scholarly journals Expression of the Saccharomyces cerevisiae inositol-1-phosphate synthase (INO1) gene is regulated by factors that affect phospholipid synthesis.

1986 ◽  
Vol 6 (10) ◽  
pp. 3320-3328 ◽  
Author(s):  
J P Hirsch ◽  
S A Henry
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Blot Hybridization ◽  
Constitutive Expression ◽  
Genomic Clone ◽  
Phospholipid Synthesis ◽  
Wild Type ◽  
Inositol 1 ◽  
Regulatory Link ◽  
In Cells ◽  
Phosphate Synthase

The INO1 gene of Saccharomyces cerevisiae encodes the regulated enzyme inositol-1-phosphate synthase, which catalyzes the first committed step in the synthesis of inositol-containing phospholipids. The expression of this gene was analyzed under conditions known to regulate phospholipid synthesis. RNA blot hybridization with a genomic clone for INO1 detected two RNA species of 1.8 and 0.6 kb. The abundance of the 1.8-kb RNA was greatly decreased when the cells were grown in the presence of the phospholipid precursor inositol, as was the enzyme activity of the synthase. Complementation analysis showed that this transcript encoded the INO1 gene product. The level of INO1 RNA was repressed 12-fold when the cells were grown in medium containing inositol, and it was repressed 33-fold when the cells were grown in the presence of inositol and choline together. The INO1 transcript was present at a very low level in cells containing mutations (ino2 and ino4) in regulatory genes unlinked to INO1 that result in inositol auxotrophy. The transcript was constitutively overproduced in cells containing a mutation (opi1) that causes constitutive expression of inositol-1-phosphate synthase and results in excretion of inositol. The expression of INO1 RNA was also examined in cells containing a mutation (cho2) affecting the synthesis of phosphatidylcholine. In contrast to what was observed in wild-type cells, growth of cho2 cells in medium containing inositol did not result in a significant decrease in INO1 RNA abundance. Inositol and choline together were required for repression of the INO1 transcript in these cells, providing evidence for a regulatory link between the synthesis of inositol- and choline-containing lipids. The level of the 0.6-kb RNA was affected, although to a lesser degree, by many of the same factors that influence INO1 expression.

Expression of the Saccharomyces cerevisiae inositol-1-phosphate synthase (INO1) gene is regulated by factors that affect phospholipid synthesis

1986 ◽  
Vol 6 (10) ◽  
pp. 3320-3328
Author(s):  
J P Hirsch ◽  
S A Henry
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Blot Hybridization ◽  
Constitutive Expression ◽  
Genomic Clone ◽  
Phospholipid Synthesis ◽  
Wild Type ◽  
Inositol 1 ◽  
Regulatory Link ◽  
In Cells ◽  
Phosphate Synthase

The INO1 gene of Saccharomyces cerevisiae encodes the regulated enzyme inositol-1-phosphate synthase, which catalyzes the first committed step in the synthesis of inositol-containing phospholipids. The expression of this gene was analyzed under conditions known to regulate phospholipid synthesis. RNA blot hybridization with a genomic clone for INO1 detected two RNA species of 1.8 and 0.6 kb. The abundance of the 1.8-kb RNA was greatly decreased when the cells were grown in the presence of the phospholipid precursor inositol, as was the enzyme activity of the synthase. Complementation analysis showed that this transcript encoded the INO1 gene product. The level of INO1 RNA was repressed 12-fold when the cells were grown in medium containing inositol, and it was repressed 33-fold when the cells were grown in the presence of inositol and choline together. The INO1 transcript was present at a very low level in cells containing mutations (ino2 and ino4) in regulatory genes unlinked to INO1 that result in inositol auxotrophy. The transcript was constitutively overproduced in cells containing a mutation (opi1) that causes constitutive expression of inositol-1-phosphate synthase and results in excretion of inositol. The expression of INO1 RNA was also examined in cells containing a mutation (cho2) affecting the synthesis of phosphatidylcholine. In contrast to what was observed in wild-type cells, growth of cho2 cells in medium containing inositol did not result in a significant decrease in INO1 RNA abundance. Inositol and choline together were required for repression of the INO1 transcript in these cells, providing evidence for a regulatory link between the synthesis of inositol- and choline-containing lipids. The level of the 0.6-kb RNA was affected, although to a lesser degree, by many of the same factors that influence INO1 expression.

scholarly journals The INO2 and INO4 loci of Saccharomyces cerevisiae are pleiotropic regulatory genes.

