Azasterol inhibitors in yeast. Inhibition of the Δ24-sterol methyltransferase and the 24-methylene sterol Δ24(28)-reductase in sterol mutants of Saccharomyces cerevisiae

1979 ◽  
Vol 57 (3) ◽  
pp. 201-208 ◽  
Author(s):  
A. M. Pierce ◽  
A. M. Unrau ◽  
A. C. Oehlschlager ◽  
R. A. Woods
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Total Sterol ◽  
Sterol Biosynthesis ◽  
Major Sterol ◽  
Low Levels ◽  
First Time ◽  
Sterol Mutants ◽  
Sterol Methyltransferase

The effects of several monoazasterols on sterol biosynthesis were examined in the ergosterol deficient mutants erg 2, erg 3, and erg 5 of Saccharomyces cerevisiae. When the mutants were aerobically cultured in the presence of 1 μM 23-azacholesterol, the 24-methylene sterol Δ24(28)-reductase was essentially blocked and the immediate Δ24(28)-unsaturated precursor of the final sterol metabolite in each respective erg strain was found to accumulate. Total sterol production was enhanced in the cultures grown in the presence of 1 μM 23-azacholesterol. In cultures which were grown in the presence of 1 μM 25-azacholesterol which effectively blocked the Δ24-sterol methyltransferase, all three erg strains accumulated zymosterol as the major sterol component with lesser quantities of predicted terminal sterols. Mutant erg 2 (block at Δ8 → Δ7 isomerase) grew poorly in the presence of 1 μM 25-azacholesterol and produced low levels of cholesta-5,8,24-trienol and cholesta-5,8,22,24-tetraenol, which were isolated and characterized for the first time. Compared with controls, erg 2 treated with 1 μM 23-azacholesterol produced increased amounts of ergosta-5,8,22,24(28)-tetraenol, which was hitherto unidentified as a yeast sterol. In erg 5 (block at Δ22-dehydrogenase) treatment with 1 μM 25-azacholestanol effectively blocked the Δ24-sterol methyltransferase and resulted in increased total sterol production. Cholesta-5,7,24-trienol accounted for 27–29% of the sterol pool in 25-azasterol inhibited erg 5 cultures. The 25-azasteroi inhibited erg 5 mutant thus provides a source of cholesta-5,7,24-trienol, a potential provitamin D3 substitute.

scholarly journals Transcriptome Analysis Reveals a Promotion of Carotenoid Production by Copper Ions in Recombinant Saccharomyces cerevisiae

2021 ◽  
Vol 9 (2) ◽  
pp. 233
Author(s):  
Buli Su ◽  
Anzhang Li ◽  
Ming-Rong Deng ◽  
Honghui Zhu
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Transcriptome Analysis ◽  
Gene Expression Analysis ◽  
Target Genes ◽  
Copper Ions ◽  
Carotenoid Production ◽  
Carotenoid Accumulation ◽  
Nutritional Components ◽  
Differential Gene ◽  
First Time

We previously constructed a Saccharomyces cerevisiae carotenoid producer BL03-D-4 which produced much more carotenoid in YPM (modified YPD) media than YPD media. In this study, the impacts of nutritional components on carotenoid accumulation of BL03-D-4 were investigated. When using YPM media, the carotenoid yield was increased 10-fold compared to using the YPD media. To elucidate the hidden mechanism, a transcriptome analysis was performed and showed that 464 genes changed significantly in YPM media. Furthermore, inspired by the differential gene expression analysis which indicated that ADY2, HES1, and CUP1 showed the most remarkable changes, we found that the improvement of carotenoid accumulation in YPM media was mainly due to the copper ions, since supplementation of 0.08 mM CuSO4 in YPD media could increase carotenoid yield 9.2-fold. Reverse engineering of target genes was performed and carotenoid yield could be increased 6.4-fold in YPD media through overexpression of ACE1. The present study revealed for the first time the prominent promotion of carotenoid yield by copper ions in engineered S. cerevisiae and provided a new target ACE1 for genetic engineering of S. cerevisiae for the bioproduction of carotenoids.

