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1

The rules of aging: are they universal? Is the yeast model relevant for gerontology?

100%

Bilinski T., Zadrag-Tecza R.

Acta Biochimica Polonica

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2014

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vol. 61

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issue 4

663-669

EN

The success of experimental biology was possible due to the use of model organisms. It is believed that the mechanisms of aging have a universal character and they are conserved in a wide range of organisms. The explanation of these universal mechanisms by tracing survival curves of model organisms clearly suggests that death of individuals is a direct consequence of aging. Furthermore, the use of unicellular organisms like yeast Saccharomyces cerevisiae to explain the aging processes of multicellular organisms runs the risk of oversimplification. Aging is a very complex process and therefore in this paper we present arguments suggesting that some of these fundamental assumptions require a deep rethinking and verification.

2

Induction of the synthesis of an additional family of long-chain dolichols in the yeast Saccharomyces cerevisiae. Effect of starvation and ageing.

100%

Szkopinska A., Swiezewska E., Rytka J.

Acta Biochimica Polonica

|

2002

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vol. 49

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issue 3

781-787

EN

The yeast Saccharomyces cerevisiae strain W303 synthesizes in the early logarithmic phase of growth dolichols of 14-18 isoprene residues. The analysis of the polyisoprenoids present in the stationary phase revealed an additional family which proved to be also dolichols but of 19-24 isoprene residues, constituting 39% of the total dolichols. The transfer of early logarithmic phase cells to a starvation medium lacking glucose or nitrogen resulted in the synthesis of the longer chain dolichols. The additional family of dolichols represented 13.8% and 10.3% of total dolichols in the glucose and nitrogen deficient media, respectively. The level of dolichols in yeast cells increased with the age of the cultures. Since both families of dolichols are present in stationary phase cells we postulate that the longer chain dolichols may be responsible for the physico-chemical changes in cellular membranes allowing yeast cells to adapt to nutrient deficient conditions to maintain long-term viability.

3

The links between hypertrophy, reproductive potential and longevity in the Saccharomyces cerevisiae yeast

100%

Molon M., Zadrag-Tecza R.

Acta Biochimica Polonica

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2016

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vol. 63

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issue 2

329-334

EN

The yeast Saccharomyces cerevisiae has long been used as a model organism for studying the basic mechanisms of aging. However, the main problem with the use of this unicellular fungus is the unit of "longevity". For all organisms, lifespan is expressed in units of time, while in the case of yeast it is defined by the number of daughter cells produced. Additionally, in yeast the phenotypic effects of mutations often show a clear dependence on the genetic background, suggesting the need for an analysis of strains representing different genetic backgrounds. Our results confirm the data presented in earlier papers that the reproductive potential is strongly associated with an increase in cell volume per generation. An excessive cell volume results in the loss of reproductive capacity. These data clearly support the hypertrophy hypothesis. The time of life of all analysed mutants, with the exception of sch9D, is the same as in the case of the wild-type strain. Interestingly, the 121% increase of the fob1D mutant's reproductive potential compared to the sfp1D mutant does not result in prolongation of the mutant's time of life (total lifespan).

4

Relationship between the replicative age and cell volume in Saccharomyces cerevisiae

100%

Zadrag R., Kwolek-Mirek M., Bartosz G., Bilinski T.

Acta Biochimica Polonica

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2006

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vol. 53

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issue 4

747-751

EN

Reaching the limit of cell divisions, a phenomenon referred to as replicative aging, of the yeast Saccharomyces cerevisiae involves a progressive increase in the cell volume. However, the exact relationship between the number of cell divisions accomplished (replicative age), the potential for further divisions and yeast cell volume has not been investigated thoroughly. In this study an increase of the yeast cell volume was achieved by treatment with pheromone α for up to 18 h. Plotting the number of cell divisions (replicative life span) of the pheromone-treated cells as a function of the cell volume attained during the treatment showed an inverse linear relationship. An analogous inverse relationship between the initial cell volume and replicative life span was found for the progeny of the pheromone-treated yeast. This phenomenon indicates that attaining an excessive volume may be a factor contributing to the limitation of cellular divisions of yeast cells.