1984 ◽  
Vol 4 (11) ◽  
pp. 2479-2485 ◽  
Author(s):  
B S Loewy ◽  
S A Henry
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Gene Product ◽  
Regulatory Genes ◽  
Wild Type ◽  
Inositol 1 ◽  
Cytoplasmic Enzyme ◽  
Pleiotropic Phenotype ◽  
Reduced Rate ◽  
Phosphate Synthase

We isolated a mutant of Saccharomyces cerevisiae defective in the formation of phosphatidylcholine via methylation of phosphatidylethanolamine. The mutant synthesized phosphatidylcholine at a reduced rate and accumulated increased amounts of methylated phospholipid intermediates. It was also found to be auxotrophic for inositol and allelic to an existing series of ino4 mutants. The ino2 and ino4 mutants, originally isolated on the basis of an inositol requirement, are unable to derepress the cytoplasmic enzyme inositol-1-phosphate synthase (myo-inositol-1-phosphate synthase; EC 5.5.1.4). The INO4 and INO2 genes were, thus, previously identified as regulatory genes whose wild-type product is required for expression of the INO1 gene product inositol-1-phosphate synthase (T. Donahue and S. Henry, J. Biol. Chem. 256:7077-7085, 1981). In addition to the identification of a new ino4-allele, further characterization of the existing series of ino4 and ino2 mutants, reported here, demonstrated that they all have a reduced capacity to convert phosphatidylethanolamine to phosphatidylcholine. The pleiotropic phenotype of the ino2 and ino4 mutants described in this paper suggests that the INO2 and INO4 loci are involved in the regulation of phospholipid methylation in the membrane as well as inositol biosynthesis in the cytoplasm.

The INO2 and INO4 loci of Saccharomyces cerevisiae are pleiotropic regulatory genes

1984 ◽  
Vol 4 (11) ◽  
pp. 2479-2485
Author(s):  
B S Loewy ◽  
S A Henry
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Gene Product ◽  
Regulatory Genes ◽  
Wild Type ◽  
Inositol 1 ◽  
Cytoplasmic Enzyme ◽  
Pleiotropic Phenotype ◽  
Reduced Rate ◽  
Phosphate Synthase

We isolated a mutant of Saccharomyces cerevisiae defective in the formation of phosphatidylcholine via methylation of phosphatidylethanolamine. The mutant synthesized phosphatidylcholine at a reduced rate and accumulated increased amounts of methylated phospholipid intermediates. It was also found to be auxotrophic for inositol and allelic to an existing series of ino4 mutants. The ino2 and ino4 mutants, originally isolated on the basis of an inositol requirement, are unable to derepress the cytoplasmic enzyme inositol-1-phosphate synthase (myo-inositol-1-phosphate synthase; EC 5.5.1.4). The INO4 and INO2 genes were, thus, previously identified as regulatory genes whose wild-type product is required for expression of the INO1 gene product inositol-1-phosphate synthase (T. Donahue and S. Henry, J. Biol. Chem. 256:7077-7085, 1981). In addition to the identification of a new ino4-allele, further characterization of the existing series of ino4 and ino2 mutants, reported here, demonstrated that they all have a reduced capacity to convert phosphatidylethanolamine to phosphatidylcholine. The pleiotropic phenotype of the ino2 and ino4 mutants described in this paper suggests that the INO2 and INO4 loci are involved in the regulation of phospholipid methylation in the membrane as well as inositol biosynthesis in the cytoplasm.

The lethality of p60v-src in Saccharomyces cerevisiae and the activation of p34CDC28 kinase are dependent on the integrity of the SH2 domain

1993 ◽  
Vol 105 (2) ◽  
pp. 519-528
Author(s):  
F. Boschelli ◽  
S.M. Uptain ◽  
J.J. Lightbody
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Protein Tyrosine Kinase ◽  
Kinase Activity ◽  
Cell Cycle Control ◽  
Sh2 Domain ◽  
Wild Type ◽  
Type V ◽  
Cdc28 Kinase ◽  
In Cells

