scholarly journals A Filamentous Growth Response Mediated by the Yeast Mating Pathway

Genetics ◽  
2001 ◽  
Vol 159 (3) ◽  
pp. 919-928 ◽  
Author(s):  
Scott Erdman ◽  
Michael Snyder
Keyword(s):  
Cell Division ◽  
Cell Shape ◽  
Cellular Response ◽  
Threshold Level ◽  
Time Lapse ◽  
Cell Polarization ◽  
Yeast Cells ◽  
Filament Formation ◽  
Yeast Saccharomyces Cerevisiae ◽  
Low Levels

Abstract Haploid cells of the budding yeast Saccharomyces cerevisiae respond to mating pheromones by arresting their cell-division cycle in G1 and differentiating into a cell type capable of locating and fusing with mating partners. Yeast cells undergo chemotactic cell surface growth when pheromones are present above a threshold level for morphogenesis; however, the morphogenetic responses of cells to levels of pheromone below this threshold have not been systematically explored. Here we show that MATa haploid cells exposed to low levels of the α-factor mating pheromone undergo a novel cellular response: cells modulate their division patterns and cell shape, forming colonies composed of filamentous chains of cells. Time-lapse analysis of filament formation shows that its dynamics are distinct from that of pseudohyphal growth; during pheromone-induced filament formation, daughter cells are delayed relative to mother cells with respect to the timing of bud emergence. Filament formation requires the RSR1(BUD1), BUD8, SLK1/BCK1, and SPA2 genes and many elements of the STE11/STE7 MAP kinase pathway; this response is also independent of FAR1, a gene involved in orienting cell polarization during the mating response. We suggest that mating yeast cells undergo a complex response to low levels of pheromone that may enhance the ability of cells to search for mating partners through the modification of cell shape and alteration of cell-division patterns.

scholarly journals Replicative Aging in Pathogenic Fungi

2020 ◽  
Vol 7 (1) ◽  
pp. 6
Author(s):  
Somanon Bhattacharya ◽  
Tejas Bouklas ◽  
Bettina C. Fries
Keyword(s):  
Cell Division ◽  
Candida Glabrata ◽  
Asymmetric Cell Division ◽  
Pathogenic Fungi ◽  
Yeast Cells ◽  
Candida Auris ◽  
Replicative Aging ◽  
Yeast Saccharomyces Cerevisiae ◽  
Phenotypic Variations ◽  
Systemic Infections

Candida albicans, Candida auris, Candida glabrata, and Cryptococcus neoformans are pathogenic yeasts which can cause systemic infections in immune-compromised as well as immune-competent individuals. These yeasts undergo replicative aging analogous to a process first described in the nonpathogenic yeast Saccharomyces cerevisiae. The hallmark of replicative aging is the asymmetric cell division of mother yeast cells that leads to the production of a phenotypically distinct daughter cell. Several techniques to study aging that have been pioneered in S. cerevisiae have been adapted to study aging in other pathogenic yeasts. The studies indicate that aging is relevant for virulence in pathogenic fungi. As the mother yeast cell progressively ages, every ensuing asymmetric cell division leads to striking phenotypic changes, which results in increased antifungal and antiphagocytic resistance. This review summarizes the various techniques that are used to study replicative aging in pathogenic fungi along with their limitations. Additionally, the review summarizes some key phenotypic variations that have been identified and are associated with changes in virulence or resistance and thus promote persistence of older cells.

scholarly journals The CDC42 Homolog of the Dimorphic FungusPenicillium marneffei Is Required for Correct Cell Polarization during Growth but Not Development

2001 ◽  
Vol 183 (11) ◽  
pp. 3447-3457 ◽  
Author(s):  
Kylie J. Boyce ◽  
Michael J. Hynes ◽  
Alex Andrianopoulos
Keyword(s):  
Cell Shape ◽  
Pathogenic Fungus ◽  
Cell Polarization ◽  
Dominant Negative ◽  
Yeast Cells ◽  
Polarized Growth ◽  
Temperature Dependent ◽  
Human Pathogenic Fungus ◽  
Rho Family

ABSTRACT The opportunistic human pathogenic fungus Penicillium marneffei is dimorphic and is thereby capable of growth either as filamentous multinucleate hyphae or as uninucleate yeast cells which divide by fission. The dimorphic switch is temperature dependent and requires regulated changes in morphology and cell shape. Cdc42p is a Rho family GTPase which in Saccharomyces cerevisiae is required for changes in polarized growth during mating and pseudohyphal development. Cdc42p homologs in higher organisms are also associated with changes in cell shape and polarity. We have cloned a highly conserved CDC42 homolog from P. marneffeinamed cflA. By the generation of dominant-negative and dominant-activated cflA transformants, we have shown that CflA initiates polarized growth and extension of the germ tube and subsequently maintains polarized growth in the vegetative mycelium. CflA is also required for polarization and determination of correct cell shape during yeast-like growth, and active CflA is required for the separation of yeast cells. However, correct cflAfunction is not required for dimorphic switching and does not appear to play a role during the generation of specialized structures during asexual development. In contrast, heterologous expression ofcflA alleles in Aspergillus nidulansprevented conidiation.