5

Different properties of four molecular forms of protein kinase CK2 from Saccharomyces cerevisiae

100%

Domańska K., Zieliński R., Kubiński K., Sajnaga E., Masłyk M., Bretner M., Szyszka R.

Acta Biochimica Polonica

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2005

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vol. 52

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issue 4

947-951

EN

CK2 is a pleiotropic constitutively active serine/threonine protein kinase composed of two catalytic α- and two regulatory β-subunits, whose regulation is still not well understood. It seems to play an essential role in regulation of many cellular processes. Four active forms of CK2, composed of αα'ββ', α2ββ', α'2ββ', and a free α'-subunit were isolated from wild-type yeast and strains containing a single deletion of the catalytic subunit. Each species exhibits properties typical for CK2, but they differ in substrate specificity and sensitivity to inhibitors. This suggests that each CK2 isomer may regulate different process or may differ in the way of its regulation.

6

Studies on oligosaccharyl transferase in yeast

100%

Lennarz W. J.

Acta Biochimica Polonica

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2007

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vol. 54

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issue 4

673-677

EN

In yeast, OT consists of nine different subunits, all of which contain one or more predicted transmembrane segments. In yeast, five of these proteins are encoded by essential genes, Swp1p, Wbp1p, Ost2p, Ost1p and Stt3p. Four others are not essential Ost3p, Ost4p, Ost5p, Ost6p. All yeast OT subunits have been cloned and sequenced (Kelleher et al., 1992; 2003; Kelleher & Gilmore, 1997; Kumar et al., 1994; 1995; Breuer & Bause, 1995) and the structure of one of them, Ost4p, has been solved by NMR (Zubkov et al., 2004). Very recently, the preliminary crystal structure of the lumenal domain of an archaeal Stt3p homolog has been reported (Mayumi et al., 2007). Homologs of all OT subunits have been identified in higher eukaryotic organisms (Kelleher et al., 1992; 2003; Kumar et al., 1994; Kelleher & Gilmore, 1997).

7

The KRR1 gene encodes a protein required for 18S rRNA synthesis and 40S ribosomal subunit assembly in Saccharomyces cerevisiae.

100%

Gromadka R., Rytka J.

Acta Biochimica Polonica

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2000

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vol. 47

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issue 4

993-1005

EN

The newly discovered Saccharomyces cerevisiae gene KRR1 (YCL059c) encodes a protein essential for cell viability. Krr1p contains a motif of clustered basic amino acids highly conserved in the evolutionarly distant species from yeast to human. We demonstrate that Krr1p is localized in the nucleolus. The KRR1 gene is highly expressed in dividing cells and its expression ceases almost completely when cells enter the stationary phase. In vivo depletion of Krr1p leads to drastic reduction of 40S ribosomal subunits due to defective 18S rRNA synthesis. We propose that Krr1p is required for proper processing of pre-rRNA and the assembly of preribosomal 40S subunits.

8

Functional relationships between the Saccharomyces cerevisiae cis-prenyltransferases required for dolichol biosynthesis.

100%

Grabińska K., Sosińska G., Orłowski J., Swiezewska E., Berges T., Karst F., Palamarczyk G.

Acta Biochimica Polonica

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2005

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vol. 52

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issue 1

221-232

EN

In the yeast Saccharomyces cerevisiae the RER2 and SRT1 genes encode Rer2 and Srt1 proteins with cis-prenyltransferase (cis-PT-ase) activity. Both cis-PT-ases utilize farnesyl diphosphate (FPP) as a starter for polyprenyl diphosphate (dolichol backbone) formation. The products of the Rer2 and Srt1 proteins consist of 14-17 and 18-23 isoprene units, respectively. In this work we demonstrate that deletion or overexpression of SRT1 up-regulates the activity of Rer2p and dolichol content. However, upon overexpression of SRT1, preferential synthesis of longer-chain dolichols and a decrease in the amount of the shorter species are observed. Furthermore, overexpression of the ERG20 gene (encoding farnesyl diphosphate synthase, Erg20p) induces transcription of SRT1 mRNA and increases the levels of mRNA for RER2 and DPM1 (dolichyl phosphate mannose synthase, Dpm1p). Subsequently the enzymatic activity of Rer2p and dolichol content are also increased. However, the amount of Dpm1p or its enzymatic activity remain unchanged.

