bims-micesi Biomed News
on Mitotic cell signalling
Issue of 2025–06–01
ten papers selected by
Valentina Piano, Uniklinik Köln
  1. Unveiling an Arpp-19 phosphorylation switch that grants chromosome stability.
  2. Controlled Exit from the G2/M Checkpoint in RPE-1 Cells Using RO3306: Enrichment of Phase-Specific Cell Populations for In-Depth Analyses of Mitotic Events.
  3. Palmitoylated importin α regulates mitotic spindle orientation through interaction with NuMA.
  4. Mitotic Shake-Off and Cell Cycle Synchronization.
  5. Force transmission through the inner kinetochore is enhanced by centromeric DNA sequences.
  6. Parthenolide disrupts mitosis by inhibiting ZNF207/BUGZ-promoted kinetochore-microtubule attachment.
  7. Two cancer cell lines utilize Myosin 10 and the kinesin HSET differentially to maintain mitotic spindle bipolarity.
  8. TRIM37 prevents ectopic spindle pole assembly by peptide motif recognition and substrate-dependent oligomerization.
  9. Mitotic signalling in progenitor cells: Integrating cell division with cell specification.
  10. Eukaryotic Centromere Remodeling: Plasticity, Dynamics, and Holocentromere Formation.
  1. Commun Biol. 2025 May 30. 8(1): 841
    Unveiling an Arpp-19 phosphorylation switch that grants chromosome stability.
    Angela Flavia Serpico, Caterina Pisauro, Asia Trano, Domenico Grieco.
      During cell division, the onset of mitosis is granted by activation of cyclin B-dependent kinase 1 (Cdk1), master mitotic kinase, coordinated with inactivation of Cdk1-counteracting phosphatases. PP2A-B55, a major of these phosphatases, is inhibited in mitosis by Arpp-19 and Ensa, two very similar proteins, once phosphorylated by the Cdk1-stimulated kinase Greatwall (Gwl). We show here that Arpp-19 is also phosphorylated in a Cdk1-dependent manner at serine 23, a site missing in mammalian Ensa, in mitotic human cells and dephosphorylated at this site during mitosis exit. Moreover, we found that this phosphorylation control grants chromosome stability since substituting endogenous Arpp-19 with a S23-Arpp-19 phosphorylation-resistant mutant increased the frequency of chromosome segregation errors and accelerated the timing of mitosis exit. Conversely, substitution with a S23-Arpp-19 phosphorylation-mimicking mutant delayed mitosis exit. S23-Arpp-19 dephosphorylation resisted to the potent PP2A inhibitor Okadaic Acid but required the phosphatase Fcp1. Our data unveil a phosphorylation switch that grants timely mitosis exit and chromosome stability.
    DOI:  https://doi.org/10.1038/s42003-025-08281-8
  2. Int J Mol Sci. 2025 May 21. pii: 4951. [Epub ahead of print]26(10):
    Controlled Exit from the G2/M Checkpoint in RPE-1 Cells Using RO3306: Enrichment of Phase-Specific Cell Populations for In-Depth Analyses of Mitotic Events.
    Teresa Anglada, Núria Pulido-Artola, Marina Rodriguez-Muñoz, Anna Genesca.
      Studying the cell cycle is essential for understanding the molecular mechanisms that regulate cell division, growth, and differentiation in living organisms. However, mitosis constitutes only a brief phase of the overall cell cycle, making its analysis challenging in asynchronous cell populations due to its transient and dynamic nature. Cell synchronization methods help to enrich populations at specific cell cycle stages, including mitosis, typically by using chemical inhibitors to arrest cells at defined checkpoints. However, many existing protocols rely on combinations of inhibitors that interfere with normal mitotic progression, disrupting dynamics and causing side effects such as chromosome non-disjunction or lagging chromosomes, which limit their applicability. In this study, we present an RO3306 block-and-release strategy to selectively enrich cell populations at defined mitotic stages without compromising cell viability or disrupting their progression to mitotic exit. This approach provides a reliable method for studying mitotic events with high temporal resolution. Furthermore, by preserving mitotic integrity, it offers a valuable framework for investigating the molecular mechanisms of cell division and the processes driving genomic instability in human cells.