scholarly journals Membrane and lipid metabolism plays an important role in desiccation resistance in the yeast Saccharomyces cerevisiae

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Qun Ren ◽  
Rebecca Brenner ◽  
Thomas C. Boothby ◽  
Zhaojie Zhang
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Desiccation Tolerance ◽  
Protein Function ◽  
Cellular Response ◽  
Lipid Droplets ◽  
Structural Changes ◽  
Membrane Integrity ◽  
Yeast Cells ◽  
Yeast Saccharomyces Cerevisiae ◽  
Desiccation Process

Abstract Background Anhydrobiotes, such as the yeast Saccharomyces cerevisiae, are capable of surviving almost total loss of water. Desiccation tolerance requires an interplay of multiple events, including preserving the protein function and membrane integrity, preventing and mitigating oxidative stress, maintaining certain level of energy required for cellular activities in the desiccated state. Many of these crucial processes can be controlled and modulated at the level of organelle morphology and dynamics. However, little is understood about what organelle perturbations manifest in desiccation-sensitive cells as a consequence of drying or how this differs from organelle biology in desiccation-tolerant organisms undergoing anhydrobiosis. Results In this study, electron and optical microscopy was used to examine the dynamic changes of yeast cells during the desiccation process. Dramatic structural changes were observed during the desiccation process, including the diminishing of vacuoles, decrease of lipid droplets, decrease in mitochondrial cristae and increase of ER membrane, which is likely caused by ER stress and unfolded protein response. The survival rate was significantly decreased in mutants that are defective in lipid droplet biosynthesis, or cells treated with cerulenin, an inhibitor of fatty acid synthesis. Conclusion Our study suggests that the metabolism of lipid droplets and membrane may play an important role in yeast desiccation tolerance by providing cells with energy and possibly metabolic water. Additionally, the decrease in mitochondrial cristae coupled with a decrease in lipid droplets is indicative of a cellular response to reduce the production of reactive oxygen species.

scholarly journals Cell division and cell shape patterns during migration of the embryonic chick neural crest revealed by in vivo time-lapse microscopy

2010 ◽  
Vol 344 (1) ◽  
pp. 473
Author(s):  
Dennis A. Ridenour ◽  
Katherine W. Prather ◽  
Rebecca McLennan ◽  
Zachary Warren ◽  
Paul M. Kulesa
Keyword(s):  
Cell Division ◽  
Neural Crest ◽  
Cell Shape ◽  
Time Lapse ◽  
Embryonic Chick ◽  
Time Lapse Microscopy

scholarly journals Membrane and lipid metabolism plays an important role in desiccation resistance in the yeast Saccharomyces cerevisiae

2020 ◽  
Author(s):  
Qun Ren ◽  
Rebecca Brenner ◽  
Thomas C. Boothby ◽  
Zhaojie Zhang
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Desiccation Tolerance ◽  
Protein Function ◽  
Cellular Response ◽  
Lipid Droplets ◽  
Structural Changes ◽  
Membrane Integrity ◽  
Yeast Cells ◽  
Yeast Saccharomyces Cerevisiae ◽  
Desiccation Process

Abstract BackgroundAnhydrobiotes, such as the yeast Saccharomyces cerevisiae, are capable of surviving almost total loss of water. Desiccation tolerance requires an interplay of multiple events, including preserving the protein function and membrane integrity, preventing and mitigating oxidative stress, maintaining certain level of energy required for cellular activities in the desiccated state. Many of these crucial processes can be controlled and modulated at the level of organelle morphology and dynamics. However, little is understood about what organelle perturbations manifest in desiccation-sensitive cells as a consequence of drying or how this differs from organelle biology in desiccation-tolerant organisms undergoing anhydrobiosis.ResultsIn this study, electron and optical microscopy was used to examine the dynamic changes of yeast cells during the desiccation process. Dramatic structural changes were observed during the desiccation process, including the diminishing of vacuoles, decrease of lipid droplets, decrease in mitochondrial cristae and increase of ER membrane, which is likely caused by ER stress and unfolded protein response. The survival rate was significantly decreased in mutants that are defective in lipid droplet biosynthesis, or cells treated with cerulenin, an inhibitor of fatty acid synthesis.ConclusionOur study suggests that the metabolism of lipid droplets and membrane may play an important role in yeast desiccation tolerance by providing cells with energy and possibly metabolic water. Additionally, the decrease in mitochondrial cristae coupled with a decrease in lipid droplets is indicative of a cellular response to reduce the production of reactive oxygen species.

