Author Correction: Characterization of Hailey-Hailey Disease-mutants in presence and absence of wild type SPCA1 using Saccharomyces cerevisiae as model organism

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.

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Biochemical and Structural Characterization of Amy1: An Alpha-Amylase from Cryptococcus flavus Expressed in Saccharomyces cerevisiae

Enzyme Research ◽

10.4061/2011/157294 ◽

2011 ◽

Vol 2011 ◽

pp. 1-7 ◽

Cited By ~ 14

Author(s):

Alexsandro Sobreira Galdino ◽

Roberto Nascimento Silva ◽

Muriele Taborda Lottermann ◽

Alice Cunha Morales Álvares ◽

Lídia Maria Pepe de Moraes ◽

...

Keyword(s):

Saccharomyces Cerevisiae ◽

Soluble Starch ◽

Alpha Amylase ◽

Enzyme Specificity ◽

Wild Type ◽

Spectra Analysis ◽

Exclusion Chromatography ◽

The Difference ◽

Thermal Stability Of

An extracellular alpha-amylase (Amy1) whose gene from Cryptococcus flavus was previously expressed in Saccharomyces cerevisiae was purified to homogeneity (67 kDa) by ion-exchange and molecular exclusion chromatography. The enzyme was activated by NH4+ and inhibited by Cu+2 and Hg+2. Significant biochemical and structural discrepancies between wild-type and recombinant α-amylase with respect to Km values, enzyme specificity, and secondary structure content were found. Far-UV CD spectra analysis at pH 7.0 revealed the high thermal stability of both proteins and the difference in folding pattern of Amy1 compared with wild-type amylase from C. flavus, which reflected in decrease (10-fold) of enzymatic activity of recombinant protein. Despite the differences, the highest activity of Amy1 towards soluble starch, amylopectin, and amylase, in contrast with the lowest activity of Amy1w, points to this protein as being of paramount biotechnological importance with many applications ranging from food industry to the production of biofuels.

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

Acta Biochimica Polonica ◽

10.18388/abp.2015_1164 ◽

2016 ◽

Vol 63 (2) ◽

Cited By ~ 3

Author(s):

Mateusz Molon ◽

Renata Zadrag-Tecza

Keyword(s):

Saccharomyces Cerevisiae ◽

Cell Volume ◽

Genetic Background ◽

Wild Type Strain ◽

Reproductive Potential ◽

Model Organism ◽

Reproductive Capacity ◽

Wild Type ◽

Yeast Saccharomyces Cerevisiae ◽

Daughter Cells

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).

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Functional characterization of Ost3p. Loss of the 34-kD subunit of the Saccharomyces cerevisiae oligosaccharyltransferase results in biased underglycosylation of acceptor substrates.

The Journal of Cell Biology ◽

10.1083/jcb.130.3.567 ◽

1995 ◽

Vol 130 (3) ◽

pp. 567-577 ◽

Cited By ~ 58

Author(s):

D Karaoglu ◽

D J Kelleher ◽

R Gilmore

Keyword(s):

Saccharomyces Cerevisiae ◽

Functional Characterization ◽

Null Mutant ◽

Wild Type ◽

Membrane Glycoproteins ◽

En Bloc ◽

Oligosaccharide Moiety

Within the lumen of the rough endoplasmic reticulum, oligosaccharyltransferase catalyzes the en bloc transfer of a high mannose oligosaccharide moiety from the lipid-linked oligosaccharide donor to asparagine acceptor sites in nascent polypeptides. The Saccharomyces cerevisiae oligosaccharyltransferase was purified as a heteroligomeric complex consisting of six subunits (alpha-zeta) having apparent molecular masses of 64 kD (Ost1p), 45 kD (Wbp1p), 34 kD, 30 kD (Swp1p), 16 kD, and 9 kD. Here we report a structural and functional characterization of Ost3p which corresponds to the 34-kD gamma-subunit of the oligosaccharyltransferase. Unlike Ost1p, Wbp1p, and Swp1p, expression of Ost3p is not essential for viability of yeast. Instead, ost3 null mutant yeast grow at wild-type rates on solid or in liquid media irrespective of culture temperature. Nonetheless, detergent extracts prepared from ost3 null mutant membranes are twofold less active than extracts prepared from wild-type membranes in an in vitro oligosaccharyltransferase assay. Furthermore, loss of Ost3p is accompanied by significant underglycosylation of soluble and membrane-bound glycoproteins in vivo. Compared to the previously characterized ost1-1 mutant in the oligosaccharyltransferase, and the alg5 mutant in the oligosaccharide assembly pathway, ost3 null mutant yeast appear to be selectively impaired in the glycosylation of several membrane glycoproteins. The latter observation suggests that Ost3p may enhance oligosaccharide transfer in vivo to a subset of acceptor substrates.

