Assessment of the essentiality of ERG genes late in ergosterol biosynthesis in Saccharomyces cerevisiae

1997 ◽  
Vol 32 (2) ◽  
pp. 93-99 ◽  
Author(s):  
Lizette M. Palermo ◽  
Frank W. Leak ◽  
Shirley Tove ◽  
L. W. Parks
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ergosterol Biosynthesis ◽  
Erg Genes

scholarly journals Genomic Approach to Identification of Mutations Affecting Caspofungin Susceptibility in Saccharomyces cerevisiae

2004 ◽  
Vol 48 (10) ◽  
pp. 3871-3876 ◽  
Author(s):  
Sarit Markovich ◽  
Aya Yekutiel ◽  
Itamar Shalit ◽  
Yona Shadkchan ◽  
Nir Osherov
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Ergosterol Biosynthesis ◽  
Membrane Function ◽  
Minimum Effective Concentration ◽  
Fourfold Increase ◽  
Microdilution Method ◽  
New Genes ◽  
Broth Microdilution Method ◽  
Glucan Synthesis

ABSTRACT The antifungal agent caspofungin (CAS) specifically interferes with glucan synthesis and cell wall formation. To further study the cellular processes affected by CAS, we analyzed a Saccharomyces cerevisiae mutant collection (4,787 individual knockout mutations) to identify new genes affecting susceptibility to the drug. This collection was screened for increased CAS sensitivity (CAS-IS) or increased CAS resistance (CAS-IR). MICs were determined by the broth microdilution method. Disruption of 20 genes led to CAS-IS (four- to eightfold reductions in the MIC). Eleven of the 20 genes are involved in cell wall and membrane function, notably in the protein kinase C (PKC) integrity pathway (MID2, FKS1, SMI1, and BCK1), chitin and mannan biosynthesis (CHS3, CHS4, CHS7, and MNN10), and ergosterol biosynthesis (ERG5 and ERG6). Four of the 20 genes (TPO1, VPS65, VPS25, and CHC1) are involved in vacuole and transport functions, 3 of the 20 genes (CCR4, POP2, and NPL3) are involved in the control of transcription, and 2 of the 20 genes are of unknown function. Disruption of nine additional genes led to CAS-IR (a fourfold increase of MIC). Five of these nine genes (SLG1, ERG3, VRP1, CSG2, and CKA2) are involved in cell wall function and signal transduction, and two of the nine genes (VPS67 and SAC2) are involved in vacuole function. To assess the specificity of susceptibility to CAS, the MICs of amphotericin B, fluconazole, flucytosine, and calcofluor for the strains were tested. Seven of 20 CAS-IS strains (with disruption of FKS1, SMI1, BCK1, CHS4, ERG5, TPO1, and ILM1) and 1 of 9 CAS-IR strains (with disruption of SLG1) demonstrated selective susceptibility to CAS. To further explore the importance of PKC in CAS susceptibility, the activity of the PKC inhibitor staurosporine in combination with CAS was tested against eight Aspergillus clinical isolates by the microdilution assay. Synergistic or synergistic-to-additive activities were found against all eight isolates by use of both MIC and minimum effective concentration endpoints.

scholarly journals Combined Biosynthetic Pathway Engineering and Storage Pool Expansion for High-Level Production of Ergosterol in Industrial Saccharomyces cerevisiae

2021 ◽  
Vol 9 ◽  
Author(s):  
Zhi-Jiao Sun ◽  
Jia-Zhang Lian ◽  
Li Zhu ◽  
Yi-Qi Jiang ◽  
Guo-Si Li ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Biosynthetic Pathway ◽  
Metabolic Flux ◽  
Feeding Strategy ◽  
Pathway Engineering ◽  
Ergosterol Biosynthesis ◽  
Sterol Esters ◽  
Storage Pool ◽  
Ergosterol Content ◽  
Dry Cell Weight

