleotide state of Ssc1 is thereby regulated by the nucleotide exchange factor Mge1. Here, we show that Mge1 interacts with Ssq1 in an ATP-dependent manner, suggesting that Mge1 also regulates Ssq1 ..
  3. Becker D, Krayl M, Strub A, Li Y, Mayer M, Voos W. Impaired interdomain communication in mitochondrial Hsp70 results in the loss of inward-directed translocation force. J Biol Chem. 2009;284:2934-46 pubmed publisher
    ..We conclude that even a partial disruption of the interdomain communication in the mtHsp70 chaperone results in an almost complete breakdown of its translocation-driving properties. ..
  4. Weiss C, Niv A, Azem A. Two-step purification of mitochondrial Hsp70, Ssc1p, using Mge1(His)(6) immobilized on Ni-agarose. Protein Expr Purif. 2002;24:268-73 pubmed
    ..Following a first step of anion exchange at pH 6.6, a column of Mge1(His)(6) immobilized on Ni(2+)-agarose provides an efficient second dimension that results in highly purified ..
  5. Moro F, Muga A. Thermal adaptation of the yeast mitochondrial Hsp70 system is regulated by the reversible unfolding of its nucleotide exchange factor. J Mol Biol. 2006;358:1367-77 pubmed
    ..b>Mge1p, a mitochondrial matrix protein with homology to bacterial GrpE, serves as the nucleotide exchange factor of ..
  6. Schiller D, Cheng Y, Liu Q, Walter W, Craig E. Residues of Tim44 involved in both association with the translocon of the inner mitochondrial membrane and regulation of mitochondrial Hsp70 tethering. Mol Cell Biol. 2008;28:4424-33 pubmed publisher
  7. Laloraya S, Gambill B, Craig E. A role for a eukaryotic GrpE-related protein, Mge1p, in protein translocation. Proc Natl Acad Sci U S A. 1994;91:6481-5 pubmed
    ..Cells with reduced expression of Mge1p accumulate the precursor form of a mitochondrial protein...
  8. Schneider H, Westermann B, Neupert W, Brunner M. The nucleotide exchange factor MGE exerts a key function in the ATP-dependent cycle of mt-Hsp70-Tim44 interaction driving mitochondrial protein import. EMBO J. 1996;15:5796-803 pubmed
    ..We show that Mge1p, a co-chaperone of mt-Hsp70, plays a key role in the ATP-dependent import reaction cycle in yeast...
  9. 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
    ..chaperone system, composed of the Hsp70 Ssq1p, its co-chaperone J-protein Jac1p, and the nucleotide release factor Mge1p, perform a critical function in the biogenesis of iron-sulfur (Fe/S) proteins...

More Information


  1. Blamowska M, Sichting M, Mapa K, Mokranjac D, Neupert W, Hell K. ATPase domain and interdomain linker play a key role in aggregation of mitochondrial Hsp70 chaperone Ssc1. J Biol Chem. 2010;285:4423-31 pubmed publisher
    ..In conclusion, our results suggest that interdomain communication makes Ssc1 prone to aggregation. Hep1 counteracts aggregation by binding to this aggregation-prone conformer. ..
  2. Miao B, Davis J, Craig E. Mge1 functions as a nucleotide release factor for Ssc1, a mitochondrial Hsp70 of Saccharomyces cerevisiae. J Mol Biol. 1997;265:541-52 pubmed
    b>Mge1, a GrpE-related protein in the mitochondrial matrix of the budding yeast Saccharomyces cerevisiae, is required for translocation of precursor proteins into mitochondria...
  3. Laloraya S, Dekker P, Voos W, Craig E, Pfanner N. Mitochondrial GrpE modulates the function of matrix Hsp70 in translocation and maturation of preproteins. Mol Cell Biol. 1995;15:7098-105 pubmed
    Mitochondrial GrpE (Mge1p) is a mitochondrial cochaperone essential for viability of the yeast Saccharomyces cerevisiae...
  4. Sakuragi S, Liu Q, Craig E. Interaction between the nucleotide exchange factor Mge1 and the mitochondrial Hsp70 Ssc1. J Biol Chem. 1999;274:11275-82 pubmed
    ..and Ssc1 of the mitochondrial matrix of Saccharomyces cerevisiae requires the nucleotide release factors, GrpE and Mge1, respectively...