The lethal effects of the expression of the oncogenic protein tyrosine kinase p60v-src in Saccharomyces cerevisiae are associated with a loss of cell cycle control at the G1/S and G2/M checkpoints. Results described here indicate that the ability of v-Src to kill yeast is dependent on the integrity of the SH2 domain, a region of the Src protein involved in recognition of proteins phosphorylated on tyrosine. Catalytically active v-Src proteins with deletions in the SH2 domain have little effect on yeast growth, unlike wild-type v-Src protein, which causes accumulation of large-budded cells, perturbation of spindle microtubules and increased DNA content when expressed. The proteins phosphorylated on tyrosine in cells expressing v-Src differ from those in cells expressing a Src protein with a deletion in the SH2 domain. Also, unlike the wild-type v-Src protein, which drastically increases histone H1-associated Cdc28 kinase activity, c-Src and an altered v-Src protein have no effect on Cdc28 kinase activity. These results indicate that the SH2 domain is functionally important in the disruption of the yeast cell cycle by v-Src.

Inositol regulates phosphatidylglycerolphosphate synthase expression in Saccharomyces cerevisiae

1988 ◽  
Vol 8 (11) ◽  
pp. 4773-4779
Author(s):  
M L Greenberg ◽  
S Hubbell ◽  
C Lam
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Biosynthetic Enzymes ◽  
Phospholipid Synthesis ◽  
Wild Type ◽  
Mitochondrial Inner Membrane ◽  
Regulatory Circuit ◽  
The Media ◽  
Constitutive Synthesis ◽  
First Time ◽  
Phosphatidylcholine Synthesis

The enzyme phosphatidylglycerolphosphate synthase (PGPS; CDPdiacylglycerol-glycerol-3-phosphate 3-phosphatidyltransferase; EC 2.7.8.5) catalyzes the committed step in the synthesis of cardiolipin, a phospholipid found predominantly in the mitochondrial inner membrane. To determine whether PGPS is regulated by cross-pathway control, we analyzed PGPS expression under conditions in which the regulation of general phospholipid synthesis could be examined. The addition of inositol resulted in a three- to fivefold reduction in PGPS expression in wild-type cells in the presence or absence of exogenous choline. The reduction in enzyme activity in response to inositol was seen in minutes, suggesting that inactivation or degradation of the enzyme plays an important role in inositol-mediated repression of PGPS. In cho2 and opi3 mutants, which are blocked in phosphatidylcholine synthesis, inositol-mediated repression of PGPS did not occur unless choline was added to the media. Three previously identified genes that regulate general phospholipid synthesis, INO2, INO4, and OP11, did not affect PGPS expression. Thus, ino2 and ino4 mutants, which are unable to derepress biosynthetic enzymes involved in general phospholipid synthesis, expressed wild-type levels of PGPS activity under derepressing conditions. PGPS expression in the opi1 mutant, which exhibits constitutive synthesis of general phospholipid biosynthetic enzymes, was fully repressed in the presence of inositol and partially repressed even in the absence of inositol. These results demonstrate for the first time that an enzymatic step in cardiolipin synthesis is coordinately controlled with general phospholipid synthesis but that this control is not mediated by the same genetic regulatory circuit.

scholarly journals The Anaphase-promoting Complex Promotes Actomyosin-Ring Disassembly during Cytokinesis in Yeast

2009 ◽  
Vol 20 (4) ◽  
pp. 1201-1212 ◽  
Author(s):  
Gregory H. Tully ◽  
Ryuichi Nishihama ◽  
John R. Pringle ◽  
David O. Morgan
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ubiquitin Ligase ◽  
Myosin Light Chain ◽  
Anaphase Promoting Complex ◽  
Wild Type ◽  
Yeast Saccharomyces Cerevisiae ◽  
Division Site ◽  
Specific Proteins ◽  
Mutant Cells ◽  
In Cells

The anaphase-promoting complex (APC) is a ubiquitin ligase that controls progression through mitosis by targeting specific proteins for degradation. It is unclear whether the APC also contributes to the control of cytokinesis, the process that divides the cell after mitosis. We addressed this question in the yeast Saccharomyces cerevisiae by studying the effects of APC mutations on the actomyosin ring, a structure containing actin, myosin, and several other proteins that forms at the division site and is important for cytokinesis. In wild-type cells, actomyosin-ring constituents are removed progressively from the ring during contraction and disassembled completely thereafter. In cells lacking the APC activator Cdh1, the actomyosin ring contracts at a normal rate, but ring constituents are not disassembled normally during or after contraction. After cytokinesis in mutant cells, aggregates of ring proteins remain at the division site and at additional foci in other parts of the cell. A key target of APCCdh1 is the ring component Iqg1, the destruction of which contributes to actomyosin-ring disassembly. Deletion of CDH1 also exacerbates actomyosin-ring disassembly defects in cells with mutations in the myosin light-chain Mlc2, suggesting that Mlc2 and the APC employ independent mechanisms to promote ring disassembly during cytokinesis.