scholarly journals Mating of 2 Laboratory Saccharomyces cerevisiae Strains Resulted in Enhanced Production of 2-Phenylethanol by Biotransformation of L-Phenylalanine

2017 ◽  
Vol 27 (2) ◽  
pp. 81-90 ◽  
Author(s):  
Jolanta Mierzejewska ◽  
Aleksandra Tymoszewska ◽  
Karolina Chreptowicz ◽  
Kamil Krol
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Batch Culture ◽  
Fold Increase ◽  
Biotechnological Production ◽  
Aromatic Alcohol ◽  
Enhanced Production ◽  
Yeast Strains ◽  
First Time

2-Phenylethanol (2-PE) is an aromatic alcohol with a rosy scent which is widely used in the food, fragrance, and cosmetic industries. Promising sources of natural 2-PE are microorganisms, especially yeasts, which can produce 2-PE by biosynthesis and biotransformation. Thus, the first challenging goal in the development of biotechnological production of 2-PE is searching for highly productive yeast strains. In the present work, 5 laboratory <i>Saccharomyces cerevisiae</i> strains were tested for the production of 2-PE. Thereafter, 2 of them were hybridized by a mating procedure and, as a result, a new diploid, <i>S. cerevisiae</i> AM1-d, was selected. Within the 72-h batch culture in a medium containing 5 g/L of <smlcap>L</smlcap>-phenylalanine, AM1-d produced 3.83 g/L of 2-PE in a shaking flask. In this way, we managed to select the diploid <i>S. cerevisiae</i> AM1-d strain, showing a 3- and 5-fold increase in 2-PE production in comparison to parental strains. Remarkably, the enhanced production of 2-PE by the hybrid of 2 yeast laboratory strains is demonstrated here for the first time.

Histone H1 expressed in Saccharomyces cerevisiae binds to chromatin and affects survival, growth, transcription, and plasmid stability but does not change nucleosomal spacing

1994 ◽  
Vol 14 (4) ◽  
pp. 2822-2835
Author(s):  
C Linder ◽  
F Thoma
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Plasmid Stability ◽  
Apparent Molecular Weight ◽  
Histone H1 ◽  
Expression Levels ◽  
Inhibition Of Growth ◽  
Gene Coding ◽  
Gal1 Promoter ◽  
Core Histones ◽  
Low Levels

Histone H1 is proposed to serve a structural role in nucleosomes and chromatin fibers, to affect the spacing of nucleosomes, and to act as a general repressor of transcription. To test these hypotheses, a gene coding for a sea urchin histone H1 was expressed from the inducible GAL1 promoter in Saccharomyces cerevisiae by use of a YEp vector for high expression levels (strain YCL7) and a centromere vector for low expression levels (strain YCL1). The H1 protein was identified by its inducibility in galactose, its apparent molecular weight, and its solubility in 5% perchloric acid. When YCL7 was shifted from glucose to galactose for more than 40 h to achieve maximal levels of H1, H1 could be copurified in approximately stoichiometric amounts with core histones of Nonidet P-40-washed nuclei and with soluble chromatin fractionated on sucrose gradients. While S. cerevisiae tolerated the expression of low levels of H1 in YCL1 without an obvious phenotype, the expression of high levels of H1 correlated with greatly reduced survival, inhibition of growth, and increased plasmid loss but no obvious change in the nucleosomal repeat length. After an initial induction, RNA levels for GAL1 and H1 were drastically reduced, suggesting that H1 acts by the repression of galactose-induced genes. Similar effects, but to a lower extent, were observed when the C-terminal tail of H1 was expressed.

