scholarly journals Physical and functional interactions between polo kinase and the spindle pole component Cut12 regulate mitotic commitment in S. pombe

2003 ◽  
Vol 17 (12) ◽  
pp. 1507-1523 ◽  
Author(s):  
F. H. MacIver
Keyword(s):  
Spindle Pole ◽  
Functional Interactions ◽  
Polo Kinase ◽  
Pole Component

scholarly journals Redistribution of centrosomal proteins by centromeres and Polo kinase controls nuclear envelope breakdown

2020 ◽  
Author(s):  
Andrew J. Bestul ◽  
Zulin Yu ◽  
Jay R. Unruh ◽  
Sue L. Jaspersen
Keyword(s):  
Nuclear Envelope ◽  
Spindle Pole Body ◽  
Spindle Pole ◽  
Ring Structure ◽  
Yeast Cells ◽  
Structured Illumination ◽  
Structured Illumination Microscopy ◽  
Spindle Formation ◽  
Nuclear Envelope Breakdown ◽  
Polo Kinase

AbstractProper mitotic progression in Schizosaccharomyces pombe requires partial nuclear envelope breakdown (NEBD) and insertion of the spindle pole body (SPB – yeast centrosome) to build the mitotic spindle. Linkage of the centromere to the SPB is vital to this process, but why that linkage is important is not well understood. Utilizing high-resolution structured illumination microscopy (SIM), we show that the conserved SUNprotein Sad1 and other SPB proteins redistribute during mitosis to form a ring complex around SPBs, which is a precursor for NEBD and spindle formation. Although the Polo kinase Plo1 is not necessary for Sad1 redistribution, it localizes to the SPB region connected to the centromere, and its activity is vital for SPB ring protein redistribution and for complete NEBD to allow for SPB insertion. Our results lead to a model in which centromere linkage to the SPB drives redistribution of Sad1 and Plo1 activation that in turn facilitate NEBD and spindle formation through building of an SPB ring structure.SummaryNuclear envelope breakdown is necessary for fission yeast cells to go through mitosis. Bestul et al. show that the SUN protein, Sad1, is vital in carrying out this breakdown and is regulated by the centromere and Polo kinase.

The spindle pole body plays a key role in controlling mitotic commitment in the fission yeast Schizosaccharomyces pombe

2008 ◽  
Vol 36 (5) ◽  
pp. 1097-1101 ◽  
Author(s):  
Iain M. Hagan
Keyword(s):  
Protein Kinase ◽  
Fission Yeast ◽  
Critical Role ◽  
Spindle Pole Body ◽  
Growth Control ◽  
Spindle Pole ◽  
Mitogen Activated Protein Kinase ◽  
Polo Kinase ◽  
Pole Body ◽  
Mitogen Activated Protein

Commitment to mitosis is regulated by a conserved protein kinase complex called MPF (mitosis-promoting factor). MPF activation triggers a positive-feedback loop that further promotes the activity of its activating phosphatase Cdc25 and is assumed to down-regulate the MPF-inhibitory kinase Wee1. Four protein kinases contribute to this amplification loop: MPF itself, Polo kinase, MAPK (mitogen-activated protein kinase) and Greatwall kinase. The fission yeast SPB (spindle pole body) component Cut12 plays a critical role in modulating mitotic commitment. In this review, I discuss the relationship between Cut12 and the fission yeast Polo kinase Plo1 in mitotic control. These results indicate that commitment to mitosis is co-ordinated by control networks on the spindle pole. I then describe how the Cut12/Plo1 control network links growth control signalling from TOR (target of rapamycin) and MAPK networks to the activation of MPF to regulate the timing of cell division.

scholarly journals A Mutational Analysis Identifies Three Functional Regions of the Spindle Pole Component Spc110p in Saccharomyces cerevisiae

1997 ◽  
Vol 8 (12) ◽  
pp. 2575-2590 ◽  
Author(s):  
Holly A. Sundberg ◽  
Trisha N. Davis
Keyword(s):  
Mutational Analysis ◽  
Spindle Pole Body ◽  
Coiled Coil ◽  
Spindle Pole ◽  
Amino Terminus ◽  
Temperature Sensitive ◽  
Functional Regions ◽  
Region I ◽  
Region Ii ◽  
Pole Component