9

Dependence of the yeast Saccharomyces cerevisiae post-reproductive lifespan on the reproductive potential

100%

Zadrag-Tecza R., Molon M., Mamczur J., Bilinski T.

Acta Biochimica Polonica

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2013

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vol. 60

|

issue 1

111-115

EN

The lifespan of budding yeast cells is divided into two stages: reproductive and post-reproductive. The post-reproductive stage of the yeast's lifespan has never been characterized before. We have analyzed the influence of various mutations on the post-reproductive (PRLS) and replicative (RLS) lifespans. The results indicate that PRLS demonstrates an inverse relationship with RLS. The observed lack of differences in the total lifespan (TLS) (expressed in units of time) of strains differing up to five times in RLS (expressed in the number of daughters formed) suggests the necessity of revision of opinions concerning the use of yeast as a model organism of gerontology.

10

Hypothesis: cell volume limits cell divisions

100%

Biliński T., Bartosz G.

Acta Biochimica Polonica

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2006

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vol. 53

|

issue 4

833-835

EN

Mammalian somatic cells and also cells of the yeast Saccharomyces cerevisiae are capable of undergoing a limited number of divisions. Reaching the division limit is referred to, apparently not very fortunately, as replicative aging. A common feature of S. cerevisiae cells and fibroblasts approaching the limit of cell divisions in vitro is attaining giant volumes. In yeast cells this phenomenon is an inevitable consequence of budding so it is not causally related to aging. Therefore, reaching a critically large cell volume may underlie the limit of cell divisions. A similar phenomenon may limit the number of cell divisions of cultured mammalian cells. The term replicative (generative) aging may be therefore illegitimate.

11

Permeation of iodide from iodine-enriched yeast through porcine intestine

100%

Ryszka F., Dolińska B., Zieliński M., Chyra D., Dobrzański Z.

Acta Biochimica Polonica

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2013

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vol. 60

|

issue 4

737-739

EN

Iodine deficiency is a common phenomenon, threatening the whole global human population. Recommended daily intake of iodine is 150 μg for adults and 250 μg for pregnant and breastfeeding women. About 50% of human population can be at risk of moderate iodine deficiency. Due to this fact, increased iodine supplementation is recommended, through intake of iodized mineral water and salt iodization. The aim of this study was to investigate permeation and absorption of iodide from iodine bioplex (experimental group) in comparison with potassium iodide (controls). Permeation and absorption processes were investigated in vitro using a porcine intestine. The experimental model was based on a standard Franz diffusion cell (FD-Cell). The iodine bioplex was produced using Saccharomyces cerevisiae yeast and whey powder: iodine content - 388 μg/g, total protein - 28.5%, total fat - 0.9%., glutamic acid - 41.2%, asparaginic acid - 29.4%, lysine - 24.8%; purchased from: F.Z.N.P. Biochefa, Sosnowiec, Poland. Potassium iodide was used as controls, at 388 μg iodine concentration, which was the same as in iodine-enriched yeast bioplex. A statistically significant increase in iodide permeation was observed for iodine-enriched yeast bioplex in comparison with controls - potassium iodide. After 5h the total amount of permeated iodide from iodine-enriched yeast bioplex was 85%, which is ~ 2-fold higher than controls - 37%. Iodide absorption was by contrast statistically significantly higher in controls - 7.3%, in comparison with 4.5% in experimental group with iodine-enriched yeast bioplex. Presented results show that iodide permeation process dominates over absorption in case of iodine-enriched yeast bioplex.

12

Extraribosomal function of the acidic ribosomal P1-protein YP1α from Saccharomyces cerevisiae

100%

Tchórzewski M., Boldyreff B., Grankowski N.

