scholarly journals The Fission Yeast Schizosaccharomyces pombe Has Two Importin-α Proteins, Imp1p and Cut15p, Which Have Common and Unique Functions in Nucleocytoplasmic Transport and Cell Cycle Progression

Genetics ◽  
2005 ◽  
Vol 171 (1) ◽  
pp. 7-21 ◽  
Author(s):  
Makoto Umeda ◽  
Shahed Izaddoost ◽  
Ian Cushman ◽  
Mary Shannon Moore ◽  
Shelley Sazer
Keyword(s):  
Cell Cycle ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Cell Cycle Progression ◽  
Nucleocytoplasmic Transport ◽  
Cycle Progression ◽  
Importin Α

Vertebrate p34cdc2 phosphorylation site mutants: effects upon cell cycle progression in the fission yeast Schizosaccharomyces pombe

1992 ◽  
Vol 102 (1) ◽  
pp. 43-53 ◽  
Author(s):  
W. Krek ◽  
J. Marks ◽  
N. Schmitz ◽  
E.A. Nigg ◽  
V. Simanis
Keyword(s):  
Cell Cycle ◽  
Schizosaccharomyces Pombe ◽  
Cell Cycle Arrest ◽  
Fission Yeast ◽  
Cell Cycle Progression ◽  
Atp Binding ◽  
In Vitro Mutagenesis ◽  
Cycle Progression ◽  
Cycle Arrest ◽  
P34 Cdc2

We have used the fission yeast Schizosaccharomyces pombe to analyse the effects of in vitro mutagenesis of the four known phosphorylation sites in the chicken p34(cdc2) protein, Thr 14, Tyr 15, Thr 161 and Ser 277, upon cell cycle progression. We have studied both the effect of overexpression of mutant proteins in a cdc2+ background and assayed their ability to rescue null and temperature-sensitive alleles of cdc2. Mutations of Thr 14 and Tyr 15 within the ATP binding domain of p34(cdc2) that mimic constitutive phosphorylation cause dominant negative cell cycle arrest when overexpressed. In contrast, some substitutions that simulate permanent dephosphorylation of the corresponding sites advance dephosphorylation of the corresponding sites advance mitosis. These data confirm the model that p34(cdc2) function is negatively regulated by phosphorylation of residues in the ATP binding site. Mutagenesis of the conserved residue Thr 161 functionally inactivates p34(cdc2), and our data suggest that both phosphorylation and dephosphorylation events at Thr 161 are required for progression through the cell cycle. Mutations at the fourth site of phosphorylation. Ser 277, lead to cold-sensitive cell cycle arrest, in minimal but not rich growth medium, suggesting that this site is involved in monitoring the nutritional status of the cell.

scholarly journals Asymmetrical localization of Nup107-160 subcomplex components within the nuclear pore complex in fission yeast

2017 ◽  
Author(s):  
Haruhiko Asakawa ◽  
Tomoko Kojidani ◽  
Hui-Ju Yang ◽  
Chizuru Ohtsuki ◽  
Hiroko Osakada ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Fission Yeast ◽  
Nuclear Pore Complex ◽  
Cell Cycle Progression ◽  
Nucleocytoplasmic Transport ◽  
Ring Structure ◽  
Outer Ring ◽  
Nuclear Pore ◽  
Cycle Progression ◽  
Cytoplasmic Side

AbstractThe nuclear pore complex (NPC) forms a gateway for nucleocytoplasmic transport. The outer ring protein complex of the NPC (the Nup107-160 subcomplex in humans) is a key component for building the NPC. Nup107-160 subcomplexes are believed to be symmetrically localized on the nuclear and cytoplasmic sides of the NPC. However, in S. pombe immunoelectron and fluorescence microscopic analyses revealed that the homologous components of the human Nup107-160 subcomplex had an asymmetrical localization: constituent proteins spNup132 and spNup107 were present only on the nuclear side (designated the spNup132 subcomplex), while spNup131, spNup120, spNup85, spNup96, spNup37, spEly5 and spSeh1 were localized only on the cytoplasmic side (designated the spNup120 subcomplex), suggesting the complex was split into two pieces at the interface between spNup96 and spNup107. This contrasts with the symmetrical localization reported in other organisms. Fusion of spNup96 (cytoplasmic localization) with spNup107 (nuclear localization) caused cytoplasmic relocalization of spNup107. In this strain, half of the spNup132 proteins, which interact with spNup107, changed their localization to the cytoplasmic side of the NPC, leading to defects in mitotic and meiotic progression similar to an spNup132 deletion strain. These observations suggest the asymmetrical localization of the outer ring spNup132 and spNup120 subcomplexes of the NPC is necessary for normal cell cycle progression in fission yeast.Author summaryThe nuclear pore complexes (NPCs) form gateways to transport intracellular molecules between the nucleus and the cytoplasm across the nuclear envelope. The Nup107-160 subcomplex, that forms nuclear and cytoplasmic outer rings, is a key complex responsible for building the NPC by symmetrical localization on the nuclear and cytoplasmic sides of the nuclear pore. This structural characteristic was found in various organisms including humans and budding yeasts, and therefore believed to be common among “all” eukaryotes. However, in this paper, we revealed an asymmetrical localization of the homologous components of the human Nup107-160 subcomplex in fission yeast by immunoelectron and fluorescence microscopic analyses: in this organism, the Nup107-160 subcomplex is split into two pieces, and each of the split pieces is differentially distributed to the nuclear and cytoplasmic side of the NPC: one piece is only in the nuclear side while the other piece is only in the cytoplasmic side. This contrasts with the symmetrical localization reported in other organisms. In addition, we confirmed that the asymmetrical configuration of the outer ring structure is necessary for cell cycle progression in fission yeast. This study provides notions of diverse structures and functions of NPCs evolved in eukaryotes.

