Aurora-PLK1 cascades as key signaling modules in the regulation of mitosis

2018 ◽  
Vol 11 (543) ◽  
pp. eaar4195 ◽  
Author(s):  
Vladimir Joukov ◽  
Arcangela De Nicolo

Mitosis is controlled by reversible protein phosphorylation involving specific kinases and phosphatases. A handful of major mitotic protein kinases, such as the cyclin B–CDK1 complex, the Aurora kinases, and Polo-like kinase 1 (PLK1), cooperatively regulate distinct mitotic processes. Research has identified proteins and mechanisms that integrate these kinases into signaling cascades that guide essential mitotic events. These findings have important implications for our understanding of the mechanisms of mitotic regulation and may advance the development of novel antimitotic drugs. We review collected evidence that in vertebrates, the Aurora kinases serve as catalytic subunits of distinct complexes formed with the four scaffold proteins Bora, CEP192, INCENP, and TPX2, which we deem “core” Aurora cofactors. These complexes and the Aurora-PLK1 cascades organized by Bora, CEP192, and INCENP control crucial aspects of mitosis and all pathways of spindle assembly. We compare the mechanisms of Aurora activation in relation to the different spindle assembly pathways and draw a functional analogy between the CEP192 complex and the chromosomal passenger complex that may reflect the coevolution of centrosomes, kinetochores, and the actomyosin cleavage apparatus. We also analyze the roles and mechanisms of Aurora-PLK1 signaling in the cell and centrosome cycles and in the DNA damage response.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ana C. Henriques ◽  
Patrícia M. A. Silva ◽  
Bruno Sarmento ◽  
Hassan Bousbaa

AbstractAntimitotic drugs arrest cells in mitosis through chronic activation of the spindle assembly checkpoint (SAC), leading to cell death. However, drug-treated cancer cells can escape death by undergoing mitotic slippage, due to premature mitotic exit. Therefore, overcoming slippage issue is a promising chemotherapeutic strategy to improve the effectiveness of antimitotics. Here, we antagonized SAC silencing by knocking down the MAD2-binding protein p31comet, to delay mitotic slippage, and tracked cancer cells treated with the antimitotic drug paclitaxel, over 3 days live-cell time-lapse analysis. We found that in the absence of p31comet, the duration of mitotic block was increased in cells challenged with nanomolar concentrations of paclitaxel, leading to an additive effects in terms of cell death which was predominantly anticipated during the first mitosis. As accumulation of an apoptotic signal was suggested to prevent mitotic slippage, when we challenged p31comet-depleted mitotic-arrested cells with the apoptosis potentiator Navitoclax (previously called ABT-263), cell fate was shifted to accelerated post-mitotic death. We conclude that inhibition of SAC silencing is critical for enhancing the lethality of antimitotic drugs as well as that of therapeutic apoptosis-inducing small molecules, with distinct mechanisms. The study highlights the potential of p31comet as a target for antimitotic therapies.


2013 ◽  
Vol 60 (11) ◽  
pp. 1809-1816 ◽  
Author(s):  
Kleiton Silva Borges ◽  
Daniel Antunes Moreno ◽  
Carlos Eduardo Martinelli ◽  
Sonir Roberto Rauber Antonini ◽  
Margaret de Castro ◽  
...  

2012 ◽  
Vol 31 (6) ◽  
pp. 1467-1479 ◽  
Author(s):  
Teresa Rivera ◽  
Cristina Ghenoiu ◽  
Miriam Rodríguez-Corsino ◽  
Satoru Mochida ◽  
Hironori Funabiki ◽  
...  

2012 ◽  
Vol 34 (2) ◽  
pp. 436-445 ◽  
Author(s):  
Anna-Leena Salmela ◽  
Jeroen Pouwels ◽  
Jenni Mäki-Jouppila ◽  
Pekka Kohonen ◽  
Pauliina Toivonen ◽  
...  

