Molecular and General Genetics MGG

, Volume 252, Issue 6, pp 746–750 | Cite as

A vital function for mitochondrial DNA in the petite-negative yeastKluyveromyces lactis

  • G. D. Clark-Walker
  • X. J. Chen
Short Communication


Petite-negative yeasts do not form viable respiratory-deficient mutants on treatment with DNA-targeting drugs that readily eliminate the mitochondial DNA (mtDNA) from petite-positive yeasts. However, in the petite-negative yeastKluyveromyces lactis, specific mutations in the nuclear genesMGI2 andMGI5 encoding theα- andγ-subunits of the mitochondrial F1-ATPase, allow mtDNA to be lost. In this study we show that wild-typeK. lactis does not survive in the absence of its mitochondrial genome and that the function ofmgi mutations is to suppress lethality caused by loss of mtDNA. Firstly, we find that loss of a multicopy plasmid bearing amgi allele readily occurs from a wild-type strain with functional mtDNA but is not tolerated in the absence of mtDNA. Secondly, we cloned theK. lactis homologue of theSaccharomyces cerevisiae mitochondrial genome maintenance geneMGM101, and disrupted one of the two copies in a diploid. Following sporulation, we find that segregants containing the disrupted gene form minicolonies containing 6-8000 inviable cells. By contrast, disruption ofMGM101 is not lethal in a haploidmgi strain with a specific mutation in a subunit of the mitochondrial F1-ATPase. These observations suggest that mtDNA inK. lactis encodes a vital function which may reside in one of the three mitochondrially encoded subunits of F0.

Key words

Mitochondrial DNA Kluyveromyces lactis MGM101/MGI genes Petite-negative yeast 


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  1. Bulder CGEA (1964a) Induction of petite mutation and inhibition of synthesis of respiratory enzymes in various yeasts. Antonie van Leeuwenhoek 30:1–9Google Scholar
  2. Bulder CGEA (1964b) Lethality of the petite mutation in petite negative yeasts. Antonic van Leeuwenhoek 30:442–454Google Scholar
  3. Chen XJ (1996) Low and high copy number shuttle vectors for replication in the budding yeastKluyveromyces lactis. Gene 172:131–136Google Scholar
  4. Chen XJ, Clark-Walker GD (1993) Mutations inMGI genes convertKluyveromyces lactis into a petite-positive yeast. Genetics 133:517–525Google Scholar
  5. Chen XJ, Clark-Walker GD (1995) Specific mutations in α- and γ-subunits of F1 ATPase affect mitochondrial genome integrity in the petite-negative yeastKluyveromyces lactis. EMBO J 14:3277–3286Google Scholar
  6. Chen XJ, Guan MX, Clark-Walker GD (1993)MGM101, a nuclear gene involved in maintenance of the mitochondrial genome inSaccharomyces cerevisiae. Nucleic Acids Res 21:3473–3477Google Scholar
  7. Clark-Walker GD, McArthur CR, Daley DJ (1981) Does mitochondrial DNA length influence the frequency of spontaneous petite mutants in yeast? Curr Genet 4:7–12Google Scholar
  8. Desjardins P, Frost E, Morais R (1985) Ethidium bromide-induced loss of mitochondrial DNA from primary chicken embryo fibroblasts. Mol Cell Biol 5:1163–1169Google Scholar
  9. Ephrussi B (1953) Nucleo-Cytoplasmic Relations in Micro-organisms. Clarendon Press, Oxford.Google Scholar
  10. Futai M, Noumi T, Maeda M (1989) ATP synthase (H+-ATPase): results by combined biochemical and molecular biological approaches. Annu Rev Biochem 58:111–136Google Scholar
  11. Gietz D, Jean AS, Woods RA, Schiestl RH (1992) Improved method for high efficiency transformation of intact yeast cells. Nucleic Acids Res 20:1425Google Scholar
  12. Hafter P, Fox TD (1992) Nuclear mutations in the petite-negative yeastSchizosaccharomyces pombe allow growth of cells lacking mitochondrial DNA. Genetics 131:255–260Google Scholar
  13. Hardy CM, Galeotti CL, Clark-Walker GD (1989) Deletions and rearrangements inKluyveromyces lactis mitochondrial DNA. Curr Genet 16:419–428Google Scholar
  14. Heritage J, Whittaker PA (1977) Isolation of metabolically activepetite mutants ofKluyveromyces lactis, a petite-negative yeast. Mol Gen Genet 156:93–98Google Scholar
  15. Hatefi Y (1993) ATP synthesis in mitochondria. Eur J Biochem 218:1759–1769Google Scholar
  16. King MP, Attardi G (1989) Human cells lacking mtDNA: repopulation with exogenous mitochondria by complementation. Science 246:500–503Google Scholar
  17. Penefsky H, Cross RL (1991) Structure and mechanism of F1F0 ATP synthases and ATPases. Adv Enzymol 64:173–214Google Scholar
  18. Rothstein RJ (1983) A one-step gene disruption in yeast. Methods Enzymol 101:202–210Google Scholar
  19. Sanger FS, Nicklen S, Coulson AR (1977) DNA sequencing with chain terminating inhibitors. Proc Natl Acad Sci USA 74:5463–5467Google Scholar
  20. Sherman F, Fink GR, Hicks JB (1983) Methods in Yeast Genetics. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New YorkGoogle Scholar
  21. Slonimski P, Perrodin G, Croft JH (1968) Ethidium bromide-induced mutation of yeast mitochondria: complete transformation of cells into respiratory deficient non-chromosomal ‘petites’. Biochem Biophys Res Commun 30:232–239Google Scholar
  22. Stark MJR, Milner JS (1989) Cloning and analysis of theKluyveromyces lactis TRPI gene: a chromosomal locus flanked by genes encoding inorganic pyrophosphatase and histone H3. Yeast 5:35–50Google Scholar
  23. Wallace DC (1994) Mitochondrial DNA sequence variation in human evolution and disease. Proc Natl Acad Sci USA 91:8739–8746Google Scholar

Copyright information

© Springer-Verlag 1996

Authors and Affiliations

  • G. D. Clark-Walker
    • 1
  • X. J. Chen
    • 1
  1. 1.Molecular and Population Genetics Group, Research School of Biological SciencesThe Australian National UniversityCanberra CityAustralia

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