Nuclear behaviour and cell wall composition in relation to budding in mutants of the yeast Saccharomyces cerevisiae

1986 ◽  
Vol 64 (1) ◽  
pp. 193-200 ◽  
Author(s):  
Mario Lachapelle ◽  
E. Roger Boothroyd
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Spindle Pole ◽  
Minor Role ◽  
Temperature Sensitive ◽  
Yeast Saccharomyces Cerevisiae ◽  
Bud Emergence ◽  
Spindle Elongation ◽  
10 Nm Filaments ◽  
A Minor

A temperature-sensitive, cell division cycle mutant (cdc24–1) and karyogamy-deficient (kar1) mutant of Saccharomyces cerevisiae, both of which can produce binucleate or multinucleate cells, were used to study certain aspects of budding, after fluorescent staining for mannan, chitin, and nuclei (DNA). In most binucleate cells the two nuclei lay close together and divided into the same bud. In a few, however, the nuclei were far apart and one or two buds were formed, each proximal to a nucleus. The proximity of daughter nuclei in most blocked cdc24–1 cells suggests a role for the CDC24 gene product in spindle elongation. The relationship between the nuclei and the number and location of buds supports the theory of a preponderant role for the nucleus in budding. Although buds develop preferentially in regions of low chitin content in kar1 heterokaryons, the ability of cdc24–1 cells to bud even with a uniformly high content of chitin and mannan suggests a minor role for these cell wall constituents in determining the sites of bud emergence. The chitin ring is not needed for bud emergence but seems to play a role in normal bud development and in septum formation. Electron microscopy of cdc24–1 cells blocked (37 °C) for 8 h and released (23 °C) for 30 min showed morphologically normal spindle pole bodies, cytoplasmic microtubules, and intranuclear spindles. Although the chitin ring was absent, the ring of 10-nm filaments was present, consistent with its proposed role in bud emergence.

scholarly journals Spindle dynamics and cell cycle regulation of dynein in the budding yeast, Saccharomyces cerevisiae.

1995 ◽  
Vol 130 (3) ◽  
pp. 687-700 ◽  
Author(s):  
E Yeh ◽  
R V Skibbens ◽  
J W Cheng ◽  
E D Salmon ◽  
K Bloom
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Nuclear Translocation ◽  
Spindle Pole ◽  
Cell Cortex ◽  
Wild Type ◽  
Immunofluorescent Localization ◽  
Yeast Saccharomyces Cerevisiae ◽  
Spindle Dynamics ◽  
Spindle Elongation ◽  
Anaphase B

We have used time-lapse digital- and video-enhanced differential interference contrast (DE-DIC, VE-DIC) microscopy to study the role of dynein in spindle and nuclear dynamics in the yeast Saccharomyces cerevisiae. The real-time analysis reveals six stages in the spindle cycle. Anaphase B onset appears marked by a rapid phase of spindle elongation, simultaneous with nuclear migration into the daughter cell. The onset and kinetics of rapid spindle elongation are identical in wild type and dynein mutants. In the absence of dynein the nucleus does not migrate as close to the neck as in wild-type cells and initial spindle elongation is confined primarily to the mother cell. Rapid oscillations of the elongating spindle between the mother and bud are observed in wild-type cells, followed by a slower growth phase until the spindle reaches its maximal length. This stage is protracted in the dynein mutants and devoid of oscillatory motion. Thus dynein is required for rapid penetration of the nucleus into the bud and anaphase B spindle dynamics. Genetic analysis reveals that in the absence of a functional central spindle (ndcl), dynein is essential for chromosome movement into the bud. Immunofluorescent localization of dynein-beta-galactosidase fusion proteins reveals that dynein is associated with spindle pole bodies and the cell cortex: with spindle pole body localization dependent on intact microtubules. A kinetic analysis of nuclear movement also revealed that cytokinesis is delayed until nuclear translocation is completed, indicative of a surveillance pathway monitoring nuclear transit into the bud.