2020 ◽  
Vol 31 (20) ◽  
pp. 2207-2218 ◽  
Author(s):  
Mary Kate Bonner ◽  
Julian Haase ◽  
Hayden Saunders ◽  
Hindol Gupta ◽  
Biyun Iris Li ◽  
...  

This study provides the molecular mechanism for the interaction of Sgo1 with the chromosomal passenger complex and explores the specific role of Sgo1 in regulating Aurora B functions that ensure the equal segregation of chromosomes.


Oncogene ◽  
2021 ◽  
Author(s):  
Lan Yu ◽  
Yue Lang ◽  
Ching-Cheng Hsu ◽  
Wei-Min Chen ◽  
Jui-Chung Chiang ◽  
...  

AbstractChromosomal instability (CIN) is a driving force for cancer development. The most common causes of CIN include the dysregulation of the spindle assembly checkpoint (SAC), which is a surveillance mechanism that prevents premature chromosome separation during mitosis by targeting anaphase-promoting complex/cyclosome (APC/C). DAB2IP is frequently silenced in advanced prostate cancer (PCa) and is associated with aggressive phenotypes of PCa. Our previous study showed that DAB2IP activates PLK1 and functions in mitotic regulation. Here, we report the novel mitotic phosphorylation of DAB2IP by Cdks, which mediates DAB2IP’s interaction with PLK1 and the activation of the PLK1-Mps1 pathway. DAB2IP interacts with Cdc20 in a phosphorylation-independent manner. However, the phosphorylation of DAB2IP inhibits the ubiquitylation of Cdc20 in response to SAC, and blocks the premature release of the APC/C-MCC. The PLK1-Mps1 pathway plays an important role in mitotic checkpoint complex (MCC) assembly. It is likely that DAB2IP acts as a scaffold to aid PLK1-Mps1 in targeting Cdc20. Depletion or loss of the Cdks-mediated phosphorylation of DAB2IP destabilizes the MCC, impairs the SAC, and increases chromosome missegregation and subsequent CIN, thus contributing to tumorigenesis. Collectively, these results demonstrate the mechanism of DAB2IP in SAC regulation and provide a rationale for targeting the SAC to cause lethal CIN against DAB2IP-deficient aggressive PCa, which exhibits a weak SAC.


2020 ◽  
Author(s):  
Janet K. Jang ◽  
Amy C. Gladstein ◽  
Arunika Das ◽  
Zachary L. Sisco ◽  
Kim S. McKim

AbstractMeiosis in female oocytes lack centrosomes, the major microtubule-organizing center, which makes them especially vulnerable to aneuploidy. In the acentrosomal oocytes of Drosophila, meiotic spindle assembly depends on the chromosomal passenger complex (CPC). Aurora B is the catalytic component of the CPC while the remaining subunits regulate its localization. Using an inhibitor of Aurora B activity, Binucleine 2, we found that continuous Aurora B activity is required to maintain the oocyte spindle during meiosis I, and this activity is antagonized by phosphatases acting on spindle associated proteins such as kinesins. Protein Phosphatase 2A (PP2A) exists in two varieties, B55 and B56. While both antagonize Aurora B, B55 has only minor roles in meiosis I spindle function. The B56 subunit is encoded by two partially redundant paralogs in the Drosophila genome, wdb and wrd. Knocking down both paralogs showed that the B56 subunit is critical for maintaining sister chromatid cohesion, establishing end-on microtubule attachments, and the metaphase I arrest in oocytes. We found that WDB recruitment to the centromeres depends on BUBR1, MEI-S332, and kinetochore protein SPC105R. While BUBR1 has been shown previously to stabilize microtubule attachments in Drosophila oocytes, only SPC105R is required for cohesion maintenance during meiosis I. We propose that SPC105R promotes cohesion maintenance by recruiting two proteins that recruit PP2A, MEI-S332, and the Soronin homolog Dalmatian.


