Plo1 Kinase Recruitment to the Spindle Pole Body and Its Role in Cell Division inSchizosaccharomyces pombe

Polo kinases execute multiple roles during cell division. The fission yeast polo related kinase Plo1 is required to assemble the mitotic spindle, the prophase actin ring that predicts the site for cytokinesis and for septation after the completion of mitosis ( Ohkuraet al., 1995 ; Bahler et al., 1998 ). We show that Plo1 associates with the mitotic but not interphase spindle pole body (SPB). SPB association of Plo1 is the earliest fission yeast mitotic event recorded to date. SPB association is strong from mitotic commitment to early anaphase B, after which the Plo1 signal becomes very weak and finally disappears upon spindle breakdown. SPB association of Plo1 requires mitosis-promoting factor (MPF) activity, whereas its disassociation requires the activity of the anaphase-promoting complex. The stf1.1 mutation bypasses the usual requirement for the MPF activator Cdc25 ( Hudson et al., 1990 ). Significantly, Plo1 associates inappropriately with the interphase SPB of stf1.1 cells. These data are consistent with the emerging theme from many systems that polo kinases participate in the regulation of MPF to determine the timing of commitment to mitosis and may indicate that pole association is a key aspect of Plo1 function. Plo1 does not associate with the SPB when septation is inappropriately driven by deregulation of the Spg1 pathway and remains SPB associated if septation occurs in the presence of a spindle. Thus, neither Plo1 recruitment to nor its departure from the SPB are required for septation; however, overexpression ofplo1+activates the Spg1 pathway and causes transient Cdc7 recruitment to the SPB and multiple rounds of septation.

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Regulation of spindle pole body assembly and cytokinesis by the centrin-binding protein Sfi1 in fission yeast

Molecular Biology of the Cell ◽

10.1091/mbc.e13-11-0699 ◽

2014 ◽

Vol 25 (18) ◽

pp. 2735-2749 ◽

Cited By ~ 22

Author(s):

I-Ju Lee ◽

Ning Wang ◽

Wen Hu ◽

Kersey Schott ◽

Jürg Bähler ◽

...

Keyword(s):

Cell Cycle ◽

Cell Division ◽

Fission Yeast ◽

Budding Yeast ◽

Binding Protein ◽

Spindle Pole Body ◽

Spindle Pole ◽

Centrosome Duplication ◽

Pole Body ◽

The Individual

Centrosomes play critical roles in the cell division cycle and ciliogenesis. Sfi1 is a centrin-binding protein conserved from yeast to humans. Budding yeast Sfi1 is essential for the initiation of spindle pole body (SPB; yeast centrosome) duplication. However, the recruitment and partitioning of Sfi1 to centrosomal structures have never been fully investigated in any organism, and the presumed importance of the conserved tryptophans in the internal repeats of Sfi1 remains untested. Here we report that in fission yeast, instead of doubling abruptly at the initiation of SPB duplication and remaining at a constant level thereafter, Sfi1 is gradually recruited to SPBs throughout the cell cycle. Like an sfi1Δ mutant, a Trp-to-Arg mutant (sfi1-M46) forms monopolar spindles and exhibits mitosis and cytokinesis defects. Sfi1-M46 protein associates preferentially with one of the two daughter SPBs during mitosis, resulting in a failure of new SPB assembly in the SPB receiving insufficient Sfi1. Although all five conserved tryptophans tested are involved in Sfi1 partitioning, the importance of the individual repeats in Sfi1 differs. In summary, our results reveal a link between the conserved tryptophans and Sfi1 partitioning and suggest a revision of the model for SPB assembly.

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Relief of the Dma1-mediated checkpoint requires Dma1 autoubiquitination and dynamic localization

Molecular Biology of the Cell ◽

10.1091/mbc.e18-04-0261 ◽

2018 ◽

Vol 29 (18) ◽

pp. 2176-2189 ◽

Cited By ~ 1

Author(s):

Christine M. Jones ◽

Jun-Song Chen ◽

Alyssa E. Johnson ◽

Zachary C. Elmore ◽

Sierra N. Cullati ◽

...

