• Animal cells and systems
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• 제7권2호
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• pp.133-137
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• 2003

Secreted proteins and membrane proteins play key roles in the formation, differentiation, and maintenance of multicellular organisms. In this study, we undertook to characterize these protein types in the central nervous system of the marine snail Aplysia kurodai using a yeast-based signal sequence trap method. One hundred and three cDNA clones were obtained by screening 300,000 clones from the signal sequence trap cDNA library. Of these, twelve were identical to previously identified Aplysia genes, 19 were related to known proteins in other organisms, and 54 clones were novel. These 54 new genes had high signal peptide scores or were found likely to contain a transmembrane domain sequence. Only 18 of the 103 clones proved to be false positive. The study demonstrates that the signal sequence trap method is an effective tool for Isolating Aplysia genes encoding secreted and membrane proteins.

• BMB Reports
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• 제34권2호
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• pp.139-143
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• 2001

Thioredoxin (Trx) is a redox protein possessing conserved sequence Cys-Gly-Pro-Cys in ail organisms. Trx acts as an electron donor of many proteins including thioredoxin peroxidase (TPx). Yeast Trx 2 has two redox active cysteine residues at positions 31 and 34. To investigate the redox activity of each cysteine, we generated mutants C31S, C34S, and C31S/C34S using site directed mutagenesis and examined the redox activity of Trx variants as an electron donor for yeast TPx enzymes. None of the three Cysmutated Trx proteins was active as a redox protein in the 5', 5'-dithiobis-(2-dinitrobenzoic acid) reduction under the condition of the presence of NADPH and thioredoxin reductase, and in the thioredoxin dependent peroxidase activity of yeast TPx II. C34S enhanced the glutamine synthetase protection activity of yeast TPx I, even though 100 times more protein was needed to exhibit the same activity to WT. The formation of a mixed disulfide intermediate between Trx and TPx II subunits was analyzed by SDS-PAGE. The mixed dieter form of TPx II was found only for C34S. These results suggest that Cys-31 more effectively acts as an electron donor for TPx enzymes.

• Journal of Microbiology and Biotechnology
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• 제15권4호
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• pp.767-771
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• 2005

Expression in yeast may prove more amenable to generating large amounts of viral antigens for a vaccine candidate. We, therefore, cloned the gene encoding the Hepatitis C virus (HCV) structural proteins (C-El-E2, c740) fused in-frame with, and immediately 3' to, the chicken-lysozyme signal peptide (C-SIG) gene and under the control of the yeast glyceraldehyde-3-phosphate dehydrogenase gene promoter. In yeast, the HCV structural proteins were expressed in two different forms: a processed and a nonprocessed aggregated form. Biophysical characterization by sucrose linear gradient centrifugation revealed that both forms were present in the same fractions with a buoyant density of 1.127-1.176 g/$cm^3$. These findings suggest that the efficient synthesis of HCV structural proteins in yeast may be an important tool to study virus assembly and may lead to the development of an HCV vaccine.

• Journal of Microbiology and Biotechnology
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• 제11권1호
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• pp.17-20
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• 2001

Whole-cell attachment by covalent linkage, thereby simulating natural and specific attachments, improves the osmotolerance of Saccharomyces cerevisiae cells. The enhanced osmoresistance is correlated with a decrease in the intercellular concentration of trehalose and accompanied by membrane compositional changed. The results obtained indicate that yeast cell-support (physical) contact is sensed and responded to.

• Journal of Microbiology and Biotechnology
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• 제27권3호
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• pp.633-643
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• 2017

To examine the pro-apoptotic role of the human ortholog (YPEL5) of the Drosophila Yippee protein, the cell viability of Saccharomyces cerevisiae mutant strain with deleted MOH1, the yeast ortholog, was compared with that of the wild-type (WT)-MOH1 strain after exposure to different apoptogenic stimulants, including UV irradiation, methyl methanesulfonate (MMS), camptothecin (CPT), heat shock, and hyperosmotic shock. The $moh1{\Delta}$ mutant exhibited enhanced cell viability compared with the WT-MOH1 strain when treated with lethal UV irradiation, 1.8 mM MMS, $100{\mu}M$ CPT, heat shock at $50^{\circ}C$, or 1.2 M KCl. At the same time, the level of Moh1 protein was commonly up-regulated in the WT-MOH1 strain as was that of Ynk1 protein, which is known as a marker for DNA damage. Although the enhanced UV resistance of the $moh1{\Delta}$ mutant largely disappeared following transformation with the yeast MOH1 gene or one of the human YPEL1-YPEL5 genes, the transformant bearing pYES2-YPEL5 was more sensitive to lethal UV irradiation and its UV sensitivity was similar to that of the WT-MOH1 strain. Under these conditions, the UV irradiation-induced apoptotic events, such as FITC-Annexin V stainability, mitochondrial membrane potential (${\Delta}{\psi}m$) loss, and metacaspase activation, occurred to a much lesser extent in the $moh1{\Delta}$ mutant compared with the WT-MOH1 strain and the mutant strain bearing pYES2-MOH1 or pYES2-YPEL5. These results demonstrate the functional conservation between yeast Moh1 and human YPEL5, and their involvement in mitochondria-dependent apoptosis induced by DNA damage.