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 Cellular morphogenesis in the Saccharomyces cerevisiae cell cycle: localization of the CDC3 gene product and the timing of events at the budding site.

1991 ◽  
Vol 112 (4) ◽  
pp. 535-544 ◽  
Author(s):  
H B Kim ◽  
B K Haarer ◽  
J R Pringle
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Gene Product ◽  
Polyclonal Antibodies ◽  
Electron Microscopic ◽  
Yeast Saccharomyces Cerevisiae ◽  
Cell Biol ◽  
Bud Emergence ◽  
Ring Structures ◽  
Bud Growth ◽  
10 Nm Filaments

Budding cells of the yeast Saccharomyces cerevisiae possess a ring of 10-nm-diameter filaments, of unknown biochemical nature, that lies just inside the plasma membrane in the neck connecting the mother cell to its bud. Electron microscopic observations suggest that these filaments assemble at the budding site coincident with bud emergence and disassemble shortly before cytokinesis (Byers, B. and L. Goetsch. 1976. J. Cell Biol. 69:717-721). Mutants defective in any of four genes (CDC3, CDC10, CDC11, or CDC12) lack these filaments and display a pleiotropic phenotype that involves abnormal bud growth and an inability to complete cytokinesis. We showed previously by immunofluorescence that the CDC12 gene product is probably a constituent of the ring of 10-nm filaments (Haarer, B. and J. Pringle. 1987. Mol. Cell. Biol. 7:3678-3687). We now report the use of fusion proteins to generate polyclonal antibodies specific for the CDC3 gene product. In immunofluorescence experiments, these antibodies decorated the neck regions of wild-type and mutant cells in patterns suggesting that the CDC3 gene product is also a constituent of the ring of 10-nm filaments. We also used the CDC3-specific and CDC12-specific antibodies to investigate the timing of localization of these proteins to the budding site. The results suggest that the CDC3 protein is organized into a ring at the budding site well before bud emergence and remains so organized for some time after cytokinesis. The CDC12 product appears to behave similarly, but may arrive at the budding site closer to the time of bud emergence, and disappear from that site more quickly after cytokinesis, than does the CDC3 product. Examination of mating cells and cells responding to purified mating pheromone revealed novel arrangements of the CDC3 and CDC12 products in the regions of cell wall reorganization. Both proteins were present in normal-looking ring structures at the bases of the first zygotic buds.

scholarly journals MIF2 is required for mitotic spindle integrity during anaphase spindle elongation in Saccharomyces cerevisiae.

1993 ◽  
Vol 123 (2) ◽  
pp. 387-403 ◽  
Author(s):  
M T Brown ◽  
L Goetsch ◽  
L H Hartwell
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Structural Integrity ◽  
Spindle Pole ◽  
Chromosome Loss ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
In Vitro Mutagenesis ◽  
Spindle Elongation

The function of the essential MIF2 gene in the Saccharomyces cerevisiae cell cycle was examined by overepressing or creating a deficit of MIF2 gene product. When MIF2 was overexpressed, chromosomes missegregated during mitosis and cells accumulated in the G2 and M phases of the cell cycle. Temperature sensitive mutants isolated by in vitro mutagenesis delayed cell cycle progression when grown at the restrictive temperature, accumulated as large budded cells that had completed DNA replication but not chromosome segregation, and lost viability as they passed through mitosis. Mutant cells also showed increased levels of mitotic chromosome loss, supersensitivity to the microtubule destabilizing drug MBC, and morphologically aberrant spindles. mif2 mutant spindles arrested development immediately before anaphase spindle elongation, and then frequently broke apart into two disconnected short half spindles with misoriented spindle pole bodies. These findings indicate that MIF2 is required for structural integrity of the spindle during anaphase spindle elongation. The deduced Mif2 protein sequence shared no extensive homologies with previously identified proteins but did contain a short region of homology to a motif involved in binding AT rich DNA by the Drosophila D1 and mammalian HMGI chromosomal proteins.

