scholarly journals The centriole protein CEP76 negatively regulates PLK1 activity in the cytoplasm for proper mitotic progression

2020 ◽  
Vol 133 (19) ◽  
pp. jcs241281 ◽  
Author(s):  
Yutaka Takeda ◽  
Kaho Yamazaki ◽  
Kaho Hashimoto ◽  
Koki Watanabe ◽  
Takumi Chinen ◽  
...  
Keyword(s):  
Kinase Activity ◽  
Rnai Screen ◽  
Human Cells ◽  
Spindle Orientation ◽  
First Person ◽  
Mitotic Progression ◽  
Strict Control ◽  
Mitotic Delay ◽  
Similar Phenotype

ABSTRACTPolo-like kinase 1 (PLK1) dynamically changes its localization and plays important roles in proper mitotic progression. In particular, strict control of cytoplasmic PLK1 is needed to prevent mitotic defects. However, the regulation of cytoplasmic PLK1 is not fully understood. In this study, we show that CEP76, a centriolar protein, physically interacts with PLK1 and tightly controls the activation of cytoplasmic PLK1 during mitosis in human cells. We found that removal of centrosomes induced ectopic aggregation of PLK1, which is highly phosphorylated, in the cytoplasm during mitosis. Importantly, a targeted RNAi screen revealed that depletion of CEP76 resulted in a similar phenotype. In addition, depletion of CEP76 caused defective spindle orientation and mitotic delay. Moreover, the formation of ectopic PLK1 aggregates and defective spindle orientation were significantly suppressed by the inhibition of PLK1 kinase activity. Overall, these results demonstrate that CEP76 suppresses the aberrant activation of cytoplasmic PLK1 for proper mitotic progression.This article has an associated First Person interview with the first author of the paper.

scholarly journals Fcp1 phosphatase controls Greatwall kinase to promote PP2A-B55 activation and mitotic progression

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Rosa Della Monica ◽  
Roberta Visconti ◽  
Nando Cervone ◽  
Angela Flavia Serpico ◽  
Domenico Grieco
Keyword(s):  
Cell Division ◽  
Protein Phosphorylation ◽  
Kinase Activity ◽  
Protein Phosphatases ◽  
Human Cells ◽  
Cyclin B ◽  
Major Protein ◽  
Phosphorylation Sites ◽  
Mitotic Progression ◽  
Greatwall Kinase

During cell division, progression through mitosis is driven by a protein phosphorylation wave. This wave namely depends on an activation-inactivation cycle of cyclin B-dependent kinase (Cdk) 1 while activities of major protein phosphatases, like PP1 and PP2A, appear directly or indirectly repressed by Cdk1. However, how Cdk1 inactivation is coordinated with reactivation of major phosphatases at mitosis exit still lacks substantial knowledge. We show here that activation of PP2A-B55, a major mitosis exit phosphatase, required the phosphatase Fcp1 downstream Cdk1 inactivation in human cells. During mitosis exit, Fcp1 bound Greatwall (Gwl), a Cdk1-stimulated kinase that phosphorylates Ensa/ARPP19 and converts these proteins into potent PP2A-B55 inhibitors during mitosis onset, and dephosphorylated it at Cdk1 phosphorylation sites. Fcp1-catalyzed dephosphorylation drastically reduced Gwl kinase activity towards Ensa/ARPP19 promoting PP2A-B55 activation. Thus, Fcp1 coordinates Cdk1 and Gwl inactivation to derepress PP2A-B55, generating a dephosphorylation switch that drives mitosis progression.

scholarly journals Human Bubr1 Is a Mitotic Checkpoint Kinase That Monitors Cenp-E Functions at Kinetochores and Binds the Cyclosome/APC

1999 ◽  
Vol 146 (5) ◽  
pp. 941-954 ◽  
Author(s):  
G.K.T. Chan ◽  
S.A. Jablonski ◽  
V. Sudakin ◽  
J.C. Hittle ◽  
T.J. Yen
Keyword(s):  
Cell Cycle ◽  
Kinase Activity ◽  
Mitotic Checkpoint ◽  
Human Cells ◽  
Anaphase Promoting Complex ◽  
Mitotic Progression ◽  
Checkpoint Kinase ◽  
Microtubule Inhibitors ◽  
Interphase Cells ◽  
Combined Data

