bims-micesi Biomed News
on Mitotic cell signalling
Issue of 2023‒02‒19
34 papers selected by
Valentina Piano
Uniklinik Köln
  1. Distinct Aurora B pools at the inner centromere and kinetochore have different contributions to meiotic and mitotic chromosome segregation.
  2. TACC3-ch-TOG interaction regulates spindle microtubule assembly by controlling centrosomal recruitment of  γ-TuRC.
  3. Synergistic stabilization of microtubules by BUB-1, HCP-1 and CLS-2 controls microtubule pausing and meiotic spindle assembly.
  4. Plasmodium ARK2-EB1 axis drives the unconventional spindle dynamics, scaffold formation and chromosome segregation of sexual transmission stages.
  5. Interrelated effects of chromosome size, mechanics, number, location-orientation and polar ejection force on the spindle accuracy: a 3D computational study.
  6. Plasmodium ARK2-EB1 axis drives the unconventional spindle dynamics, scaffold formation and chromosome segregation of sexual transmission stages.
  7. Differential nuclear import regulates nuclear RNA inheritance following mitosis.
  8. Microtubule competition and cell growth recenter the nucleus after anaphase in fission yeast.
  9. Destructive testing on mitotic machinery: Probing the mechanics of fission yeast cell division by laser ablation.
  10. Initial spindle positioning at the oocyte center protects against incorrect kinetochore-microtubule attachment and aneuploidy in mice.
  11. A nuclear Pandora's box: functions of nuclear envelope proteins in cell division.
  12. Deciphering the mechanics of microtubule bundles in mitosis.
  13. Cell cycle oscillations driven by two interlinked bistable switches.
  14. Chromosome size affects alignment efficiency in mammalian mitosis.
  15. Importin α/β Promote Kif18B Microtubule Association and Enhance Microtubule Destabilization Activity.
  16. Naegleria's mitotic spindles are built from unique tubulins and associated microtubule binding proteins.
  17. AurkA nuclear localization is promoted by TPX2 and counteracted by protein degradation.
  18. The midbody component Prc1-like is required for microtubule reorganization during cytokinesis and dorsal determinant segregation in the early zebrafish embryo.
  19. Unraveling mitotic chromosome structure using optical tweezers.
  20. Photo-switching compound that controls ATPase and motor activities of mitotic kinesin Eg5.
  21. Expression, regulating mechanism and therapeutic target of KIF20A in multiple cancer.
  22. Revealing and manipulating the structure of mitotic chromosomes using atomic force microscopy.
  23. Dynamic self-organization of the human genome during the cell cycle.
  24. Quantifying yeast microtubules and spindles using the Toolkit for Automated Microtubule Tracking (TAMiT).
  25. Increased sampling and intra-complex homologies favor vertical over horizontal inheritance of the Dam1 complex.
  26. Working strokes produced by curling protofilaments at disassembling microtubule tips: Their role in kinetochore motility and microtubule dynamics.
  27. NQO1 regulates cell cycle progression at the G2/M phase.
  28. Eukaryotic-like gephyrin and cognate membrane receptor coordinate corynebacterial cell division and polar elongation.
  29. Mitochondrial dynamics control of mitoKv1.3 during cell cycle progression.
  30. Cytokinesis in Trypanosoma brucei relies on an orphan kinesin that dynamically crosslinks microtubules.
  31. Sexually dimorphic regulation of gonadotrope cell hyperplasia in medaka pituitary via mitosis and transdifferentiation.
  32. Diastereodivergent Desymmetric Annulation to Access Spirooxindoles: Chemical Probes for Mitosis.
  33. CD8 T cell diversification: asymmetric cell division and its functional implications.
  34. Segregation of Ca2+ signaling in olfactory signal transduction.
  1. bioRxiv. 2023 Feb 05. pii: 2023.02.05.527197. [Epub ahead of print]
    Distinct Aurora B pools at the inner centromere and kinetochore have different contributions to meiotic and mitotic chromosome segregation.
    Gisela Cairo, Cora Greiwe, Gyu Ik Jung, Cecilia Blengini, Karen Schindler, Soni Lacefield.
      Proper chromosome segregation depends on establishment of bioriented kinetochore-microtubule attachments, which often requires multiple rounds of release and reattachment. Aurora B and C kinases phosphorylate kinetochore proteins to release tensionless attachments. Multiple pathways recruit Aurora B/C to the centromere and kinetochore. We studied how these pathways contribute to anaphase onset timing and correction of kinetochore-microtubule attachments in budding yeast meiosis and mitosis. We find that the pool localized by the Bub1/Bub3 pathway sets the normal duration of meiosis and mitosis, in differing ways. Our meiosis data suggests that disruption of this pathway leads to PP1 kinetochore localization, which dephosphorylates Cdc20 for premature anaphase onset. For error correction, the Bub1/Bub3 and COMA pathways are individually important in meiosis but compensatory in mitosis. Finally, we find that the haspin and Bub1/3 pathways function together to ensure error correction in mouse oogenesis. Our results suggest that each recruitment pathway localizes spatially distinct kinetochore-localized Aurora B/C pools that function differently between meiosis and mitosis.
    DOI:  https://doi.org/10.1101/2023.02.05.527197
  2. Biosci Rep. 2023 Feb 15. pii: BSR20221882. [Epub ahead of print]
    TACC3-ch-TOG interaction regulates spindle microtubule assembly by controlling centrosomal recruitment of  γ-TuRC.
    Resmi Rajeev, Swarnendu Mukhopadhyay, Suresh Bhagyanath, Manu Rani S Devu Priya, Tapas K Manna.