scholarly journals Membrane and lipid metabolism plays an important role in desiccation resistance in the yeast Saccharomyces cerevisiae

2020 ◽  
Author(s):  
Qun Ren ◽  
Rebecca Brenner ◽  
Thomas C. Boothby ◽  
Zhaojie Zhang
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Desiccation Tolerance ◽  
Cellular Response ◽  
Lipid Droplets ◽  
Structural Changes ◽  
Membrane Integrity ◽  
Yeast Cells ◽  
Initial Increase ◽  
Yeast Saccharomyces Cerevisiae ◽  
Desiccation Process

Abstract Background: Anhydrobiotes, such as the yeast Saccharomyces cerevisiae , are capable of surviving almost total loss of water. Desiccation tolerance requires an interplay of multiple events, including preserving the protein function and membrane integrity, preventing and mitigating oxidative stress, maintaining certain level of energy required for cellular activities in the desiccated state. Many of these crucial processes can be controlled and modulated at the level of organelle morphology and dynamics. However, little is understood about what organelle perturbations manifest in desiccation-sensitive cells as a consequence of drying or how this differs from organelle biology in desiccation-tolerant organisms undergoing anhydrobiosis. Results: In this study, electron and optical microscopy was used to examine the dynamic changes of yeast cells during the desiccation process. Dramatic structural changes were observed during the desiccation process, including the diminishing of vacuoles, and increase and then decrease of lipid droplets as well as a decrease in mitochondria and mitochondrial cristae and an increase of ER membrane, which is likely caused by ER stress and unfolded protein response. The survival rate was significantly decreased in mutants that are defective in lipid droplet biosynthesis, or cells treated with cerulenin, an inhibitor of fatty acid synthesis. Conclusion: Our study suggests that the metabolism of lipid droplets and membrane may play an important role in yeast desiccation tolerance by providing cells with energy and possibly metabolic water. Additionally, the decrease in mitochondria and cristae coupled with an initial increase and then drop in lipid droplets number is indicative of a cellular response to reduce the production of reactive oxygen species.

scholarly journals Cdc42 regulates junctional actin but not cell polarization in the Caenorhabditis elegans epidermis

2017 ◽  
Vol 216 (11) ◽  
pp. 3729-3744 ◽  
Author(s):  
Yuliya Zilberman ◽  
Joshua Abrams ◽  
Dorian C. Anderson ◽  
Jeremy Nance
Keyword(s):  
Caenorhabditis Elegans ◽  
Epidermal Cell ◽  
Cell Shape ◽  
Time Lapse ◽  
Cell Polarization ◽  
Epithelial Morphogenesis ◽  
Actin Organization ◽  
Protein Levels ◽  
Guanosine Triphosphatase ◽  
Shape Changes

During morphogenesis, adherens junctions (AJs) remodel to allow changes in cell shape and position while preserving adhesion. Here, we examine the function of Rho guanosine triphosphatase CDC-42 in AJ formation and regulation during Caenorhabditis elegans embryo elongation, a process driven by asymmetric epidermal cell shape changes. cdc-42 mutant embryos arrest during elongation with epidermal ruptures. Unexpectedly, we find using time-lapse fluorescence imaging that cdc-42 is not required for epidermal cell polarization or junction assembly, but rather is needed for proper junctional actin regulation during elongation. We show that the RhoGAP PAC-1/ARHGAP21 inhibits CDC-42 activity at AJs, and loss of PAC-1 or the interacting linker protein PICC-1/CCDC85A-C blocks elongation in embryos with compromised AJ function. pac-1 embryos exhibit dynamic accumulations of junctional F-actin and an increase in AJ protein levels. Our findings identify a previously unrecognized molecular mechanism for inhibiting junctional CDC-42 to control actin organization and AJ protein levels during epithelial morphogenesis.

scholarly journals Keeping the Vimentin Network under Control: Cell–Matrix Adhesion–associated Plectin 1f Affects Cell Shape and Polarity of Fibroblasts

2010 ◽  
Vol 21 (19) ◽  
pp. 3362-3375 ◽  
Author(s):  
Gerald Burgstaller ◽  
Martin Gregor ◽  
Lilli Winter ◽  
Gerhard Wiche
Keyword(s):  
Cell Shape ◽  
Network Formation ◽  
De Novo ◽  
Control Cell ◽  
Focal Adhesions ◽  
Time Lapse ◽  
Cell Polarization ◽  
Dependent Manner ◽  
Cell Matrix ◽  
Contractile Stress

