scholarly journals Molecular analysis of the yeast VPS3 gene and the role of its product in vacuolar protein sorting and vacuolar segregation during the cell cycle.

1990 ◽  
Vol 111 (3) ◽  
pp. 877-892 ◽  
Author(s):  
C K Raymond ◽  
P J O'Hara ◽  
G Eichinger ◽  
J H Rothman ◽  
T H Stevens
Keyword(s):  
Selection Procedure ◽  
Temperature Shift ◽  
Yeast Cells ◽  
Carboxypeptidase Y ◽  
Wild Type ◽  
Yeast Saccharomyces Cerevisiae ◽  
Yeast Strains ◽  
Type Pattern ◽  
Mother Cells ◽  
Vacuolar Protein

vps3 mutants of the yeast Saccharomyces cerevisiae are impaired in the sorting of newly synthesized soluble vacuolar proteins and in the acidification of the vacuole (Rothman, J. H., and T. H. Stevens. Cell. 47:1041-1051; Rothman, J. H., C. T. Yamashiro, C. K. Raymond, P. M. Kane, and T. H. Stevens. 1989. J. Cell Biol. 109:93-100). The VPS3 gene, which was cloned using a novel selection procedure, encodes a low abundance, hydrophilic protein of 117 kD that most likely resides in the cytoplasm. Yeast strains bearing a deletion of the VPS3 gene (vps3-delta 1) are viable, yet their growth rate is significantly reduced relative to wild-type cells. Temperature shift experiments with strains carrying a temperature conditional vps3 allele demonstrate that cells rapidly lose the capacity to sort the vacuolar protein carboxypeptidase Y upon loss of VPS3 function. Vacuolar morphology was examined in wild-type and vps3-delta 1 yeast strains by fluorescence microscopy. The vacuoles in wild-type yeast cells are morphologically complex, and they appear to be actively partitioned between mother cells and buds during an early phase of bud growth. Vacuolar morphology in vps3-delta 1 mutants is significantly altered from the wild-type pattern, and the vacuolar segregation process seen in wild-type strains is defective in these mutants. With the exception of a vacuolar acidification defect, the phenotypes of vps3-delta 1 strains are significantly different from those of mutants lacking the vacuolar proton-translocating ATPase. These data demonstrate that the acidification defect in vps3-delta 1 cells is not the primary cause of the pleiotropic defects in vacuolar function observed in these mutants.

scholarly journals Effect of stress on the life span of the yeast Saccharomyces cerevisiae.

2000 ◽  
Vol 47 (2) ◽  
pp. 355-364 ◽  
Author(s):  
A Swieciło ◽  
Z Krawiec ◽  
J Wawryn ◽  
G Bartosz ◽  
T Biliński
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Life Span ◽  
Yeast Cells ◽  
Wild Type ◽  
Maximum Life Span ◽  
Yeast Saccharomyces Cerevisiae ◽  
Yeast Strains ◽  
Resistance To Stress ◽  
The Mean ◽  
C 30

A correlation is known to exist in yeast and other organisms between the cellular resistance to stress and the life span. The aim of this study was to examine whether stress treatment does affect the generative life span of yeast cells. Both heat shock (38 degrees C, 30 min) and osmotic stress (0.3 M NaCl, 1 h) applied cyclically were found to increase the mean and maximum life span of Saccharomyces cerevisiae. Both effects were more pronounced in superoxide dismutase-deficient yeast strains (up to 50% prolongation of mean life span and up to 30% prolongation of maximum life span) than in their wild-type counterparts. These data point to the importance of the antioxidant barrier in the stress-induced prolongation of yeast life span.