      Gamma-tubulin ring complex (γ-TuRC), composed of γ-tubulin and multiple γ-tubulin complex proteins (GCPs),  serve as the major microtubule nucleating complex in animal cells. However, several γ-TuRC-associated proteins have been shown to control its function. Centrosomal adaptor protein, TACC3, is one such γ-TuRC-interacting factor that is essential for proper mitotic spindle assembly across organisms.  ch-TOG is another microtubule assembly-promoting protein, which interacts with TACC3 and cooperates in mitotic spindle assembly. However, the mechanism how TACC3-ch-TOG interaction regulates  microtubule assembly and the γ-TuRC functions at the centrosomes remain unclear. Here, we show that deletion of the ch-TOG-binding region in TACC3 enhances recruitment of the γ-TuRC proteins to centrosomes and aggravates spindle microtubule assembly in human cells. Loss of TACC3-ch-TOG binding imparts stabilization on TACC3 interaction with the γ-TuRC proteins and it does so by stimulating TACC3 phosphorylation and thereby enhancing phospho-TACC3 recruitment to the centrosomes. We also show that localization of ch-TOG at the centrosomes is substantially reduced and the same on the spindle microtubules is increased in its TACC3-unbound condition.  Additional results reveal that ch-TOG depletion stimulates γ-tubulin localization on the spindles without significantly affecting the centrosomal γ-tubulin level.   The results indicate that ch-TOG binding to TACC3 controls TACC3 phosphorylation and TACC3-mediated stabilization of the γ-TuRCs at the centrosomes. They also implicate that the spatio-temporal control of TACC3 phosphorylation via ch-TOG-binding ensures mitotic spindle assembly to the optimal level.
    Keywords:  TACC3; centrosome; microtubule; mitosis; mitotic spindle
    DOI:  https://doi.org/10.1042/BSR20221882
  3. Elife. 2023 Feb 17. pii: e82579. [Epub ahead of print]12
    Synergistic stabilization of microtubules by BUB-1, HCP-1 and CLS-2 controls microtubule pausing and meiotic spindle assembly.
    Nicolas Macaisne, Laura Bellutti, Kimberley Laband, Frances Edwards, Laras Pitayu-Nugroho, Alison Gervais, Thadshagine Ganeswaran, Hélène Geoffroy, Gilliane Maton, Julie C Canman, Benjamin Lacroix, Julien Dumont.
      During cell division, chromosome segregation is orchestrated by a microtubule-based spindle. Interaction between spindle microtubules and kinetochores is central to the bi-orientation of chromosomes. Initially dynamic to allow spindle assembly and kinetochore attachments, which is essential for chromosome alignment, microtubules are eventually stabilized for efficient segregation of sister chromatids and homologous chromosomes during mitosis and meiosis I respectively. Therefore, the precise control of microtubule dynamics is of utmost importance during mitosis and meiosis. Here, we study the assembly and role of a kinetochore module, comprised of the kinase BUB-1, the two redundant CENP-F orthologs HCP-1/2, and the CLASP family member CLS-2 (hereafter termed the BHC module), in the control of microtubule dynamics in Caenorhabditis elegans oocytes. Using a combination of in vivo structure-function analyses of BHC components and in vitro microtubule-based assays, we show that BHC components stabilize microtubules, which is essential for meiotic spindle formation and accurate chromosome segregation. Overall, our results show that BUB-1 and HCP-1/2 do not only act as targeting components for CLS-2 at kinetochores, but also synergistically control kinetochore-microtubule dynamics by promoting microtubule pause. Together, our results suggest that BUB-1 and HCP-1/2 actively participate in the control of kinetochore-microtubule dynamics in the context of an intact BHC module to promote spindle assembly and accurate chromosome segregation in meiosis.
    Keywords:  C. elegans; cell biology
    DOI:  https://doi.org/10.7554/eLife.82579
  4. bioRxiv. 2023 Jan 31. pii: 2023.01.29.526106. [Epub ahead of print]
    Plasmodium ARK2-EB1 axis drives the unconventional spindle dynamics, scaffold formation and chromosome segregation of sexual transmission stages.
    Mohammad Zeeshan, Edward Rea, Steven Abel, Kruno Vukušić, Robert Markus, Declan Brady, Antonius Eze, Ravish Raspa, Aurelia Balestra, Andrew R Bottrill, Mathieu Brochet, David S Guttery, Iva M Tolić, Anthony A Holder, Karine G Le Roch, Eelco C Tromer, Rita Tewari.
      Mechanisms of cell division are remarkably diverse, suggesting the underlying molecular networks among eukaryotes differ extensively. The Aurora family of kinases orchestrates the process of chromosome segregation and cytokinesis during cell division through precise spatiotemporal regulation of their catalytic activities by distinct scaffolds. Plasmodium spp., the causative agents of malaria, are unicellular eukaryotes that have three divergent aurora-related kinases (ARKs) and lack most canonical scaffolds/activators. The parasite uses unconventional modes of chromosome segregation during endomitosis and meiosis in sexual transmission stages within mosquito host. This includes a rapid threefold genome replication from 1N to 8N with successive cycles of closed mitosis, spindle formation and chromosome segregation within eight minutes (termed male gametogony). Kinome studies had previously suggested likely essential functions for all three Plasmodium ARKs during asexual mitotic cycles; however, little is known about their location, function, or their scaffolding molecules during unconventional sexual proliferative stages. Using a combination of super-resolution microscopy, mass spectrometry, and live-cell fluorescence imaging, we set out to investigate the role of the atypical Aurora paralog ARK2 to proliferative sexual stages using rodent malaria model Plasmodium berghei . We find that ARK2 primarily localises to the spindle apparatus in the vicinity of kinetochores during both mitosis and meiosis. Interactomics and co-localisation studies reveal a unique ARK2 scaffold at the spindle including the microtubule plus end-binding protein EB1, lacking conserved Aurora scaffold proteins. Gene function studies indicate complementary functions of ARK2 and EB1 in driving endomitotic divisions and thereby parasite transmission. Our discovery of a novel Aurora kinase spindle scaffold underlines the emerging flexibility of molecular networks to rewire and drive unconventional mechanisms of chromosome segregation in the malaria parasite Plasmodium .
    DOI:  https://doi.org/10.1101/2023.01.29.526106
  5. Mol Biol Cell. 2023 Feb 15. mbcE22110507
    Interrelated effects of chromosome size, mechanics, number, location-orientation and polar ejection force on the spindle accuracy: a 3D computational study.
    Evgenii Kliuchnikov, Kenneth A Marx, Alex Mogilner, Valeri Barsegov.
