Markers of cell polarity during and after nitrogen starvation in Schizosaccharomyces pombe

1997 ◽  
Vol 75 (6) ◽  
pp. 697-708
Author(s):  
Ivan Rupes ◽  
Jana Jochová ◽  
Paul G. Young
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Cell Polarity ◽  
Nitrogen Starvation

Markers of cell polarity during and after nitrogen starvation in Schizosaccharomyces pombe

1997 ◽  
Vol 75 (6) ◽  
pp. 697-708 ◽  
Author(s):  
Ivan Rupes ◽  
Jana Jochová ◽  
Paul G Young
Keyword(s):  
Cell Division ◽  
Schizosaccharomyces Pombe ◽  
Cell Polarity ◽  
Nitrogen Starvation ◽  
Size Control ◽  
Starvation Period ◽  
Wild Type ◽  
Small Deviations ◽  
Cell Wall Deposition

In Schizosaccharomyces pombe, nitrogen starvation induces transient acceleration of cell division and reduction in cell size with a final arrest in G1. The division size control appears to be impaired by mutations in cdr1/nim1 and cdr2, genes that encode protein kinases mediating nutritional control over the mitotic cycle. cdr- cells arrest after fewer rounds of division and are larger than the wild type. Recent work suggests that long-term nitrogen starvation causes S. pombe wild-type cells to become spherical, which suggests loss of cell polarity. cdr mutants retain the elongated shape, indicating a potential difference in cell polarity control relative to the wild type. We examined several markers related to maintenance of cell polarity in S. pombe following nitrogen starvation including cell division scar pattern and actin and microtubule cytoskeleton. Wild-type cells as well as cdr mutants maintained a normal cell division scar pattern throughout nitrogen starvation but cells dividing under these conditions developed a wall malformation in the center of the septum. In cells arrested by nitrogen starvation, actin patches, normally associated with sites of cell wall deposition, were larger and distributed randomly along the cell surface. Cytoplasmic arrays of microtubules, which are thought to be involved in control of the polarity signal, were not visibly affected. The effects were similar in wild-type cells and in cdr- mutants. Upon refeeding, the new growth always reoccurred at the tip zones and there were only small deviations of its direction from the original axis. The results indicate that cell polarity is preserved both in wild-type cells, which arrest in G1 and appear spherical, and in cdr1/nim1 and cdr2 mutants, which arrest in G2 and appear polarized throughout the starvation period. Key words: cell polarity, fission yeast, nitrogen starvation, actin, microtubules, cdr1/nim1, cdr2.

scholarly journals Schizosaccharomyces pombe map3+ encodes the putative M-factor receptor.

1993 ◽  
Vol 13 (1) ◽  
pp. 80-88 ◽  
Author(s):  
K Tanaka ◽  
J Davey ◽  
Y Imai ◽  
M Yamamoto
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Nitrogen Starvation ◽  
Transmembrane Protein ◽  
Strong Support ◽  
Amino Acid Identity ◽  
Nucleotide Sequence Analysis ◽  
Mating Pheromone ◽  
Pheromone Signaling ◽  
P Factor ◽  
Coding Capacity

A defect in the map3 gene of the fission yeast Schizosaccharomyces pombe causes h+ mating-type-specific sterility. This gene was cloned by complementation. Nucleotide sequence analysis showed that it has a coding capacity of 365 amino acids. The deduced map3 gene product is a putative seven-transmembrane protein and has 20.0% amino acid identity with the a-factor receptor of Saccharomyces cerevisiae, encoded by STE3. It is also homologous with the Ustilago maydis mating pheromone receptors. The map3 gene is expressed in h+ cells but not in h- cells, and the transcripts are induced in response to nitrogen starvation. h+ cells defective in map3 do not respond to purified M-factor. When map3 is expressed ectopically in h- cells, they apparently acquire the ability to respond to the M-factor produced by themselves. The gpa1 gene, which encodes the alpha-subunit of a G-protein presumed to couple with the mating pheromone receptors, is essential for this function of map3. These observations strongly suggest that map3 encodes the M-factor receptor. Furthermore, this study provides strong support for the notion that pheromone signaling is essential for initiation of meiosis in S. pombe and that either M-factor signaling or P-factor signaling alone is sufficient.

