scholarly journals The concerted actions of Tip1/CLIP-170, Klp5/Kinesin-8, and Alp14/XMAP215 regulate microtubule catastrophe at the cell end

2019 ◽  
Vol 11 (11) ◽  
pp. 956-966 ◽  
Author(s):  
Xiaojia Niu ◽  
Fan Zheng ◽  
Chuanhai Fu
Keyword(s):  
Cell Growth ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Cell Polarity ◽  
Residence Time ◽  
Dependent Manner ◽  
Spatial Regulation ◽  
Live Cell Microscopy ◽  
Stabilizing Factors ◽  
Cell Microscopy

Abstract Spatial regulation of microtubule catastrophe is important for controlling microtubule length and consequently contributes to the proper establishment of cell polarity and cell growth. The +TIP proteins including Tip1/CLIP-170, Klp5/Kinesin-8, and Alp14/XMAP215 reside at microtubule plus ends to regulate microtubule dynamics. In the fission yeast Schizosaccharomyces pombe, Tip1 and Alp14 serve as microtubule-stabilizing factors, while Klp5 functions oppositely as a catastrophe-promoting factor. Despite that Tip1 has been shown to play a key role in restricting microtubule catastrophe to the cell end, how Tip1 fulfills the role remains to be determined. Employing live-cell microscopy, we showed that the absence of Tip1 impairs the localization of both Klp5 and Alp14 at microtubule plus ends, but the absence of Klp5 prolongs the residence time of Tip1 at microtubule plus ends. We further revealed that Klp5 accumulates behind Tip1 at microtubule plus ends in a Tip1-dependent manner. In addition, artificially tethering Klp5 to microtubule plus ends promotes premature microtubule catastrophe, while tethering Alp14 to microtubule plus ends in the cells lacking Tip1 rescues the phenotype of short microtubules. These findings establish that Tip1 restricts microtubule catastrophe to the cell end likely by spatially restricting the microtubule catastrophe activity of Klp5 and stabilizing Alp14 at microtubule plus ends. Thus, the work demonstrates the orchestration of Tip1, Alp14, and Klp5 in ensuring microtubule catastrophe at the cell end.

scholarly journals Activation of polarized cell growth by inhibition of cell polarity

2018 ◽  
Author(s):  
Marco Geymonat ◽  
Anatole Chessel ◽  
James Dodgson ◽  
Hannah Punter ◽  
Felix Horns ◽  
...  
Keyword(s):  
Cell Growth ◽  
Fission Yeast ◽  
Cell Polarity ◽  
Rho Gtpase ◽  
Dependent Manner ◽  
Polarized Cell Growth ◽  
And Control ◽  
Polarity Factor ◽  
Pak Kinase

AbstractA key feature of cells is the capacity to activate new functional polarized domains contemporaneously to pre-existing ones. How cells accomplish this is not clear. Here, we show that in fission yeast inhibition of cell polarity at pre-existing domains of polarized cell growth is required to activate new growth. This inhibition is mediated by the ERM-related polarity factor Tea3, which antagonizes the activation of the Rho-GTPase Cdc42 by its co-factor Scd2. We demonstrate that Tea3 acts in a phosphorylation-dependent manner controlled by the PAK kinase Shk1 and that, like Scd2, Tea3 is direct substrate of Shk1. Importantly, we show that Tea3 and Scd2 compete for their binding to Shk1, indicating that their biochemical competition for Shk1 underpins their antagonistic roles in controlling polarity. Thus, by preventing pre-existing growth domains from becoming overpowering, Tea3 allows cells to redistribute their polarity-activating machinery to prospective sites and control their timing of activation.

Ascorbic acid supplementation suppresses cadmium-derived alterations in the fission yeast Schizosaccharomyces pombe

10.5219/1618 ◽  
2021 ◽  
Vol 15 ◽  
pp. 423-432
Author(s):  
Marek Kovár ◽  
Alica Navrátilová ◽  
Anna Trakovická ◽  
Miroslava Požgajová
Keyword(s):  
Ascorbic Acid ◽  
Cell Growth ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Membrane Lipids ◽  
Cadmium Toxicity ◽  
Model Organism ◽  
Cell Types ◽  
Dependent Manner ◽  
The Impact