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Characterization of Chlamydomonas reinhardtii Mutants That Exhibit Strong Positive Phototaxis

Plants ◽

10.3390/plants10071483 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1483

Author(s):

Jun Morishita ◽

Ryutaro Tokutsu ◽

Jun Minagawa ◽

Toru Hisabori ◽

Ken-ichi Wakabayashi

Keyword(s):

Chlamydomonas Reinhardtii ◽

Regulatory Mechanism ◽

Model Organism ◽

Negative Phototaxis ◽

Light Conditions ◽

Wild Type ◽

Positive Phototaxis ◽

Unicellular Green Alga ◽

Cellular Factors

The most motile phototrophic organisms exhibit photo-induced behavioral responses (photobehavior) to inhabit better light conditions for photosynthesis. The unicellular green alga Chlamydomonas reinhardtii is an excellent model organism to study photobehavior. Several years ago, we found that C. reinhardtii cells reverse their phototactic signs (i.e., positive and negative phototaxis) depending on the amount of reactive oxygen species (ROS) accumulated in the cell. However, its molecular mechanism is unclear. In this study, we isolated seven mutants showing positive phototaxis, even after the induction of negative phototaxis (ap1~7: always positive) to understand the ROS-dependent regulatory mechanism for the phototactic sign. We found no common feature in the mutants regarding their growth, high-light tolerance, and photosynthetic phenotypes. Interestingly, five of them grew faster than the wild type. These data suggest that the ROS-dependent regulation of the phototactic sign is not a single pathway and is affected by various cellular factors. Additionally, the isolation and analyses of mutants with defects in phototactic-sign regulation may provide clues for their application to the efficient cultivation of algae.

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

Molecular and Cellular Biology ◽

10.1128/mcb.4.11.2479-2485.1984 ◽

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.

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L-Phenylalanine Transport in Saccharomyces cerevisiae: Participation of GAP1, BAP2, and AGP1

Journal of Amino Acids ◽

10.1155/2014/283962 ◽

2014 ◽

Vol 2014 ◽

pp. 1-9 ◽

Cited By ~ 8

Author(s):

Daniel A. Sáenz ◽

Mónica S. Chianelli ◽

Carlos A. Stella

Keyword(s):

Saccharomyces Cerevisiae ◽

Substrate Specificity ◽

Nitrogen Source ◽

Type Strain ◽

Wild Type Strain ◽

Ammonium Ion ◽

Wild Type ◽

Synthetic Media ◽

Phenylalanine Transport

We focused on the participation of GAP1, BAP2, and AGP1 in L-phenylalanine transport in yeast. In order to study the physiological functions of GAP1, BAP2, and AGP1 in L-phenylalanine transport, we examined the kinetics, substrate specificity, and regulation of these systems, employing isogenic haploid strains with the respective genes disrupted individually and in combination. During the characterization of phenylalanine transport, we noted important regulatory phenomena associated with these systems. Our results show that Agp1p is the major transporter of the phenylalanine in a gap1 strain growing in synthetic media with leucine present as an inducer. In a wild type strain grown in the presence of leucine, when ammonium ion was the nitrogen source, Bap2p is the principal phenylalanine carrier.

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Isolation and characterization of the positive regulatory gene ADR1 from Saccharomyces cerevisiae

Molecular and Cellular Biology ◽

10.1128/mcb.3.3.360-370.1983 ◽

1983 ◽

Vol 3 (3) ◽

pp. 360-370

Author(s):

C L Denis ◽

E T Young

Keyword(s):

Saccharomyces Cerevisiae ◽

Restriction Site ◽

Glucose Repression ◽

Regulatory Gene ◽

Wild Type ◽

Isolation And Characterization ◽

Site Mapping ◽

Nonfermentable Carbon Source ◽

Restriction Site Mapping

The DNA segments containing the ADR1 gene and a mutant allele, ADR1-5c, have been isolated by complementation of function in Saccharomyces cerevisiae. The ADR1 gene is required for synthesis of the glucose-repressible alcohol dehydrogenase (ADHII) when S. cerevisiae cells are grown on a nonfermentable carbon source, whereas the ADR1-5c allele allows ADHII synthesis even during glucose repression. A plasmid pool consisting of yeast DNA fragments isolated from a strain carrying the ADR1-5c allele was used to transform a strain containing the adr1-1 allele, which prevents ADHII depression. Transformants were isolated which expressed ADHII during glucose repression. A plasmid isolated from one of these transformants was shown to carry the ADR1-5c allele by its ability to integrate at the chromosomal adr1-1 locus. The wild-type ADR1 gene was isolated by colony hybridization, using the cloned ADR1-5c gene as a probe. The ADR1-5c and ADR1 DNA segments were indistinguishable by restriction site mapping. A partial ADR1 phenotype could be conferred by a 1.9-kilobase region, but DNA outside of this region appeared to be necessary for normal activation of ADHII by the ADR1 gene.

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