      The search-and-capture model of spindle assembly has been a guiding principle for understanding prometaphase for decades. The computational model presented allows one to address two questions: how rapidly the microtubule-kinetochore connections are made, and how accurate these connections are. In most previous numerical simulations, the model geometry was drastically simplified. Using the CellDynaMo computational platform, we previously introduced a geometrically and mechanically realistic 3D model of the prometaphase mitotic spindle, and used it to evaluate thermal noise and microtubule kinetics effects on the capture of a single chromosome. Here, we systematically investigate how geometry and mechanics affect spindle assembly's speed and accuracy, including nuanced distinctions between merotelic, mero-amphitelic and mero-syntelic chromosomes. We find that softening of the centromere spring improves accuracy for short chromosome arms, but accuracy disappears for long chromosome arms. Initial proximity of chromosomes to one spindle pole makes assembly accuracy worse, while initial chromosome orientation matters less. Chromokinesins, added onto flexible chromosome arms, allow modeling of the polar ejection force, improving spindle assembly's accuracy for a single chromosome. However, spindle space crowding by multiple chromosomes worsens assembly accuracy. Our simulations suggest that the complex microtubule network of the early spindle is key to rapid and accurate assembly. [Media: see text] [Media: see text] [Media: see text].
    DOI:  https://doi.org/10.1091/mbc.E22-11-0507
  6. Res Sq. 2023 Feb 08. pii: rs.3.rs-2539372. [Epub ahead of print]
    Plasmodium ARK2-EB1 axis drives the unconventional spindle dynamics, scaffold formation and chromosome segregation of sexual transmission stages.
    Mohammad Zeeshan, Edward Rea, Steven Abel, Kruno Vukusic, Robert Markus, Declan Brady, Anthonius Eze, Ravish Rashpa, Aurélia Balestra, Andrew Bottrill, Mathieu Brochet, David Guttery, Iva Tolić, Anthony Holder, Karine Le Roch, Eelco Tromer, Rita Tewari.
      Mechanisms of cell division are remarkably diverse, suggesting the underlying molecular networks among eukaryotes differ extensively. The Aurora family of kinases orchestrates the process of chromosome segregation and cytokinesis during cell division through precise spatiotemporal regulation of their catalytic activities by distinct scaffolds. Plasmodium spp., the causative agents of malaria, are unicellular eukaryotes that have three divergent aurora-related kinases (ARKs) and lack most canonical scaffolds/activators. The parasite uses unconventional modes of chromosome segregation during endomitosis and meiosis in sexual transmission stages within mosquito host. This includes a rapid threefold genome replication from 1N to 8N with successive cycles of closed mitosis, spindle formation and chromosome segregation within eight minutes (termed male gametogony). Kinome studies had previously suggested likely essential functions for all three Plasmodium ARKs during asexual mitotic cycles; however, little is known about their location, function, or their scaffolding molecules during unconventional sexual proliferative stages. Using a combination of super-resolution microscopy, mass spectrometry, omics and live-cell fluorescence imaging, we set out to investigate the contribution of the atypical Aurora paralog ARK2 to proliferative sexual stages using rodent malaria model Plasmodium berghei. We find that ARK2 primarily localises to the spindle apparatus associated with kinetochores during both mitosis and meiosis. Interactomics and co-localisation studies reveal a unique ARK2 scaffold at the spindle including the microtubule plus end-binding protein EB1 and lacking some other conserved molecules. Gene function studies indicate complementary functions of ARK2 and EB1 in driving endomitotic divisions and thereby parasite transmission. Our discovery of a novel Aurora spindle scaffold underlines the emerging flexibility of molecular networks to rewire and drive unconventional mechanisms of chromosome segregation in the malaria parasite Plasmodium.
    DOI:  https://doi.org/10.21203/rs.3.rs-2539372/v1
  7. Mol Biol Cell. 2023 Feb 15. mbcE23010004
    Differential nuclear import regulates nuclear RNA inheritance following mitosis.
    Michael D Blower, Wei Wang, Judith Sharp.
      Mitosis results in a dramatic reorganization of chromatin structure in order to promote chromosome compaction and segregation to daughter cells. Consequently, mitotic entry is accompanied by transcriptional silencing and removal of most chromatin-bound RNAs from chromosomes. As cells exit mitosis chromatin rapidly decondenses and transcription restarts as waves of differential gene expression. However, little is known about the fate of chromatin-bound RNAs following cell division. Here we explored whether nuclear RNA from the previous cell cycle is present in G1 nuclei following mitosis. We found that half of all nuclear RNAs are inherited in a transcription-independent manner following mitosis. Interestingly, the snRNA U2 is efficiently inherited by G1 nuclei while lncRNAs NEAT1 and MALAT1 show no inheritance following mitosis. We found that the nuclear protein SAF-A, which is hypothesized to tether RNA to DNA, did not play a prominent role in nuclear RNA inheritance, indicating the mechanism for RNA inheritance may not involve RNA chaperones that have chromatin binding activity. Instead, we observe that the timing of RNA inheritance indicates a select group of nuclear RNAs are reimported into the nucleus after the nuclear envelope has reassembled. Taken together, our work demonstrates that there is a fraction of nuclear RNA from the previous cell cycle that is reimported following mitosis and suggest that mitosis may serve as a time to reset the interaction of lncRNAs with chromatin.
    DOI:  https://doi.org/10.1091/mbc.E23-01-0004
  8. bioRxiv. 2023 Feb 01. pii: 2023.01.31.526443. [Epub ahead of print]
    Microtubule competition and cell growth recenter the nucleus after anaphase in fission yeast.
    Kimberly Bellingham-Johnstun, Annelise Thorn, Julio Belmonte, Caroline Laplante.
      Cells actively position their nucleus based on their activity. In fission yeast, microtubule-dependent nuclear centering is critical for symmetrical cell division. After spindle disassembly at the end of anaphase, the nucleus recenters over a ~90 min period, approximately half of the duration of the cell cycle. Live cell and simulation experiments support the cooperation of two distinct mechanisms in the slow recentering of the nucleus. First, a push-push mechanism acts from spindle disassembly to septation and involves the opposing actions of the mitotic Spindle Pole Body microtubules that push the nucleus away from the ends of the cell while post-anaphase array of microtubules basket the nucleus and limit its migration toward the division plane. Second, a slow-and-grow mechanism finalizes nuclear centering in the newborn cell. In this mechanism, microtubule competition stalls the nucleus while asymmetric cell growth slowly centers it. Our work underlines how intrinsic properties of microtubules differently impact nuclear positioning according to microtubule network organization and cell size.