The central coiled coil of the essential spindle pole component Spc110p spans the distance between the central and inner plaques of theSaccharomyces cerevisiae spindle pole body (SPB). The carboxy terminus of Spc110p, which binds calmodulin, resides at the central plaque, and the amino terminus resides at the inner plaque from which nuclear microtubules originate. To dissect the functions of Spc110p, we created temperature-sensitive mutations in the amino and carboxy termini. Analysis of the temperature-sensitivespc110 mutations and intragenic complementation analysis of the spc110 alleles defined three functional regions of Spc110p. Region I is located at the amino terminus. Region II is located at the carboxy-terminal end of the coiled coil, and region III is the previously defined calmodulin-binding site. Overexpression ofSPC98 suppresses the temperature sensitivity conferred by mutations in region I but not the phenotypes conferred by mutations in the other two regions, suggesting that the amino terminus of Spc110p is involved in an interaction with the γ-tubulin complex composed of Spc97p, Spc98p, and Tub4p. Mutations in region II lead to loss of SPB integrity during mitosis, suggesting that this region is required for the stable attachment of Spc110p to the central plaque. Our results strongly argue that Spc110p links the γ-tubulin complex to the central plaque of the SPB.

scholarly journals A novel mitotic spindle pole component that originates from the cytoplasm during prophase.

1986 ◽  
Vol 103 (5) ◽  
pp. 1863-1872 ◽  
Author(s):  
P R Sager ◽  
N L Rothfield ◽  
J M Oliver ◽  
R D Berlin
Keyword(s):  
Mitotic Spindle ◽  
Spindle Pole ◽  
Early Prophase ◽  
Microtubule Organizing Center ◽  
Spindle Poles ◽  
Interphase Cells ◽  
Organizing Center ◽  
Mitotic Spindle Pole ◽  
Pole Component

Several unique aspects of mitotic spindle formation have been revealed by investigation of an autoantibody present in the serum of a patient with the CREST (calcinosis, Raynaud's phenomenon, esophageal dysmotility, schlerodacytyly, and telangiectasias) syndrome. This antibody was previously shown to label at the spindle poles of metaphase and anaphase cells and to be absent from interphase cells. We show here that the serum stained discrete cytoplasmic foci in early prophase cells and only later localized to the spindle poles. The cytoplasmic distribution of the antigen was also seen in nocodazole-arrested cells and prophase cells in populations treated with taxol. In normal and taxol-treated cells, the microtubules appeared to emanate from the cytoplasmic foci and polar stain, and in cells released from nocodazole block, microtubules regrew from antigen-containing centers. This characteristic distribution suggests that the antigen is part of a microtubule organizing center. Thus, we propose that a prophase originating polar antigen functions in spindle pole organization as a coalescing microtubule organizing center that is present only during mitosis. Characterization of the serum showed reactions with multiple proteins at 115, 110, 50, 36, 30, and 28 kD. However, affinity-eluted antibody from the 115/110-kD bands was shown to specifically label the spindle pole and cytosolic foci in prophase cells.

scholarly journals Novel Functional Dissection of the Localization-Specific Roles of Budding Yeast Polo Kinase Cdc5p

2004 ◽  
Vol 24 (22) ◽  
pp. 9873-9886 ◽  
Author(s):  
Jung-Eun Park ◽  
Chong J. Park ◽  
Krisada Sakchaisri ◽  
Tatiana Karpova ◽  
Satoshi Asano ◽  
...  
Keyword(s):  
Budding Yeast ◽  
Spindle Pole Body ◽  
Kinase Domain ◽  
Spindle Pole ◽  
Mitotic Exit ◽  
Negative Regulator ◽  
Triple Mutant ◽  
Polo Kinase ◽  
Bud Neck ◽  
M Phase

ABSTRACT Budding yeast polo kinase Cdc5p localizes to the spindle pole body (SPB) and to the bud-neck and plays multiple roles during M-phase progression. To dissect localization-specific mitotic functions of Cdc5p, we tethered a localization-defective N-terminal kinase domain of Cdc5p (Cdc5pΔC) to the SPB or to the bud-neck with components specifically localizing to one of these sites and characterized these mutants in a cdc5Δ background. Characterization of a viable, SPB-localizing, CDC5ΔC-CNM67 mutant revealed that it is defective in timely degradation of Swe1p, a negative regulator of Cdc28p. Loss of BFA1, a negative regulator of mitotic exit, rescued the lethality of a neck-localizing CDC5ΔC-CDC12 or CDC5ΔC-CDC3 mutant but yielded severe defects in cytokinesis. These data suggest that the SPB-associated Cdc5p activity is critical for both mitotic exit and cytokinesis, whereas the bud neck-localized Cdc5p is required for proper Swe1p regulation. Interestingly, a cdc5Δ bfa1Δ swe1Δ triple mutant is viable but grows slowly, whereas cdc5Δ cells bearing both CDC5ΔC-CNM67 and CDC5ΔC-CDC12 grow well with only a mild cell cycle delay. Thus, SPB- and the bud-neck-localized Cdc5p control most of the critical Cdc5p functions and downregulation of Bfa1p and Swe1p at the respective locations are two critical factors that require Cdc5p.