scholarly journals A Temperature-Sensitive dcw1 Mutant of Saccharomyces cerevisiae Is Cell Cycle Arrested with Small Buds Which Have Aberrant Cell Walls

2004 ◽  
Vol 3 (5) ◽  
pp. 1297-1306 ◽  
Author(s):  
Hiroshi Kitagaki ◽  
Kiyoshi Ito ◽  
Hitoshi Shimoi
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Cell Wall ◽  
Cell Walls ◽  
Spindle Pole ◽  
Temperature Sensitive ◽  
Mrna Levels ◽  
Homologous Proteins ◽  
Aberrant Cell ◽  
Cell Wall Biogenesis

ABSTRACT Dcw1p and Dfg5p in Saccharomyces cerevisiae are homologous proteins that were previously shown to be involved in cell wall biogenesis and to be essential for growth. Dcw1p was found to be a glycosylphosphatidylinositol-anchored membrane protein. To investigate the roles of these proteins in cell wall biogenesis and cell growth, we constructed mutant alleles of DCW1 by random mutagenesis, introduced them into a Δdcw1 Δdfg5 background, and isolated a temperature-sensitive mutant, DC61 (dcw1-3 Δdfg5). When DC61 cells were incubated at 37°C, most cells had small buds, with areas less than 20% of those of the mother cells. This result indicates that DC61 cells arrest growth with small buds at 37°C. At 37°C, fewer DC61 cells had 1N DNA content and most of them still had a single nucleus located apart from the bud neck. In addition, in DC61 cells incubated at 37°C, bipolar spindles were not formed. These results indicate that DC61 cells, when incubated at 37°C, are cell cycle arrested after DNA replication and prior to the separation of spindle pole bodies. The small buds of DC61 accumulated chitin in the bud cortex, and some of them were lysed, which indicates that they had aberrant cell walls. A temperature-sensitive dfg5 mutant, DF66 (Δdcw1 dfg5-29), showed similar phenotypes. DCW1 and DFG5 mRNA levels peaked in the G1 and S phases, respectively. These results indicate that Dcw1p and Dfg5p are involved in bud formation through their involvement in biogenesis of the bud cell wall.

scholarly journals Role of astral microtubules and actin in spindle orientation and migration in the budding yeast, Saccharomyces cerevisiae.

1992 ◽  
Vol 119 (3) ◽  
pp. 583-593 ◽  
Author(s):  
R E Palmer ◽  
D S Sullivan ◽  
T Huffaker ◽  
D Koshland
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Chromosome Segregation ◽  
Mother Cell ◽  
Fold Increase ◽  
Spindle Pole ◽  
Spindle Orientation ◽  
Temperature Sensitive ◽  
Chromosome Movement ◽  
Yeast Saccharomyces Cerevisiae ◽  
Cytoskeletal Elements

In the yeast Saccharomyces cerevisiae, before the onset of anaphase, the spindle apparatus is always positioned with one spindle pole at, or through, the neck between the mother cell and the growing bud. This spindle orientation enables proper chromosome segregation to occur during anaphase, allowing one replicated genome to be segregated into the bud and the other to remain in the mother cell. In this study, we synchronized a population of cells before the onset of anaphase such that > 90% of the cells in the population had spindles with the correct orientation, and then disrupted specific cytoskeletal elements using temperature-sensitive mutations. Disruption of either the astral microtubules or actin function resulted in improper spindle orientation in approximately 40-50% of the cells. When cells with disrupted astral microtubules or actin function entered into anaphase, there was a 100-200-fold increase in the frequency of binucleated cell bodies. Thus, the maintenance of proper spindle orientation by these cytoskeletal elements was essential for proper chromosome segregation. These data are consistent with the model that proper spindle orientation is maintained by directly or indirectly tethering the astral microtubules to the actin cytoskeleton. After nuclear migration, but before anaphase, bulk chromosome movement occurs within the nucleus apparently because the chromosomes are attached to a mobile spindle. The frequency and magnitude of bulk chromosome movement is greatly diminished by disruption of the astral microtubules but not by disruption of the nonkinetochore spindle microtubules. These results suggest that astral microtubules are not only important for spindle orientation before anaphase, but they also mediate force on the spindle, generating spindle displacement and in turn chromosome movement. Potential roles for this force in spindle assembly and orientation are discussed.

