scholarly journals Saccharomyces cerevisiae as a Tool for Studying Mutations in Nuclear Genes Involved in Diseases Caused by Mitochondrial DNA Instability

Genes ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1866
Author(s):  
Alexandru Ionut Gilea ◽  
Camilla Ceccatelli Berti ◽  
Martina Magistrati ◽  
Giulia di Punzio ◽  
Paola Goffrini ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mitochondrial Dna ◽  
Specific Model ◽  
Nuclear Genes ◽  
Model Systems ◽  
Respiratory Chain Complexes ◽  
Yeast Saccharomyces Cerevisiae ◽  
Mtdna Depletion ◽  
Genetic Suppressors ◽  
Mitochondrial Dna Instability

Mitochondrial DNA (mtDNA) maintenance is critical for oxidative phosphorylation (OXPHOS) since some subunits of the respiratory chain complexes are mitochondrially encoded. Pathological mutations in nuclear genes involved in the mtDNA metabolism may result in a quantitative decrease in mtDNA levels, referred to as mtDNA depletion, or in qualitative defects in mtDNA, especially in multiple deletions. Since, in the last decade, most of the novel mutations have been identified through whole-exome sequencing, it is crucial to confirm the pathogenicity by functional analysis in the appropriate model systems. Among these, the yeast Saccharomyces cerevisiae has proved to be a good model for studying mutations associated with mtDNA instability. This review focuses on the use of yeast for evaluating the pathogenicity of mutations in six genes, MPV17/SYM1, MRM2/MRM2, OPA1/MGM1, POLG/MIP1, RRM2B/RNR2, and SLC25A4/AAC2, all associated with mtDNA depletion or multiple deletions. We highlight the techniques used to construct a specific model and to measure the mtDNA instability as well as the main results obtained. We then report the contribution that yeast has given in understanding the pathogenic mechanisms of the mutant variants, in finding the genetic suppressors of the mitochondrial defects and in the discovery of molecules able to improve the mtDNA stability.

scholarly journals Maintenance of Mitochondrial Morphology Is Linked to Maintenance of the Mitochondrial Genome in Saccharomyces cerevisiae

Genetics ◽  
2002 ◽  
Vol 162 (3) ◽  
pp. 1147-1156 ◽  
Author(s):  
Theodor Hanekamp ◽  
Mary K Thorsness ◽  
Indrani Rebbapragada ◽  
Elizabeth M Fisher ◽  
Corrine Seebart ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Growth Rate ◽  
Mitochondrial Dna ◽  
Carbon Sources ◽  
Mitochondrial Morphology ◽  
Yeast Saccharomyces Cerevisiae ◽  
Slow Growth Rate ◽  
Dna Migration ◽  
Mitochondrial Dna Stability ◽  
Extragenic Suppressors

Abstract In the yeast Saccharomyces cerevisiae, certain mutant alleles of YME4, YME6, and MDM10 cause an increased rate of mitochondrial DNA migration to the nucleus, carbon-source-dependent alterations in mitochondrial morphology, and increased rates of mitochondrial DNA loss. While single mutants grow on media requiring mitochondrial respiration, any pairwise combination of these mutations causes a respiratory-deficient phenotype. This double-mutant phenotype allowed cloning of YME6, which is identical to MMM1 and encodes an outer mitochondrial membrane protein essential for maintaining normal mitochondrial morphology. Yeast strains bearing null mutations of MMM1 have altered mitochondrial morphology and a slow growth rate on all carbon sources and quantitatively lack mitochondrial DNA. Extragenic suppressors of MMM1 deletion mutants partially restore mitochondrial morphology to the wild-type state and have a corresponding increase in growth rate and mitochondrial DNA stability. A dominant suppressor also suppresses the phenotypes caused by a point mutation in MMM1, as well as by specific mutations in YME4 and MDM10.

scholarly journals Expression of the Saccharomyces cerevisiae Gene YME1 in the Petite-Negative Yeast Schizosaccharomyces pombe Converts It to Petite-Positive

Genetics ◽  
2000 ◽  
Vol 154 (1) ◽  
pp. 147-154 ◽  
Author(s):  
Douglas J Kominsky ◽  
Peter E Thorsness
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mitochondrial Dna ◽  
Schizosaccharomyces Pombe ◽  
Atp Synthase ◽  
Kluyveromyces Lactis ◽  
Blot Hybridization ◽  
Inner Mitochondrial Membrane ◽  
Yeast Saccharomyces Cerevisiae ◽  
Mitochondrial Atp Synthase ◽  
Petite Negative Yeast