    Keywords:  RO3306; cell cycle; cell division; mitosis; synchronization
    DOI:  https://doi.org/10.3390/ijms26104951
  3. EMBO Rep. 2025 May 27.
    Palmitoylated importin α regulates mitotic spindle orientation through interaction with NuMA.
    Patrick James Sutton, Natalie Mosqueda, Christopher W Brownlee.
      Regulation of cell division orientation is a fundamental process critical to differentiation and tissue homeostasis. Microtubules emanating from the mitotic spindle pole bind a conserved complex of proteins at the cell cortex which orients the spindle and ultimately the cell division plane. Control of spindle orientation is of particular importance in developing tissues, such as the developing brain. Misorientation of the mitotic spindle and thus subsequent division plane misalignment can contribute to improper segregation of cell fate determinants in developing neuroblasts, leading to a rare neurological disorder known as microcephaly. We demonstrate that the nuclear transport protein importin α, when palmitoylated, plays a critical role in mitotic spindle orientation through localizing factors, such as NuMA, to the cell cortex. We also observe craniofacial developmental defects in Xenopus laevis when importin α palmitoylation is abrogated, including smaller head and brains, a hallmark of spindle misorientation and microcephaly. These findings characterize not only a role for importin α in spindle orientation, but also a broader role for importin α palmitoylation which has significance for many cellular processes.
    Keywords:  Importin α; Microcephaly; NuMA; Palmitoylation; Spindle Orientation
    DOI:  https://doi.org/10.1038/s44319-025-00484-8
  4. Methods Mol Biol. 2025 ;2933 81-85
    Mitotic Shake-Off and Cell Cycle Synchronization.
    Takamitsu A Kato.
      The mitotic shake-off method is a laboratory technique used to isolate cells that are actively undergoing mitosis from a population of cells in culture. During mitosis, cells undergo a series of characteristic changes. After the cells have been induced to enter mitosis, they are gently dislodged from the culture vessel using a mild mechanical agitation technique, such as shaking or tapping. Since cells in mitosis typically round up and detach from the substrate as they prepare to divide, they are more easily released from the culture surface compared to cells in other phases of the cell cycle. Those isolated mitotic cells can be transferred to other cell culture vessels to release cell cycle progression. Mitotic cells go through next cell cycle phases with time. Using this method, cell cycle-dependent cellular activity such as cell cycle-specific protein expression and activation, and cell cycle-specific sensitivity to agents, can be carried out. Since this method is completely drug free, it has series of benefits including no drug cost and no potential toxicity from drug exposure. This chapter introduces cellular synchronization technique by mitotic shake-off method.
    Keywords:  Cell cycle; Mitotic shake-off; Radiosensitivity; Synchronization
    DOI:  https://doi.org/10.1007/978-1-0716-4574-1_11
  5. Elife. 2025 May 29. pii: RP105150. [Epub ahead of print]14
    Force transmission through the inner kinetochore is enhanced by centromeric DNA sequences.
    Elise Miedlar, Grace E Hamilton, Samuel R Witus, Sara J Gonske, Michael Riffle, Alex Zelter, Rachel E Klevit, Charles L Asbury, Yoana N Dimitrova, Trisha N Davis.
      Previously, we reconstituted a minimal functional kinetochore from recombinant Saccharomyces cerevisiae proteins that was capable of transmitting force from dynamic microtubules to nucleosomes containing the centromere-specific histone variant Cse4 (Hamilton et al., 2020). This work revealed two paths of force transmission through the inner kinetochore: through Mif2 and through the Okp1/Ame1 complex (OA). Here, using a chimeric DNA sequence that contains crucial centromere-determining elements of the budding yeast point centromere, we demonstrate that the presence of centromeric DNA sequences in Cse4-containing nucleosomes significantly strengthens OA-mediated linkages. Our findings indicate that centromeric sequences are important for the transmission of microtubule-based forces to the chromosome.
    Keywords:  S. cerevisiae; cell biology; centromere; kinetochore; microtubule; mitosis; nucleosome; tension
    DOI:  https://doi.org/10.7554/eLife.105150
  6. EMBO J. 2025 May 27.
    Parthenolide disrupts mitosis by inhibiting ZNF207/BUGZ-promoted kinetochore-microtubule attachment.