    DOI:  https://doi.org/10.1101/2023.01.31.526443
  9. Biophys J. 2023 Feb 10. pii: S0006-3495(22)03294-5. [Epub ahead of print]122(3S1): 440a
    Destructive testing on mitotic machinery: Probing the mechanics of fission yeast cell division by laser ablation.
    Mary W Elting.
      
    DOI:  https://doi.org/10.1016/j.bpj.2022.11.2378
  10. Sci Adv. 2023 Feb 17. 9(7): eadd7397
    Initial spindle positioning at the oocyte center protects against incorrect kinetochore-microtubule attachment and aneuploidy in mice.
    Jessica N Kincade, Avery Hlavacek, Takashi Akera, Ahmed Z Balboula.
      Spindle positioning within the oocyte must be tightly regulated. In mice, the spindle is predominantly assembled at the oocyte center before its migration toward the cortex to achieve the highly asymmetric division, a characteristic of female meiosis. The significance of the initial central positioning of the spindle is largely unknown. We show that initial spindle positioning at the oocyte center is an insurance mechanism to avoid the premature exposure of the spindle to cortical CDC42 signaling, which perturbs proper kinetochore-microtubule attachments, leading to the formation of aneuploid gametes. These findings contribute to understanding why female gametes are notoriously associated with high rates of aneuploidy, the leading genetic cause of miscarriage and congenital abnormalities.
    DOI:  https://doi.org/10.1126/sciadv.add7397
  11. AoB Plants. 2023 Feb;15(2): plac065
    A nuclear Pandora's box: functions of nuclear envelope proteins in cell division.
    M Arif Ashraf.
      The nucleus is characteristic of eukaryotic cells and nuclear envelope proteins are conserved across the kingdoms. Over the years, the function of these proteins was studied in the intact nuclear envelope. Knowledge regarding the localization and function of nuclear envelope proteins during mitosis, after the nuclear envelope breaks down, is limited. Until recently, the localization of nuclear envelope proteins during mitosis has been observed with the mitotic apparatus. In this context, research in plant cell biology is more advanced compared to non-plant model systems. Although current studies shed light on the localization of nuclear envelope proteins, further experiments are required to determine what, if any, functional role different nuclear envelope proteins play during mitosis. This review will highlight our current knowledge about the role of nuclear envelope proteins and point out the unanswered questions as future direction.
    Keywords:  Cell division; LINC complexes; land plant evolution; mitosis; nuclear envelope proteins; nuclear pore complex
    DOI:  https://doi.org/10.1093/aobpla/plac065
  12. Biophys J. 2023 Feb 10. pii: S0006-3495(22)01181-X. [Epub ahead of print]122(3S1): 6a
    Deciphering the mechanics of microtubule bundles in mitosis.
    Scott Forth.
      
    DOI:  https://doi.org/10.1016/j.bpj.2022.11.265
  13. Mol Biol Cell. 2023 Feb 15. mbcE22110527
    Cell cycle oscillations driven by two interlinked bistable switches.
    Pedro Parra-Rivas, Daniel Ruiz-Reynés, Lendert Gelens.
      Regular transitions between interphase and mitosis during the cell cycle are driven by changes in the activity of the enzymatic protein complex cyclin B with cyclin-dependent kinase 1 (Cdk1). At the most basic level, this cell cycle oscillator is driven by negative feedback: active cyclin B - Cdk1 activates the Anaphase-Promoting Complex - Cyclosome, which triggers the degradation of cyclin B. Such cell cycle oscillations occur fast and periodically in the early embryos of the frog Xenopus laevis, where several positive feedback loops leading to bistable switches in parts of the regulatory network have been experimentally identified. Here, we build cell cycle oscillator models to show how single and multiple bistable switches in parts of the underlying regulatory network change the properties of the oscillations and how they can confer robustness to the oscillator. We present a detailed bifurcation analysis of these models.
    DOI:  https://doi.org/10.1091/mbc.E22-11-0527
  14. Biophys J. 2023 Feb 10. pii: S0006-3495(22)01970-1. [Epub ahead of print]122(3S1): 167a
    Chromosome size affects alignment efficiency in mammalian mitosis.
    Megan K Chong, Sophie Dumont.
      
    DOI:  https://doi.org/10.1016/j.bpj.2022.11.1054
  15. Mol Biol Cell. 2023 Feb 15. mbcE22030113
    Importin α/β Promote Kif18B Microtubule Association and Enhance Microtubule Destabilization Activity.
    Sanjay Shrestha, Stephanie C Ems-McClung, Mark A Hazelbaker, Amber L Yount, Sidney L Shaw, Claire E Walczak.
      Tight regulation of microtubule (MT) dynamics is necessary for proper spindle assembly and chromosome segregation. The MT destabilizing Kinesin-8, Kif18B, controls astral MT dynamics and spindle positioning. Kif18B interacts with importin α/β as well as with the plus-tip tracking protein EB1, but how these associations modulate Kif18B is not known. We mapped the key binding sites on Kif18B, made residue-specific mutations, and assessed their impact on Kif18B function. Blocking EB1 interaction disrupted Kif18B MT plus-end accumulation and inhibited its ability to control MT length on monopolar spindles in cells. Blocking importin α/β interaction disrupted Kif18B localization without affecting aster size. In vitro, importin α/β increased Kif18B MT association by increasing the on-rate and decreasing the off-rate from MTs, which stimulated MT destabilization. In contrast, EB1 promoted MT destabilization without increasing lattice binding in vitro, which suggests that EB1 and importin α/β have distinct roles in the regulation of Kif18B-mediated MT destabilization. We propose that importin α/β-spatially modulate Kif18B association with MTs to facilitate its MT destabilization activity. Our results suggest that Ran-regulation is important not only to control molecular motor function near chromatin but also provides a spatial control mechanism to modulate MT binding of NLS-containing spindle assembly factors. [Media: see text] [Media: see text].