Reorganization of chromatin is an early response to nitrogen starvation in Schizosaccharomyces pombe

Chromosoma ◽  
2008 ◽  
Vol 118 (1) ◽  
pp. 99-112 ◽  
Author(s):  
Jenny Alfredsson-Timmins ◽  
Carolina Kristell ◽  
Frida Henningson ◽  
Sara Lyckman ◽  
Pernilla Bjerling
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Nitrogen Starvation ◽  
Early Response

scholarly journals Functional Genomics of Adhesion, Invasion, and Mycelial Formation in Schizosaccharomyces pombe

2009 ◽  
Vol 8 (8) ◽  
pp. 1298-1306 ◽  
Author(s):  
James Dodgson ◽  
Hema Avula ◽  
Kwang-Lae Hoe ◽  
Dong-Uk Kim ◽  
Han-Oh Park ◽  
...  
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Cell Polarity ◽  
Nitrogen Limitation ◽  
Molecular Level ◽  
Actin Assembly ◽  
Rich Media ◽  
Second Mode ◽  
Dependent Cell ◽  
Deletion Library ◽  
Mycelial Development

ABSTRACT Investigation into the switch between single-celled and filamentous forms of fungi may provide insights into cell polarity, differentiation, and fungal pathogenicity. At the molecular level, much of this investigation has fallen on two closely related budding yeasts, Candida albicans and Saccharomyces cerevisiae. Recently, the much more distant fission yeast Schizosaccharomyces pombe was shown to form invasive filaments after nitrogen limitation (E. Amoah-Buahin, N. Bone, and J. Armstrong, Eukaryot. Cell 4:1287-1297, 2005) and this genetically tractable organism provides an alternative system for the study of dimorphic growth. Here we describe a second mode of mycelial formation of S. pombe, on rich media. Screening of an S. pombe haploid deletion library identified 12 genes required for mycelial development which encode potential transcription factors, orthologues of S. cerevisiae Sec14p and Tlg2p, and the formin For3, among others. These were further grouped into two phenotypic classes representing different stages of the process. We show that galactose-dependent cell adhesion and actin assembly are both required for mycelial formation and mutants lacking a range of genes controlling cell polarity all produce mycelia but with radically altered morphology.

scholarly journals Cig2, a B-type cyclin, promotes the onset of S in Schizosaccharomyces pombe.

1996 ◽  
Vol 16 (4) ◽  
pp. 1527-1533 ◽  
Author(s):  
O Mondesert ◽  
C H McGowan ◽  
P Russell
Keyword(s):  
Dna Replication ◽  
Schizosaccharomyces Pombe ◽  
Double Mutant ◽  
Kinase Activity ◽  
Nitrogen Starvation ◽  
Gradual Increase ◽  
S Phase ◽  
G1 Arrest ◽  
Cyclin Dependent Kinases ◽  
M Phase

Cdc2, a catalytic subunit of cyclin-dependent kinases, is required for both the G1-to-S and G2-to-M transitions in the fission yeast Schizosaccharomyces pombe. Cdc13, a B-type cyclin, is required for the M-phase induction function of Cd2. Two additional B-type cyclins, Cig1 and Cig2, have been identified in S. pombe, but none of the B-type cyclins are individually required for the onset of S. We report that Cdc13 is important for DNA replication in a strain lacking Cig2. Unlike deltacdc13 cells, double-mutant deltacdc13 deltacig2 cells are defective in undergoing multiple rounds of DNA replication. The conclusion that Cig2 promotes S is further supported by the finding that Cig2 protein and Cig2-associated kinase activity appear soon after the completion of M and peak during S, as well as the observation that S is delayed in deltacig2 cells as they recover from a G1 arrest induced by nitrogen starvation. These studies indicate that Cig2 is the primary S-phase-promoting cyclin in S. pombe but that Cdc13 can effectively substitute for Cig2 in deltacig2 cells. These observations also suggest that the gradual increase in the activity of Cdc2-Cdc13 kinase can be sufficient for the correct temporal ordering of S and M phases in deltacig2 cells.