scholarly journals Immunofluorescence localization of the Saccharomyces cerevisiae CDC12 gene product to the vicinity of the 10-nm filaments in the mother-bud neck.

1987 ◽  
Vol 7 (10) ◽  
pp. 3678-3687 ◽  
Author(s):  
B K Haarer ◽  
J R Pringle
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Gene Product ◽  
Polyclonal Antibodies ◽  
Affinity Purification ◽  
Neck Region ◽  
Yeast Saccharomyces Cerevisiae ◽  
Bud Growth ◽  
10 Nm Filaments ◽  
Mutant Cells

Budding cells of the yeast Saccharomyces cerevisiae possess a ring of 10-nm-diameter filaments, of unknown biochemical nature, that lies just inside the plasma membrane in the neck connecting the mother cell to its bud (B. Byers and L. Goetsch, J. Cell Biol. 69:717-721, 1976). Mutants defective in any of four genes (CDC3, CDC10, CDC11, and CDC12) lack these filaments and display a pleiotropic phenotype that involves abnormal bud growth and cell-wall deposition and an inability to complete cytokinesis. We fused the cloned CDC12 gene to the Escherichia coli lacZ and trpE genes and used the resulting fusion proteins to raise polyclonal antibodies specific for the CDC12 gene product. In immunofluorescence experiments with affinity-purified antibodies, the neck region of wild-type and mutant cells stained in patterns consistent with the hypothesis that the CDC12 gene product is a constituent of the ring of 10-nm filaments. Without careful affinity purification of the CDC12-specific antibodies, these staining patterns were completely obscured by the staining of residual cell wall components in the neck by antibodies present even in the "preimmune" sera of all rabbits tested.

Immunofluorescence localization of the Saccharomyces cerevisiae CDC12 gene product to the vicinity of the 10-nm filaments in the mother-bud neck

1987 ◽  
Vol 7 (10) ◽  
pp. 3678-3687
Author(s):  
B K Haarer ◽  
J R Pringle
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Gene Product ◽  
Polyclonal Antibodies ◽  
Affinity Purification ◽  
Neck Region ◽  
Yeast Saccharomyces Cerevisiae ◽  
Bud Growth ◽  
10 Nm Filaments ◽  
Mutant Cells

Budding cells of the yeast Saccharomyces cerevisiae possess a ring of 10-nm-diameter filaments, of unknown biochemical nature, that lies just inside the plasma membrane in the neck connecting the mother cell to its bud (B. Byers and L. Goetsch, J. Cell Biol. 69:717-721, 1976). Mutants defective in any of four genes (CDC3, CDC10, CDC11, and CDC12) lack these filaments and display a pleiotropic phenotype that involves abnormal bud growth and cell-wall deposition and an inability to complete cytokinesis. We fused the cloned CDC12 gene to the Escherichia coli lacZ and trpE genes and used the resulting fusion proteins to raise polyclonal antibodies specific for the CDC12 gene product. In immunofluorescence experiments with affinity-purified antibodies, the neck region of wild-type and mutant cells stained in patterns consistent with the hypothesis that the CDC12 gene product is a constituent of the ring of 10-nm filaments. Without careful affinity purification of the CDC12-specific antibodies, these staining patterns were completely obscured by the staining of residual cell wall components in the neck by antibodies present even in the "preimmune" sera of all rabbits tested.

scholarly journals SEN1, a positive effector of tRNA-splicing endonuclease in Saccharomyces cerevisiae.