    DOI:  https://doi.org/10.1091/mbc.E22-03-0113
  16. Biophys J. 2023 Feb 10. pii: S0006-3495(22)03292-1. [Epub ahead of print]122(3S1): 440a
    Naegleria's mitotic spindles are built from unique tubulins and associated microtubule binding proteins.
    Andrew Kennard, Katrina Velle, Lillian Fritz-Laylin.
      
    DOI:  https://doi.org/10.1016/j.bpj.2022.11.2376
  17. Life Sci Alliance. 2023 May;pii: e202201726. [Epub ahead of print]6(5):
    AurkA nuclear localization is promoted by TPX2 and counteracted by protein degradation.
    Italia Anna Asteriti, Federica Polverino, Venturina Stagni, Valentina Sterbini, Camilla Ascanelli, Francesco Davide Naso, Anna Mastrangelo, Alessandro Rosa, Alessandro Paiardini, Catherine Lindon, Giulia Guarguaglini.
      The AurkA kinase is a well-known mitotic regulator, frequently overexpressed in tumors. The microtubule-binding protein TPX2 controls AurkA activity, localization, and stability in mitosis. Non-mitotic roles of AurkA are emerging, and increased nuclear localization in interphase has been correlated with AurkA oncogenic potential. Still, the mechanisms leading to AurkA nuclear accumulation are poorly explored. Here, we investigated these mechanisms under physiological or overexpression conditions. We observed that AurkA nuclear localization is influenced by the cell cycle phase and nuclear export, but not by its kinase activity. Importantly, AURKA overexpression is not sufficient to determine its accumulation in interphase nuclei, which is instead obtained when AURKA and TPX2 are co-overexpressed or, to a higher extent, when proteasome activity is impaired. Expression analyses show that AURKA, TPX2, and the import regulator CSE1L are co-overexpressed in tumors. Finally, using MCF10A mammospheres we show that TPX2 co-overexpression drives protumorigenic processes downstream of nuclear AurkA. We propose that AURKA/TPX2 co-overexpression in cancer represents a key determinant of AurkA nuclear oncogenic functions.
    DOI:  https://doi.org/10.26508/lsa.202201726
  18. Development. 2023 Feb 15. pii: dev200564. [Epub ahead of print]150(4):
    The midbody component Prc1-like is required for microtubule reorganization during cytokinesis and dorsal determinant segregation in the early zebrafish embryo.
    Sreelaja Nair, Elaine L Welch, Cara E Moravec, Ryan L Trevena, Christina L Hansen, Francisco Pelegri.
      We show that the zebrafish maternal-effect mutation too much information (tmi) corresponds to zebrafish prc1-like (prc1l), which encodes a member of the MAP65/Ase1/PRC1 family of microtubule-associated proteins. Embryos from tmi homozygous mutant mothers display cytokinesis defects in meiotic and mitotic divisions in the early embryo, indicating that Prc1l has a role in midbody formation during cell division at the egg-to-embryo transition. Unexpectedly, maternal Prc1l function is also essential for the reorganization of vegetal pole microtubules required for the segregation of dorsal determinants. Whereas Prc1 is widely regarded to crosslink microtubules in an antiparallel conformation, our studies provide evidence for an additional function of Prc1l in the bundling of parallel microtubules in the vegetal cortex of the early embryo during cortical rotation and prior to mitotic cycling. These findings highlight common yet distinct aspects of microtubule reorganization that occur during the egg-to-embryo transition, driven by maternal product for the midbody component Prc1l and required for embryonic cell division and pattern formation.
    Keywords:  Cytokinesis; Dorsal determinant; Microtubule reorganization; Midbody; Prc1; Zebrafish
    DOI:  https://doi.org/10.1242/dev.200564
  19. Biophys J. 2023 Feb 10. pii: S0006-3495(22)03570-6. [Epub ahead of print]122(3S1): 497a
    Unraveling mitotic chromosome structure using optical tweezers.
    Constantijn P van der Smagt, Christian F Nielsen, Ian D Hickson, Erwin J Peterman, Gijs J Wuite.
      
    DOI:  https://doi.org/10.1016/j.bpj.2022.11.2654
  20. Biophys J. 2023 Feb 10. pii: S0006-3495(22)03143-5. [Epub ahead of print]122(3S1): 410a
    Photo-switching compound that controls ATPase and motor activities of mitotic kinesin Eg5.
    Islam Md Alrazi, Shinsaku Maruta.
      
    DOI:  https://doi.org/10.1016/j.bpj.2022.11.2227
  21. Heliyon. 2023 Feb;9(2): e13195
    Expression, regulating mechanism and therapeutic target of KIF20A in multiple cancer.
    Zheng Jin, Fei Peng, Chao Zhang, Shuang Tao, Damo Xu, Zhenhua Zhu.
      Kinesin family member 20A (KIF20A) is a member of the kinesin family. It transports chromosomes during mitosis, plays a key role in cell division. Recently, studies proved that KIF20A was highly expressed in cancer. High expression of KIF20A was correlated with poor overall survival (OS). In this review, we summarized all the cancer that highly expressed KIF20A, described the role of KIF20A in cancer. We also organized phase I and phase II clinical trials of KIF20A peptides vaccine. All results indicated that KIF20A was a promising therapeutic target for multiple cancer.
    Keywords:  ATP, adenosine triphosphate; BTC, biliary tract cancer; CPC, chromosomal passenger complex; CTL, cytotoxic T lymphocyte; Cancer; Cdk1, cyclin-dependent kinase 1; DLG5, discs large MAGUK scaffold protein 5; EMT, epithelial-mesenchymal transition; Expression; FoxM1, forkhead box protein M1; GC, gastric cancer; GEM, gemcitabine; Gli2, glioma-associated oncogene 2; HLA, human leukocyte antigen; HNMT, head-and-neck malignant tumor; IRF, interferon regulatory factor; JAK, Janus kinase; KIF20A; KIF20A, kinesin family member 20A; LP, long peptide; MHC I, major histocompatibility complex I; MKlp2, mitotic kinesin-like protein 2; Mad2, mitotic arrest deficient 2; OS, overall survival; PBMC, peripheral blood mononuclear cell; Plk1, polo-like kinase 1; Regulating mechanisms; Therapeutic target; circRNA, circular RNA; miRNA, microRNA
    DOI:  https://doi.org/10.1016/j.heliyon.2023.e13195
  22. Biophys J. 2023 Feb 10. pii: S0006-3495(22)03812-7. [Epub ahead of print]122(3S1): 547a
    Revealing and manipulating the structure of mitotic chromosomes using atomic force microscopy.