    Susana Eibes, R Bhagya Lakshmi, Girish Rajendraprasad, Brian T Weinert, Fadhil S Kamounah, Luke F Gamon, Sergi Rodriguez-Calado, Morten Meldal, Michael J Davies, Michael Pittelkow, Chunaram Choudhary, Marin Barisic.
      Parthenolide is a natural compound that has shown highly promising anticancer activity. Even though its mode of action has been studied for decades, its antimitotic activity has been largely overlooked, limiting the understanding of its full anticancer potential. In this study, we combined click-chemistry with quantitative mass spectrometry and cell biology to elucidate the mechanism of action of parthenolide in mitosis. We show that parthenolide does not act as a microtubule-targeting agent in cells. Instead, it binds to the kinetochore protein ZNF207/BUGZ, preventing the establishment of proper kinetochore-microtubule attachment. Our results show that parthenolide covalently binds to Cys54 of BUGZ via Michael addition to its α-methylene-γ-lactone moiety. Since Cys54 is located within the second zinc-finger domain of the BUGZ microtubule-targeting region, we propose that parthenolide interferes with the microtubule-binding ability of BUGZ, consequently preventing kinetochore-microtubule attachments required for accurate chromosome congression to the spindle equator.
    Keywords:  BUGZ; Kinetochore; Microtubules; Mitosis; Parthenolide
    DOI:  https://doi.org/10.1038/s44318-025-00469-2
  7. PLoS One. 2025 ;20(5): e0325016
    Two cancer cell lines utilize Myosin 10 and the kinesin HSET differentially to maintain mitotic spindle bipolarity.
    Yang-In Yim, Xufeng Wu, Anjelika Gasilina, John A Hammer.
      Cancer cells often undergo mitosis possessing more than two centrosomes. To avoid a multipolar mitosis, the consequences of which are typically aneuploidy induced senescence, they must cluster their extra centrosomes to create a pseudo-bipolar spindle. Such supernumerary centrosome clustering (SNCC) requires Myosin 10 (Myo10) and the pole-focusing kinesin HSET. We showed recently that Myo10 promotes SNCC in HeLa cells by promoting retraction fiber-based cell adhesion, and that it further supports spindle bipolarity by preventing the generation of extra spindle poles via pericentriolar material (PCM) fragmentation. Here we quantified the contribution that Myo10 and HSET make individually and together to SNCC and PCM/pole integrity in HeLa cells and in MDA-MB-231 cells, which differ from HeLa in being more dependent on SNCC and less dependent on retraction fiber-based cell adhesion. As expected, knockdown of Myo10 and HSET individually increased the frequency of multipolar spindles in both cell types. Their effects were surprisingly not additive, however. For HeLa and MDA-MB-231 cells undergoing mitosis with more than two centrosomes, the defect in SNCC was almost entirely responsible for their multipolar phenotype following knockdown of either Myo10 or HSET. For HeLa and MDA-MB-231 cells undergoing mitosis with two centrosomes, PCM/pole fragmentation was the primary cause of multipolar spindles following HSET knockdown. Unlike HeLa, however, MDA-MB-231 cells exhibited very little PCM/pole fragmentation following Myo10 knockdown. This difference may be due to the smaller role that Myo10 plays in retraction fiber-based adhesion in MDA-MB-231. Finally, we show that HSET knockdown disrupts retraction fiber formation and organization, which may explain why the defects in double knockdown cells were not significantly greater than in HSET knockdown cells. These and other results can inform efforts to target these two motor proteins to selectively kill cancer cells by increasing their frequency of multipolar divisions.
    DOI:  https://doi.org/10.1371/journal.pone.0325016
  8. Nat Struct Mol Biol. 2025 May 25.
    TRIM37 prevents ectopic spindle pole assembly by peptide motif recognition and substrate-dependent oligomerization.
    Andrew Bellaart, Amanda Brambila, Jiawei Xu, Francisco Mendez Diaz, Amar Deep, John Anzola, Franz Meitinger, Midori Ohta, Kevin D Corbett, Arshad Desai, Karen Oegema.