RPD3 encodes a second factor required to achieve maximum positive and negative transcriptional states in Saccharomyces cerevisiae

1991 ◽  
Vol 11 (12) ◽  
pp. 6317-6327 ◽  
Author(s):  
M Vidal ◽  
R F Gaber
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Target Genes ◽  
Current Data ◽  
Regulatory Function ◽  
Fourfold Increase ◽  
Recessive Mutations ◽  
Activation Of Transcription ◽  
Transcriptional Regulatory ◽  
Low Levels ◽  
Full Activation

In Saccharomyces cerevisiae, TRK1 and TRK2 encode the high- and low-affinity K+ transporters, respectively. In cells containing a deletion of TRK1, transcription levels of TRK2 are extremely low and are limiting for growth in media containing low levels of K+ (Trk- phenotype). Recessive mutations in RPD1 and RPD3 suppress the TRK2, conferring an approximately fourfold increase in transcription. rpd3 mutations confer pleiotropic phenotypes, including (i) mating defects, (ii) hypersensitivity to cycloheximide, (iii) inability to sporulate as homozygous diploids, and (iv) constitutive derepression of acid phosphatase. RPD3 was cloned and is predicted to encode a 48-kDa protein with no extensive similarity to proteins contained in current data bases. Deletion of RPD3 is not lethal but confers phenotypes identical to those caused by spontaneous mutations. RPD3 is required for both full repression and full activation of transcription of target genes including PHO5, STE6, and TY2. RPD3 is the second gene required for this function, since RPD1 is also required. The effects of mutations in RPD1 and RPD3 are not additive, suggesting that these genes are involved in the same transcriptional regulatory function or pathway.

scholarly journals Effects of Temperature on the Meiotic Recombination Landscape of the Yeast Saccharomyces cerevisiae

mBio ◽  
2017 ◽  
Vol 8 (6) ◽  
Author(s):  
Ke Zhang ◽  
Xue-Chang Wu ◽  
Dao-Qiong Zheng ◽  
Thomas D. Petes
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Gene Conversion ◽  
Meiotic Recombination ◽  
Hot Spots ◽  
Genetic Maps ◽  
Dna Breaks ◽  
Low Levels ◽  
C 30 ◽  
Recombination Hot Spots ◽  
In Cells

ABSTRACT Although meiosis in warm-blooded organisms takes place in a narrow temperature range, meiosis in many organisms occurs over a wide variety of temperatures. We analyzed the properties of meiosis in the yeast Saccharomyces cerevisiae in cells sporulated at 14°C, 30°C, or 37°C. Using comparative-genomic-hybridization microarrays, we examined the distribution of Spo11-generated meiosis-specific double-stranded DNA breaks throughout the genome. Although there were between 300 and 400 regions of the genome with high levels of recombination (hot spots) observed at each temperature, only about 20% of these hot spots were found to have occurred independently of the temperature. In S. cerevisiae , regions near the telomeres and centromeres tend to have low levels of meiotic recombination. This tendency was observed in cells sporulated at 14°C and 30°C, but not at 37°C. Thus, the temperature of sporulation in yeast affects some global property of chromosome structure relevant to meiotic recombination. Using single-nucleotide polymorphism (SNP)-specific whole-genome microarrays, we also examined crossovers and their associated gene conversion events as well as gene conversion events that were unassociated with crossovers in all four spores of tetrads obtained by sporulation of diploids at 14°C, 30°C, or 37°C. Although tetrads from cells sporulated at 30°C had slightly (20%) more crossovers than those derived from cells sporulated at the other two temperatures, spore viability was good at all three temperatures. Thus, despite temperature-induced variation in the genetic maps, yeast cells produce viable haploid products at a wide variety of sporulation temperatures. IMPORTANCE In the yeast Saccharomyces cerevisiae , recombination is usually studied in cells that undergo meiosis at 25°C or 30°C. In a genome-wide analysis, we showed that the locations of genomic regions with high and low levels of meiotic recombination (hot spots and cold spots, respectively) differed dramatically in cells sporulated at 14°C, 30°C, and 37°C. Thus, in yeast, and likely in other non-warm-blooded organisms, genetic maps are strongly affected by the environment.

scholarly journals Fermentación de la almendra de copoazú (Theobroma grandiflorum [Willd. ex Spreng.] Schum.): evaluación y optimización del proceso