Schizosaccharomyces pombe map3+ encodes the putative M-factor receptor

1993 ◽  
Vol 13 (1) ◽  
pp. 80-88
Author(s):  
K Tanaka ◽  
J Davey ◽  
Y Imai ◽  
M Yamamoto
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Nitrogen Starvation ◽  
Transmembrane Protein ◽  
Strong Support ◽  
Amino Acid Identity ◽  
Nucleotide Sequence Analysis ◽  
Mating Pheromone ◽  
Pheromone Signaling ◽  
P Factor ◽  
Coding Capacity

A defect in the map3 gene of the fission yeast Schizosaccharomyces pombe causes h+ mating-type-specific sterility. This gene was cloned by complementation. Nucleotide sequence analysis showed that it has a coding capacity of 365 amino acids. The deduced map3 gene product is a putative seven-transmembrane protein and has 20.0% amino acid identity with the a-factor receptor of Saccharomyces cerevisiae, encoded by STE3. It is also homologous with the Ustilago maydis mating pheromone receptors. The map3 gene is expressed in h+ cells but not in h- cells, and the transcripts are induced in response to nitrogen starvation. h+ cells defective in map3 do not respond to purified M-factor. When map3 is expressed ectopically in h- cells, they apparently acquire the ability to respond to the M-factor produced by themselves. The gpa1 gene, which encodes the alpha-subunit of a G-protein presumed to couple with the mating pheromone receptors, is essential for this function of map3. These observations strongly suggest that map3 encodes the M-factor receptor. Furthermore, this study provides strong support for the notion that pheromone signaling is essential for initiation of meiosis in S. pombe and that either M-factor signaling or P-factor signaling alone is sufficient.

Schizosaccharomyces pombe taf1 + is required for nitrogen starvation-induced sexual development and for entering the dormant G0 state

2001 ◽  
Vol 38 (6) ◽  
pp. 307-313 ◽  
Author(s):  
Masaru Ueno ◽  
Rumi Kurokawa ◽  
Hubert Renauld ◽  
Kousuke Watanabe ◽  
Takashi Ushimaru ◽  
...  
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Sexual Development ◽  
Nitrogen Starvation

scholarly journals The Schizosaccharomyces pombe HIRA-Like Protein Hip1 Is Required for the Periodic Expression of Histone Genes and Contributes to the Function of Complex Centromeres

2004 ◽  
Vol 24 (10) ◽  
pp. 4309-4320 ◽  
Author(s):  
Chris Blackwell ◽  
Kate A. Martin ◽  
Amanda Greenall ◽  
Alison Pidoux ◽  
Robin C. Allshire ◽  
...  
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Nitrogen Starvation ◽  
Synthetic Lethality ◽  
Chromosome Loss ◽  
Histone Genes ◽  
Histone H2a ◽  
Genes Expression ◽  
Evolutionarily Conserved ◽  
A Cell ◽  
Increased Sensitivity

ABSTRACT HIRA-like (Hir) proteins are evolutionarily conserved and are implicated in the assembly of repressive chromatin. In Saccharomyces cerevisiae, Hir proteins contribute to the function of centromeres. However, S. cerevisiae has point centromeres that are structurally different from the complex centromeres of metazoans. In contrast, Schizosaccharomyces pombe has complex centromeres whose domain structure is conserved with that of human centromeres. Therefore, we examined the functions of the fission yeast Hir proteins Slm9 and the previously uncharacterised protein Hip1. Deletion of hip1+ resulted in phenotypes that were similar to those described previously for slm9Δ cells: a cell cycle delay, synthetic lethality with cdc25-22, and poor recovery from nitrogen starvation. However, while it has previously been shown that Slm9 is not required for the periodic expression of histone H2A, we found that loss of Hip1 led to derepression of core histone genes expression outside of S phase. Importantly, we found that deletion of either hip1+ or slm9+ resulted in increased rates of chromosome loss, increased sensitivity to spindle damage, and reduced transcriptional silencing in the outer centromeric repeats. Thus, S. pombe Hir proteins contribute to pericentromeric heterochromatin, and our data thus suggest that Hir proteins may be required for the function of metazoan centromeres.

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