Focal adhesions (FAs) located at the ends of actin/myosin-containing contractile stress fibers form tight connections between fibroblasts and their underlying extracellular matrix. We show here that mature FAs and their derivative fibronectin fibril-aligned fibrillar adhesions (FbAs) serve as docking sites for vimentin intermediate filaments (IFs) in a plectin isoform 1f (P1f)-dependent manner. Time-lapse video microscopy revealed that FA-associated P1f captures mobile vimentin filament precursors, which then serve as seeds for de novo IF network formation via end-to-end fusion with other mobile precursors. As a consequence of IF association, the turnover of FAs is reduced. P1f-mediated IF network formation at FbAs creates a resilient cage-like core structure that encases and positions the nucleus while being stably connected to the exterior of the cell. We show that the formation of this structure affects cell shape with consequences for cell polarization.

scholarly journals Membrane and lipid metabolism plays an important role in desiccation resistance in the yeast Saccharomyces cerevisiae

2020 ◽  
Author(s):  
Qun Ren ◽  
Rebecca Brenner ◽  
Thomas C. Boothby ◽  
Zhaojie Zhang
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Desiccation Tolerance ◽  
Protein Function ◽  
Cellular Response ◽  
Lipid Droplets ◽  
Structural Changes ◽  
Membrane Integrity ◽  
Yeast Cells ◽  
Yeast Saccharomyces Cerevisiae ◽  
Desiccation Process

Abstract Background Anhydrobiotes, such as the yeast Saccharomyces cerevisiae, are capable of surviving almost total loss of water. Desiccation tolerance requires an interplay of multiple events, including preserving the protein function and membrane integrity, preventing and mitigating oxidative stress, maintaining certain level of energy required for cellular activities in the desiccated state. Many of these crucial processes can be controlled and modulated at the level of organelle morphology and dynamics. However, little is understood about what organelle perturbations manifest in desiccation-sensitive cells as a consequence of drying or how this differs from organelle biology in desiccation-tolerant organisms undergoing anhydrobiosis.Results In this study, electron and optical microscopy was used to examine the dynamic changes of yeast cells during the desiccation process. Dramatic structural changes were observed during the desiccation process, including the diminishing of vacuoles, decrease of lipid droplets, decrease in mitochondrial cristae and increase of ER membrane, which is likely caused by ER stress and unfolded protein response. The survival rate was significantly decreased in mutants that are defective in lipid droplet biosynthesis, or cells treated with cerulenin, an inhibitor of fatty acid synthesis.Conclusion Our study suggests that the metabolism of lipid droplets and membrane may play an important role in yeast desiccation tolerance by providing cells with energy and possibly metabolic water. Additionally, the decrease in mitochondrial cristae coupled with a decrease in lipid droplets is indicative of a cellular response to reduce the production of reactive oxygen species.

scholarly journals The Fate of Lipid-Coated and Uncoated Fluorescent Nanodiamonds during Cell Division in Yeast

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 516
Author(s):  
Aryan Morita ◽  
Thamir Hamoh ◽  
Felipe P. Perona Martinez ◽  
Mayeul Chipaux ◽  
Alina Sigaeva ◽  
...  
Keyword(s):  
Cell Division ◽  
Cell Biology ◽  
Mammalian Cells ◽  
Model Organism ◽  
Yeast Cells ◽  
Yeast Saccharomyces Cerevisiae ◽  
Daughter Cells ◽  
Diamond Particles ◽  
Fluorescent Nanodiamonds ◽  
Intracellular Fate

Fluorescent nanodiamonds are frequently used as biolabels. They have also recently been established for magnetic resonance and temperature sensing at the nanoscale level. To properly use them in cell biology, we first have to understand their intracellular fate. Here, we investigated, for the first time, what happens to diamond particles during and after cell division in yeast (Saccharomyces cerevisiae) cells. More concretely, our goal was to answer the question of whether nanodiamonds remain in the mother cells or end up in the daughter cells. Yeast cells are widely used as a model organism in aging and biotechnology research, and they are particularly interesting because their asymmetric cell division leads to morphologically different mother and daughter cells. Although yeast cells have a mechanism to prevent potentially harmful substances from entering the daughter cells, we found an increased number of diamond particles in daughter cells. Additionally, we found substantial excretion of particles, which has not been reported for mammalian cells. We also investigated what types of movement diamond particles undergo in the cells. Finally, we also compared bare nanodiamonds with lipid-coated diamonds, and there were no significant differences in respect to either movement or intracellular fate.

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