Acta Biochimica Polonica

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1999

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vol. 46

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issue 4

901-910

EN

The yeast acidic ribosomal P-proteins YP1α, YP1β, YP2a and YP2b were studied for a possible transactivation potential beside their ribosomal function. The fusions of P-proteins with the GAL4 DNA-binding domain were assayed toward their transcriptional activity with the aid of reporter genes in yeast. Two of the P-proteins, YP1α and YP1β, exhibited transactivation potential, however, only YP1α can be regarded as a potent transactivator. This protein was able to transactivate a reporter gene associated with two distinct promoter systems, GAL1 or CYC1. Additionally, truncated proteins of YP1α and YP1β were analyzed. The N-terminal part of YP1α fused to GAL4-BD showed transactivation potential but the C-terminal part did not. Our results suggest a putative extraribosomal function for these ribosomal proteins which consequently may be classified as "moonlighting" proteins.

13

Locally isolated yeasts from Malaysia: Identification, phylogenetic study and characterization

100%

Oslan S. N., Salleh A. B., Rahman R. N. Z. R. A., Basri M., Chor A. L. T.

Acta Biochimica Polonica

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2012

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vol. 59

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issue 2

225-229

EN

Yeasts are a convenient platform for many applications. They have been widely used as the expression hosts. There is a need to have a new yeast expression system to contribute the molecular cloning demands. Eight yeast isolates were screened from various environment sources and identified through ribosomal DNA (rDNA) Internal Transcribed Spacer (ITS). Full sequence of the rDNA ITS region for each isolate was BLASTed and phylogenetic study was constructed by using MEGA4. Among the isolates, isolate WB from 'ragi' (used to ferment carbohydrates) could be identified as a new species in order Saccharomycetales according to rDNA ITS region, morphology and biochemical tests. Isolate SO (from spoiled orange), RT (rotten tomato) and RG (different type of 'ragi') were identified as Pichia sp. Isolates R1 and R2, S4 and S5 (from the surrounding of a guava tree) were identified as Issatchenkia sp. and Hanseniaspora sp., respectively. Geneticin, 50 µg/mL, was determined to be the antibiotic marker for all isolates excepted for isolates RT and SO which used 500 µg/mL and 100 µg/mL Zeocin, respectively. Intra-extracellular proteins were screened for lipolytic activity at 30°C and 70°C. Thermostable lipase activity was detected in isolates RT and R1 with 0.6 U/mg and 0.1 U/mg, respectively. In conclusion, a new yeast-vector system for isolate WB can be developed by using phleomycin or geneticin as the drugs resistance marker. Moreover, strains RT and R1 can be investigated as a novel source of a thermostable lipase.

14

Dynamics of neutral lipid storage in yeast.

88%

Müllner H., Daum G.

Acta Biochimica Polonica

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2004

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vol. 51

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issue 2

323-347

EN

Since energy storage is a basic metabolic process, the synthesis of neutral lipids occurs in all kingdoms of life. The yeast, Saccharomyces cerevisiae, widely accepted as a model eukaryotic cell, contains two classes of neutral lipids, namely steryl esters and triacylglycerols. Triacylglycerols are synthesized through two pathways governed by the acyl-CoA diacylglycerol acyltransferase Dga1p and the phospholipid diacylglycerol acyltransferase Lro1p, respectively. Steryl esters are formed by the two steryl ester synthases Are1p and Are2p, two enzymes with overlapping function which also catalyze triacylglycerol formation, although to a minor extent. Storage of neutral lipids is tightly linked to the biogenesis of so called lipid particles. The role of this compartment in lipid homeostasis and its interplay with other organelles involved in neutral lipid dynamics, especially the endoplasmic reticulum and the plasma membrane, are subject of current investigations. In contrast to neutral lipid formation, mobilization of triacylglycerols and steryl esters in yeast are less characterized at the molecular level. Only recently, the triacylglycerol lipase Tgl3p was identified as the first yeast enzyme of this kind by function. Genes and gene products governing steryl ester mobilization still await identification. Besides biochemical properties of enzymes involved in yeast neutral lipid synthesis and degradation, regulatory aspects of these pathways and cell biological consequences of neutral lipid depletion will be discussed in this minireview.