Abstract Organisms that can grow without mitochondrial DNA are referred to as “petite-positive” and those that are inviable in the absence of mitochondrial DNA are termed “petite-negative.” The petite-positive yeast Saccharomyces cerevisiae can be converted to a petite-negative yeast by inactivation of Yme1p, an ATP- and metal-dependent protease associated with the inner mitochondrial membrane. Suppression of this yme1 phenotype can occur by virtue of dominant mutations in the α- and γ-subunits of mitochondrial ATP synthase. These mutations are similar or identical to those occurring in the same subunits of the same enzyme that converts the petite-negative yeast Kluyveromyces lactis to petite-positive. Expression of YME1 in the petite-negative yeast Schizosaccharomyces pombe converts this yeast to petite-positive. No sequence closely related to YME1 was found by DNA-blot hybridization to S. pombe or K. lactis genomic DNA, and no antigenically related proteins were found in mitochondrial extracts of S. pombe probed with antisera directed against Yme1p. Mutations that block the formation of the F1 component of mitochondrial ATP synthase are also petite-negative. Thus, the F1 complex has an essential activity in cells lacking mitochondrial DNA and Yme1p can mediate that activity, even in heterologous systems.

scholarly journals Transformation of Saccharomyces cerevisiae with nonhomologous DNA: illegitimate integration of transforming DNA into yeast chromosomes and in vivo ligation of transforming DNA to mitochondrial DNA sequences

1993 ◽  
Vol 13 (5) ◽  
pp. 2697-2705
Author(s):  
R H Schiestl ◽  
M Dominska ◽  
T D Petes
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mitochondrial Dna ◽  
Dna Sequences ◽  
Topoisomerase I ◽  
Target Sequence ◽  
Base Pairing ◽  
Base Pairs ◽  
Yeast Saccharomyces Cerevisiae ◽  
Dna Fragment

When the yeast Saccharomyces cerevisiae was transformed with DNA that shares no homology to the genome, three classes of transformants were obtained. In the most common class, the DNA was inserted as the result of a reaction that appears to require base pairing between the target sequence and the terminal few base pairs of the transforming DNA fragment. In the second class, no such homology was detected, and the transforming DNA was integrated next to a CTT or GTT in the target; it is likely that these integration events were mediated by topoisomerase I. The final class involved the in vivo ligation of transforming DNA with nucleus-localized linear fragments of mitochondrial DNA.

scholarly journals High-affinity iron and calcium transport pathways are involved in U(VI) uptake in the budding yeast Saccharomyces cerevisiae

2021 ◽  
Author(s):  
Benoît REVEL ◽  
Patrice CATTY ◽  
Stéphane RAVANEL ◽  
Jacques BOURGUIGNON ◽  
Claude ALBAN
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Living Organism ◽  
Functional Expression ◽  
Model Systems ◽  
Rapid Screening ◽  
Unicellular Eukaryote ◽  
Yeast Saccharomyces Cerevisiae ◽  
Transport Pathways ◽  
Living Organisms ◽  
Calcium Iron

Uranium (U) is a naturally-occurring radionuclide toxic for living organisms that can take it up. To date, the mechanisms of U uptake are far from being understood. Here, we used the yeast Saccharomyces cerevisiae as a unicellular eukaryote model to identify U assimilation pathways. Thus, we have identified, for the first time, transport machineries capable of transporting U in a living organism. First, we evidenced a metabolism-dependent U transport in yeast. Then, competition experiments with essential metals allowed us to identify calcium, iron and copper entry pathways as potential routes for U uptake. The analysis of various metal transport mutants revealed that mid1Δ, cch1Δ and ftr1Δ mutants, affected in calcium (Mid1/Cch1 channel) and Fe(III) (Ftr1/Fet3 complex) transport, respectively, exhibited highly reduced U uptake rates and accumulation, demonstrating the implication of these import systems in U uptake. Finally, expression of the Mid1 gene into the mid1Δ mutant restored U uptake levels of the wild type strain, underscoring the central role of the Mid1/Cch1 calcium channel in U absorption process in yeast. Our results also open up the opportunity for rapid screening of U-transporter candidates by functional expression in yeast, before their validation in more complex higher eukaryote model systems.

scholarly journals The cold sensitivity of a mutant of Saccharomyces cerevisiae lacking a mitochondrial heat shock protein 70 is suppressed by loss of mitochondrial DNA.