scholarly journals Compartmentalized nodes control mitotic entry signaling in fission yeast

2013 ◽  
Vol 24 (12) ◽  
pp. 1872-1881 ◽  
Author(s):  
Lin Deng ◽  
James B. Moseley
Keyword(s):  
Cell Cycle ◽  
Cell Growth ◽  
Fission Yeast ◽  
Cell Polarity ◽  
Cell Cycle Progression ◽  
Interaction Network ◽  
Yeast Cells ◽  
Cell Cortex ◽  
Cycle Progression ◽  
Mitotic Entry

Cell cycle progression is coupled to cell growth, but the mechanisms that generate growth-dependent cell cycle progression remain unclear. Fission yeast cells enter into mitosis at a defined size due to the conserved cell cycle kinases Cdr1 and Cdr2, which localize to a set of cortical nodes in the cell middle. Cdr2 is regulated by the cell polarity kinase Pom1, suggesting that interactions between cell polarity proteins and the Cdr1-Cdr2 module might underlie the coordination of cell growth and division. To identify the molecular connections between Cdr1/2 and cell polarity, we performed a comprehensive pairwise yeast two-hybrid screen. From the resulting interaction network, we found that the protein Skb1 interacted with both Cdr1 and the Cdr1 inhibitory target Wee1. Skb1 inhibited mitotic entry through negative regulation of Cdr1 and localized to both the cytoplasm and a novel set of cortical nodes. Skb1 nodes were distinct structures from Cdr1/2 nodes, and artificial targeting of Skb1 to Cdr1/2 nodes delayed entry into mitosis. We propose that the formation of distinct node structures in the cell cortex controls signaling pathways to link cell growth and division.

scholarly journals Fission yeast Clp1p phosphatase regulates G2/M transition and coordination of cytokinesis with cell cycle progression

2001 ◽  
Vol 11 (12) ◽  
pp. 931-940 ◽  
Author(s):  
Susanne Trautmann ◽  
Benjamin A. Wolfe ◽  
Paul Jorgensen ◽  
Mike Tyers ◽  
Kathleen L. Gould ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Fission Yeast ◽  
Cell Cycle Progression ◽  
Cycle Progression

scholarly journals A fission yeast homolog of CDC20/p55CDC/Fizzy is required for recovery from DNA damage and genetically interacts with p34cdc2.

1997 ◽  
Vol 17 (2) ◽  
pp. 742-750 ◽  
Author(s):  
T Matsumoto
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Dna Repair ◽  
Fission Yeast ◽  
Cell Cycle Progression ◽  
Eukaryotic Cell ◽  
Cycle Progression ◽  
Cell Cycle Delay ◽  
Successful Recovery ◽  
Synthetically Lethal

Successful recovery from DNA damage requires coordination of several biological processes. Eukaryotic cell cycle progression is delayed when the cells encounter DNA-damaging agents. This cell cycle delay allows the cells to cope with DNA damage by utilizing DNA repair enzymes. Thus, at least two processes, induction of the cell cycle delay and repair of damaged DNA, are coordinately required for recovery. In this study, a fission yeast rad mutant (slp1-362) was genetically investigated. In response to radiation, slp1 stops cell division; however, it does not restart it. This defect is suppressed when slp1-362 is combined with wee1-50 or cdc2-3w; in these mutants, the onset of mitosis is advanced due to the premature activation of p34cdc2. In contrast, slp1 is synthetically lethal with cdc25, nim1/cdr1, or cdr2, all of which are unable to activate the p34cdc2 kinase correctly. These genetic interactions of slp1 with cdc2 and its modulators imply that slp1 is not defective in either "induction of cell cycle delay" or "DNA repair." slp1+ may be involved in a critical process which restarts cell cycle progression after the completion of DNA repair. Molecular cloning of slp1+ revealed that slp1+ encodes a putative 488-amino-acid polypeptide exhibiting significant homology to WD-domain proteins, namely, CDC20 (budding yeast), p55CDC (human), and Fizzy (fly). A possible role of slp1+ is proposed.

Mpg1, a fission yeast protein required for proper septum structure, is involved in cell cycle progression through cell-size checkpoint

2005 ◽  
Vol 274 (2) ◽  
Author(s):  
I. Donoso ◽  
M. C. Muñoz-Centeno ◽  
M. A. Sànchez-Durán ◽  
A. Flores ◽  
R. R. Daga ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Fission Yeast ◽  
Cell Size ◽  
Cell Cycle Progression ◽  
Yeast Protein ◽  
Cycle Progression
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