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

2014 ◽  
Vol 25 (18) ◽  
pp. 2735-2749 ◽  
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.

scholarly journals Intrinsic and Cyclin-dependent Kinase-dependent Control of Spindle Pole Body Duplication in Budding Yeast

2008 ◽  
Vol 19 (8) ◽  
pp. 3243-3253 ◽  
Author(s):  
Laura A. Simmons Kovacs ◽  
Christine L. Nelson ◽  
Steven B. Haase
Keyword(s):  
Cell Cycle ◽  
Budding Yeast ◽  
Spindle Pole Body ◽  
Spindle Pole ◽  
Cyclin Dependent Kinase ◽  
Multipolar Spindle ◽  
Cyclin Dependent Kinases ◽  
Pole Body ◽  
Intrinsic Mechanism ◽  
Mitotic Cyclin

Centrosome duplication must be tightly controlled so that duplication occurs only once each cell cycle. Accumulation of multiple centrosomes can result in the assembly of a multipolar spindle and lead to chromosome mis-segregation and genomic instability. In metazoans, a centrosome-intrinsic mechanism prevents reduplication until centriole disengagement. Mitotic cyclin/cyclin-dependent kinases (CDKs) prevent reduplication of the budding yeast centrosome, called a spindle pole body (SPB), in late S-phase and G2/M, but the mechanism remains unclear. How SPB reduplication is prevented early in the cell cycle is also not understood. Here we show that, similar to metazoans, an SPB-intrinsic mechanism prevents reduplication early in the cell cycle. We also show that mitotic cyclins can inhibit SPB duplication when expressed before satellite assembly in early G1, but not later in G1, after the satellite had assembled. Moreover, electron microscopy revealed that SPBs do not assemble a satellite in cells expressing Clb2 in early G1. Finally, we demonstrate that Clb2 must localize to the cytoplasm in order to inhibit SPB duplication, suggesting the possibility for direct CDK inhibition of satellite components. These two mechanisms, intrinsic and extrinsic control by CDK, evoke two-step system that prevents SPB reduplication throughout the cell cycle.

scholarly journals Translational control of MPS1 links protein synthesis with the initiation of cell division and spindle pole body duplication in yeast

2020 ◽  
Author(s):  
Heidi M. Blank ◽  
Annabel Alonso ◽  
Mark Winey ◽  
Michael Polymenis
Keyword(s):  
Cell Cycle ◽  
Protein Synthesis ◽  
Cell Division ◽  
Translational Control ◽  
Spindle Pole Body ◽  
Spindle Pole ◽  
Microtubule Organizing Center ◽  
Structured Illumination Microscopy ◽  
Couple Growth ◽  
Pole Body

ABSTRACTProtein synthesis underpins cell growth and controls when cells commit to a new round of cell division at a point in late G1 of the cell cycle called Start. Passage through Start also coincides with the duplication of the microtubule-organizing centers, the yeast spindle pole bodies, which will form the two poles of the mitotic spindle that segregates the chromosomes in mitosis. The conserved Mps1p kinase governs the duplication of the spindle pole body in Saccharomyces cerevisiae. Here, we show that the MPS1 transcript has a short upstream open reading frame that represses the synthesis of Mps1p. Mutating the MPS1 uORF makes the cells smaller, accelerates the appearance of Mps1p in late G1, and promotes completion of Start. The accelerated Start of MPS1 uORF mutants depends on the G1 cyclin Cln3p. Monitoring the spindle pole body in the cell cycle using structured illumination microscopy revealed that mutating the MPS1 uORF enabled cells to duplicate their spindle pole body earlier, at a smaller cell size. For the first time, these results identify growth inputs in mechanisms that control duplication of the microtubule-organizing center and implicate these processes in general mechanisms that couple growth with division.

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

1999 ◽  
Vol 10 (8) ◽  
pp. 2771-2785 ◽  
Author(s):  
Daniel P. Mulvihill ◽  
Janni Petersen ◽  
Hiroyuki Ohkura ◽  
David M. Glover ◽  
Iain M. Hagan
Keyword(s):  
Cell Division ◽  
Fission Yeast ◽  
Spindle Pole Body ◽  
Spindle Pole ◽  
Multiple Roles ◽  
Anaphase Promoting Complex ◽  
Pole Body ◽  
Early Anaphase ◽  
Anaphase B ◽  
Mitotic Event

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.

