scholarly journals An MBoC Favorite: Cytokinesis depends on the motor domains of myosin-II in fission yeast but not in budding yeast

2012 ◽  
Vol 23 (9) ◽  
pp. 1608-1608
Author(s):  
Daniel Lew
Keyword(s):  
Fission Yeast ◽  
Budding Yeast ◽  
Myosin Ii

scholarly journals Cytokinesis Depends on the Motor Domains of Myosin-II in Fission Yeast but Not in Budding Yeast

2005 ◽  
Vol 16 (11) ◽  
pp. 5346-5355 ◽  
Author(s):  
Matthew Lord ◽  
Ellen Laves ◽  
Thomas D. Pollard
Keyword(s):  
Atpase Activity ◽  
Fission Yeast ◽  
Mechanism Of Action ◽  
Budding Yeast ◽  
Myosin Ii ◽  
Cellular Function ◽  
Motor Domain ◽  
Actin Binding ◽  
Contractile Ring ◽  
Head Domain

Budding yeast possesses one myosin-II, Myo1p, whereas fission yeast has two, Myo2p and Myp2p, all of which contribute to cytokinesis. We find that chimeras consisting of Myo2p or Myp2p motor domains fused to the tail of Myo1p are fully functional in supporting budding yeast cytokinesis. Remarkably, the tail alone of budding yeast Myo1p localizes to the contractile ring, supporting both its constriction and cytokinesis. In contrast, fission yeast Myo2p and Myp2p require both the catalytic head domain as well as tail domains for function, with the tails providing distinct functions ( Bezanilla and Pollard, 2000 ). Myo1p is the first example of a myosin whose cellular function does not require a catalytic motor domain revealing a novel mechanism of action for budding yeast myosin-II independent of actin binding and ATPase activity.

Use of electron microscopy to characterize the surfaces of flocculent and nonflocculent yeast cells

1989 ◽  
Vol 35 (12) ◽  
pp. 1081-1086 ◽  
Author(s):  
Byron F. Johnson ◽  
L. C. Sowden ◽  
Teena Walker ◽  
Bong Y. Yoo ◽  
Gode B. Calleja
Keyword(s):  
Electron Microscopy ◽  
Fission Yeast ◽  
Budding Yeast ◽  
The Other ◽  
Yeast Cells ◽  
Scanning Electron Micrographs ◽  
Soft Or ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Scanning Electron

The surfaces of flocculent and nonflocculent yeast cells have been examined by electron microscopy. Nonextractive preparative procedures for scanning electron microscopy allow comparison in which sharp or softened images of surface details (scars, etc.) are the criteria for relative abundance of flocculum material. Asexually flocculent budding-yeast cells cannot be distinguished from nonflocculent budding-yeast cells in scanning electron micrographs because the scar details of both are well resolved, being hard and sharp. On the other hand, flocculent fission-yeast cells are readily distinguished from nonflocculent cells because fission scars are mostly soft or obscured on flocculent cells, but sharp on nonflocculent cells. Sexually and asexually flocculent fission-yeast cells cannot be distinguished from one another as both are heavily clad in "mucilaginous" or "hairy" coverings. Examination of lightly extracted and heavily extracted flocculent fission-yeast cells by transmission electron microscopy provides micrographs consistent with the scanning electron micrographs.Key words: flocculation, budding yeast, fission yeast, scanning, transmission.

scholarly journals Repeat-Associated Fission Yeast-Like Regional Centromeres in the Ascomycetous Budding Yeast Candida tropicalis

PLoS Genetics ◽  
2016 ◽  
Vol 12 (2) ◽  
pp. e1005839 ◽  
Author(s):  
Gautam Chatterjee ◽  
Sundar Ram Sankaranarayanan ◽  
Krishnendu Guin ◽  
Yogitha Thattikota ◽  
Sreedevi Padmanabhan ◽  
...  
Keyword(s):  
Fission Yeast ◽  
Candida Tropicalis ◽  
Budding Yeast

scholarly journals Cleavage of Model Replication Forks by Fission Yeast Mus81-Eme1 and Budding Yeast Mus81-Mms4

2002 ◽  
Vol 278 (9) ◽  
pp. 6928-6935 ◽  
Author(s):  
Matthew C. Whitby ◽  
Fekret Osman ◽  
Julie Dixon
Keyword(s):  
Fission Yeast ◽  
Budding Yeast ◽  
Replication Forks

scholarly journals Myosins generate contractile force and maintain organization in the cytokinetic contractile ring