scholarly journals Proteomic analysis revealed the roles of YRR1 deletion in enhancing the vanillin resistance of Saccharomyces cerevisiae

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Wenyan Cao ◽  
Weiquan Zhao ◽  
Bolun Yang ◽  
Xinning Wang ◽  
Yu Shen ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Level ◽  
Ribosomal Proteins ◽  
Pentose Phosphate ◽  
Wild Type ◽  
Transcription Level ◽  
Translation Process ◽  
Enhanced Resistance ◽  
Yeast Strains ◽  
In Cells

Abstract Background Vanillin is one of the important phenolic inhibitors in Saccharomyces cerevisiae for bioconversion of lignocellulosic materials and has been reported to inhibit the translation process in cells. In our previous studies, it was confirmed that the deletion of the transcription factor gene YRR1 enhanced vanillin resistance by promoting some translation-related processes at the transcription level. In this work, we investigated the effects of proteomic changes upon induction of vanillin stress and deletion of YRR1 to provide unique perspectives from a transcriptome analysis for comprehending the mechanisms of YRR1 deletion in the protective response of yeast to vanillin. Results In wild-type cells, vanillin reduced two dozens of ribosomal proteins contents while upregulated proteins involved in glycolysis, oxidative phosphorylation, and the pentose phosphate pathway in cells. The ratios of NADPH/NADP+ and NADH/NAD+ were increased when cells responded to vanillin stress. The differentially expressed proteins perturbed by YRR1 deletion were much more abundant than and showed no overlaps with transcriptome changes, indicating that Yrr1 affects the synthesis of certain proteins. Forty-eight of 112 upregulated proteins were involved in the stress response, translational and transcriptional regulation. YRR1 deletion increased the expression of HAA1-encoding transcriptional activator, TMA17-encoding proteasome assembly chaperone and MBF1-encoding coactivator at the protein level, as confirmed by ELISA. Cultivation data showed that the overexpression of HAA1 and TMA17 enhanced resistance to vanillin in S. cerevisiae. Conclusions Cells conserve energy by decreasing the content of ribosomal proteins, producing more energy and NAD(P)H for survival in response to vanillin stress. Yrr1 improved vanillin resistance by increasing the protein quantities of Haa1, Tma17 and Mbf1. These results showed the response of S. cerevisiae to vanillin and how YRR1 deletion increases vanillin resistance at the protein level. These findings may advance our knowledge of how YRR1 deletion protects yeast from vanillin stress and offer novel targets for genetic engineering of designing inhibitor-resistant ethanologenic yeast strains.

scholarly journals Disruption of the Candida albicans TPS1Gene Encoding Trehalose-6-Phosphate Synthase Impairs Formation of Hyphae and Decreases Infectivity

1998 ◽  
Vol 180 (15) ◽  
pp. 3809-3815 ◽  
Author(s):  
Oscar Zaragoza ◽  
Miguel A. Blazquez ◽  
Carlos Gancedo
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Candida Albicans ◽  
Type Strain ◽  
Wild Type Strain ◽  
Calf Serum ◽  
Sugar Metabolism ◽  
Functional Complementation ◽  
Wild Type ◽  
Growth Defects ◽  
Phosphate Synthase

ABSTRACT The TPS1 gene from Candida albicans, which encodes trehalose-6-phosphate synthase, has been cloned by functional complementation of a tps1 mutant from Saccharomyces cerevisiae. In contrast with the wild-type strain, the doubletps1/tps1 disruptant did not accumulate trehalose at stationary phase or after heat shock. Growth of thetps1/tps1 disruptant at 30°C was indistinguishable from that of the wild type. However, at 42°C it did not grow on glucose or fructose but grew normally on galactose or glycerol. At 37°C, the yeast-hypha transition in the mutant in glucose-calf serum medium did not occur. During growth at 42°C, the mutant did not form hyphae in galactose or in glycerol. Some of the growth defects observed may be traced to an unbalanced sugar metabolism that reduces the cellular content of ATP. Mice inoculated with 106 CFU of thetps1/tps1 mutant did not show visible symptoms of infection 16 days after inoculation, while those similarly inoculated with wild-type cells were dead 12 days after inoculation.

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