15

Suppressors of translation initiation defect in hem12 locus of Saccharomyces cerevisiae.

88%

Góra M., Pluta K., Chełstowska A., Żołądek T.

Acta Biochimica Polonica

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2000

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vol. 47

|

issue 1

181-190

EN

A system for the positive selection of transational initiation suppressors in S. cerevisiae has been developed. A mutant with an ATA initiation codon in the HEM12 gene, encoding uroporphyrinogen decarboxylase, was used to select cis- and trans-acting suppressors. These suppressors partially restore growth on nonfermentable carbon sources, such as glycerol, but still allow the accumulation of porphyrins. All extragenic suppressors are mapped to the SUI1 locus, encoding initiation factor eIF1. The effect of the hem12 mutation is also partially reversed by the known SUI3 suppressor encoding the β subunit of eIF2. In contrast, the sui2 suppressor encoding the α subunit of eIF2 does not affect the hem 12 phenotype. The intragenic suppressors are able to restore the translation of hem12 due to the generation of additional, in frame AUG codons upstream of the hem12-14 mutation. Mutational analysis of the HEM12 leader sequence was also performed to determine the role of small open reading frames (uORFs) present upstream of the HEM12 ORF. Studies on the expression of integrated hem12-1/4-lacZ fusion, devoid of all upstream ATGs, indicate a lack of regulatory effect of uORFs on HEM12 translation.

16

Yeast as a biosensor for antioxidants: simple growth tests employing a Saccharomyces cerevisiae mutant defective in superoxide dismutase

88%

Żyracka E., Zadrąg R., Kozioł S., Krzepiłko A., Bartosz G., Biliński T.

Acta Biochimica Polonica

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2005

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vol. 52

|

issue 3

679-684

EN

Mutants of Saccharomyces cerevisiae devoid of Cu,Zn-superoxide dismutase are hypersensitive to a range of oxidants, hyperbaric oxygen and hyperosmotic media, show lysine and methionine auxotrophy when grown under the atmosphere of air and have a shortened replicative life span when compared to the wild-type strain. Ascorbate and other antioxidants can ameliorate these defects, which may be a basis of simple tests sensing the presence of antioxidants. In particular, tests of growth on solid medium (colony formation) in the absence of methionine and/or lysine, or in the presence of 0.8 M NaCl can be useful for detection and semiquantitative estimation of compounds of antioxidant properties. Hypoxic atmosphere was found to increase the sensitivity of detection of antioxidants. The test of abolishment of lysine auxotrophy showed a concentration dependence of the antioxidant effects of cysteine and N-acetylcysteine which, however, lost their protective action at high concentration, in contrast to glutathione which was effective also at higher concentrations.

17

The YJL185C, YLR376C and YJR129C genes of Saccharomyces cerevisiae are probably involved in regulation of the glyoxylate cycle

88%

Boniewska-Bernacka E., Wysocki R., Grochowalska R., Machnicka B., Ułaszewski S., Lachowicz T.

Acta Biochimica Polonica

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2006

|

vol. 53

|

issue 4

739-745

EN

The ER24 aci (acidification) mutant of Saccharomyces cerevisiae excreting protons in the absence of glucose was transformed with a multicopy yeast DNA plasmid library. Three different DNA fragments restored the wild-type phenotype termed Aci- because it does not acidify the complete glucose medium under the tested conditions. Molecular dissection of the transforming DNA fragments identified two multicopy suppressor genes YJL185C, YJR129C and one allelic YLR376C. Disruption of either of the three genes in wild-type yeast strain resulted in acidification of the medium (Aci+ phenotype) similarly to the original ER24 mutant. These data indicate the contribution of the ER24 gene product Ylr376Cp and of the two suppressor gene products Yjl185Cp and Yjr129Cp to a complex regulation of the glyoxylate cycle in yeast.