Evolution of ethylene by Saccharomyces cerevisiae as influenced by the carbon source for growth and the presence of air

1978 ◽  
Vol 24 (6) ◽  
pp. 637-642 ◽  
Author(s):  
K. C. Thomas ◽  
Mary Spencer
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Carbon Source ◽  
Ethylene Production ◽  
Atp Synthesis ◽  
Yeast Cells ◽  
Yeast Culture ◽  
Wild Type ◽  
Yeast Saccharomyces Cerevisiae ◽  
Absolute Requirement ◽  
Wild Type Yeast

Effects of the carbon source and oxygen on ethylene production by the yeast Saccharomyces cerevisiae have been studied. The amounts of ethylene evolved by the yeast culture were less than those detected in the blank (an equal volume of uninoculated medium), suggesting a net absorption of ethylene by the yeast cells. Addition of glucose to the lactate-grown yeast culture induced ethylene production. This glucose-induced stimulation of ethylene production was inhibited to a great extent by cycloheximide. Results suggested that the yeast cells in the presence of glucose synthesized an ethylene precursor and passed it into the medium. The conversion of this precursor to ethylene might be stimulated by oxygen. The fact that ethylene was produced by the yeast growing anaerobically and also by respiration-deficient mutants isolated from the wild-type yeast suggested that mitochondrial ATP synthesis was not an absolute requirement for ethylene biogenesis.

The yeast VPS5/GRD2 gene encodes a sorting nexin-1-like protein required for localizing membrane proteins to the late Golgi

1997 ◽  
Vol 110 (9) ◽  
pp. 1063-1072 ◽  
Author(s):  
S.F. Nothwehr ◽  
A.E. Hindes
Keyword(s):  
Membrane Proteins ◽  
Membrane Protein ◽  
Protein Localization ◽  
Endocytic Pathway ◽  
Yeast Cells ◽  
Carboxypeptidase Y ◽  
Golgi Membrane ◽  
Sorting Nexin ◽  
Vacuolar Protein ◽  
Sorting Nexin 1

Genetic analysis of late Golgi membrane protein localization in Saccharomyces cerevisiae has uncovered a large number of genes (called GRD) that are required for retention of A-ALP, a model late Golgi membrane protein. Here we describe one of the GRD genes, VPSS/GRD2, that encodes a hydrophilic protein similar to human sorting nexin-1, a protein involved in trafficking of the epidermal growth factor receptor. In yeast cells containing a vps5 null mutation the late Golgi membrane proteins A-ALP and Kex2p were rapidly mislocalized to the vacuolar membrane. A-ALP was delivered to the vacuole in vps5 mutants in a manner independent of a block in the early endocytic pathway. vps5 null mutants also exhibited defects in both vacuolar morphology and in sorting of a soluble vacuolar protein, carboxypeptidase Y. The latter defect is apparently due to an inability to localize the carboxypeptidase Y sorting receptor, Vps10p, to the Golgi since it is rapidly degraded in the vacuole in vps5 mutants. Fractionation studies indicate that Vps5p is distributed between a free cytosolic pool and a particulate fraction containing Golgi, transport vesicles, and possibly endosomes, but lacking vacuolar membranes. Immunofluorescence microscopy experiments show that the membrane-associated pool of Vps5p localizes to an endosome-like organelle that accumulates in the class E vps27 mutant. These results support a model in which Vps5p is required for retrieval of membrane proteins from a prevacuolar/late endosomal compartment back to the late Golgi apparatus.

scholarly journals Peroxisome Maintenance Depends on De Novo Peroxisome Formation in Yeast Mutants Defective in Peroxisome Fission and Inheritance

2019 ◽  
Vol 20 (16) ◽  
pp. 4023 ◽  
Author(s):  
Justyna P. Wróblewska ◽  
Ida J. van der Klei
Keyword(s):  
De Novo ◽  
Hansenula Polymorpha ◽  
Yeast Cells ◽  
Wild Type ◽  
Double Deletion ◽  
Mother Cells ◽  
Yeast Mutants ◽  
Rescue Mechanism ◽  
Wild Type Yeast ◽  
In Cells