      Tightly controlled duplication of centrosomes, the primary microtubule-organizing centers of animal cells, ensures bipolarity of the mitotic spindle and accurate chromosome segregation. The RING-B-box-coiled coil ubiquitin ligase tripartite motif-containing protein 37 (TRIM37), whose loss is associated with elevated chromosome missegregation and the tumor-prone human developmental disorder Mulibrey nanism, prevents the formation of ectopic spindle poles assembling around structured condensates that contain the centrosomal protein centrobin. Here, we show that TRIM37's tumor necrosis factor receptor-associated factor (TRAF) domain, which is unique in the extended TRIM family, engages peptide motifs in centrobin to suppress condensate formation. TRIM family proteins form antiparallel coiled-coil dimers with RING-B-box domains at each end. Oligomerization resulting from RING-RING interactions and conformational regulation through B-box 2-B-box 2 interfaces are essential for TRIM37 to suppress centrobin condensate formation. These results indicate that, similar to antiviral TRIM ligases, TRIM37 activation is coupled to detection of oligomerized substrates, facilitated by recognition of specific motifs in the substrate, to enforce ubiquitination-mediated clearance of ectopic centrosomal protein assemblies.
    DOI:  https://doi.org/10.1038/s41594-025-01562-0
  9. Curr Opin Cell Biol. 2025 May 27. pii: S0955-0674(25)00080-8. [Epub ahead of print]95 102542
    Mitotic signalling in progenitor cells: Integrating cell division with cell specification.
    Torcato Martins, Yuu Kimata.
      Mitotic signalling mediated by cell cycle regulators (CCRs) is pivotal for coordinating cell division and fate specification across metazoans. CCRs, including cyclin-dependent kinases and ubiquitin ligases, use post-translational modifications for rapid, dynamic regulation of the cell cycle, ensuring its unidirectionality and integration with fate determination. This review explores recent findings that further elucidate CCRs' noncanonical functions, particularly in progenitor cells. Advancements in quantitative in vivo imaging, precise genome editing, and single-cell omics have provided unprecedented spatiotemporal resolution into the mechanisms through which CCRs regulate asymmetric cell division, epigenetic regulation, and cell cycle variations. The evolution of CCRs underscores their crucial role in integrating cellular and developmental signals in multicellular organisms, with implications for disease and therapeutic strategies.
    DOI:  https://doi.org/10.1016/j.ceb.2025.102542
  10. Plant Cell Environ. 2025 May 27.
    Eukaryotic Centromere Remodeling: Plasticity, Dynamics, and Holocentromere Formation.
    Dan Yang, Zhaoxin Xiao, Ke Li, Jiayi Hou, Fengfeng Zhang, Jianjun Qiao, Ning Li, Mingzhang Wen.
      Eukaryotic centromeres highlight the remarkable plasticity of eukaryotic chromosomes through their conserved functionality and sequence divergence. Holocentric chromosomes, where centromere activity is distributed along the entire chromosome length, offer a unique model for investigating the molecular mechanisms underlying adaptive evolution between centromeres and chromosomes. In this review, we summarise and speculate on the multiple changes and prerequisites potentially involved in the evolution of holocentromeres. The interplay between environmental factors, chromosomal rearrangements, and centromere plasticity drives the transition from regional to holocentric characteristics. The centromeric histone H3 (CenH3) protein mediates neocentromere formation by recognising non-centromeric chromosomal regions with appropriate AT content, thereby facilitating chromosome restructuring in the transition from regional to holocentric chromosomes. Dynamic changes in repetitive sequences provide functional sites for centromere assembly, chromosomal recombination and repair and centromere spreading and maturation. Epigenetic modifications maintain functional coordination among multiple centromeric units by modulating chromatin states, CenH3 localisation, and kinetochore assembly. This review provides a comprehensive framework for understanding the evolutionary mechanisms of holocentromeres derived from monocentromere and offers insights into the design of artificial centromeres.
    Keywords:  centromere; holocentromere; plasticity; remodelling
    DOI:  https://doi.org/10.1111/pce.15652
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