The pleiotropic cell separation mutation spl1-1 is a nucleotide substitution in the internal promoter of the proline tRNACGG gene of Schizosaccharomyces pombe

2009 ◽  
Vol 55 (5) ◽  
pp. 511-520 ◽  
Author(s):  
Ida Miklos ◽  
Katalin Ludanyi ◽  
Matthias Sipiczki
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Cell Separation ◽  
Nucleotide Substitution ◽  
Internal Promoter

scholarly journals The α-glucanase Agn1p is required for cell separation in Schizosaccharomyces pombe

2005 ◽  
Vol 97 (7) ◽  
pp. 569-576 ◽  
Author(s):  
Ignacio García ◽  
David Jiménez ◽  
Victoria Martín ◽  
Angel Durán ◽  
Yolanda Sánchez
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Cell Separation

Regulation of the start of DNA replication in Schizosaccharomyces pombe

1999 ◽  
Vol 112 (6) ◽  
pp. 939-946 ◽  
Author(s):  
C.R. Carlson ◽  
B. Grallert ◽  
T. Stokke ◽  
E. Boye
Keyword(s):  
Cell Cycle ◽  
Flow Cytometry ◽  
Growth Rate ◽  
Schizosaccharomyces Pombe ◽  
Growth Rates ◽  
Cell Separation ◽  
Cell Mass ◽  
Nitrogen Sources ◽  
S Phase ◽  
G1 Phase

Cells of Schizosaccharomyces pombe were grown in minimal medium with different nitrogen sources under steady-state conditions, with doubling times ranging from 2.5 to 14 hours. Flow cytometry and fluorescence microscopy confirmed earlier findings that at rapid growth rates, the G1 phase was short and cell separation occurred at the end of S phase. For some nitrogen sources, the growth rate was greatly decreased, the G1 phase occupied 30–50% of the cell cycle, and cell separation occurred in early G1. In contrast, other nitrogen sources supported low growth rates without any significant increase in G1 duration. The method described allows manipulation of the length of G1 and the relative cell cycle position of S phase in wild-type cells. Cell mass was measured by flow cytometry as scattered light and as protein-associated fluorescence. The extensions of G1 were not related to cell mass at entry into S phase. Our data do not support the hypothesis that the cells must reach a certain fixed, critical mass before entry into S. We suggest that cell mass at the G1/S transition point is variable and determined by a set of molecular parameters. In the present experiments, these parameters were influenced by the different nitrogen sources in a way that was independent of the actual growth rate.

scholarly journals Scw1p Antagonizes the Septation Initiation Network To Regulate Septum Formation and Cell Separation in the Fission Yeast Schizosaccharomyces pombe

2003 ◽  
Vol 2 (3) ◽  
pp. 510-520 ◽  
Author(s):  
Quan-Wen Jin ◽  
Dannel McCollum
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Cell Separation ◽  
Deletion Mutant ◽  
Temperature Sensitive ◽  
Growth Defects ◽  
Septum Formation ◽  
Primary Septum ◽  
Septation Initiation Network ◽  
Ring Constriction

ABSTRACT Cytokinesis in the fission yeast Schizosaccharomyces pombe is regulated by a signaling pathway termed the septation initiation network (SIN). The SIN is essential for initiation of actomyosin ring constriction and septum formation. In a screen to search for mutations that can rescue the sid2-250 SIN mutant, we obtained scw1-18. Both the scw1-18 mutant and the scw1 deletion mutant (scw1Δ mutant), have defects in cell separation. Both the scw1-18 and scw1Δ mutations rescue the growth defects of not just the sid2-250 mutant but also the other temperature-sensitive SIN mutants. Other cytokinesis mutants, such as those defective for actomyosin ring formation, are not rescued by scw1Δ. scw1Δ does not seem to rescue the SIN by restoring SIN signaling defects. However, scw1Δ may function downstream of the SIN to promote septum formation, since scw1Δ can rescue the septum formation defects of the cps1-191β-1,3-glucan synthase mutant, which is required for synthesis of the primary septum.

scholarly journals Phylogenetic and comparative functional analysis of the cell-separation α-glucanase Agn1p in Schizosaccharomyces

Microbiology ◽  
2014 ◽  
Vol 160 (6) ◽  
pp. 1063-1074 ◽  
Author(s):  
Matthias Sipiczki ◽  
Anita Balazs ◽  
Aniko Monus ◽  
Laszlo Papp ◽  
Anna Horvath ◽  
...  
Keyword(s):  
Cell Wall ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Mother Cell ◽  
Cell Separation ◽  
Yeast Cells ◽  
Glycoside Hydrolase Family ◽  
Binding Domains ◽  
Yeast Phase ◽  
Mother Cell Wall

