10 results on '"A. S. Borchsenius"'
Search Results
2. Prion variant maintained only at high levels of the Hsp104 disaggregase
- Author
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Sergey G. Inge-Vechtomov, A. S. Borchsenius, Susanne Müller, Gary P. Newnam, and Yury O. Chernoff
- Subjects
Gene isoform ,Saccharomyces cerevisiae Proteins ,biology ,Prions ,Cell ,Saccharomyces cerevisiae ,General Medicine ,biology.organism_classification ,Yeast ,Hsp70 ,medicine.anatomical_structure ,Biochemistry ,Chaperone (protein) ,Genetics ,medicine ,biology.protein ,Biophysics ,Prion protein ,Overproduction ,Heat-Shock Proteins ,Molecular Chaperones ,Peptide Termination Factors - Abstract
The yeast prion [PSI + ] is a self-perpetuating aggregated isoform of the translation termination factor Sup35. [PSI + ] propagation is promoted by moderate levels and antagonized by high levels of the chaperone Hsp104. In agreement with the model postulating that excess Hsp104 acts on [PSI + ] by disaggregating prion polymers, we show that an increase in Sup35 levels, accompanied by an increase in size of prion aggregates, also partially protects [PSI + ] from elimination by excess Hsp104. Despite retention of [PSI + ], excess Hsp104 decreases toxicity of overproduced Sup35 in [PSI + ] strains. A heritable variant of [PSI + ], which has been isolated and is maintained only in the presence of increased levels of Hsp104, is characterized by an abnormally large aggregate size, and exhibits an altered response to overproduction of the Hsp70 chaperone Ssa1. These features resemble the previously described prion generated by a deletion derivative of Sup35, but are not associated with any sequence alteration and are controlled exclusively at the protein level. Our data provide a proof of the existence of conditionally stable prion variants maintained only at altered levels of Hsps, that could in principle be beneficial if the normal cellular function of a prion protein becomes detrimental to the cell in such conditions. more...
- Published
- 2005
- Full Text
- View/download PDF
Catalog
3. Association between defects of karyogamy and translation termination in yeast Saccharomyces cerevisiae
- Author
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Sergey G. Inge-Vechtomov, A. S. Borchsenius, Cornelia Kurischko, and Repnevskaia Mv
- Subjects
Genetics ,biology ,Strain (chemistry) ,Cosegregation ,Saccharomyces cerevisiae ,Mutant ,biology.organism_classification ,Cytoskeleton ,Gene ,Yeast ,Karyogamy - Abstract
Mutants capable of a high frequency of cytoduction (Hfc+) were obtained in a haploid strain of Saccharomyces cerevisiae, suggesting impaired cytogamy. Nine of the 68 Hfc+ mutants showed the antisuppressor effect with respect to mutations of the SUP35 and SUP45 genes, which code for translation termination factors, or to the [PSI+] factor, which is the prion form of Sup35. Cosegregation of the characters “higher frequency of cytoduction” and “antisuppression” was demonstrated for three Hfc+ mutants. One (HFC12-2) of the Hfc+ mutations exerted a dominant antisuppressor effect with respect to [PSI+] and had no effect on [PSI+] maintenance. On the strength of the results, an interaction was assumed for translation termination components and cytoskeleton proteins, which play a role in karyogamy in yeasts. more...
- Published
- 2005
- Full Text
- View/download PDF
4. [Untitled]
- Author
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V. A. Starzev, Sergey G. Inge-Vechtomov, Yu. V. Sopova, S. P. Zadorsky, and A. S. Borchsenius
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Genetics ,Mutation ,Termination factor ,media_common.quotation_subject ,Nonsense ,Saccharomyces cerevisiae ,macromolecular substances ,Biology ,Pichia methanolica ,biology.organism_classification ,medicine.disease_cause ,Yeast ,Frameshift mutation ,medicine ,Gene ,media_common - Abstract
Mutations in genes of omnipotent nonsense suppressors SUP35 and SUP45 in yeast Saccharomyces cerevisiae encoding translation termination factors eRF3 and eRF1, respectively, and prionization of the eRF3 protein may lead to the suppression of some frameshift mutations (CPC mutations). Partial inactivation of the translation termination factor eRF3 was studied in strains with unstable genetically modified prions and also in transgenic yeast S. cerevisiae strains with the substitution of the indigenous SUP35 gene for its homolog from Pichia methanolica or for a recombinant S. cerevisiae SUP35gene. It was shown that this partial inactivation leads not only to nonsense suppression, but also to suppression of the frameshift lys2-90 mutation. Possible reasons for the correlation between nonsense suppression and suppression of the CPC lys2-90 mutation and mechanisms responsible for the suppression of CPC mutations during inactivation of translation termination factors are discussed. more...