Keyword(s):

Cell Division ◽

Chromosome Segregation ◽

Ubiquitin Ligase ◽

Spindle Pole Body ◽

Mitotic Checkpoint ◽

Spindle Pole ◽

Checkpoint Activation ◽

Pole Body ◽

Septation Initiation Network ◽

Anaphase B

Chromosome segregation and cell division are coupled to prevent aneuploidy and cell death. In the fission yeast Schizosaccharomyces pombe, the septation initiation network (SIN) promotes cytokinesis, but upon mitotic checkpoint activation, the SIN is actively inhibited to prevent cytokinesis from occurring before chromosomes have safely segregated. SIN inhibition during the mitotic checkpoint is mediated by the E3 ubiquitin ligase Dma1. Dma1 binds to the CK1-phosphorylated SIN scaffold protein Sid4 at the spindle pole body (SPB), and ubiquitinates it. Sid4 ubiquitination antagonizes the SPB localization of the Pololike kinase Plo1, the major SIN activator, so that SIN signaling is delayed. How this checkpoint is silenced once spindle defects are resolved has not been clear. Here we establish that Dma1 transiently leaves SPBs during anaphase B due to extensive autoubiquitination. The SIN is required for Dma1 to return to SPBs later in anaphase. Blocking Dma1 removal from SPBs by permanently tethering it to Sid4 prevents SIN activation and cytokinesis. Therefore, controlling Dma1’s SPB dynamics in anaphase is an essential step in S. pombe cell division and the silencing of the Dma1-dependent mitotic checkpoint.

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Pcp1/pericentrin controls the SPB number in fission yeast meiosis and ploidy homeostasis

The Journal of Cell Biology ◽

10.1083/jcb.202104099 ◽

2021 ◽

Vol 221 (1) ◽

Author(s):

Qian Zhu ◽

Zhaodi Jiang ◽

Xiangwei He

Keyword(s):

Cell Division ◽

Sexual Reproduction ◽

Schizosaccharomyces Pombe ◽

Fission Yeast ◽

Spindle Pole Body ◽

Spindle Pole ◽

Bipolar Spindle ◽

Pole Body ◽

Yeast Meiosis ◽

Quantity Control

During sexual reproduction, the zygote must inherit exactly one centrosome (spindle pole body [SPB] in yeasts) from the gametes, which then duplicates and assembles a bipolar spindle that supports the subsequent cell division. Here, we show that in the fission yeast Schizosaccharomyces pombe, the fusion of SPBs from the gametes is blocked in polyploid zygotes. As a result, the polyploid zygotes cannot proliferate mitotically and frequently form supernumerary SPBs during subsequent meiosis, which leads to multipolar nuclear divisions and the generation of extra spores. The blockage of SPB fusion is caused by persistent SPB localization of Pcp1, which, in normal diploid zygotic meiosis, exhibits a dynamic association with the SPB. Artificially induced constitutive localization of Pcp1 on the SPB is sufficient to cause blockage of SPB fusion and formation of extra spores in diploids. Thus, Pcp1-dependent SPB quantity control is crucial for sexual reproduction and ploidy homeostasis in fission yeast.

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Faculty Opinions recommendation of Aurora promotes cell division during recovery from TOR-mediated cell cycle arrest by driving spindle pole body recruitment of Polo.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.13471956.14851055 ◽

2012 ◽

Author(s):

Christopher McInerny

Keyword(s):

Cell Cycle ◽

Cell Division ◽

Cell Cycle Arrest ◽

Spindle Pole Body ◽

Spindle Pole ◽

Cycle Arrest ◽

Pole Body

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Faculty Opinions recommendation of Fission yeast Myo51 is a meiotic spindle pole body component with discrete roles during cell fusion and spore formation.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.2137023.1737135 ◽