  5. Mokranjac D, Sichting M, Neupert W, Hell K. Tim14, a novel key component of the import motor of the TIM23 protein translocase of mitochondria. EMBO J. 2003;22:4945-56 pubmed
    ..We propose a model in which Tim14 is required for the activation of mtHsp70 and enables this chaperone to act in a rapid and regulated manner in the Tim44-mediated trapping of unfolded preproteins entering the matrix. ..
  6. von Ahsen O, Voos W, Henninger H, Pfanner N. The mitochondrial protein import machinery. Role of ATP in dissociation of the Hsp70.Mim44 complex. J Biol Chem. 1995;270:29848-53 pubmed
    ..We conclude that binding of ATP, not hydrolysis, is required to dissociate the mt-Hsp70.Mim44 complex and that the reaction cycle includes an ATP-induced conformational change of mt-Hsp70. ..
  7. Vögtle F, Wortelkamp S, Zahedi R, Becker D, Leidhold C, Gevaert K, et al. Global analysis of the mitochondrial N-proteome identifies a processing peptidase critical for protein stability. Cell. 2009;139:428-39 pubmed publisher
    ..Our results suggest that Icp55 is critical for stabilization of the mitochondrial proteome and illustrate how the N-proteome can serve as rich source for a systematic analysis of mitochondrial protein targeting, cleavage and turnover. ..
  8. Sikor M, Mapa K, von Voithenberg L, Mokranjac D, Lamb D. Real-time observation of the conformational dynamics of mitochondrial Hsp70 by spFRET. EMBO J. 2013;32:1639-49 pubmed publisher
    ..The nucleotide-exchange factor Mge1 did not induce ADP release, as expected, but rather facilitated binding of ATP...
  9. Schneider H, Berthold J, Bauer M, Dietmeier K, Guiard B, Brunner M, et al. Mitochondrial Hsp70/MIM44 complex facilitates protein import. Nature. 1994;371:768-74 pubmed
    ..The complex appears to act as a molecular ratchet which is energetically driven by the hydrolysis of ATP. ..
  10. 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
    ..interaction with the preprotein translocase subunit Tim44, the cochaperone Mdj1, and the nucleotide exchange factor Mge1. In contrast, only limited information is available on Ssq1...
  11. Adam A, Bornhovd C, Prokisch H, Neupert W, Hell K. The Nfs1 interacting protein Isd11 has an essential role in Fe/S cluster biogenesis in mitochondria. EMBO J. 2006;25:174-83 pubmed
    ..In the absence of Isd11, Nfs1 is prone to aggregation. We propose that Isd11 acts together with Nfs1 in an early step in the biogenesis of Fe/S proteins. ..
  12. Baumann F, Milisav I, Neupert W, Herrmann J. Ecm10, a novel hsp70 homolog in the mitochondrial matrix of the yeast Saccharomyces cerevisiae. FEBS Lett. 2000;487:307-12 pubmed
    ..Like Ssc1, Ecm10 interacts with the nucleotide exchange factor Mge1 in an ATP-dependent manner...
  13. Allu P, Marada A, Boggula Y, Karri S, Krishnamoorthy T, Sepuri N. Methionine sulfoxide reductase 2 reversibly regulates Mge1, a cochaperone of mitochondrial Hsp70, during oxidative stress. Mol Biol Cell. 2015;26:406-19 pubmed publisher
    ..Our earlier studies showed that Mge1, an evolutionarily conserved nucleotide exchange factor of Hsp70, acts as an oxidative sensor to regulate ..
  14. Kubo Y, Tsunehiro T, Nishikawa S, Nakai M, Ikeda E, Toh e A, et al. Two distinct mechanisms operate in the reactivation of heat-denatured proteins by the mitochondrial Hsp70/Mdj1p/Yge1p chaperone system. J Mol Biol. 1999;286:447-64 pubmed
    ..We have observed a similar two-pathway reactivation of heat-denatured luciferase by the bacterial Hsp70 and the yeast cytosolic Hsp70 systems. ..
  15. Merlin A, von Ahsen O, Craig E, Dietmeier K, Pfanner N. A mutant form of mitochondrial GrpE suppresses the sorting defect caused by an alteration in the presequence of cytochrome b2. J Mol Biol. 1997;273:1-6 pubmed
    ..Together with its co-chaperone mitochondrial GrpE (Mge1), mtHsp70 transiently binds to the inner membrane translocase subunit Tim44 in a nucleotide-regulated manner, ..