There is an ongoing debate on how peroxisomes form: by growth and fission of pre-existing peroxisomes or de novo from another membrane. It has been proposed that, in wild type yeast cells, peroxisome fission and careful segregation of the organelles over mother cells and buds is essential for organelle maintenance. Using live cell imaging we observed that cells of the yeast Hansenula polymorpha, lacking the peroxisome fission protein Pex11, still show peroxisome fission and inheritance. Also, in cells of mutants without the peroxisome inheritance protein Inp2 peroxisome segregation can still occur. In contrast, peroxisome fission and inheritance were not observed in cells of a pex11 inp2 double deletion strain. In buds of cells of this double mutant, new organelles likely appear de novo. Growth of pex11 inp2 cells on methanol, a growth substrate that requires functional peroxisomes, is retarded relative to the wild type control. Based on these observations we conclude that in H. polymorpha de novo peroxisome formation is a rescue mechanism, which is less efficient than organelle fission and inheritance to maintain functional peroxisomes.

scholarly journals Purification of profilin from Saccharomyces cerevisiae and analysis of profilin-deficient cells.

1990 ◽  
Vol 110 (1) ◽  
pp. 105-114 ◽  
Author(s):  
B K Haarer ◽  
S H Lillie ◽  
A E Adams ◽  
V Magdolen ◽  
W Bandlow ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Actin Polymerization ◽  
Yeast Cells ◽  
Predicted Amino Acid Sequence ◽  
Temperature Sensitive ◽  
Wild Type ◽  
Yeast Saccharomyces Cerevisiae ◽  
Ellipsoidal Shape ◽  
Hydrolysis Of

We have isolated profilin from yeast (Saccharomyces cerevisiae) and have microsequenced a portion of the protein to confirm its identity; the region microsequenced agrees with the predicted amino acid sequence from a profilin gene recently isolated from S. cerevisiae (Magdolen, V., U. Oechsner, G. Müller, and W. Bandlow. 1988. Mol. Cell. Biol. 8:5108-5115). Yeast profilin resembles profilins from other organisms in molecular mass and in the ability to bind to polyproline, retard the rate of actin polymerization, and inhibit hydrolysis of ATP by monomeric actin. Using strains that carry disruptions or deletions of the profilin gene, we have found that, under appropriate conditions, cells can survive without detectable profilin. Such cells grow slowly, are temperature sensitive, lose the normal ellipsoidal shape of yeast cells, often become multinucleate, and generally grow much larger than wild-type cells. In addition, these cells exhibit delocalized deposition of cell wall chitin and have dramatically altered actin distributions.

scholarly journals Deletion of Budding Yeast MAD2 Suppresses Clone-to-Clone Differences in Artificial Linear Chromosome Copy Numbers and Gives Rise to Higher Retention Rates

2020 ◽  
Vol 8 (10) ◽  
pp. 1495
Author(s):  
Scott C. Schuyler ◽  
Lin-Ing Wang ◽  
Yi-Shan Ding ◽  
Yi-Chieh Lee ◽  
Hsin-Yu Chen
Keyword(s):  
Budding Yeast ◽  
Retention Rate ◽  
Retention Rates ◽  
Yeast Cells ◽  
Wild Type ◽  
Yeast Saccharomyces Cerevisiae ◽  
Linear Chromosome ◽  
Copy Numbers ◽  
Clone Differences ◽  
Linear Chromosomes

Our goal was to investigate the changes in artificial short-linear chromosome average copy numbers per cell arising from partial or full loss of Mitotic Arrest-Deficient 2 (MAD2) spindle checkpoint function in budding yeast Saccharomyces cerevisiae. Average artificial linear chromosome copy numbers in a population of cells, as measured by quantitative polymerase chain reactions (qPCR), and retention rates, as measured by fluctuation analyses, were performed on a total of 62 individual wild type and mad2∆ mutant haploid and diploid clones. Wild type cells, both haploids and diploids, displayed phenotypically unique clone-to-clone differences: one group of 15 clones displayed low-copy numbers per cell and high retention rates, were 1 clone was found to have undergone a genomic integration event, and the second group of 15 clones displayed high copy numbers per cell and low retention rates, with the latter values being consistent with the previously published results where only a single clone had been measured. These chromosome states were observed to be unstable when propagated for 10 days under selection, where high copy-low retention rate clones evolved into low copy-high retention rate clones, but no evidence for integration events was observed. By contrast, mad2∆ haploid and mad2∆/mad2∆ diploids displayed a suppression of the clone-to-clone differences, where 20 out of 21 clones had mid-level artificial linear chromosome copy numbers per cell, but maintained elevated chromosome retention rates. The elevated levels in retention rates in mad2∆ and mad2∆/mad2∆ cells were also maintained even in the absence of selection during growth over 3 days. MAD2/mad2∆ heterozygous diploids displayed multiple clonal groups: 4 with low copy numbers, 5 with mid-level copy numbers, and 1 with a high copy number of artificial linear chromosomes, but all 10 clones uniformly displayed low retention rates. Our observations reveal that MAD2 function contributes to the ability of yeast cells to maintain a high number of artificial linear chromosomes per cell in some clones, but, counter-intuitively, mad2∆ suppresses clone-to-clone differences and leads to an improvement in artificial linear chromosome retention rates yielding a more uniform and stable clonal population with mid-level chromosome copy numbers per cell.