Cadmium (Cd) a highly toxic environmental pollutant, that does not have any physiological function in the organism, represents a great concern for human health as it can be easily transported from its environmental sources to the food chain. Food, water, and air are the major sources of Cd exposure to the population. Cd-mediated impairments of the basic cellular properties largely depend on its ability to enhance the formation of reactive oxygen species (ROS) and thus triggers oxidative stress to the cell. With the use of fission yeast Schizosaccharomyces pombe (S. pombe) as the model organism, we have analyzed the impact of Cd on the cell growth intensity, as it represents the fundamental feature of all living organisms. Cells were incubated with different Cd concentrations for 3, 6, and 9 hours to investigate the effect of Cd on cell growth in a time and dose-dependent manner. Further possible Cd-derived alterations, as the peroxidation of membrane lipids or the functional impairment of the enzymatic antioxidant protection mechanisms, were investigated by determination of the MDA content and via catalase (CAT) activity detection. Moreover, ascorbic acid (AsA) pre-treatment was subjected to investigate the assumed positive effect of AsA against Cd toxicity. We show here on one hand that cells suffer under the influence of Cd, but on the other hand, they substantially profit from AsA supplementation. Because S. pombe is known to shares many molecular, and biochemical similarities with higher organisms, the effect of AsA in cadmium toxicity elimination might be expected to a similar extent also in other cell types.

scholarly journals Alp7-Mto1 and Alp14 synergize to promote interphase microtubule regrowth from the nuclear envelope

2019 ◽  
Vol 11 (11) ◽  
pp. 944-955 ◽  
Author(s):  
Wenyue Liu ◽  
Fan Zheng ◽  
Yucai Wang ◽  
Chuanhai Fu
Keyword(s):  
Nuclear Envelope ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Microtubule Assembly ◽  
Dependent Manner ◽  
Microtubule Nucleation ◽  
Microtubule Organizing Centers ◽  
Evolutionarily Conserved ◽  
Microtubule Growth ◽  
In Cells

Abstract Microtubules grow not only from the centrosome but also from various noncentrosomal microtubule-organizing centers (MTOCs), including the nuclear envelope (NE) and pre-existing microtubules. The evolutionarily conserved proteins Mto1/CDK5RAP2 and Alp14/TOG/XMAP215 have been shown to be involved in promoting microtubule nucleation. However, it has remained elusive as to how the microtubule nucleation promoting factors are specified to various noncentrosomal MTOCs, particularly the NE, and how these proteins coordinate to organize microtubule assembly. Here, we demonstrate that in the fission yeast Schizosaccharomyces pombe, efficient interphase microtubule growth from the NE requires Alp7/TACC, Alp14/TOG/XMAP215, and Mto1/CDK5RAP2. The absence of Alp7, Alp14, or Mto1 compromises microtubule regrowth on the NE in cells undergoing microtubule repolymerization. We further demonstrate that Alp7 and Mto1 interdependently localize to the NE in cells without microtubules and that Alp14 localizes to the NE in an Alp7 and Mto1-dependent manner. Tethering Mto1 to the NE in cells lacking Alp7 partially restores microtubule number and the efficiency of microtubule generation from the NE. Hence, our study delineates that Alp7, Alp14, and Mto1 work in concert to regulate interphase microtubule regrowth on the NE.

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 The Melaminophenyl Arsenicals Melarsoprol and Melarsen Oxide Interfere with Thiamine Metabolism in the Fission Yeast Schizosaccharomyces pombe

2004 ◽  
Vol 48 (9) ◽  
pp. 3268-3271 ◽  
Author(s):  
M. Ernst Schweingruber
Keyword(s):  
Membrane Protein ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Trypanosoma Brucei ◽  
Human Body ◽  
Active Metabolite ◽  
Vitamin B ◽  
Dependent Manner ◽  
Pyrimidine Moiety ◽  
Thiamine Analogues

ABSTRACT The melaminophenyl arsenical melarsoprol is the main drug used against late-stage sleeping sickness caused by Trypanosoma brucei subspecies. Its active metabolite in the human body is melarsen oxide. Here, it is shown that this metabolite inhibits growth of the fission yeast Schizosaccharomyces pombe and that its toxicity can be abolished efficiently by thiamine (vitamin B1), thiamine analogues, and the pyrimidine moiety of the thiamine molecule. Uptake of melarsen oxide is mediated by a membrane protein (car1p), which is involved in the uptake of thiamine and its pyrimidine moiety. Melarsoprol is taken up by cells in a thiamine- and car1p-dependent manner but is not toxic to cells.