    Andrea Ridolfi, Christian F Nielsen, Erwin J Peterman, Ian D Hickson, Gijs J Wuite.
      
    DOI:  https://doi.org/10.1016/j.bpj.2022.11.2896
  23. Biophys J. 2023 Feb 10. pii: S0006-3495(22)01247-4. [Epub ahead of print]122(3S1): 19a
    Dynamic self-organization of the human genome during the cell cycle.
    Suho Lee, Alexandra Zidovska.
      
    DOI:  https://doi.org/10.1016/j.bpj.2022.11.331
  24. bioRxiv. 2023 Feb 08. pii: 2023.02.07.527544. [Epub ahead of print]
    Quantifying yeast microtubules and spindles using the Toolkit for Automated Microtubule Tracking (TAMiT).
    Saad Ansari, Zachary R Gergely, Patrick Flynn, Gabriella Li, Jeffrey K Moore, Meredith D Betterton.
      Fluorescently labeled proteins absorb and emit light, appearing as Gaussian spots in fluorescence imaging. When fluorescent tags are added to cytoskeletal polymers such as microtubules, a line of fluorescence and even non-linear structures results. While much progress has been made in techniques for imaging and microscopy, image analysis is less well developed. Current analysis of fluorescent microtubules uses either manual tools, such as kymographs, or automated software. As a result, our ability to quantify microtubule dynamics and organization from light microscopy remains limited. Despite development of automated microtubule analysis tools for in vitro studies, analysis of images from cells often depends heavily on manual analysis. One of the main reasons for this disparity is the low signal-to-noise ratio in cells, where background fluorescence is typically higher than in reconstituted systems. Here, we present the Toolkit for Automated Microtubule Tracking (TAMiT), which automatically detects, optimizes and tracks fluorescent microtubules in living yeast cells with sub-pixel accuracy. Using basic information about microtubule organization, TAMiT detects linear and curved polymers using a geometrical scanning technique. Images are fit via an optimization problem for the microtubule image parameters that is solved using non-linear least squares in Matlab. We benchmark our software using simulated images and show that it reliably detects microtubules, even at low signal-to-noise ratios. Then, we use TAMiT to measure monopolar spindle microtubule bundle number, length, and lifetime in a large dataset that includes several S. pombe mutants that affect microtubule dynamics and bundling. The results from the automated analysis are consistent with previous work, and suggest a direct role for CLASP/Cls1 in bundling spindle microtubules. We also illustrate automated tracking of single curved astral microtubules in S. cerevisiae , with measurement of dynamic instability parameters. The results obtained with our fully-automated software are similar to results using hand-tracked measurements. Therefore, TAMiT can facilitate automated analysis of spindle and microtubule dynamics in yeast cells.
    DOI:  https://doi.org/10.1101/2023.02.07.527544
  25. Genome Biol Evol. 2023 Feb 15. pii: evad017. [Epub ahead of print]
    Increased sampling and intra-complex homologies favor vertical over horizontal inheritance of the Dam1 complex.
    Laura E van Rooijen, Eelco C Tromer, Jolien J E van Hooff, Geert J P L Kops, Berend Snel.
      Kinetochores connect chromosomes to spindle microtubules to ensure their correct segregation during cell division. Kinetochores of human and yeasts are largely homologous, their ability to track depolymerizing microtubules however is carried out by the non-homologous complexes Ska1-C and Dam1-C, respectively. We previously reported the unique anti-correlating phylogenetic profiles of Dam1-C and Ska-C found amongst a wide variety of eukaryotes. Based on these profiles and the limited presence of Dam1-C, we speculated that horizontal gene transfer (HGT) could have played a role in the evolutionary history of Dam1-C. Here, we present an expanded analysis of Dam1-C evolution, using additional genome as well as transcriptome sequences and recently published 3D structures. This analysis revealed a wider and more complete presence of Dam1-C in Cryptista, Rhizaria, Ichthyosporea, CRuMs, and Colponemidia. The fungal Dam1-C cryo-EM structure supports earlier hypothesized intra-complex homologies, which enables the reconstruction of rooted and unrooted phylogenies. The rooted tree of concatenated Dam1-C subunits is statistically consistent with the species tree of eukaryotes, suggesting that Dam1-C is ancient, and that the present-day phylogenetic distribution is best explained by multiple, independent losses and no HGT was involved. Furthermore, we investigated the ancient origin of Dam1-C via profile-profile searches. Homology among eight out of the ten Dam1-C subunits suggests that the complex largely evolved from a single multimerizing subunit that diversified into a hetero-octameric core via stepwise subunit duplication and sub-functionalization of the subunits before the origin of the Last Eukaryotic Common Ancestor.
    Keywords:  Horizontal Gene Transfer; Kinetochore; Last Eukaryotic Common Ancestor; intra complex homologies; protein complex evolution; vertical inheritance
    DOI:  https://doi.org/10.1093/gbe/evad017
  26. Biophys J. 2023 Feb 10. pii: S0006-3495(22)01760-X. [Epub ahead of print]122(3S1): 125a
    Working strokes produced by curling protofilaments at disassembling microtubule tips: Their role in kinetochore motility and microtubule dynamics.
    Lucas E Murray, Lucia Maki-Fern, Luke Rice, Charles L Asbury.
      
    DOI:  https://doi.org/10.1016/j.bpj.2022.11.844
  27. Theranostics. 2023 ;13(3): 873-895
    NQO1 regulates cell cycle progression at the G2/M phase.
    Eun-Taex Oh, Ha Gyeong Kim, Chul Hoon Kim, Jeonghun Lee, Chulhee Kim, Jae-Seon Lee, Yunmi Cho, Heon Joo Park.