Ergosterol, a terpenoid compound produced by fungi, is an economically important metabolite serving as the direct precursor of steroid drugs. Herein, ergsosterol biosynthetic pathway modification combined with storage capacity enhancement was proposed to synergistically improve the production of ergosterol in Saccharomyces cerevisiae. S. cerevisiae strain S1 accumulated the highest amount of ergosterol [7.8 mg/g dry cell weight (DCW)] among the wild-type yeast strains tested and was first selected as the host for subsequent metabolic engineering studies. Then, the push and pull of ergosterol biosynthesis were engineered to increase the metabolic flux, overexpression of the sterol acyltransferase gene ARE2 increased ergosterol content to 10 mg/g DCW and additional overexpression of a global regulatory factor allele (UPC2-1) increased the ergosterol content to 16.7 mg/g DCW. Furthermore, considering the hydrophobicity sterol esters and accumulation in lipid droplets, the fatty acid biosynthetic pathway was enhanced to expand the storage pool for ergosterol. Overexpression of ACC1 coding for the acetyl-CoA carboxylase increased ergosterol content from 16.7 to 20.7 mg/g DCW. To address growth inhibition resulted from premature accumulation of ergosterol, auto-inducible promoters were employed to dynamically control the expression of ARE2, UPC2-1, and ACC1. Consequently, better cell growth led to an increase of ergosterol content to 40.6 mg/g DCW, which is 4.2-fold higher than that of the starting strain. Finally, a two-stage feeding strategy was employed for high-density cell fermentation, with an ergosterol yield of 2986.7 mg/L and content of 29.5 mg/g DCW. This study provided an effective approach for the production of ergosterol and other related terpenoid molecules.

scholarly journals Transcriptomic Response of Saccharomyces cerevisiae during Fermentation under Oleic Acid and Ergosterol Depletion

Fermentation ◽  
2019 ◽  
Vol 5 (3) ◽  
pp. 57 ◽  
Author(s):  
Giacomo Zara ◽  
Hennie J. J. van Vuuren ◽  
Ilaria Mannazzu ◽  
Severino Zara ◽  
Marilena Budroni
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Oleic Acid ◽  
Lipid Fraction ◽  
Membrane Lipid ◽  
Ergosterol Biosynthesis ◽  
Methionine Biosynthesis ◽  
Transcriptomic Response ◽  
Hypoxic Conditions ◽  
Lipid Supplementation ◽  
Time Point

Under anaerobic/hypoxic conditions, Saccharomyces cerevisiae relies on external lipid supplements to modulate membrane lipid fraction in response to different stresses. Here, transcriptomic responses of two S. cerevisiae wine strains were evaluated during hypoxic fermentation of a synthetic must with/without ergosterol and oleic acid supplementation. In the absence of lipids, the two strains, namely EC1118 and M25, showed different behaviour, with M25 significantly decreasing its fermentation rate from the 72 h after inoculum. At this time point, the whole genome transcriptomic analysis revealed common and strain-specific responses to the lack of lipid supplementation. Common responses included the upregulation of the genes involved in ergosterol biosynthesis, as well as the seripauperin and the heat shock protein multigene families. In addition, the upregulation of the aerobic isoforms of genes involved in mitochondrial electron transport is compatible with the previously observed accumulation of reactive oxygen species in the two strains during growth in absence of lipids. Considering the strain-specific responses, M25 downregulated the transcription of genes involved in glucose transport, methionine biosynthesis and of those encoding mannoproteins required for adaptation to low temperatures and hypoxia. The identification of these pathways, which are presumably involved in yeast resistance to stresses, will assist industrial strain selection.

scholarly journals The introduction of the C-22–C-23 ethylenic linkage in ergosterol biosynthesis

1968 ◽  
Vol 106 (3) ◽  
pp. 623-626 ◽  
Author(s):  
M Akhtar ◽  
M. A. Parvez ◽  
P. F. Hunt
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Chemical Synthesis ◽  
Good Yield ◽  
The Other ◽  
Side Chain ◽  
Ergosterol Biosynthesis ◽  
Hydrogen Atoms ◽  
Whole Cells ◽  
C 23 ◽  
Methylene Derivative

Methods for the chemical synthesis of [23−3H2]lanosterol, [23,25−3H3]24-methyldihydrolanosterol and [24,28−3H2]24-methyldihydrolanosterol are described. It is shown that, in the biosynthesis of ergosterol from [26,27−14C2,23−3H2]lanosterol by the whole cells of Saccharomyces cerevisiae, one of the original C-23 hydrogen atoms is lost and the other is retained at C-23 of ergosterol. It is also shown that 24-methyldihydrolanosterol is converted into ergosterol in good yield and without prior conversion into a 24-methylene derivative. On the basis of these results possible pathways for the formation of the ergosterol side chain from a 24-methylene side chain are discussed.

scholarly journals The cytochrome b5 dependent C-5(6) sterol desaturase DES5A from the endoplasmic reticulum of Tetrahymena thermophila complements ergosterol biosynthesis mutants in Saccharomyces cerevisiae

Steroids ◽  
2012 ◽  
Vol 77 (13) ◽  
pp. 1313-1320 ◽  
Author(s):  
Tomas J. Poklepovich ◽  
Mauro A. Rinaldi ◽  
Mariela L. Tomazic ◽  
Nicolas O. Favale ◽  
Aaron P. Turkewitz ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Endoplasmic Reticulum ◽  
Tetrahymena Thermophila ◽  
Cytochrome B5 ◽  
Ergosterol Biosynthesis

scholarly journals Sterol Composition Modulates the Response of Saccharomyces cerevisiae to Iron Deficiency