  16. Horst M, Oppliger W, Rospert S, Schönfeld H, Schatz G, Azem A. Sequential action of two hsp70 complexes during protein import into mitochondria. EMBO J. 1997;16:1842-9 pubmed
    ..A precursor protein entering the matrix interacts first with the import complex and then with the folding complex. A chaperone can thus function as part of two different complexes within the same organelle. ..
  17. Bolliger L, Deloche O, Glick B, Georgopoulos C, Jeno P, Kronidou N, et al. A mitochondrial homolog of bacterial GrpE interacts with mitochondrial hsp70 and is essential for viability. EMBO J. 1994;13:1998-2006 pubmed
    ..Yeast GrpEp is made as a precursor that is cleaved upon import into isolated mitochondria. GrpEp is essential for viability. We suggest that this protein interacts with mhsp70 in a manner analogous to that of GrpE with DnaK of E.coli. ..
  18. Marada A, Karri S, Singh S, Allu P, Boggula Y, Krishnamoorthy T, et al. A Single Point Mutation in Mitochondrial Hsp70 Cochaperone Mge1 Gains Thermal Stability and Resistance. Biochemistry. 2016;55:7065-7072 pubmed publisher
    b>Mge1, a yeast homologue of Escherichia coli GrpE, is an evolutionarily conserved homodimeric nucleotide exchange factor of mitochondrial Hsp70...
  19. Geissler A, Rassow J, Pfanner N, Voos W. Mitochondrial import driving forces: enhanced trapping by matrix Hsp70 stimulates translocation and reduces the membrane potential dependence of loosely folded preproteins. Mol Cell Biol. 2001;21:7097-104 pubmed
  20. Sichting M, Mokranjac D, Azem A, Neupert W, Hell K. Maintenance of structure and function of mitochondrial Hsp70 chaperones requires the chaperone Hep1. EMBO J. 2005;24:1046-56 pubmed
    ..This process is efficiently counteracted by Hep1. We conclude that Hep1 acts as a chaperone that is necessary and sufficient to prevent self-aggregation and to thereby maintain the function of the mitochondrial Hsp70 chaperones. ..
  21. Marada A, Allu P, Murari A, Pullareddy B, Tammineni P, Thiriveedi V, et al. Mge1, a nucleotide exchange factor of Hsp70, acts as an oxidative sensor to regulate mitochondrial Hsp70 function. Mol Biol Cell. 2013;24:692-703 pubmed publisher
    ..Dimeric yeast Mge1, the cochaperone of heat shock protein 70 (Hsp70), is essential for exchanging ATP for ADP on Hsp70 and thus for ..
  22. Voos W, Gambill B, Laloraya S, Ang D, Craig E, Pfanner N. Mitochondrial GrpE is present in a complex with hsp70 and preproteins in transit across membranes. Mol Cell Biol. 1994;14:6627-34 pubmed
    ..After being imported into the matrix, the preprotein could be coprecipitated only by antibodies against mt-hsp70. We propose that mt-hsp70 and MGE cooperate in membrane translocation of preproteins. ..
  23. Chacinska A, Rehling P, Guiard B, Frazier A, Schulze Specking A, Pfanner N, et al. Mitochondrial translocation contact sites: separation of dynamic and stabilizing elements in formation of a TOM-TIM-preprotein supercomplex. EMBO J. 2003;22:5370-81 pubmed
    ..Thus, Tim50 functions as a dynamic factor and the IMS domain of Tom22 represents a stabilizing element in formation of a productive translocation contact site supercomplex. ..
  24. Nakai M, Kato Y, Ikeda E, Toh e A, Endo T. Yge1p, a eukaryotic Grp-E homolog, is localized in the mitochondrial matrix and interacts with mitochondrial Hsp70. Biochem Biophys Res Commun. 1994;200:435-42 pubmed
    Yeast Yge1p, the gene product of YGE1, is a eukaryotic GrpE homolog found recently (Ikeda et al., 1994). We have revealed here that Yge1p is a soluble protein in the mitochondrial matrix...
  25. Samaddar M, Goswami A, Purushotham J, Hegde P, D Silva P. Role of the loop L4,5 in allosteric regulation in mtHsp70s: in vivo significance of domain communication and its implications in protein translocation. Mol Biol Cell. 2014;25:2129-42 pubmed publisher