      Rationale: Overexpression of NAD(P)H:quinone oxidoreductase 1 (NQO1) is associated with tumor cell proliferation and growth in several human cancer types. However, the molecular mechanisms underlying the activity of NQO1 in cell cycle progression are currently unclear. Here, we report a novel function of NQO1 in modulation of the cell cycle regulator, cyclin-dependent kinase subunit-1 (CKS1), at the G2/M phase through effects on the stability of c‑Fos. Methods: The roles of the NQO1/c-Fos/CKS1 signaling pathway in cell cycle progression were analyzed in cancer cells using synchronization of the cell cycle and flow cytometry. The mechanisms underlying NQO1/c-Fos/CKS1-mediated regulation of cell cycle progression in cancer cells were studied using siRNA approaches, overexpression systems, reporter assays, co-immunoprecipitation, pull-down assays, microarray analysis, and CDK1 kinase assays. In addition, publicly available data sets and immunohistochemistry were used to investigate the correlation between NQO1 expression levels and clinicopathological features in cancer patients. Results: Our results suggest that NQO1 directly interacts with the unstructured DNA-binding domain of c-Fos, which has been implicated in cancer proliferation, differentiation, and development as well as patient survival, and inhibits its proteasome-mediated degradation, thereby inducing CKS1 expression and regulation of cell cycle progression at the G2/M phase. Notably, a NQO1 deficiency in human cancer cell lines led to suppression of c-Fos-mediated CKS1 expression and cell cycle progression. Consistent with this, high NQO1 expression was correlated with increased CKS1 and poor prognosis in cancer patients. Conclusions: Collectively, our results support a novel regulatory role of NQO1 in the mechanism of cell cycle progression at the G2/M phase in cancer through effects on c‑Fos/CKS1 signaling.
    Keywords:  CKS1; NQO1; c-Fos; cancer cell; cell cycle
    DOI:  https://doi.org/10.7150/thno.77444
  28. bioRxiv. 2023 Feb 01. pii: 2023.02.01.526586. [Epub ahead of print]
    Eukaryotic-like gephyrin and cognate membrane receptor coordinate corynebacterial cell division and polar elongation.
    M Martinez, J Petit, A Leyva, A Sogues, D Megrian, A Rodriguez, Q Gaday, M Ben Assaya, M Portela, A Haouz, A Ducret, C Grangeasse, P M Alzari, R Dur N, A Wehenkel.
      The order Corynebacteriales includes major industrial and pathogenic actinobacteria such as Corynebacterium glutamicum or Mycobacterium tuberculosis . Their elaborate multi-layered cell wall, composed primarily of the mycolyl-arabinogalactan-peptidoglycan complex, and their polar growth mode impose a stringent coordination between the septal divisome, organized around the tubulin-like protein FtsZ, and the polar elongasome, assembled around the tropomyosin-like protein Wag31. Here, we report the identification of two new divisome members, a gephyrin-like repurposed molybdotransferase (GLP) and its membrane receptor (GLPR). We show that the interplay between the GLPR/GLP module, FtsZ and Wag31 is crucial for orchestrating cell cycle progression. Our results provide a detailed molecular understanding of the crosstalk between two essential machineries, the divisome and elongasome, and reveal that Corynebacteriales have evolved a protein scaffold to control cell division and morphogenesis similar to the gephyrin/GlyR system that in higher eukaryotes mediates synaptic signaling through network organization of membrane receptors and the microtubule cytoskeleton.
    DOI:  https://doi.org/10.1101/2023.02.01.526586
  29. Biophys J. 2023 Feb 10. pii: S0006-3495(22)02337-2. [Epub ahead of print]122(3S1): 244a
    Mitochondrial dynamics control of mitoKv1.3 during cell cycle progression.
    Jesusa Capera-Aragones, María Navarro-Pérez, Carla Viñola-Renart, Anna Benavente-Garcia, Ildiko Szabó, Antonio Felipe.
      
    DOI:  https://doi.org/10.1016/j.bpj.2022.11.1421
  30. Curr Biol. 2023 Feb 10. pii: S0960-9822(23)00069-6. [Epub ahead of print]
    Cytokinesis in Trypanosoma brucei relies on an orphan kinesin that dynamically crosslinks microtubules.
    Thomas E Sladewski, Paul C Campbell, Neil Billington, Alexandra D'Ordine, James L Cole, Christopher L de Graffenried.
      Many single-celled eukaryotes have complex cell morphologies defined by microtubules arranged into higher-order structures. The auger-like shape of the parasitic protist Trypanosoma brucei (T. brucei) is mediated by a parallel array of microtubules that underlies the plasma membrane. The subpellicular array must be partitioned and segregated using a microtubule-based mechanism during cell division. We previously identified an orphan kinesin, KLIF, that localizes to the ingressing cleavage furrow and is essential for the completion of cytokinesis. We have characterized the biophysical properties of a truncated KLIF construct in vitro to gain mechanistic insight into the function of this novel kinesin. We find that KLIF is a non-processive dimeric kinesin that dynamically crosslinks microtubules. Microtubules crosslinked by KLIF in an antiparallel orientation are translocated relative to one another, while microtubules crosslinked parallel to one another remain static, resulting in the formation of organized parallel bundles. In addition, we find that KLIF stabilizes the alignment of microtubule plus ends. These features provide a mechanistic understanding for how KLIF functions to form a new pole of aligned microtubule plus ends that defines the shape of the new cell posterior, which is an essential requirement for the completion of cytokinesis in T. brucei.
    Keywords:  Trypanosoma; cytokinesis; cytoskeleton; kinesin; microtubules; morphology; subpellicular array
    DOI:  https://doi.org/10.1016/j.cub.2023.01.035
  31. Endocrinology. 2023 Feb 15. pii: bqad030. [Epub ahead of print]
    Sexually dimorphic regulation of gonadotrope cell hyperplasia in medaka pituitary via mitosis and transdifferentiation.
    Muhammad Rahmad Royan, Daichi Kayo, Finn-Arne Weltzien, Romain Fontaine.