2021 ◽  
Vol 7 (11) ◽  
pp. 901
Author(s):  
Tania Jordá ◽  
Nicolas Rozès ◽  
Sergi Puig
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Iron Deficiency ◽  
Transcriptional Activation ◽  
Fungal Infections ◽  
Iron Acquisition ◽  
Sterol Composition ◽  
Yeast Cells ◽  
Cellular Respiration ◽  
Ergosterol Biosynthesis ◽  
Yeast Saccharomyces Cerevisiae

Iron is a vital micronutrient that functions as an essential cofactor in multiple biological processes, including oxygen transport, cellular respiration, and metabolic pathways, such as sterol biosynthesis. However, its low bioavailability at physiological pH frequently leads to nutritional iron deficiency. The yeast Saccharomyces cerevisiae is extensively used to study iron and lipid metabolisms, as well as in multiple biotechnological applications. Despite iron being indispensable for yeast ergosterol biosynthesis and growth, little is known about their interconnections. Here, we used lipid composition analyses to determine that changes in the pattern of sterols impair the response to iron deprivation of yeast cells. Yeast mutants defective in ergosterol biosynthesis display defects in the transcriptional activation of the iron-acquisition machinery and growth defects in iron-depleted conditions. The transcriptional activation function of the iron-sensing Aft1 factor is interrupted due to its mislocalization to the vacuole. These data uncover novel links between iron and sterol metabolisms that need to be considered when producing yeast-derived foods or when treating fungal infections with drugs that target the ergosterol biosynthesis pathway.

scholarly journals The intermediary role of a steroid 8,14-dien-3β-ol system in ergosterol biosynthesis

1969 ◽  
Vol 115 (2) ◽  
pp. 135-137 ◽  
Author(s):  
M Akhtar ◽  
W. A. Brooks ◽  
I. A. Watkinson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ergosterol Biosynthesis ◽  
Methyl Group ◽  
Diene System ◽  
Intermediary Role

1. A mechanism for the removal of the 14α-methyl group in ergosterol biosynthesis that involves the intermediacy of an 8,14-diene system is outlined. 2. In accordance with the requirements of this scheme, it is shown that 5α-ergosta-8,14-dien-3β-ol is converted into ergosterol by Saccharomyces cerevisiae.

scholarly journals Regulation of transcription by Saccharomyces cerevisiae 14-3-3 proteins

2004 ◽  
Vol 382 (3) ◽  
pp. 867-875 ◽  
Author(s):  
Astrid BRUCKMANN ◽  
H. Yde STEENSMA ◽  
M. Joost TEIXEIRA de MATTOS ◽  
G. Paul H. van HEUSDEN
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Stress Response ◽  
Open Reading Frames ◽  
Ergosterol Biosynthesis ◽  
Temperature Sensitive ◽  
Regulation Of Transcription ◽  
Mrna Levels ◽  
Transcription Analysis ◽  
A Genome ◽  
Reading Frames

14-3-3 proteins form a family of highly conserved eukaryotic proteins involved in a wide variety of cellular processes, including signalling, apoptosis, cell-cycle control and transcriptional regulation. More than 150 binding partners have been found for these proteins. The yeast Saccharomyces cerevisiae has two genes encoding 14-3-3 proteins, BMH1 and BMH2. A bmh1 bmh2 double mutant is unviable in most laboratory strains. Previously, we constructed a temperature-sensitive bmh2 mutant and showed that mutations in RTG3 and SIN4, both encoding transcriptional regulators, can suppress the temperature-sensitive phenotype of this mutant, suggesting an inhibitory role of the 14-3-3 proteins in Rtg3-dependent transcription [van Heusden and Steensma (2001) Yeast 18, 1479–1491]. In the present paper, we report a genome-wide transcription analysis of a temperature-sensitive bmh2 mutant. Steady-state mRNA levels of 60 open reading frames were increased more than 2.0-fold in the bmh2 mutant, whereas those of 78 open reading frames were decreased more than 2.0-fold. In agreement with our genetic experiments, six genes known to be regulated by Rtg3 showed elevated mRNA levels in the mutant. In addition, several genes with other cellular functions, including those involved in gluconeogenesis, ergosterol biosynthesis and stress response, had altered mRNA levels in the mutant. Our data show that the yeast 14-3-3 proteins negatively regulate Rtg3-dependent transcription, stimulate the transcription of genes involved in ergosterol metabolism and in stress response and are involved in transcription regulation of multiple other genes.

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