2021 ◽  
Author(s):  
Zachary A. McDargh ◽  
Shuyuan Wang ◽  
Harvey F. Chin ◽  
Sathish Thiyagarajan ◽  
Erdem Karatekin ◽  
...  
Keyword(s):  
Fission Yeast ◽  
Striated Muscle ◽  
Protein Complexes ◽  
Myosin Ii ◽  
Force Production ◽  
Super Resolution ◽  
Building Blocks ◽  
Contractile Ring ◽  
Ring Model ◽  
Self Assembling

During cytokinesis, cells assemble an actomyosin contractile ring whose tension constricts and divides cells, but the ring tension was rarely measured. Actomyosin force generation is well understood for the regular sarcomeric architecture of striated muscle, but recent super-resolution studies of fission yeast contractile rings revealed organizational building blocks that are not sarcomeres but irregularly positioned plasma membrane-anchored protein complexes called nodes. Here, we measured contractile ring tensions in fission yeast protoplast cells. The myosin II isoforms Myo2 and Myp2 generated the tension, with a ~2-fold greater contribution from Myo2. Simulations of a molecularly detailed ring model revealed a sliding node mechanism for tension, where nodes hosting tense actin filaments were pulled bidirectionally around the ring. Myo2 and Myp2 chaperoned self-assembling components into the ring organization, and anchored the ring against bridging instabilities. Thus, beyond force production, Myo2 and Myp2 are the principal organizers, bundlers and anchors of the contractile ring.

scholarly journals Functional Comparison of the Tup11 and Tup12 Transcriptional Corepressors in Fission Yeast

2005 ◽  
Vol 25 (2) ◽  
pp. 716-727 ◽  
Author(s):  
Fredrik Fagerström-Billai ◽  
Anthony P. H. Wright
Keyword(s):  
Gene Expression ◽  
Gene Duplication ◽  
Fission Yeast ◽  
Budding Yeast ◽  
Functional Difference ◽  
Evolutionary Mechanism ◽  
Genome Wide ◽  
Number Of Genes ◽  
Transcriptional Corepressors ◽  
Genome Wide Gene Expression

ABSTRACT Gene duplication is considered an important evolutionary mechanism. Unlike many characterized species, the fission yeast Schizosaccharomyces pombe contains two paralogous genes, tup11 + and tup12 + , that encode transcriptional corepressors similar to the well-characterized budding yeast Tup1 protein. Previous reports have suggested that Tup11 and Tup12 proteins play redundant roles. Consistently, we show that the two Tup proteins can interact together when expressed at normal levels and that each can independently interact with the Ssn6 protein, as seen for Tup1 in budding yeast. However, tup11 − and tup12 − mutants have different phenotypes on media containing KCl and CaCl2. Consistent with the functional difference between tup11 − and tup12 − mutants, we identified a number of genes in genome-wide gene expression experiments that are differentially affected by mutations in the tup11 + and tup12 + genes. Many of these genes are differentially derepressed in tup11 − mutants and are over-represented in genes that have previously been shown to respond to a range of different stress conditions. Genes specifically derepressed in tup12 − mutants require the Ssn6 protein for their repression. As for Tup12, Ssn6 is also required for efficient adaptation to KCl- and CaCl2-mediated stress. We conclude that Tup11 and Tup12 are at least partly functionally diverged and suggest that the Tup12 and Ssn6 proteins have adopted a specific role in regulation of the stress response.

Fission yeast Pds5 is required for accurate chromosome segregation and for survival after DNA damage or metaphase arrest

2002 ◽  
Vol 115 (3) ◽  
pp. 587-598 ◽  
Author(s):  
Shao-Win Wang ◽  
Rebecca L. Read ◽  
Chris J. Norbury
Keyword(s):  
Dna Damage ◽  
Fission Yeast ◽  
Sister Chromatid ◽  
Budding Yeast ◽  
Eukaryotic Cell ◽  
Sister Chromatid Cohesion ◽  
Chromosome Loss ◽  
Dependent Manner ◽  
Yeast Saccharomyces Cerevisiae ◽  
Chromatid Cohesion

Sister chromatid cohesion, which is established during the S phase of the eukaryotic cell cycle and persists until the onset of anaphase, is essential for the maintenance of genomic integrity. Cohesion requires the multi-protein complex cohesin, as well as a number of accessory proteins including Pds5/BIMD/Spo76. In the budding yeast Saccharomyces cerevisiae Pds5 is an essential protein that localises to chromosomes in a cohesin-dependent manner. Here we describe the characterisation in the fission yeast Schizosaccharomyces pombe of pds5+, a novel,non-essential orthologue of S. cerevisiae PDS5. The S. pombePds5 protein was localised to punctate nuclear foci in a manner that was dependent on the Rad21 cohesin component. This, together with additional genetic evidence, points towards an involvement of S. pombe Pds5 in sister chromatid cohesion. S. pombe pds5 mutants were hypersensitive to DNA damage and to mitotic metaphase delay, but this sensitivity was apparently not due to precocious loss of sister chromatid cohesion. These cells also suffered increased spontaneous chromosome loss and meiotic defects and their viability was dependent on the spindle checkpoint protein Bub1. Thus, while S. pombe Pds5 has an important cohesin-related role, this differs significantly from that of the equivalent budding yeast protein.