Human cells express two kinases that are related to the yeast mitotic checkpoint kinase BUB1. hBUB1 and hBUBR1 bind to kinetochores where they are postulated to be components of the mitotic checkpoint that monitors kinetochore activities to determine if chromosomes have achieved alignment at the spindle equator (Jablonski, S.A., G.K.T. Chan, C.A. Cooke, W.C. Earnshaw, and T.J. Yen. 1998. Chromosoma. 107:386–396). In support of this, hBUB1 and the homologous mouse BUB1 have been shown to be important for the mitotic checkpoint (Cahill, D.P., C. Lengauer, J. Yu, G.J. Riggins, J.K. Willson, S.D. Markowitz, K.W. Kinzler, and B. Vogelstein. 1998. Nature. 392:300–303; Taylor, S.S., and F. McKeon. 1997. Cell. 89:727–735). We now demonstrate that hBUBR1 is also an essential component of the mitotic checkpoint. hBUBR1 is required by cells that are exposed to microtubule inhibitors to arrest in mitosis. Additionally, hBUBR1 is essential for normal mitotic progression as it prevents cells from prematurely entering anaphase. We establish that one of hBUBR1's checkpoint functions is to monitor kinetochore activities that depend on the kinetochore motor CENP-E. hBUBR1 is expressed throughout the cell cycle, but its kinase activity is detected after cells have entered mitosis. hBUBR1 kinase activity was rapidly stimulated when the spindle was disrupted in mitotic cells. Finally, hBUBR1 was associated with the cyclosome/anaphase-promoting complex (APC) in mitotically arrested cells but not in interphase cells. The combined data indicate that hBUBR1 can potentially provide two checkpoint functions by monitoring CENP-E–dependent activities at the kinetochore and regulating cyclosome/APC activity.

scholarly journals Fighting tubulin-targeting anticancer drug toxicity and resistance

2017 ◽  
Vol 24 (9) ◽  
pp. T107-T117 ◽  
Author(s):  
Roberta Visconti ◽  
Domenico Grieco
Keyword(s):  
Drug Toxicity ◽  
Kinase Activity ◽  
Triple Negative ◽  
Molecular Targets ◽  
Vinca Alkaloids ◽  
Drug Resistant ◽  
Castration Resistant Prostate Cancer ◽  
Mitotic Progression ◽  
Castration Resistant

Tubulin-targeting drugs, like taxanes and vinca alkaloids, are among the most effective anticancer therapeutics used in the clinic today. Specifically, anti-microtubule cancer drugs (AMCDs) have proven to be effective in the treatment of castration-resistant prostate cancer and triple-negative breast cancer. AMCDs, however, have limiting toxicities that include neutropenia and neurotoxicity, and, in addition, tumor cells can become resistant to the drugs after long-term use. Co-targeting mitotic progression/slippage with inhibition of the protein kinases WEE1 and MYT1 that regulate CDK1 kinase activity may improve AMCD efficacy, reducing the acquisition of resistance by the tumor and side effects from the drug and/or its vehicle. Other possible treatments that improve outcomes in the clinic for these two drug-resistant cancers, including new formulations of the AMCDs and pursuing different molecular targets, will be discussed.

scholarly journals Bimodal Interaction of Mammalian Polo-Like Kinase 1 and a Centrosomal Scaffold, Cep192, in the Regulation of Bipolar Spindle Formation

2015 ◽  
Vol 35 (15) ◽  
pp. 2626-2640 ◽  
Author(s):  
Lingjun Meng ◽  
Jung-Eun Park ◽  
Tae-Sung Kim ◽  
Eun Hye Lee ◽  
Suk-Youl Park ◽  
...  
Keyword(s):  
Xenopus Laevis ◽  
Spindle Assembly ◽  
Human Cells ◽  
Mitotic Progression ◽  
Spindle Formation ◽  
Content Type ◽  
Bipolar Spindle ◽  
Egg Extracts ◽  
Cultured Human Cells ◽  
Bipolar Spindles