The Budding Yeast Cdc15 Localizes to the Spindle Pole Body in a Cell-Cycle-Dependent Manner

1999 ◽  
Vol 2 (3) ◽  
pp. 178-184 ◽  
Author(s):  
R. Cenamor ◽  
J. Jiménez ◽  
V.J. Cid ◽  
C. Nombela ◽  
M. Sánchez
Keyword(s):  
Cell Cycle ◽  
Budding Yeast ◽  
Spindle Pole Body ◽  
Spindle Pole ◽  
Dependent Manner ◽  
Pole Body ◽  
A Cell ◽  
Cycle Dependent

scholarly journals The N-terminus of Sfi1 and yeast centrin Cdc31 provide the assembly site for a new spindle pole body

2021 ◽  
Vol 220 (3) ◽  
Author(s):  
Diana Rüthnick ◽  
Jlenia Vitale ◽  
Annett Neuner ◽  
Elmar Schiebel
Keyword(s):  
Cell Cycle ◽  
Binding Sites ◽  
Binding Protein ◽  
Spindle Pole Body ◽  
Inhibitory Effect ◽  
Spindle Pole ◽  
Satellite Formation ◽  
Pole Body ◽  
N Terminus ◽  
Assembly Site

The spindle pole body (SPB) provides microtubule-organizing functions in yeast and duplicates exactly once per cell cycle. The first step in SPB duplication is the half-bridge to bridge conversion via the antiparallel dimerization of the centrin (Cdc31)-binding protein Sfi1 in anaphase. The bridge, which is anchored to the old SPB on the proximal end, exposes free Sfi1 N-termini (N-Sfi1) at its distal end. These free N-Sfi1 promote in G1 the assembly of the daughter SPB (dSPB) in a yet unclear manner. This study shows that N-Sfi1 including the first three Cdc31 binding sites interacts with the SPB components Spc29 and Spc42, triggering the assembly of the dSPB. Cdc31 binding to N-Sfi1 promotes Spc29 recruitment and is essential for satellite formation. Furthermore, phosphorylation of N-Sfi1 has an inhibitory effect and delays dSPB biogenesis until G1. Taking these data together, we provide an understanding of the initial steps in SPB assembly and describe a new function of Cdc31 in the recruitment of dSPB components.

Cell cycle control of spindle pole body duplication and splitting by Sfi1 and Cdc31 in fission yeast

2015 ◽  
Vol 128 (8) ◽  
pp. 1481-1493 ◽  
Author(s):  
I. B. Bouhlel ◽  
M. Ohta ◽  
A. Mayeux ◽  
N. Bordes ◽  
F. Dingli ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Fission Yeast ◽  
Cell Cycle Control ◽  
Spindle Pole Body ◽  
Spindle Pole ◽  
Pole Body

The fission yeast cut1+ gene regulates spindle pole body duplication and has homology to the budding yeast ESP1 gene

Cell ◽  
1990 ◽  
Vol 62 (5) ◽  
pp. 913-925 ◽  
Author(s):  
Satoru Uzawa ◽  
Itaru Samejima ◽  
Tatsuya Hirano ◽  
Kenji Tanaka ◽  
Mitsuhiro Yanagida
Keyword(s):  
Fission Yeast ◽  
Budding Yeast ◽  
Spindle Pole Body ◽  
Spindle Pole ◽  
Pole Body

Evidence for cell cycle-specific, spindle pole body-mediated, nuclear positioning in the fission yeast Schizosaccharomyces pombe

1997 ◽  
Vol 110 (16) ◽  
pp. 1851-1866 ◽  
Author(s):  
I. Hagan ◽  
M. Yanagida
Keyword(s):  
Cell Cycle ◽  
Fission Yeast ◽  
Spindle Pole Body ◽  
Spindle Pole ◽  
Nuclear Positioning ◽  
Central Location ◽  
Pole Body ◽  
Spindle Pole Bodies ◽  
A Cell ◽  
Multiple Spindle

Specific changes in spatial order occur during cell cycle progression in fission yeast. Growth of the rod-shaped cells is highly regulated and undergoes a cell cycle and size-regulated switch from monopolar to bipolar tip extension. During both phases of growth, the interphase nucleus is maintained in a central location. Following the separation of the genome to the cell tips in mitosis, the two nuclei migrate back towards the cell equator before stopping in two new positions that will become the middle of the two new cells. Here we use simultaneous labeling of microtubules, chromatin and spindle pole bodies in wild-type and cdc mutants, to show that nuclear positioning is achieved by regulation of spindle pole body-mediated nuclear migration. We show that the number and location of nuclear positioning signals is regulated in a cell cycle-specific manner and that spindle pole body-mediated forces are likely to be responsible for maintaining correct nuclear position once the nuclei have reached the appropriate position in the cell. Accentuating the movement of the nuclei back towards the cell equator after mitosis by artificially increasing cell length shows that the spindle pole body leads the nucleus during this migration. When multiple spindle pole bodies are associated with the same or different nuclei they all go to the same point indicating that the different spindle pole bodies are responding to the same positional cue. In a septation-defective mutant cell, which contains four nuclei, the spindle pole bodies on the four different nuclei initially group as two pairs in regions that would become the middle of the new cells, were the cell able to divide. In the subsequent interphase, the nuclei aggregate as a group of four in the centre of the cell. The presence of two or three clusters of spindle pole bodies in larger cells with eight nuclei suggests that the mechanisms specifying the normally central location for multiple nuclei may be unable to operate properly as the cells get larger. Perturbation of microtubules with the microtubule poison thiabendazole prevents the spindle pole body clustering in septation mutants, demonstrating that nuclear positioning requires a functional microtubule cytoskeleton.

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