2010 ◽

Author(s):

Christopher McInerny

Keyword(s):

Fission Yeast ◽

Cell Fusion ◽

Spindle Pole Body ◽

Spindle Pole ◽

Spore Formation ◽

Meiotic Spindle ◽

Pole Body ◽

Body Component

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Distinct nuclear and spindle pole body populations of cyclin–cdc2 in fission yeast

Nature ◽

10.1038/347680a0 ◽

1990 ◽

Vol 347 (6294) ◽

pp. 680-682 ◽

Cited By ~ 110

Author(s):

Caroline E. Alfa ◽

Bernard Ducommun ◽

David Beach ◽

Jeremy S. Hyams

Keyword(s):

Fission Yeast ◽

Spindle Pole Body ◽

Spindle Pole ◽

Pole Body

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The Fission Yeast Homolog of the Human Transcription Factor EAP30 Blocks Meiotic Spindle Pole Body Amplification

Developmental Cell ◽

10.1016/j.devcel.2005.04.016 ◽

2005 ◽

Vol 9 (1) ◽

pp. 63-73 ◽

Cited By ~ 20

Author(s):

Ye Jin ◽

Joel J. Mancuso ◽

Satoru Uzawa ◽

Daniela Cronembold ◽

W. Zacheus Cande

Keyword(s):

Transcription Factor ◽

Fission Yeast ◽

Spindle Pole Body ◽

Spindle Pole ◽

Meiotic Spindle ◽

Pole Body ◽

Yeast Homolog ◽

Human Transcription Factor

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A microtubule polymerase cooperates with the kinesin-6 motor and a microtubule cross-linker to promote bipolar spindle assembly in the absence of kinesin-5 and kinesin-14 in fission yeast

Molecular Biology of the Cell ◽

10.1091/mbc.e17-08-0497 ◽

2017 ◽

Vol 28 (25) ◽

pp. 3647-3659 ◽

Cited By ~ 23

Author(s):

Masashi Yukawa ◽

Tomoki Kawakami ◽

Masaki Okazaki ◽

Kazunori Kume ◽

Ngang Heok Tang ◽

...

Keyword(s):

Fission Yeast ◽

Chromosome Segregation ◽

Spindle Pole Body ◽

Spindle Assembly ◽

Spindle Pole ◽

Temperature Sensitive ◽

Bipolar Spindle ◽

Pole Body ◽

Cross Linker ◽

Spindle Elongation

Accurate chromosome segregation relies on the bipolar mitotic spindle. In many eukaryotes, spindle formation is driven by the plus-end–directed motor kinesin-5 that generates outward force to establish spindle bipolarity. Its inhibition leads to the emergence of monopolar spindles with mitotic arrest. Intriguingly, simultaneous inactivation of the minus-end–directed motor kinesin-14 restores spindle bipolarity in many systems. Here we show that in fission yeast, three independent pathways contribute to spindle bipolarity in the absence of kinesin-5/Cut7 and kinesin-14/Pkl1. One is kinesin-6/Klp9 that engages with spindle elongation once short bipolar spindles assemble. Klp9 also ensures the medial positioning of anaphase spindles to prevent unequal chromosome segregation. Another is the Alp7/TACC-Alp14/TOG microtubule polymerase complex. Temperature-sensitive alp7cut7pkl1 mutants are arrested with either monopolar or very short spindles. Forced targeting of Alp14 to the spindle pole body is sufficient to render alp7cut7pkl1 triply deleted cells viable and promote spindle assembly, indicating that Alp14-mediated microtubule polymerization from the nuclear face of the spindle pole body could generate outward force in place of Cut7 during early mitosis. The third pathway involves the Ase1/PRC1 microtubule cross-linker that stabilizes antiparallel microtubules. Our study, therefore, unveils multifaceted interplay among kinesin-dependent and -independent pathways leading to mitotic bipolar spindle assembly.

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