The post-cytokinetic separation of cells in cell-walled organisms involves enzymic processes that degrade a specific layer of the division septum and the region of the mother cell wall that edges the septum. In the fission yeast Schizosaccharomyces pombe, the 1,3-α-glucanase Agn1p, originally identified as a mutanase-like glycoside hydrolase family 71 (GH71) enzyme, dissolves the mother cell wall around the septum edge. Our search in the genomes of completely sequenced fungi identified GH71 hydrolases in Basidiomycota, Taphrinomycotina and Pezizomycotina, but not in Saccharomycotina. The most likely Agn1p orthologues in Pezizomycotina species are not mutanases having mutanase-binding domains, but experimentally non-characterized hypothetical proteins that have no carbohydrate-binding domains. The analysis of the GH71 domains corroborated the phylogenetic relationships of the Schizosaccharomyces species determined by previous studies, but suggested a closer relationship to the Basidiomycota proteins than to the Ascomycota proteins. In the Schizosaccharomyces genus, the Agn1p proteins are structurally conserved: their GH71 domains are flanked by N-terminal secretion signals and C-terminal sequences containing the conserved block YNFNAY/HTG. The inactivation of the agn1Sj gene in Schizosaccharomyces japonicus, the only true dimorphic member of the genus, caused a severe cell-separation defect in its yeast phase, but had no effect on the hyphal growth and yeast-to-mycelium transition. It did not affect the mycelium-to-yeast transition either, only delaying the separation of the yeast cells arising from the fragmenting hyphae. The heterologous expression of agn1Sj partially rescued the separation defect of the agn1Δ cells of Schizosaccharomyces pombe. The results presented indicate that the fission yeast Agn1p 1,3-α-glucanases of Schizosaccharomyces japonicus and Schizosaccharomyces pombe share conserved functions in the yeast phase.

scholarly journals The Multiprotein Exocyst Complex Is Essential for Cell Separation in Schizosaccharomyces pombe

2002 ◽  
Vol 13 (2) ◽  
pp. 515-529 ◽  
Author(s):  
Hongyan Wang ◽  
Xie Tang ◽  
Jianhua Liu ◽  
Susanne Trautmann ◽  
David Balasundaram ◽  
...  
Keyword(s):  
Acid Phosphatase ◽  
Schizosaccharomyces Pombe ◽  
Cell Separation ◽  
Contractile Ring ◽  
Medial Region ◽  
Independent Manner ◽  
Daughter Cells ◽  
Exocyst Complex ◽  
Interphase Cells ◽  
Ring Constriction

Schizosaccharomyces pombe cells divide by medial fission through the use of an actomyosin-based contractile ring. A mulitlayered division septum is assembled in concert with ring constriction. Finally, cleavage of the inner layer of the division septum results in the liberation of daughter cells. Although numerous studies have focused on actomyosin ring and division septum assembly, little information is available on the mechanism of cell separation. Here we describe a mutant, sec8-1, that is defective in cell separation but not in other aspects of cytokinesis.sec8-1 mutants accumulate ∼100-nm vesicles and have reduced secretion of acid phosphatase, suggesting that they are defective in exocytosis. Sec8p is a component of the exocyst complex. Using biochemical methods, we show that Sec8p physically interacts with other members of the exocyst complex, including Sec6p, Sec10p, and Exo70p. These exocyst proteins localize to regions of active exocytosis—at the growing ends of interphase cells and in the medial region of cells undergoing cytokinesis—in an F-actin–dependent and exocytosis-independent manner. Analysis of a number of mutations in various exocyst components has established that these components are essential for cell viability. Interestingly, all exocyst mutants analyzed appear to be able to elongate and to assemble division septa but are defective for cell separation. We therefore propose that the fission yeast exocyst is involved in targeting of enzymes responsible for septum cleavage. We further propose that cell elongation and division septum assembly can continue with minimal levels of exocyst function.

The kic1 kinase of schizosaccharomyces pombe is a CLK/STY orthologue that regulates cell–cell separation

2003 ◽  
Vol 283 (1) ◽  
pp. 101-115 ◽  
Author(s):  
Zhaohua Tang ◽  
Linda L Mandel ◽  
Shyue-Lee Yean ◽  
Cindy X Lin ◽  
Tina Chen ◽  
...  
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Cell Separation ◽  
Cell Cell

scholarly journals Rho3p Regulates Cell Separation by Modulating Exocyst Function in Schizosaccharomyces pombe

Genetics ◽  
2003 ◽  
Vol 164 (4) ◽  
pp. 1323-1331
Author(s):  
Hongyan Wang ◽  
Xie Tang ◽  
Mohan K Balasubramanian
Keyword(s):  
Cell Division ◽  
Schizosaccharomyces Pombe ◽  
Cell Separation ◽  
Model Organism ◽  
Temperature Sensitive ◽  
Complex Cells ◽  
Exocyst Complex ◽  
Primary Septum ◽  
Rho Family ◽  
Growth Phenotype

Abstract Cytokinesis is the final stage of the cell division cycle in which the mother cell is physically divided into two daughters. In recent years the fission yeast Schizosaccharomyces pombe has emerged as an attractive model organism for the study of cytokinesis, since it divides using an actomyosin ring whose constriction is coordinated with the centripetal deposition of new membranes and a division septum. The final step of cytokinesis in S. pombe requires the digestion of the primary septum to liberate two daughters. We have previously shown that the multiprotein exocyst complex is essential for this process. Here we report the isolation of rho3+, encoding a Rho family GTPase, as a high-copy suppressor of an exocyst mutant, sec8-1. Overproduction of Rho3p also suppressed the temperature-sensitive growth phenotype observed in cells lacking Exo70p, another conserved component of the S. pombe exocyst complex. Cells deleted for rho3 arrest at higher growth temperatures with two or more nuclei and uncleaved division septa between pairs of nuclei. rho3Δ cells accumulate ∼100-nm vesicle-like structures. These phenotypes are all similar to those observed in exocyst component mutants, consistent with a role for Rho3p in modulation of exocyst function. Taken together, our results suggest the possibility that S. pombe Rho3p regulates cell separation by modulation of exocyst function.

Sign in / Sign up

Export Citation Format

Share Document