      The two pituitary gonadotropins, FSH and LH, regulate the reproductive function in all vertebrates. While many studies have investigated the regulation of gonadotropin production and release by the sex steroid feedback, its role on the regulation of gonadotrope cell number remains unclear. Using medaka as a model and an optimized protocol to restore physiological sex steroids levels following gonadectomy, we show that gonadal sex steroids not only decrease fshb transcript levels, but also Fsh cell number in both sexes. We then investigated the origin of the Fsh cell hyperplasia induced by gonadectomy. In both sexes, BrdU incubation shows that this is achieved via Fsh cell mitosis. In situ hybridization reveals that new Fsh cells also originate from transdifferentiating Tsh cells in females, but not in males. Both phenomena are inhibited by sex steroid supplementation via feeding. In males (but not females), gonadectomy (without recovery with sex steroid supplementation) also reduces sox2 transcript levels and Sox2-immunopositive population size, suggesting that sox2-progenitors may be recruited to produce new Fsh cells. Opposite to Fsh cells, gonadectomy decreases lhb levels in both sexes, and levels are not restored by sex steroid supplementation. In addition, the regulation of Lh cell number also seems to be sex dependent. Removal of gonadal sex steroids stimulates Lh cell mitosis in male (like Fsh cells), but not in females. To conclude, our study provides the first evidence on sexually dimorphic mechanisms used in the fish pituitary to remodel gonadotrope populations in response to sex steroids.
    Keywords:  gonadotropes; mitosis; pituitary; plasticity; sex steroids; transdifferentiation
    DOI:  https://doi.org/10.1210/endocr/bqad030
  32. J Am Chem Soc. 2023 Feb 13.
    Diastereodivergent Desymmetric Annulation to Access Spirooxindoles: Chemical Probes for Mitosis.
    Yu-Hua Wen, Fengrui Yang, Shuai Li, Xuebiao Yao, Jin Song, Liu-Zhu Gong.
      Spirooxindoles have emerged as promising architectures for engineering biologically active compounds. The diastereodivergent construction of unique scaffolds of this type with full control of continuous chiral centers including an all-carbon quaternary stereogenic center is yet to be developed. Here, we report an unprecedented diastereodivergent desymmetric [3 + 3] annulation of oxabicyclic alkenes with enals enabled by N-heterocyclic carbene (NHC)/Rh cooperative catalysis, leading to a series of enantiomerically enriched spirooxindole lactones with excellent enantioselectivities (up to >99% ee) and diastereoselectivities (up to >95:5 dr). The combined catalyst system comprises a rhodium complex that controls the configuration at the electrophilic carbon and an NHC catalyst that controls the configuration at the nucleophilic oxindole-containing carbon; thus, four stereoisomers of the spirooxindole products can be readily obtained simply by switching the configurations of the two chiral catalysts. Transformations of the chiral spirooxindoles delivered synthetically useful compounds. Importantly, those chiral spirooxindoles arrested mammalian cells in mitosis and exhibited potent antiproliferative activities against HeLa cells. Significantly, both absolute and relative configurations exert prominent effects on the bioactivities, underscoring great importance of catalytic asymmetric diastereodivergent synthesis beyond creating useful tools for the exploration of structure-activity relationships.
    DOI:  https://doi.org/10.1021/jacs.2c12648
  33. Eur J Immunol. 2023 Feb 14. e2250225
    CD8 T cell diversification: asymmetric cell division and its functional implications.
    Fabienne Gräbnitz, Annette Oxenius.
      Establishment of cellular diversity is a basic requirement for the development of multicellular organisms. Cellular diversification can be induced by asymmetric cell division (ACD), during which the emerging two daughter cells unequally inherit lineage specific cargo (including transcription factors, receptors for specific signaling inputs, metabolic platforms and possibly different epigenetic landscapes), resulting in two daughter cells endowed with different fates. While ACD is strongly involved in lineage choices in mammalian stem cells, its role in fate diversification in lineage committed cell subsets that still exhibit plastic potential, such as T cells, is currently investigated. In this review, we focus predominantly on the role of ACD in fate diversification of CD8 T cells. Further, we discuss the impact of differential T cell receptor stimulation strengths and differentiation history on ACD-mediated fate diversification and highlight a particular importance of ACD in the development of memory CD8 T cells upon high affinity stimulation conditions. This article is protected by copyright. All rights reserved.
    Keywords:  Asymmetric cell division; CD8 T cells; Cell fate; Memory T cells; T cell differentiation
    DOI:  https://doi.org/10.1002/eji.202250225
  34. J Gen Physiol. 2023 Apr 03. pii: e202213165. [Epub ahead of print]155(4):
    Segregation of Ca2+ signaling in olfactory signal transduction.
    Hiroko Takeuchi, Takashi Kurahashi.
      Olfactory signal transduction is conducted through a cAMP-mediated second messenger cascade. The cytoplasmic Ca2+ concentration increases through the opening of CNG channels, a phenomenon that underlies two major functions, namely, signal boosting and olfactory adaptation. Signal boosting is achieved by an additional opening of the Ca2+-activated Cl- channel whereas adaptation is regulated by Ca2+ feedback to the CNG channel. Thus, the influx of Ca2+ and the resultant increase in cytoplasmic Ca2+ levels play seemingly opposing effects: increasing the current while reducing the current through adaptation. The two functions could be interpreted as compensating for each other. However, in real cells, both functions should be segregated. Ca2+ dynamics in olfactory cilia need to be directly measured, but technical difficulties accompanying the thin structure of olfactory cilia have prevented systematic analyses. In this study, using a combination of electrophysiology, local photolysis of caged cAMP, and Ca2+ imaging, we found that free Ca2+ in the local ciliary cytoplasm decreased along with a reduction in the current containing Ca2+-activated Cl- components returning to the basal level, whereas Ca2+-dependent adaptation persisted for a longer period. The activity of Cl- channels is highly likely to be regulated by the free Ca2+ that is present only immediately after the influx through the CNG channel, and an exclusive interaction between Ca2+ and Ca2+-binding proteins that mediate the adaptation may modulate the adaptation lifetime.
    DOI:  https://doi.org/10.1085/jgp.202213165
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