scholarly journals Requirements and Reasons for Effective Inhibition of the Anaphase Promoting Complex Activator Cdh1

2010 ◽  
Vol 21 (6) ◽  
pp. 914-925 ◽  
Author(s):  
Jonathan A. Robbins ◽  
Frederick R. Cross
Keyword(s):  
Gene Dosage ◽  
Spindle Pole Body ◽  
Gene Replacement ◽  
Spindle Pole ◽  
Anaphase Promoting Complex ◽  
Regulatory Pathways ◽  
Endogenous Gene ◽  
Polo Kinase ◽  
Mitotic Cyclin ◽  
Cdk Phosphorylation

Anaphase promoting complex (APC)-Cdh1 targets multiple mitotic proteins for degradation upon exit from mitosis into G1; inhibitory phosphorylation of Cdh1 by cyclin-dependent kinase (CDK) and Polo kinase has been proposed to prevent the premature degradation of substrates in the ensuing cell cycle. Here, we demonstrate essentiality of CDK phosphorylation of Cdh1 in Saccharomyces cerevisiae by exact endogenous gene replacement of CDH1 with CDK-unphosphorylatable CDH1-m11; in contrast, neither Cdh1 polo kinase sites nor polo interaction motifs are required. CDH1-m11 cells arrest in the first cycle with replicated DNA and sustained polarized growth; most cells have monopolar spindles. Blocking proteolysis of the Cin8 kinesin in CDH1-m11 cells does not promote spindle pole body (SPB) separation. In contrast, expression of undegradable mitotic cyclin results in both SPB separation and the restoration of isotropic growth. A minority of CDH1-m11 cells arrest with short bipolar spindles that fail to progress to anaphase; this can be accounted for by a failure to accumulate Cdc20 and consequent failure to cleave cohesin. Bipolar spindle assembly in CDH1-m11 cells is strikingly sensitive to gene dosage of the stoichiometric Cdh1 inhibitor ACM1. Thus, different spindle-regulatory pathways have distinct sensitivities to Cdh1, and ACM1 may buffer essential CDK phosphorylation of Cdh1.

scholarly journals Requirement for the Budding Yeast Polo Kinase Cdc5 in Proper Microtubule Growth and Dynamics

2008 ◽  
Vol 7 (3) ◽  
pp. 444-453 ◽  
Author(s):  
Chong J. Park ◽  
Jung-Eun Park ◽  
Tatiana S. Karpova ◽  
Nak-Kyun Soung ◽  
Li-Rong Yu ◽  
...  
Keyword(s):  
Budding Yeast ◽  
Spindle Pole Body ◽  
Spindle Pole ◽  
Growth Defect ◽  
Temperature Sensitive ◽  
Independent Manner ◽  
Polo Kinase ◽  
Early Anaphase

ABSTRACT In many organisms, polo kinases appear to play multiple roles during M-phase progression. To provide new insights into the function of the budding yeast polo kinase Cdc5, we generated novel temperature-sensitive cdc5 mutants by mutagenizing the C-terminal noncatalytic polo box domain, a region that is critical for proper subcellular localization. One of these mutants, cdc5-11, exhibited a temperature-sensitive growth defect with an abnormal spindle morphology. Strikingly, provision of a moderate level of benomyl, a microtubule-depolymerizing drug, permitted cdc5-11 cells to grow significantly better than the isogenic CDC5 wild type in a FEAR (cdc Fourteen Early Anaphase Release)-independent manner. In addition, cdc5-11 required MAD2 for both cell growth and the benomyl-remedial phenotype. These results suggest that cdc5-11 is defective in proper spindle function. Consistent with this view, cdc5-11 exhibited abnormal spindle morphology, shorter spindle length, and delayed microtubule regrowth at the nonpermissive temperature. Overexpression of CDC5 moderately rescued the spc98-2 growth defect. Interestingly, both Cdc28 and Cdc5 were required for the proper modification of the spindle pole body components Nud1, Slk19, and Stu2 in vivo. They also phosphorylated these three proteins in vitro. Taken together, these observations suggest that concerted action of Cdc28 and Cdc5 on Nud1, Slk19, and Stu2 is important for proper spindle functions.