NADPH is important for isobutanol tolerance in a minimal medium of Saccharomyces cerevisiae

2021 ◽  
Author(s):  
Yuki Yoshikawa ◽  
Ryo Nasuno ◽  
Hiroshi Takagi
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Minimal Medium ◽  
Yeast Cells ◽  
Yeast Saccharomyces Cerevisiae ◽  
Acetaldehyde Dehydrogenase ◽  
Phosphogluconate Dehydrogenase ◽  
Yeast Strains ◽  
Glucose 6 Phosphate Dehydrogenase

Abstract We showed that the isobutanol sensitivity in glucose-6-phosphate dehydrogenase-deficient cells of the yeast Saccharomyces cerevisiae was rescued by an alternative NADPH producer, acetaldehyde dehydrogenase, but not in the cells lacking 6-phosphogluconate dehydrogenase. This phenotype correlated with the intracellular NADPH/NADP+ ratio in yeast strains. Our findings indicate the importance of NADPH for the isobutanol tolerance of yeast cells.

Translation initiation factor 5A and its hypusine modification are essential for cell viability in the yeast Saccharomyces cerevisiae

1991 ◽  
Vol 11 (6) ◽  
pp. 3105-3114
Author(s):  
J Schnier ◽  
H G Schwelberger ◽  
Z Smit-McBride ◽  
H A Kang ◽  
J W Hershey
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Peptide Bond ◽  
Translation Initiation Factor ◽  
Site Directed Mutagenesis ◽  
Yeast Cells ◽  
Initiation Factor ◽  
Mutant Form ◽  
Wild Type ◽  
Yeast Saccharomyces Cerevisiae

Translation intitiation factor eIF-5A (previously named eIF-4D) is a highly conserved protein that promotes formation of the first peptide bond. One of its lysine residues is modified by spermidine to form hypusine, a posttranslational modification unique to eIF-5A. To elucidate the function of eIF-5A and determine the role of its hypusine modification, the cDNA encoding human eIF-5A was used as a probe to identify and clone the corresponding genes from the yeast Saccharomyces cerevisiae. Two genes named TIF51A and TIF51B were cloned and sequenced. The two yeast proteins are closely related, sharing 90% sequence identity, and each is ca. 63% identical to the human protein. The purified protein expressed from the TIF51A gene substitutes for HeLa eIF-5A in the mammalian methionyl-puromycin synthesis assay. Strains lacking the A form of eIF-5A, constructed by disruption of TIF51A with LEU2, grow slowly, whereas strains lacking the B form, in which HIS3 was used to disrupt TIF51B, show no growth rate phenotype. However, strains with both TIF51A and TIF51B disrupted are not viable, indicating that eIF-5a is essential for cell growth in yeast cells. Northern (RNA) blot analysis shows two mRNA species, a larger mRNA (0.9 kb) transcribed from TIF51A and a smaller mRNA (0.8 kb) encoded by TIF51B. Under the aerobic growth conditions of this study, the 0.8-kb TIF51B transcript is not detected in the wild-type strain and is expressed only when TIF51A is disrupted. The TIF51A gene was altered by site-directed mutagenesis at the site of hypusination by changing the Lys codon to that for Arg, thereby producing a stable protein that retains the positive charge but is not modified to the hypusine derivative. The plasmid shuffle technique was used to replace the wild-type gene with the mutant form, resulting in failure of the yeast cells to grow. This result indicates that hypusine very likely is required for the vital in vivo function of eIF-5A and suggests a precise, essential role for the polyamine spermidine in cell metabolism.