2010 ◽  
Vol 11 (2) ◽  
pp. 107 ◽  
Author(s):  
Jenifer Criollo ◽  
Dagoberto Criollo ◽  
Angélica Sandoval Aldana
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Process Optimization ◽  
Fermentation Process ◽  
Raw Material ◽  
Sensory Panel ◽  
Yeast Saccharomyces Cerevisiae ◽  
Theobroma Grandiflorum ◽  
Cutting Test ◽  
Maximum Range ◽  
Low Levels

<p>La almendra de copoazú como producto promisorio para la industria de cosméticos, chocolate, bebidas, licores y conservas, se evaluó el proceso de fermentación variando el tiempo de remoción de la masa (24 y 48 horas) y la pulpa inicial (30 y 100%). Se tuvieron en cuenta las condiciones de los productores en el acceso a equipos de despulpado. Se cuantificó la temperatura de la masa en tres puntos (superior, medio e inferior), acidez, pH, humedad, prueba de corte y análisis sensorial. Se encontró bajo desarrollo de la temperatura de fermentación en los tratamientos con 100% de pulpa y se registraron las máximas temperaturas entre 35 y 36°C que indican deficiencias en el proceso; no se alcanzó los 40°C requeridos para la muerte del embrión. El 30% de pulpa inicial y la remoción cada 24 horas por 9 días, fueron las mejores condiciones encontradas. La optimización con 0,1% de levadura (Saccharomyces cerevisiae) aumentó la temperatura de fermentación hasta 44°C, los granos fermentados hasta 56,14% y el mayor desarrollo de sabores frutales con intensidad de 4, mostrando un mejor proceso de fermentación. El panel sensorial mostró que los licores de copoazú tienen notas frutales destacadas y bajos valores de otros sabores evaluados. Los resultados son semejantes a los cacaos criollos, conocidos en el mundo como materia prima de licores finos y de aroma.</p><p> </p><p><strong>Fermentation of the copoazu kernel (Theobroma grandiflorum [Willd. ex Spreng.] Schum.): Assessmente and process optimization</strong></p><p>The fermentation of copoazu kernels (a promising product for the cosmetics industry, chocolate, beverages, liquors and preserves) was evaluated varying the time of mass removal (24 and 48 hours) and the initial pulp (30 and 100%). This study took into account the degree of access the producers had to pulping equipment. We quantified temperature of the mass at three points (top, middle and bottom), acidity, pH, moisture, cutting test and sensory analysis. The observed temperatures during fermentation in the treatments with 100% pulp reached a maximum range between 35 and 36°C which indicated deficiencies in the process as the 40°C required for the death of the seed was not attained. Thirty percent initial pulp with removal every 24 hours for 9 days yielded the best results. Optimization with 0.1% yeast (Saccharomyces cerevisiae) increased the fermentation temperature to 44°C, augmented fermented beans to 56.14% and saw a development of fruit flavors with an intensity of 4, demonstrating a better fermentation process. The sensory panel showed that copoazu liquors have outstanding fruity notes and low levels of other evaluated flavors. The results are similar to the criollo cacao, known worldwide as a raw material for fine liquors and fragrances.</p>

scholarly journals Experimental infection of sheep with visna/maedi virus via the conjunctival space

2008 ◽  
Vol 89 (6) ◽  
pp. 1329-1337 ◽  
Author(s):  
Heide Niesalla ◽  
Tom N. McNeilly ◽  
Margaret Ross ◽  
Susan M. Rhind ◽  
Gordon D. Harkiss
Keyword(s):  
Post Infection ◽  
Mononuclear Cells ◽  
Mediastinal Lymph Node ◽  
Ocular Tissue ◽  
Ocular Infection ◽  
Peripheral Blood Mononuclear ◽  
Ocular Tissues ◽  
Virus Dose ◽  
Low Levels ◽  
First Time