scholarly journals Yeast Mps1p Phosphorylates the Spindle Pole Component Spc110p in the N-terminal Domain

2001 ◽  
Vol 276 (21) ◽  
pp. 17958-17967 ◽  
Author(s):  
David B. Friedman ◽  
Joshua W. Kern ◽  
Brenda J. Huneycutt ◽  
Dani B. N. Vinh ◽  
Douglas K. Crawford ◽  
...  
Keyword(s):  
Spindle Pole ◽  
Terminal Domain ◽  
Pole Component

scholarly journals Role of Polo Kinase and Mid1p in Determining the Site of Cell Division in Fission Yeast

1998 ◽  
Vol 143 (6) ◽  
pp. 1603-1616 ◽  
Author(s):  
Jürg Bähler ◽  
Alexander B. Steever ◽  
Sally Wheatley ◽  
Yu-li Wang ◽  
John R. Pringle ◽  
...  
Keyword(s):  
Fission Yeast ◽  
Spindle Pole ◽  
Temperature Sensitive ◽  
Kinase Gene ◽  
Division Plane ◽  
Daughter Cells ◽  
Polo Kinase ◽  
Spindle Pole Bodies ◽  
Reduced Mobility ◽  
Mitotic Cells

The fission yeast Schizosaccharomyces pombe divides symmetrically using a medial F-actin– based contractile ring to produce equal-sized daughter cells. Mutants defective in two previously described genes, mid1 and pom1, frequently divide asymmetrically. Here we present the identification of three new temperature-sensitive mutants defective in localization of the division plane. All three mutants have mutations in the polo kinase gene, plo1, and show defects very similar to those of mid1 mutants in both the placement and organization of the medial ring. In both cases, ring formation is frequently initiated near the cell poles, indicating that Mid1p and Plo1p function in recruiting medial ring components to the cell center. It has been reported previously that during mitosis Mid1p becomes hyperphosphorylated and relocates from the nucleus to a medial ring. Here we show that Mid1p first forms a diffuse cortical band during spindle formation and then coalesces into a ring before anaphase. Plo1p is required for Mid1p to exit the nucleus and form a ring, and Pom1p is required for proper placement of the Mid1p ring. Upon overexpression of Plo1p, Mid1p exits the nucleus prematurely and displays a reduced mobility on gels similar to that of the hyperphosphorylated form observed previously in mitotic cells. Genetic and two-hybrid analyses suggest that Plo1p and Mid1p act in a common pathway distinct from that involving Pom1p. Plo1p localizes to the spindle pole bodies and spindles of mitotic cells and also to the medial ring at the time of its formation. Taken together, the data indicate that Plo1p plays a role in the positioning of division sites by regulating Mid1p. Given its previously known functions in mitosis and the timing of cytokinesis, Plo1p is thus implicated as a key molecule in the spatial and temporal coordination of cytokinesis with mitosis.

scholarly journals SPC72: a spindle pole component required for spindle orientation in the yeast Saccharomyces cerevisiae

1998 ◽  
Vol 111 (18) ◽  
pp. 2809-2818 ◽  
Author(s):  
S. Soues ◽  
I.R. Adams
Keyword(s):  
Cell Cycle ◽  
Spindle Pole Body ◽  
Coiled Coil ◽  
Spindle Pole ◽  
Spindle Orientation ◽  
Yeast Saccharomyces Cerevisiae ◽  
Spindle Positioning ◽  
Pole Body ◽  
Per Se ◽  
Pole Component

The monoclonal antibody 78H6 recognises an 85 kDa component of the yeast spindle pole body. Here we identify and characterise this component as Spc72p, the product of YAL047C. The sequence of SPC72 contains potential coiled-coil domains; its overexpression induced formation of large polymers that were strictly localised at the outer plaque and at the bridge of the spindle pole body. Immunoelectron microscopy confirmed that Spc72p was a component of these polymers. SPC72 was found to be non-essential for cell growth, but its deletion resulted in abnormal spindle positioning, aberrant nuclear migration and defective mating capability. Precisely, deletion of SPC72 resulted in a decreased number of astral microtubules: early in the cell cycle only few were detectable, and these were unattached to the spindle pole body in small-budded cells. Later in the cell cycle few, if any, remained, and they were unable to align the spindle properly. We conclude that Spc72p is not absolutely required for nucleation per se, but is needed for normal abundance and stability of astral microtubules.

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