1992 ◽  
Vol 12 (5) ◽  
pp. 2154-2164 ◽  
Author(s):  
D J DeMarini ◽  
M Winey ◽  
D Ursic ◽  
F Webb ◽  
M R Culbertson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Amino Acids ◽  
Amino Acid ◽  
Gene Product ◽  
Signal Sequence ◽  
Null Alleles ◽  
Nucleoside Triphosphate ◽  
Temperature Sensitive ◽  
Yeast Saccharomyces Cerevisiae ◽  
Amino Terminal

The SEN1 gene, which is essential for growth in the yeast Saccharomyces cerevisiae, is required for endonucleolytic cleavage of introns from all 10 families of precursor tRNAs. A mutation in SEN1 conferring temperature-sensitive lethality also causes in vivo accumulation of pre-tRNAs and a deficiency of in vitro endonuclease activity. Biochemical evidence suggests that the gene product may be one of several components of a nuclear-localized splicing complex. We have cloned the SEN1 gene and characterized the SEN1 mRNA, the SEN1 gene product, the temperature-sensitive sen1-1 mutation, and three SEN1 null alleles. The SEN1 gene corresponds to a 6,336-bp open reading frame coding for a 2,112-amino-acid protein (molecular mass, 239 kDa). Using antisera directed against the C-terminal end of SEN1, we detect a protein corresponding to the predicted molecular weight of SEN1. The SEN1 protein contains a leucine zipper motif, consensus elements for nucleoside triphosphate binding, and a potential nuclear localization signal sequence. The carboxy-terminal 1,214 amino acids of the SEN1 protein are essential for growth, whereas the amino-terminal 898 amino acids are dispensable. A sequence of approximately 500 amino acids located in the essential region of SEN1 has significant similarity to the yeast UPF1 gene product, which is involved in mRNA turnover, and the mouse Mov-10 gene product, whose function is unknown. The mutation that creates the temperature-sensitive sen1-1 allele is located within this 500-amino-acid region, and it causes a substitution for an amino acid that is conserved in all three proteins.

scholarly journals Transcripts repressed at the stop of phloem unloading highlight the energy efficiency of sugar import in the ripening V. vinifera fruit.

2021 ◽  
Author(s):  
Stefania Savoi ◽  
Laurent Torregrosa ◽  
Charles Romieu
Keyword(s):  
Cell Wall ◽  
Regulatory Elements ◽  
Solute Concentration ◽  
Growth Patterns ◽  
Individual Growth ◽  
Sugar Accumulation ◽  
Minor Role ◽  
Phloem Unloading ◽  
Sugar Transporters ◽  
A Minor

AbstractTranscriptomic changes at the cessation of sugar accumulation in the pericarp of Vitis vinifera were addressed on single berries re-synchronized according to their individual growth patterns. The net rates of water, sugars and K+ accumulation inferred from individual growth and solute concentration confirmed that these inflows stopped simultaneously in the ripe berry, while the small amount of malic acid remaining at this stage was still being oxidized at a low rate. Resynchronized individual berries displayed negligible variations in gene expression among triplicates. RNA-Seq studies revealed sharp reprogramming of cell wall enzymes and structural proteins, associated with an 80% repression of specific sugar transporters and aquaporins on the plasma or tonoplast membranes, at the stop of phloem unloading in the three genotypes and two environments investigated. The prevalence of SWEET transporters suggests that electrogenic transporters would just play a minor role on the plasma membrane of SE/CC complex, and the one of the flesh, while sucrose/H+ exchangers dominate on its tonoplast. Cis-regulatory elements present in their promoters allowed to sort these transporters in different groups, also including specific TIPs and PIPs paralogs, and cohorts of cell wall related genes. These results lead us to propose which structural, developmental and energy adaptations would give this fruit such a power of attraction for water and photoassimilates.

Sign in / Sign up

Export Citation Format

Share Document