• BMB Reports
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• 제28권4호
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• pp.342-347
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• 1995

The induction of glucoamylase biosynthesis from the yeast Candida tsukubaensis by different carbon sources was investigated by using either an enzyme activity assay or immunoblot analysis. The induction by C. tsukubaensis appears to be independent of the carbon sources, although the level of enzyme activity was lower in slowly utilizable carbon sources such as galactose. This glucoamylase is a constitutive enzyme and its biosynthesis is resistant to carbon catabolite repression. Glucose was more effective for the enzyme induction than starch, maltose or glycerol. In addition, this enzyme is regulated by both induction and repression.

• Journal of Microbiology
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• 제40권1호
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• pp.55-62
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• 2002

Biodiversity af yeasts in various natural environments including soils, swamps and plants was investigated. By molecular identification methods based on the partial sequences of 265 rDNA, 69 isolates were assigned to 44 taxa including 27 known species. The remaining 17 taxa could potentially form new species. All of them were classified into Ascomycota, Hymenomycetes, Urediniomycetes and Ustilaginomycetes. Ascomycetous and ustilaginomycetous yeasts were generally isolated from flower samples, and hymenomycetous and urediniomycetous yeasts were generally isolated from soil samples. Distribution of yeast groups exhibited geographical variation. Yeast biodiversity of root sail also varied according to the associated plant species.

• Journal of Microbiology and Biotechnology
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• 제4권1호
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• pp.56-62
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• 1994

A yeast strain, BT001, which can directly ferment D-xylose to ethanol was isolated from forest soils, and then identified as Candida sp. Cultural conditions for the optimum ethanol production, along with the effects of aeration on cell growth and ethanol production were investigated. Aeration stimulated the cell growth and the volumetric rate of ethanol production, but decreased the ethanol yield. Optimum temperature and initial pH for the ethanol production were $33{\circ}^C$ and 6.0, respectively. In a shake flask culture, this strain produced 52.3 g ethanol per liter from 12%(w/v) D-xylose after incubation for 96 hours. Ethanol yield was 0.436 g per g D-xylose consumed. This corresponds to 85.8% of theoretical yield. Also, this yeast strain produced ethanol from D-galactose, D-glucose and D-mannose, but not from L-arabinose and L-rhamnose. Among these sugars, D-glucose was the fastest in being converted to ethanol sugars.

• 미생물학회지
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• 제30권6호
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• pp.479-482
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• 1992

The sequence of the cytoplasmic 5S-rRNA from Trimorphomyces papilionaceus, a basidiomycetous yeast, was determined by the direct chemical method for sequencing RNA and compared to known 5S rRNA sequences of 19 basidiomycetous fuungi. There were 26 nucleotide differences between T. papilionaceus and Tremella mesenterica both of which belong to the Tremellaceae of the Tremellales. Based on Knuc values, the closest fungus was Tilletiaria anomala, another basidiomycetous yeast which belong to the Sporbolomycetaceae of the Sporobolomycetales. T. papilionaceus did not show any significant phylogenetic relationship with other fungi.

• Biomolecules & Therapeutics
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• 제17권1호
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• pp.12-16
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• 2009

One of the WHSC1/MMSET/NSD2 variant RE-IIBP is a histone H3-K27 methyltransferase with transcriptional repression activity. Overexpression of RE-IIBP in various types of leukemia suggests it's role in leukemogenesis. Here we identify two proteins, KRAB zinc finger protein ZNF 350 and enolase-1 as RE-IIBP interacting proteins by yeast two-hybrid screening and confirmed direct interaction in vivo and in vitro. Both proteins have been known for their role in transcriptional repression. Reporter assays using transient transfection demonstrated that both ZNF 350 and enolase-1 proteins synergistically repressed transcription with RE-IIBP, respectively. These results indicate both proteins have roles in RE-IIBP mediated transcriptional repression by involving co-repressor complex.