Serving as microtubule-organizing centers, centrosomes play a key role in forming bipolar spindles. The mechanism of how centrosomes promote bipolar spindle assembly in various organisms remains largely unknown. A recent study withXenopus laevisegg extracts suggested that the Plk1 ortholog Plx1 interacts with the phospho-T46 (p-T46) motif ofXenopusCep192 (xCep192) to form an xCep192-mediated xAurA-Plx1 cascade that is critical for bipolar spindle formation. Here, we demonstrated that in cultured human cells, Cep192 recruits AurA and Plk1 in a cooperative manner, and this event is important for the reciprocal activation of AurA and Plk1. Strikingly, Plk1 interacted with Cep192 through either the p-T44 (analogous toXenopusp-T46) or the newly identified p-S995 motif via its C-terminal noncatalytic polo-box domain. The interaction between Plk1 and the p-T44 motif was prevalent in the presence of Cep192-bound AurA, whereas the interaction of Plk1 with the p-T995 motif was preferred in the absence of AurA binding. Notably, the loss of p-T44- and p-S995-dependent Cep192-Plk1 interactions induced an additive defect in recruiting Plk1 and γ-tubulin to centrosomes, which ultimately led to a failure in proper bipolar spindle formation and mitotic progression. Thus, we propose that Plk1 promotes centrosome-based bipolar spindle formation by forming two functionally nonredundant complexes with Cep192.

Centrosome cohesion is regulated by a balance of kinase and phosphatase activities

2001 ◽  
Vol 114 (20) ◽  
pp. 3749-3757 ◽  
Author(s):  
Patrick Meraldi ◽  
Erich A. Nigg
Keyword(s):  
Protein Phosphatase ◽  
Kinase Activity ◽  
Dominant Negative ◽  
Dominant Negative Mutant ◽  
Microtubule Depolymerization ◽  
Drug Induced ◽  
Microtubule Network ◽  
Similar Phenotype ◽  
Underlying Mechanisms

Centrosome cohesion and separation are regulated throughout the cell cycle, but the underlying mechanisms are not well understood. Since overexpression of a protein kinase, Nek2, is able to trigger centrosome splitting (the separation of parental centrioles), we have surveyed a panel of centrosome-associated kinases for their ability to induce a similar phenotype. Cdk2, in association with either cyclin A or E, was as effective as Nek2, but several other kinases tested did not significantly interfere with centrosome cohesion. Centrosome splitting could also be triggered by inhibition of phosphatases, and protein phosphatase 1α (PP1α) was identified as a likely physiological antagonist of Nek2. Furthermore, we have revisited the role of the microtubule network in the control of centrosome cohesion. We could confirm that microtubule depolymerization by nocodazole causes centrosome splitting. Surprisingly, however, this drug-induced splitting also required kinase activity and could specifically be suppressed by a dominant-negative mutant of Nek2. These studies highlight the importance of protein phosphorylation in the control of centrosome cohesion, and they point to Nek2 and PP1α as critical regulators of centrosome structure.

Isolation of proteins with kinase activity and related to pp60 src from human cells

1984 ◽  
Vol 121 (3) ◽  
pp. 779-787 ◽  
Author(s):  
Nadine Pavloff ◽  
Jean-Michel Biquard ◽  
Nicole Hanania ◽  
Marianne Semmel
Keyword(s):  
Kinase Activity ◽  
Human Cells

scholarly journals VX-680 Inhibits Aurora A and Aurora B Kinase Activity in Human Cells

Cell Cycle ◽  
2007 ◽  
Vol 6 (22) ◽  
pp. 2846-2854 ◽  
Author(s):  
Rebecca K. Tyler ◽  
Natalia Shpiro ◽  
Rodolfo Marquez ◽  
Patrick A. Eyers
Keyword(s):  
Kinase Activity ◽  
Human Cells ◽  
Aurora B ◽  
Aurora A ◽  
Aurora B Kinase

scholarly journals MISP regulates the IQGAP1/Cdc42 complex to collectively orchestrate spindle orientation and mitotic progression

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Barbara Vodicska ◽  
Berati Cerikan ◽  
Elmar Schiebel ◽  
Ingrid Hoffmann
Keyword(s):  
Spindle Orientation ◽  
Mitotic Progression
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