- Published
- 2003
- Full Text
- View/download PDF
5. [PIN (+)]-dependent induction of protease-resistant amyloids by Ade2p protein fused with prionizing NM domain of Sup35 protein of the yeast Saccharomyces cerevisiae
- Author
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A. S. Borchsenius, S. P. Zadorsky, A. A. Pogoda, V. V. Alenin, V. V. Manukhov, and Sergey G. Inge-Vechtomov
- Subjects
Binding Sites ,Saccharomyces cerevisiae Proteins ,biology ,Chemistry ,Peptide Termination Factors ,Saccharomyces cerevisiae ,Biophysics ,Amyloidogenic Proteins ,General Chemistry ,General Medicine ,Plasma protein binding ,biology.organism_classification ,Biochemistry ,Yeast ,Domain (software engineering) ,Protein Structure, Tertiary ,Protease resistant ,Peptide Hydrolases ,Binding site ,Protein Binding - Published
- 2010
6. [Association between defects of karyogamy and translation termination in yeast Saccharomyces cerevisiae]
- Author
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A S, Borchsenius, M V, Repnevskaia, C, Kurischko, and S G, Inge-Vechtomov
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Saccharomyces cerevisiae Proteins ,Suppression, Genetic ,Prions ,Protein Biosynthesis ,Mutation ,Saccharomyces cerevisiae ,Haploidy ,Cytoskeleton ,Peptide Termination Factors - Abstract
Mutants capable of a high frequency of cytoduction (Hfc+) were obtained in a haploid strain of Saccharomyces cerevisiae, suggesting impaired cytogamy. Nine of the 68 Hfc+ mutants showed the antisuppressor effect with respect to mutations of the SUP35 and SUP45 genes, which code for translation termination factors, or to the [PSI+] factor, which is the prion form of Sup35. Cosegregation of the characters "higher frequency of cytoduction" and "antisuppression" was demonstrated for three Hfc+ mutants. One (HFC12-2) of the Hfc+ mutations exerted a dominant antisuppressor effect with respect to [PSI+] and had no effect on [PSI+] maintenance. On the strength of the results, an interaction was assumed for translation termination components and cytoskeleton proteins, which play a role in karyogamy in yeasts. more...
- Published
- 2005
7. Yeast prion protein derivative defective in aggregate shearing and production of new ‘seeds’
- Author
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A. S. Borchsenius, Gary P. Newnam, Yury O. Chernoff, Renee D. Wegrzyn, and Sergey G. Inge-Vechtomov
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Cytoplasm ,Saccharomyces cerevisiae Proteins ,Time Factors ,Genotype ,Prions ,Recombinant Fusion Proteins ,Saccharomyces cerevisiae ,Green Fluorescent Proteins ,Mitosis ,Protein aggregation ,General Biochemistry, Genetics and Molecular Biology ,Article ,Fungal Proteins ,Protein structure ,Protein biosynthesis ,Protein Isoforms ,HSP70 Heat-Shock Proteins ,Molecular Biology ,Alleles ,Heat-Shock Proteins ,Fungal protein ,General Immunology and Microbiology ,biology ,General Neuroscience ,Temperature ,DNA ,biology.organism_classification ,Yeast ,Protein Structure, Tertiary ,Luminescent Proteins ,Biochemistry ,Microscopy, Fluorescence ,Chaperone (protein) ,Protein Biosynthesis ,Mutation ,Biophysics ,biology.protein ,Gene Deletion ,Molecular Chaperones ,Plasmids - Abstract
According to the nucleated polymerization model, in vivo prion proliferation occurs via dissociation (shearing) of the huge prion polymers into smaller oligomeric 'seeds', initiating new rounds of prion replication. Here, we identify the deletion derivative of yeast prion protein Sup35 (Sup35-Delta22/69) that is specifically defective in aggregate shearing and 'seed' production. This derivative, [PSI+], previously thought to be unable to turn into a prion state, in fact retains the ability to form a prion ([PSI+](Delta22/69)) that can be maintained in selective conditions and transmitted by cytoplasmic infection (cytoduction), but which is mitotically unstable in non-selective conditions. MorePSI+](Delta22/69) retains its mitotic stability defect. The [PSI+](Delta22/69) cells contain more Sup35 protein in the insoluble fraction and form larger Sup35 aggregates compared with the conventional [PSI+] cells. Moderate excess of Hsp104 disaggregase increases transmission of the [PSI+](Delta22/69) prion, while excess Hsp70-Ssa chaperone antagonizes it, opposite to their effects on conventional [PSI+]. Our results shed light on the mechanisms determining the differences between transmissible prions and non-transmissible protein aggregates. more...