scholarly journals The Sodium/Proton Exchanger Nhx1p Is Required for Endosomal Protein Trafficking in the YeastSaccharomyces cerevisiae

2000 ◽  
Vol 11 (12) ◽  
pp. 4277-4294 ◽  
Author(s):  
Katherine Bowers ◽  
Boaz P. Levi ◽  
Falguny I. Patel ◽  
Tom H. Stevens
Keyword(s):  
Protein Trafficking ◽  
Protein Sorting ◽  
Proton Exchange ◽  
Carboxypeptidase Y ◽  
Wild Type ◽  
Ion Balance ◽  
Sodium Proton Exchanger ◽  
Sodium Proton Exchange ◽  
Prevacuolar Compartment ◽  
Vacuolar Protein

We show that the vacuolar protein sorting gene VPS44is identical to NHX1, a gene that encodes a sodium/proton exchanger. The Saccharomyces cerevisiaeprotein Nhx1p shows high homology to mammalian sodium/proton exchangers of the NHE family. Nhx1p is thought to transport sodium ions into the prevacuole compartment in exchange for protons. Pulse-chase experiments show that ∼35% of the newly synthesized soluble vacuolar protein carboxypeptidase Y is missorted in nhx1Δ cells, and is secreted from the cell.nhx1Δ cells accumulate late Golgi, prevacuole, and lysosome markers in an aberrant structure next to the vacuole, and late Golgi proteins are proteolytically cleaved more rapidly than in wild-type cells. Our results show that efficient transport out of the prevacuolar compartment requires Nhx1p, and that nhx1Δ cells exhibit phenotypes characteristic of the “class E” group ofvps mutants. In addition, we show that Nhx1p is required for protein trafficking even in the absence of the vacuolar ATPase. Our analysis of Nhx1p provides the first evidence that a sodium/proton exchange protein is important for correct protein sorting, and that intraorganellar ion balance may be important for endosomal function in yeast.

scholarly journals Morphological classification of the yeast vacuolar protein sorting mutants: evidence for a prevacuolar compartment in class E vps mutants.

1992 ◽  
Vol 3 (12) ◽  
pp. 1389-1402 ◽  
Author(s):  
C K Raymond ◽  
I Howald-Stevenson ◽  
C A Vater ◽  
T H Stevens
Keyword(s):  
Protein Sorting ◽  
Carboxypeptidase Y ◽  
Vacuolar Protein Sorting ◽  
Complementation Groups ◽  
Prevacuolar Compartment ◽  
Golgi Protein ◽  
Mother Cells ◽  
Vacuolar Protein ◽  
Morphological Phenotype

The collection of vacuolar protein sorting mutants (vps mutants) in Saccharomyces cerevisiae comprises of 41 complementation groups. The vacuoles in these mutant strains were examined using immunofluorescence microscopy. Most of the vps mutants were found to possess vacuolar morphologies that differed significantly from wild-type vacuoles. Furthermore, mutants representing independent vps complementation groups were found to share aberrant morphological features. Six distinct classes of vacuolar morphology were observed. Mutants from eight vps complementation groups were defective both for vacuolar segregation from mother cells into developing buds and for acidification of the vacuole. Another group of mutants, represented by 13 complementation groups, accumulated a novel organelle distinct from the vacuole that contained a late-Golgi protein, active vacuolar H(+)-ATPase complex, and soluble vacuolar hydrolases. We suggest that this organelle may represent an exaggerated endosome-like compartment. None of the vps mutants appeared to mislocalize significant amounts of the vacuolar membrane protein alkaline phosphatase. Quantitative immunoprecipitations of the soluble vacuolar hydrolase carboxypeptidase Y (CPY) were performed to determine the extent of the sorting defect in each vps mutant. A good correlation between morphological phenotype and the extent of the CPY sorting defect was observed.

Sign in / Sign up

Export Citation Format

Share Document