Experiments were performed to determine whether visna/maedi virus (VMV), a small ruminant lentivirus (SRLV), could infect sheep via ocular tissues. The EV1 strain of VMV was administered into the conjunctival space of uninfected sheep, and the animals monitored for the presence of provirus DNA and anti-VMV antibodies in blood. The results showed that provirus DNA appeared in peripheral blood mononuclear cells of all animals within a few weeks of receiving either 106 TCID50 or 103 TCID50 of VMV. Of the animals receiving the higher dose of virus via the conjunctival space, two seroconverted by 7 and 10 weeks post-infection, one seroconverted 8 months post-infection, and one had not seroconverted by 15 months post-infection. With the lower virus dose, the animals infected via the trachea seroconverted by 4 and 14 weeks, respectively. After ocular infection with this dose, one animal showed a transitory seroconversion with low levels of antibody, peaking at 2 weeks post-administration. The remaining three of the animals infected via the eyes did not seroconvert over a period of 13 months. At post-mortem, evidence for the presence of proviral DNA was obtained from ocular tissue, lungs or mediastinal lymph node in both groups of animals. Histological analysis of lung tissue from animals receiving the lower dose of virus showed the presence of early inflammatory lesions. The results thus show for the first time that transmission of VMV can occur via ocular tissues, suggesting that the conjunctival space may be an additional route of natural transmission.

scholarly journals Factors of psychological well-being of adolescents in the aspect of self-knowledge

2021 ◽  
Vol 122 ◽  
pp. 06004
Author(s):  
Inessa Leonidovna Feldman ◽  
Valery Sergeevich Agapov ◽  
Svetlana Vasilyevna Feoktistova ◽  
Oksana Ivanovna Griboyedova
Keyword(s):  
Well Being ◽  
Internal Factors ◽  
Psychological Well Being ◽  
Successful Communication ◽  
Scientific Opinion ◽  
Specific Factors ◽  
Self Knowledge ◽  
Low Levels ◽  
First Time ◽  
The Relationship

The premise for the present study lies in the lack of a unanimous scientific opinion on the relationship between self-knowledge and psychological well-being. The article presents the results of a study of the factors of psychological well-being of adolescents associated with their self-knowledge. The relevance of the conducted study is due to the need to integrate scientific knowledge on the internal factors contributing to psychological well-being. The scientific novelty is shaped by the fact that adolescents’ self-knowledge in the context of their psychological well-being is understudied and is examined for the first time. The study includes 500 adolescents aged 13-17 years old from schools in Tula, Lipetsk, and Moscow regions. The conducted factor analysis reveals common and specific factors of psychological well-being that are significant for adolescents with varying levels of psychological well-being. The common factors found in the entire sample are the desire for self-reflective analysis, for successful communication, for physical harmony, and for a meaningful perception of one’s future. The specific factors relevant for each group – adolescents with high, average, and low levels of psychological well-being – are also identified. The results of the analysis allow concluding that the psychological well-being of adolescents at different levels of psychological well-being is determined by factors related to self-knowledge. The presented work is of interest for researchers concerned with the problems of adolescents’ psychological well-being, as well as in designing educational programs and projects aimed at improving the psychological well-being of adolescents.

Cloning and molecular analysis of the HAP2 locus: a global regulator of respiratory genes in Saccharomyces cerevisiae

1985 ◽  
Vol 5 (12) ◽  
pp. 3410-3416
Author(s):  
J L Pinkham ◽  
L Guarente
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Molecular Analysis ◽  
Carbon Sources ◽  
Direct Integration ◽  
Global Regulator ◽  
Low Levels ◽  
Gene Maps ◽  
Derivatives Of ◽  
In Cells

We report here the cloning of the HAP2 gene, a locus required for the expression of many cytochromes and respiratory functions in Saccharomyces cerevisiae. The cloned sequences were found to direct integration of a marked vector to the chromosomal HAP2 locus, and derivatives of these sequences were shown to yield chromosomal disruptions with a Hap2- phenotype. The gene maps 18 centimorgans centromere proximal to ade5 on the left arm of chromosome VII, distinguishing it from any other previously characterized nuclear petite locus. The HAP2 locus encodes a 1.3-kilobase transcript which is present at extremely low levels and which is derepressed in cells grown in media containing nonfermentable carbon sources. Levels of HAP2 mRNA are not reduced in strains bearing a mutation at the HAP3 locus, which is also required for expression of respiratory functions. Models outlining possible interactions of the products of the HAP2 and HAP3 genes are presented.

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