- Published
- 2001
8. Recessive mutations in SUP35 and SUP45 genes coding for translation release factors affect chromosome stability in Saccharomyces cerevisiae
- Author
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Sergey G. Inge-Vechtomov, Anna A. Tchourikova, and A. S. Borchsenius
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Saccharomyces cerevisiae Proteins ,Prions ,Ultraviolet Rays ,Mutant ,Genes, Recessive ,Saccharomyces cerevisiae ,Biology ,Chromosome segregation ,Fungal Proteins ,Chromosome instability ,Genetics ,Gene ,Anaphase ,Autosome ,Chromosome ,General Medicine ,Fungicides, Industrial ,Protein Biosynthesis ,Mutation ,Benomyl ,Ploidy ,Chromosome Deletion ,Chromosomes, Fungal ,Cell Division ,Peptide Termination Factors - Abstract
Chromosome stability in suppressor mutants for SUP35 and SUP45 genes coding for translation release factors was studied. We obtained spontaneous and UV-induced sup35 or sup45 mutants in a haploid strain disomic for chromosome III and tested the stability of an extra copy of this chromosome. The majority of the mutants showed increased chromosome instability. This phenotype was correlated with an increased sensitivity to the microtubule-poisoning drug benomyl which affects chromosome segregation at anaphase. Our data suggest that termination-translation factors eRF3 and eRF1 control chromosome transmission at mitotic anaphase in Saccharomyces cerevisiae. more...
- Published
- 2000
9. Authors' reply
- Author
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E. Korolev, Ya. Komissarchik, and S. Borchsenius
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Microbiology - Published
- 1994
- Full Text
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10. The influence of mutations at ATG triplets of the open reading frame SUP35 on viability of the yeast Saccharomyces cerevisiae
- Author
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Sergey G. Inge-Vechtomov, N. A. Ryabinkova, and A. S. Borchsenius
- Subjects
Genetics ,Open reading frame ,Eukaryotic translation ,biology ,Transcription (biology) ,Point mutation ,Saccharomyces cerevisiae ,Mutant ,Reading frame ,macromolecular substances ,biology.organism_classification ,Gene - Abstract
The open reading frame SUP35 encoding the translation termination eRF3 factor vital to life contains three ATG codons (ATG1, ATG124, and ATG254). Previously, other authors detected two SUP35 transcripts: a major one that corresponds to the full-length open reading frame and a minor transcript that corresponds to the 3′ terminal site of SUP35 starting at the third ATG codon (ATG254). In this work, mutations at triplets ATG1, ATG124, and ATG254 were obtained as well as double mutations, which combine the point mutation in one of three ATG triplets and a deletion at the site for binding with the transcription factor Abf1 within the SUP35 (sup35-ΔAbf1) promoter. The influence of these mutations on the yeast viability was analyzed. Mutations at triplets ATG124 and ATG254 did not affect yeast viability in their own right or in the background of deletion sup35-ΔAbf1. Mutation sup35-AGG1 (ATG1 → AGG) causes the lethal effect in cells grown on media containing glucose as the sole source of carbon. The replacement of glucose by galactose, or histidine starvation, partially restore the viability of sup35-AGG1 mutants, but not that of double mutants sup35-ΔAbf1,AGG1. The restoration of sup35-AGG1 mutant viability under these conditions can be explained by either the appearance (or enhancement) of the production of short peptides synthesized on the mRNA triplets SUP35 AUG124 and AUG254, or by the enhanced production of the full-length SUP35 transcript coupled with translation initiation from the noncanonical AGG1 codon. These data confirm that the expression of gene SUP35 at the transcription and(or) translation level is regulated by environmental conditions. more...
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