1996 ◽  
Vol 134 (3) ◽  
pp. 603-613 ◽  
Author(s):  
B Schilke ◽  
J Forster ◽  
J Davis ◽  
P James ◽  
W Walter ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mitochondrial Dna ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Cold Sensitivity ◽  
Growth Defect ◽  
Wild Type ◽  
Yeast Saccharomyces Cerevisiae ◽  
The Matrix ◽  
Cold Sensitive

SSH1, a newly identified member of the heat shock protein (hsp70) multigene family of the budding yeast Saccharomyces cerevisiae, encodes a protein localized to the mitochondrial matrix. Deletion of the SSH1 gene results in extremely slow growth at 23 degrees C or 30 degrees C, but nearly wild-type growth at 37 degrees C. The matrix of the mitochondria contains another hsp70, Ssc1, which is essential for growth and required for translocation of proteins into mitochondria. Unlike SSC1 mutants, an SSH1 mutant showed no detectable defects in import of several proteins from the cytosol to the matrix compared to wild type. Increased expression of Ssc1 partially suppressed the cold-sensitive growth defect of the SSH1 mutant, suggesting that when present in increased amounts, Ssc1 can at least partially carry out the normal functions of Ssh1. Spontaneous suppressors of the cold-sensitive phenotype of an SSH1 null mutant were obtained at a high frequency at 23 degrees C, and were all found to be respiration deficient. 15 of 16 suppressors that were analyzed lacked mitochondrial DNA, while the 16th had reduced amounts. We suggest that Ssh1 is required for normal mitochondrial DNA replication, and that disruption of this process in ssh1 cells results in a defect in mitochondrial function at low temperatures.

The Saccharomyces cerevisiae Cdc68 transcription activator is antagonized by San1, a protein implicated in transcriptional silencing

1993 ◽  
Vol 13 (12) ◽  
pp. 7553-7565
Author(s):  
Q Xu ◽  
G C Johnston ◽  
R A Singer
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Copy Number ◽  
Null Allele ◽  
Transcriptional Silencing ◽  
Restrictive Temperature ◽  
Wild Type ◽  
Transcription Activator ◽  
Yeast Saccharomyces Cerevisiae ◽  
Suppressor Genes ◽  
Genetic Suppressors

The CDC68 gene (also called SPT16) encodes a transcription factor for the expression of a diverse set of genes in the budding yeast Saccharomyces cerevisiae. To identify other proteins that are functionally related to the Cdc68 protein, we searched for genetic suppressors of a cdc68 mutation. Four suppressor genes in which mutations reverse the temperature sensitivity imposed by the cdc68-1 mutation were found. We show here that one of the suppressor genes is the previously reported SAN1 gene; san1 mutations were originally identified as suppressors of a sir4 mutation, implicated in the chromatin-mediated transcriptional silencing of the two mating-type loci HML and HMR. Each san1 mutation, including a san1 null allele, reversed all aspects of the cdc68 mutant phenotype. Conversely, increased copy number of the wild-type SAN1 gene lowered the restrictive temperature for the cdc68-1 mutation. Our findings suggest that the San1 protein antagonizes the transcriptional activator function of the Cdc68 protein. The identification of san1 mutations as suppressors of cdc68 mutations suggests a role for Cdc68 in chromatin structure.

scholarly journals A Genomewide Screen for Petite-negative Yeast Strains Yields a New Subunit of the i-AAA Protease Complex

2006 ◽  
Vol 17 (1) ◽  
pp. 213-226 ◽  
Author(s):  
Cory D. Dunn ◽  
Marina S. Lee ◽  
Forrest A. Spencer ◽  
Robert E. Jensen
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mitochondrial Dna ◽  
Cell Viability ◽  
Yeast Saccharomyces Cerevisiae ◽  
Inner Membrane ◽  
Mitochondrial Inner Membrane ◽  
Yeast Strains ◽  
Petite Negative Yeast ◽  
Yeast Mutants ◽  
The Relationship

Unlike many other organisms, the yeast Saccharomyces cerevisiae can tolerate the loss of mitochondrial DNA (mtDNA). Although a few proteins have been identified that are required for yeast cell viability without mtDNA, the mechanism of mtDNA-independent growth is not completely understood. To probe the relationship between the mitochondrial genome and cell viability, we conducted a microarray-based, genomewide screen for mitochondrial DNA-dependent yeast mutants. Among the several genes that we discovered is MGR1, which encodes a novel subunit of the i-AAA protease complex located in the mitochondrial inner membrane. mgr1Δ mutants retain some i-AAA protease activity, yet mitochondria lacking Mgr1p contain a misassembled i-AAA protease and are defective for turnover of mitochondrial inner membrane proteins. Our results highlight the importance of the i-AAA complex and proteolysis at the inner membrane in cells lacking mitochondrial DNA.

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