scholarly journals Phosphatidylethanolamine Is Required for Normal Cell Morphology and Cytokinesis in the Fission Yeast Schizosaccharomyces pombe

2009 ◽  
Vol 8 (5) ◽  
pp. 790-799 ◽  
Author(s):  
Jun Luo ◽  
Yasuhiro Matsuo ◽  
Galina Gulis ◽  
Haylee Hinz ◽  
Jana Patton-Vogt ◽  
...  
Keyword(s):  
Cell Growth ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Minimal Medium ◽  
Growth Media ◽  
Decarboxylase Activity ◽  
Rich Medium ◽  
Wild Type ◽  
Cellular Functions ◽  
Kennedy Pathway

ABSTRACT To investigate the contributions of phosphatidylethanolamine to the growth and morphogenesis of the fission yeast Schizosaccharomyces pombe, we have characterized three predicted genes in this organism, designated psd1, psd2, and psd3, encoding phosphatidylserine decarboxylases, which catalyze the conversion of phosphatidylserine to phosphatidylethanolamine in both eukaryotic and prokaryotic organisms. S. pombe mutants carrying deletions in any one or two psd genes are viable in complex rich medium and synthetic defined minimal medium. However, mutants carrying deletions in all three psd genes (psd1-3Δ mutants) grow slowly in rich medium and are inviable in minimal medium, indicating that the psd1 to psd3 gene products share overlapping essential cellular functions. Supplementation of growth media with ethanolamine, which can be converted to phosphatidylethanolamine by the Kennedy pathway, restores growth to psd1-3Δ cells in minimal medium, indicating that phosphatidylethanolamine is essential for S. pombe cell growth. psd1-3Δ cells produce lower levels of phosphatidylethanolamine than wild-type cells, even in medium supplemented with ethanolamine, indicating that the Kennedy pathway can only partially compensate for the loss of phosphatidylserine decarboxylase activity in S. pombe. psd1-3Δ cells appear morphologically indistinguishable from wild-type S. pombe cells in medium supplemented with ethanolamine, but when cultured in nonsupplemented medium, they produce high frequencies of abnormally shaped cells as well as cells exhibiting severe septation defects, including multiple, mispositioned, deformed, and misoriented septa. Our results demonstrate that phosphatidylethanolamine is essential for cell growth and for normal cytokinesis and cellular morphogenesis in S. pombe, and they illustrate the usefulness of this model eukaryote for investigating potentially conserved biological and molecular functions of phosphatidylethanolamine.

scholarly journals Mitotic spindle disassembly in human cells relies on CRIPT-bearing hierarchical redox signals

2019 ◽  
Author(s):  
Kehan Xu ◽  
Lingling Yang ◽  
Xiu Cheng ◽  
Xiaoyan Liu ◽  
Hao Huang ◽  
...  
Keyword(s):  
Human Cells ◽  
Live Cell ◽  
Dependent Manner ◽  
Microtubule Depolymerization ◽  
Cysteine Substitution ◽  
Cysteine Rich Protein ◽  
Biochemical Assays ◽  
Spindle Disassembly ◽  
Live Cell Microscopy ◽  
Cell Microscopy

AbstractSwift and complete spindle disassembly is essential for cell survival, yet how it happens is largely unknown. Here we used real-time live-cell microscopy and biochemical assays to show that a cysteine-rich protein CRIPT dictates the spindle disassembly in a redox-dependent manner in human cells. This previously reported cytoplasmic protein was found to have a confined nuclear localization during interphase but was distributed to spindles and underwent redox modifications to form disulfides within CXXC pairs during mitosis. Then, it interacts with and transfers redox response to tubulin subunits to induce microtubule depolymerization. The mutants with any of cysteine substitution completely block the spindle disassembly generating two cell populations with long-lasting metaphase spindles or spindle remnants. The live cell recordings of a disease-relevant mutant (CRIPTC3Y) revealed that microtubule depolymerization at spindle ends during anaphase and the entire spindle dissolution during telophase may share a common CRIPT-bearing redox-controlled mechanism.

Sign in / Sign up

Export Citation Format

Share Document