Does mitochondrial DNA length influence the frequency of spontaneous petite mutants in yeasts?

Clark-Walker, G. D.; McArthur, C. R.; Daley, D. J.

doi:10.1007/bf00376779

Cited by 47 publications

(18 citation statements)

References 28 publications

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“…5). For the control cells, the percentage of respiratory-deficient cells (cells incubated for 3 h in buffer in the absence of Pb) was~2 %, which is within the values described in the literature for the spontaneous formation of these mutants (Clark-Walker et al 1981). The increased formation of RD mutants strongly suggests that mtDNA is one of the targets of Pb-induced ROS.…”

Section: Pb-induced Production Of Superoxide Anion and Hydrogen Peroxidesupporting

confidence: 82%

Mitochondria are the main source and one of the targets of Pb (lead)-induced oxidative stress in the yeast Saccharomyces cerevisiae

Sousa

Soares

2014

Appl Microbiol Biotechnol

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The yeast Saccharomyces cerevisiae is a useful model organism for studying lead (Pb) toxicity. Yeast cells of a laboratory S. cerevisiae strain (WT strain) were incubated with Pb concentrations up to 1,000 μmol/l for 3 h. Cells exposed to Pb lost proliferation capacity without damage to the cell membrane, and they accumulated intracellular superoxide anion (O 2 .− ) and hydrogen peroxide (H 2 O 2 ). The involvement of the mitochondrial electron transport chain (ETC) in the generation of reactive oxygen species (ROS) induced by Pb was evaluated. For this purpose, an isogenic derivative ρ 0 strain, lacking mitochondrial DNA, was used. The ρ 0 strain, without respiratory competence, displayed a lower intracellular ROS accumulation and a higher resistance to Pb compared to the WT strain. The kinetic study of ROS generation in yeast cells exposed to Pb showed that the production of O 2 .− precedes the accumulation of H 2 O 2 , which is compatible with the leakage of electrons from the mitochondrial ETC. Yeast cells exposed to Pb displayed mutations at the mitochondrial DNA level. This is most likely a consequence of oxidative stress. In conclusion, mitochondria are an important source of Pb-induced ROS and, simultaneously, one of the targets of its toxicity.

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Section: Pb-induced Production Of Superoxide Anion and Hydrogen Peroxidesupporting

confidence: 82%

Mitochondria are the main source and one of the targets of Pb (lead)-induced oxidative stress in the yeast Saccharomyces cerevisiae

Sousa

Soares

2014

Appl Microbiol Biotechnol

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“…From the resulting supernatant, mitochondria were pelleted by centrifugation in the same rotor at 9,770g for 5 rain, then lysed by adding 2.0% sarcosyl. From the resulting lysate, DNA was obtained by centrifugation to equilibrium in a bisbenzimide (13 mg/ml) cesium chloride density gradient followed by two phenol extractions (Clark-Walker et al 1981).…”

Section: Methodsmentioning

confidence: 99%

Mitochondrial DNA of the coral sarcophyton glaucum contains a gene for a homologue of bacterial muts: A possible case of gene transfer from the nucleus to the mitochondrion