2021 ◽  
Vol 478 (14) ◽  
pp. 2759-2774
Author(s):  
Henning Mühlenbeck ◽  
Kyle W. Bender ◽  
Cyril Zipfel

Reversible protein phosphorylation is a widespread post-translational modification fundamental for signaling across all domains of life. Tyrosine (Tyr) phosphorylation has recently emerged as being important for plant receptor kinase (RK)-mediated signaling, particularly during plant immunity. How Tyr phosphorylation regulates RK function is however largely unknown. Notably, the expansion of protein Tyr phosphatase and SH2 domain-containing protein families, which are the core of regulatory phospho-Tyr (pTyr) networks in choanozoans, did not occur in plants. Here, we summarize the current understanding of plant RK Tyr phosphorylation focusing on the critical role of a pTyr site (‘VIa-Tyr’) conserved in several plant RKs. Furthermore, we discuss the possibility of metazoan-like pTyr signaling modules in plants based on atypical components with convergent biochemical functions.


2008 ◽  
Vol 19 (5) ◽  
pp. 1873-1882 ◽  
Author(s):  
Liliana Torosantucci ◽  
Maria De Luca ◽  
Giulia Guarguaglini ◽  
Patrizia Lavia ◽  
Francesca Degrassi

Centrosomes are the major sites for microtubule nucleation in mammalian cells, although both chromatin- and kinetochore-mediated microtubule nucleation have been observed during spindle assembly. As yet, it is still unclear whether these pathways are coregulated, and the molecular requirements for microtubule nucleation at kinetochore are not fully understood. This work demonstrates that kinetochores are initial sites for microtubule nucleation during spindle reassembly after nocodazole. This process requires local RanGTP accumulation concomitant with delocalization from kinetochores of the hydrolysis factor RanGAP1. Kinetochore-driven microtubule nucleation is also activated after cold-induced microtubule disassembly when centrosome nucleation is impaired, e.g., after Polo-like kinase 1 depletion, indicating that dominant centrosome activity normally masks the kinetochore-driven pathway. In cells with unperturbed centrosome nucleation, defective RanGAP1 recruitment at kinetochores after treatment with the Crm1 inhibitor leptomycin B activates kinetochore microtubule nucleation after cold. Finally, nascent microtubules associate with the RanGTP-regulated microtubule-stabilizing protein HURP in both cold- and nocodazole-treated cells. These data support a model for spindle assembly in which RanGTP-dependent abundance of nucleation/stabilization factors at centrosomes and kinetochores orchestrates the contribution of the two spindle assembly pathways in mammalian cells. The complex of RanGTP, the export receptor Crm1, and nuclear export signal-bearing proteins regulates microtubule nucleation at kinetochores.


2009 ◽  
Vol 187 (1) ◽  
pp. 43-51 ◽  
Author(s):  
Christopher B. O'Connell ◽  
Jadranka Lončarek ◽  
Petr Kaláb ◽  
Alexey Khodjakov

During mitosis and meiosis in animal cells, chromosomes actively participate in spindle assembly by generating a gradient of Ran guanosine triphosphate (RanGTP). A high concentration of RanGTP promotes microtubule nucleation and stabilization in the vicinity of chromatin. However, the relative contributions of chromosome arms and centromeres/kinetochores in this process are not known. In this study, we address this issue using cells undergoing mitosis with unreplicated genomes (MUG). During MUG, chromatin is rapidly separated from the forming spindle, and both centrosomal and noncentrosomal spindle assembly pathways are active. MUG chromatin is coated with RCC1 and establishes a RanGTP gradient. However, a robust spindle forms around kinetochores/centromeres outside of the gradient peak. When stable kinetochore microtubule attachment is prevented by Nuf2 depletion in both MUG and normal mitosis, chromatin attracts astral microtubules but cannot induce spindle assembly. These results support a model in which kinetochores play the dominant role in the chromosome-mediated pathway of mitotic spindle assembly.


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