18

Adsorptive removal of cochineal red a dye from aqueous solutions using yeast

88%

Borysiak M., Gabruś E., Borysiak M., Gabruś E.

Chemical and Process Engineering

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2020

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vol. 41

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issue 2

19

Translational readthrough of a termination codon in the yeast mitochondrial mRNA VAR1 as a result of mutation in the release factor mRF1.

88%

Claisse M. L., Boguta M., Zagórski W.

Acta Biochimica Polonica

|

2005

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vol. 52

|

issue 1

129-137

EN

Yeast mitochondrial DNA codes for eight major polypeptides. Translation of he mitochondrially encoded polypeptides in strains with mutated mitochondrial release factor, mRF1, was found to result in the synthesis of a novel protein, V2. Different mrf1 alleles were associated with different efficiency of V2p synthesis. Translation of V2p was enhanced by paromomycin. Comparative analysis of peptides resulting from protease digestion indicated that V2p is a derivative of Var1p. According to our hypothesis, V2p represents a readthrough product of the natural stop codon in VAR1 mRNA.

20

YOR129c, a new element interacting with Cnm67p, a component of the spindle pole body of Saccharomyces cerevisiae.

88%

Wysocka M., Białkowska A., Miciałkiewicz A., Kurlandzka A.

Acta Biochimica Polonica

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2003

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vol. 50

|

issue 3

883-890

EN

The Saccharomyces cerevisiae spindle pole body (SPB) consists of numerous proteins forming the outer, inner and central plaques. The protein Cnm67 is an important component of the outer plaque. The C-terminus of this protein contains a determinant important for its SPB localization. We identified a protein encoded by YOR129c which interacts with this C-terminus in the two-hybrid system. YOR129c and CNM67 exhibit weak genetic interaction. The double deletion strain yor129cΔ cnm67Δ exhibits moderately increased resistance to 0.1 M LiCl and hygromycin B compared with the cnm67Δ single mutant. We propose that the YOR129c protein is an accessory factor associated with the cytoplasmic face of SPB and plays a role in cation homeostasis and/or multidrug resistance.

Refine search results

The rules of aging: are they universal? Is the yeast model relevant for gerontology?

Induction of the synthesis of an additional family of long-chain dolichols in the yeast Saccharomyces cerevisiae. Effect of starvation and ageing.

The links between hypertrophy, reproductive potential and longevity in the Saccharomyces cerevisiae yeast

Relationship between the replicative age and cell volume in Saccharomyces cerevisiae

Different properties of four molecular forms of protein kinase CK2 from Saccharomyces cerevisiae

Studies on oligosaccharyl transferase in yeast

The KRR1 gene encodes a protein required for 18S rRNA synthesis and 40S ribosomal subunit assembly in Saccharomyces cerevisiae.

Functional relationships between the Saccharomyces cerevisiae cis-prenyltransferases required for dolichol biosynthesis.

Dependence of the yeast Saccharomyces cerevisiae post-reproductive lifespan on the reproductive potential

Hypothesis: cell volume limits cell divisions

Permeation of iodide from iodine-enriched yeast through porcine intestine

Extraribosomal function of the acidic ribosomal P1-protein YP1α from Saccharomyces cerevisiae

Locally isolated yeasts from Malaysia: Identification, phylogenetic study and characterization

Dynamics of neutral lipid storage in yeast.

Suppressors of translation initiation defect in hem12 locus of Saccharomyces cerevisiae.

Yeast as a biosensor for antioxidants: simple growth tests employing a Saccharomyces cerevisiae mutant defective in superoxide dismutase

The YJL185C, YLR376C and YJR129C genes of Saccharomyces cerevisiae are probably involved in regulation of the glyoxylate cycle

Adsorptive removal of cochineal red a dye from aqueous solutions using yeast

Translational readthrough of a termination codon in the yeast mitochondrial mRNA VAR1 as a result of mutation in the release factor mRF1.

YOR129c, a new element interacting with Cnm67p, a component of the spindle pole body of Saccharomyces cerevisiae.