The novel human protein serine/threonine phosphatase 6 is a functional homologue of budding yeast Sit4p and fission yeast ppe1, which are involved in cell cycle regulation

1996 ◽  
Vol 109 (12) ◽  
pp. 2865-2874 ◽  
Author(s):  
H. Bastians ◽  
H. Ponstingl
Keyword(s):  
Cell Cycle ◽  
Fission Yeast ◽  
Shape Control ◽  
Cell Cycle Regulation ◽  
Budding Yeast ◽  
Mitotic Checkpoint ◽  
Human Protein ◽  
Predicted Amino Acid Sequence ◽  
Temperature Sensitive ◽  
Cycle Regulation

We identified a novel human protein serine/threonine phosphatase cDNA, designated protein phosphatase 6 (PP6) by using a homology-based polymerase chain reaction. The predicted amino acid sequence indicates a 35 kDa protein showing high homology to other protein phosphatases including human PP2A (57%), human PP4 (59%), rat PPV (98%), Drosophila PPV (74%), Schizosaccharomyces pombe ppe1 (68%) and Saccharomyces cerevisiae Sit4p (61%). In human cells, three forms of PP6 mRNA were found with highest levels of expression in testis, heart and skeletal muscle. The PP6 protein was detected in lysates of human heart muscle and in bull testis. Complementation studies using a temperature sensitive mutant strain of S. cerevisiae SIT4, which is required for the G1 to S transition of the cell cycle, showed that PP6 can rescue the mutant growth arrest. In addition, a loss of function mutant of S. pombe ppe1, described as a gene interacting with the pim1/spi1 mitotic checkpoint and involved in cell shape control, can be complemented by expression of human PP6. These data indicate that human PP6 is a functional homologue of budding yeast Sit4p and fission yeast ppe1, implying a function of PP6 in cell cycle regulation.

scholarly journals Anchoring of actin to the plasma membrane enables tension production in the fission yeast cytokinetic ring

2019 ◽  
Vol 30 (16) ◽  
pp. 2053-2064 ◽  
Author(s):  
Shuyuan Wang ◽  
Ben O’Shaughnessy
Keyword(s):  
Plasma Membrane ◽  
Fission Yeast ◽  
Actin Filaments ◽  
Tensile Force ◽  
Myosin Ii ◽  
Quantitative Evidence ◽  
Explicit Simulation ◽  
Adjacent Segments ◽  
Develop Tension

The cytokinetic ring generates tensile force that drives cell division, but how tension emerges from the relatively disordered ring organization remains unclear. Long ago, a musclelike sliding filament mechanism was proposed, but evidence for sarcomeric order is lacking. Here we present quantitative evidence that in fission yeast, ring tension originates from barbed-end anchoring of actin filaments to the plasma membrane, providing resistance to myosin forces that enables filaments to develop tension. The role of anchoring was highlighted by experiments on isolated fission yeast rings, where sections of ring became unanchored from the membrane and shortened ∼30-fold faster than normal. The dramatically elevated constriction rates are unexplained. Here we present a molecularly explicit simulation of constricting partially anchored rings as studied in these experiments. Simulations accurately reproduced the experimental constriction rates and showed that following anchor release, a segment becomes tensionless and shortens via a novel noncontractile reeling-in mechanism at about the velocity of load-free myosin II. The ends are reeled in by barbed end–anchored actin filaments in adjacent segments. Other actin anchoring schemes failed to constrict rings. Our results quantitatively support a specific organization and anchoring scheme that generate tension in the cytokinetic ring.

scholarly journals Genetic suppression of defective profilin by attenuated Myosin II reveals a potential role for Myosin II in actin dynamics in vivo in fission yeast

2020 ◽  
Vol 31 (19) ◽  
pp. 2107-2114 ◽  
Author(s):  
Paola Zambon ◽  
Saravanan Palani ◽  
Shekhar Sanjay Jadhav ◽  
Pananghat Gayathri ◽  
Mohan K. Balasubramanian
Keyword(s):  
Fission Yeast ◽  
Double Mutant ◽  
Potential Role ◽  
Myosin Ii ◽  
Model Organism ◽  
Actin Dynamics ◽  
Mutant Analysis ◽  
Genetic Suppression

This work reveals an in vivo role for Myosin II in actin dynamics, potentially in its disassembly and turnover. The work uses double mutant analysis to arrive at this conclusion using the fission yeast as a model organism.

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