et al. 1998

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The nucleotide sequences of two segments of 6,737 ntp and 258 nto of the 18.4-kb circular mitochondrial (mt) DNA molecule of the soft coral Sarcophyton glaucum (phylum Cnidaria, class Anthozoa, subclass Octocorallia, order Alcyonacea) have been determined. The larger segment contains the 3' 191 ntp of the gene for subunit 1 of the respiratory chain NADH dehydrogenase (ND1), complete genes for cytochrome b (Cyt b), ND6, ND3, ND4L, and a bacterial MutS homologue (MSH), and the 5' terminal 1,124 ntp of the gene for the large subunit rRNA (1-rRNA). These genes are arranged in the order given and all are transcribed from the same strand of the molecule. The smaller segment contains the 3' terminal 134 ntp of the ND4 gene and a complete tRNA(f-Met) gene, and these genes are transcribed in opposite directions. As in the hexacorallian anthozoan, Metridium senile, the mt-genetic code of S. glaucum is near standard: that is, in contrast to the situation in mt-genetic codes of other invertebrate phyla, AGA and AGG specify arginine, and ATA specifies isoleucine. However, as appears to be universal for metazoan mt-genetic codes, TGA specifies tryptophan rather than termination. Also, as in M. senile the mt-tRNA(f-Met) gene has primary and secondary structural features resembling those of Escherichia coli initiator tRNA, including standard dihydrouridine and T psi C loop sequences, and a mismatched nucleotide pair at the top of the amino-acyl stem. The presence of a mutS gene homologue, which has not been reported to occur in any other known mtDNA, suggests that there is mismatch repair activity in S. glaucum mitochondria. In support of this, phylogenetic analysis of MutS family protein sequences indicates that the S. glaucum mtMSH protein is more closely related to the nuclear DNA-encoded mitochondrial mismatch repair protein (MSH1) of the yeast Saccharomyces cerevisiae than to eukaryotic homologues involved in nuclear function, or to bacterial homologues. Regarding the possible origin of the S. glaucum mtMSH gene, the phylogenetic analysis results, together with comparative base composition considerations, and the absence of an MSH gene in any other known mtDNA best support the hypothesis that S. glaucum mtDNA acquired the mtMSH gene from nuclear DNA early in the evolution of octocorals. The presence of mismatch repair activity in S. glaucum mitochondria might be expected to influence the rate of evolution of this organism's mtDNA.

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“…For isolation of mtDNA, cultures were grown in 1 1 of GYP at 28°C, and spheroplasts were made by digestion with Zymolyase. Spheroplasts were broken in a French press and mtDNA was isolated using bisbenzimide-CsCl buoyant density centrifugation according to a procedure described in detail in Clark-Walker et al (1981). Cloning and Sequencing. Mapping studies of each mtDNA had established the most convenient restriction enzyme sites for use in cloning the COX2 gene (Hoeben and Clark-Walker 1986).…”

Section: Methodsmentioning

confidence: 99%

Larger rearranged mitochondrial genomes in Dekkera/Brettanomyces yeasts are more closely related than smaller genomes with a conserved gene order

Hoeben¹,

Weiller

Clark-Walker³

1993

J Mol Evol

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Mitochondrial genomes from yeasts in the Dekkera/Brettanomyces/Eeniella group vary in size from 28 to 101 kb. Mapping of genes has shown that the three smallest genomes, of 28-42 kb, have the same gene order, whereas the three larger mitochondrial DNAs of 57-101 kb are rearranged relative to the smaller molecules and between themselves. To examine the relationships between these genomes, a phylogenetic tree has been constructed by sequence comparison of the mitochondrial-encoded cytochrome oxidase subunit gene (COX2) from the six species. Contrary to expectation, the tree shows that the larger rearranged genomes are more closely related than the smaller mtDNAs. This result indicates that the gene order of the smaller mtDNAs (28-42 kb) is ancestral and that larger mtDNA molecules (57-101 kb) are more prone to rearrangement than smaller forms.

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Does mitochondrial DNA length influence the frequency of spontaneous petite mutants in yeasts?

Cited by 47 publications

References 28 publications

Mitochondria are the main source and one of the targets of Pb (lead)-induced oxidative stress in the yeast Saccharomyces cerevisiae

Mitochondria are the main source and one of the targets of Pb (lead)-induced oxidative stress in the yeast Saccharomyces cerevisiae

Mitochondrial DNA of the coral sarcophyton glaucum contains a gene for a homologue of bacterial muts: A possible case of gene transfer from the nucleus to the mitochondrion

Larger rearranged mitochondrial genomes in Dekkera/Brettanomyces yeasts are more closely related than smaller genomes with a conserved gene order

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