Abstract
Following targeted disruption of the unique CYC1 gene, the petite-negative yeast, Kluyveromyces lactis, was found to grow fermentatively in the absence of cytochrome c-mediated respiration. This observation encouraged us to seek mitochondrial mutants by treatment of K. lactis with ethidium bromide at the highest concentration permitting survival. By this technique, we isolated four mtDNA mutants, three lacking mtDNA and one with a deleted mitochondrial genome. In the three isolates lacking mtDNA, a nuclear mutation is present that permits petite formation. The three mutations occur at two different loci, designated MGI1 and MGI2 (for Mitochondrial Genome Integrity). The mgi mutations convert K. lactis into a petite-positive yeast. Like bakers' yeast, the mgi mutants spontaneously produce petites with deletions in mtDNA and lose this genome at high frequency on treatment with ethidium bromide. We suggest that the MGI gene products are required for maintaining the integrity of the mitochondrial genome and that, petite-positive yeasts may be naturally altered in one or other of these genes.
Full Text
The Full Text of this article is available as a PDF (3.8 MB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Chen X. J., Saliola M., Falcone C., Bianchi M. M., Fukuhara H. Sequence organization of the circular plasmid pKD1 from the yeast Kluyveromyces drosophilarum. Nucleic Acids Res. 1986 Jun 11;14(11):4471–4481. doi: 10.1093/nar/14.11.4471. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Clark-Walker G. D. Contrasting mutation rates in mitochondrial and nuclear genes of yeasts versus mammals. Curr Genet. 1991 Aug;20(3):195–198. doi: 10.1007/BF00326232. [DOI] [PubMed] [Google Scholar]
- Clark-Walker G. D., Miklos G. L. Mitochondrial genetics, circular DNA and the mechanism of the petite mutation in yeast. Genet Res. 1974 Aug;24(1):43–57. doi: 10.1017/s0016672300015068. [DOI] [PubMed] [Google Scholar]
- De Deken R. H. The Crabtree effects and its relation to the petite mutation. J Gen Microbiol. 1966 Aug;44(2):157–165. doi: 10.1099/00221287-44-2-157. [DOI] [PubMed] [Google Scholar]
- Faye G., Fukuhara H., Grandchamp C., Lazowska J., Michel F., Casey J., Getz G. S., Locker J., Rabinowitz M., Bolotin-Fukuhara M. Mitochondrial nucleic acids in the petite colonie mutants: deletions and repetition of genes. Biochimie. 1973;55(6):779–792. doi: 10.1016/s0300-9084(73)80030-6. [DOI] [PubMed] [Google Scholar]
- Goffrini P., Algeri A. A., Donnini C., Wesolowski-Louvel M., Ferrero I. RAG1 and RAG2: nuclear genes involved in the dependence/independence on mitochondrial respiratory function for growth on sugars. Yeast. 1989 Mar-Apr;5(2):99–106. doi: 10.1002/yea.320050205. [DOI] [PubMed] [Google Scholar]
- Goffrini P., Wesolowski-Louvel M., Ferrero I., Fukuhara H. RAG1 gene of the yeast Kluyveromyces lactis codes for a sugar transporter. Nucleic Acids Res. 1990 Sep 11;18(17):5294–5294. doi: 10.1093/nar/18.17.5294. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Haffter P., Fox T. D. Nuclear mutations in the petite-negative yeast Schizosaccharomyces pombe allow growth of cells lacking mitochondrial DNA. Genetics. 1992 Jun;131(2):255–260. doi: 10.1093/genetics/131.2.255. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hardy C. M., Galeotti C. L., Clark-Walker G. D. Deletions and rearrangements in Kluyveromyces lactis mitochondrial DNA. Curr Genet. 1989 Dec;16(5-6):419–427. doi: 10.1007/BF00340721. [DOI] [PubMed] [Google Scholar]
- Herman A. I., Griffin P. S. Respiratory-deficient mutants in Saccharomyces lactis. J Bacteriol. 1968 Aug;96(2):457–461. doi: 10.1128/jb.96.2.457-461.1968. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kolarov J., Kolarova N., Nelson N. A third ADP/ATP translocator gene in yeast. J Biol Chem. 1990 Jul 25;265(21):12711–12716. [PubMed] [Google Scholar]
- Kovácová V., Irmlerová J., Kovác L. Oxidative phosphorylatiion in yeast. IV. Combination of a nuclear mutation affecting oxidative phosphorylation with cytoplasmic mutation to respiratory deficiency. Biochim Biophys Acta. 1968 Aug 20;162(2):157–163. doi: 10.1016/0005-2728(68)90097-2. [DOI] [PubMed] [Google Scholar]
- Tingle M., Herman A., Halvorson H. O. Characterization and mapping of histidine genes in Saccharomyces lactis. Genetics. 1968 Mar;58(3):361–371. doi: 10.1093/genetics/58.3.361. [DOI] [PMC free article] [PubMed] [Google Scholar]