bims-micesi Biomed News
on Mitotic cell signalling
Issue of 2022‒05‒22
ten papers selected by
Valentina Piano
Max Planck Institute of Molecular Physiology
  1. Spindle Assembly and Mitosis in Plants.
  2. Kinetochore tracking in 3D from lattice light sheet imaging data with KiT.
  3. Cortical Cyclin A controls spindle orientation during asymmetric cell divisions in Drosophila.
  4. The Astrin-SKAP complex reduces friction at the kinetochore-microtubule interface.
  5. Kinetochore size scales with chromosome size in bimodal karyotypes of Agavoideae.
  6. Acentrosomal spindle assembly and maintenance in C. elegans oocytes requires a kinesin-12 non-motor microtubule interaction domain.
  7. Prognostic Biomarker KIF18A and Its Correlations With Immune Infiltrates and Mitosis in Glioma.
  8. Apicoplast Dynamics During Plasmodium Cell Cycle.
  9. The deubiquitinase USP8 targets ESCRT-III to promote incomplete cell division.
  10. MOR1/MAP215 acts synergistically with katanin to control cell division and anisotropic cell elongation in Arabidopsis.
  1. Annu Rev Plant Biol. 2022 May 20. 73 227-254
    Spindle Assembly and Mitosis in Plants.
    Bo Liu, Yuh-Ru Julie Lee.
      In contrast to well-studied fungal and animal cells, plant cells assemble bipolar spindles that exhibit a great deal of plasticity in the absence of structurally defined microtubule-organizing centers like the centrosome. While plants employ some evolutionarily conserved proteins to regulate spindle morphogenesis and remodeling, many essential spindle assembly factors found in vertebrates are either missing or not required for producing the plant bipolar microtubule array. Plants also produce proteins distantly related to their fungal and animal counterparts to regulate critical events such as the spindle assembly checkpoint. Plant spindle assembly initiates with microtubule nucleation on the nuclear envelope followed by bipolarization into the prophase spindle. After nuclear envelope breakdown, kinetochore fibers are assembled and unified into the spindle apparatus with convergent poles. Of note, compared to fungal and animal systems, relatively little is known about how plant cells remodel the spindle microtubule array during anaphase. Uncovering mitotic functions of novel proteins for spindle assembly in plants will illuminate both common and divergent mechanisms employed by different eukaryotic organisms to segregate genetic materials.
    Keywords:  Aurora kinase; central spindle; kinesins; microtubule nucleation; mitosis; prophase spindle; spindle assembly checkpoint; γ-tubulin
    DOI:  https://doi.org/10.1146/annurev-arplant-070721-084258
  2. Bioinformatics. 2022 May 17. pii: btac330. [Epub ahead of print]
    Kinetochore tracking in 3D from lattice light sheet imaging data with KiT.
    Jonathan U Harrison, Onur Sen, Andrew D McAinsh, Nigel J Burroughs.
      MOTIVATION: Lattice light sheet microscopy is revolutionizing cell biology since it enables fast, high-resolution extended imaging in three dimensions combined with a drastic reduction in photo-toxicity and bleaching. However analysis of such data sets still remains a major challenge.RESULTS: Automated tracking of kinetochores, the protein complex facilitating and controlling microtubule attachment of the chromosomes within the mitotic spindle, provides quantitative assessment of chromosome dynamics in mitosis. Here we extend existing open-source kinetochore tracking software (KiT Armond et al. [2016]) to track (and pair) kinetochores throughout pro-metaphase to anaphase in lattice light sheet microscopy data. One of the key improvements is a regularization term in the objective function to enforce biological information about the number of kinetochores in a human mitotic cell, as well as improved diagnostic tools. This software provides quantitative insights into how kinetochores robustly ensure congression and segregation of chromosomes during mitosis.
    AVAILABILITY AND IMPLEMENTATION: KiT is free, open-source software implemented in MATLAB and can be downloaded as a package from https://github.com/cmcb-warwick/KiT. The source repository is available at https://bitbucket.org/jarmond/kit (tag v2.4.0) and under continuing development.
    SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.
    DOI:  https://doi.org/10.1093/bioinformatics/btac330
  3. Nat Commun. 2022 May 17. 13(1): 2723
    Cortical Cyclin A controls spindle orientation during asymmetric cell divisions in Drosophila.
    Pénélope Darnat, Angélique Burg, Jérémy Sallé, Jérôme Lacoste, Sophie Louvet-Vallée, Michel Gho, Agnès Audibert.
      The coordination between cell proliferation and cell polarity is crucial to orient the asymmetric cell divisions to generate cell diversity in epithelia. In many instances, the Frizzled/Dishevelled planar cell polarity pathway is involved in mitotic spindle orientation, but how this is spatially and temporally coordinated with cell cycle progression has remained elusive. Using Drosophila sensory organ precursor cells as a model system, we show that Cyclin A, the main Cyclin driving the transition to M-phase of the cell cycle, is recruited to the apical-posterior cortex in prophase by the Frizzled/Dishevelled complex. This cortically localized Cyclin A then regulates the orientation of the division by recruiting Mud, a homologue of NuMA, the well-known spindle-associated protein. The observed non-canonical subcellular localization of Cyclin A reveals this mitotic factor as a direct link between cell proliferation, cell polarity and spindle orientation.
    DOI:  https://doi.org/10.1038/s41467-022-30182-1
  4. Curr Biol. 2022 May 11. pii: S0960-9822(22)00679-0. [Epub ahead of print]
    The Astrin-SKAP complex reduces friction at the kinetochore-microtubule interface.
    Miquel Rosas-Salvans, Renaldo Sutanto, Pooja Suresh, Sophie Dumont.
      The kinetochore links chromosomes to spindle microtubules to drive chromosome segregation at cell division. While we know nearly all mammalian kinetochore proteins, how these give rise to the strong yet dynamic microtubule attachments required for function remains poorly understood. Here, we focus on the Astrin-SKAP complex, which localizes to bioriented kinetochores and is essential for chromosome segregation but whose mechanical role is unclear. Live imaging reveals that SKAP depletion dampens the movement and decreases the coordination of metaphase sister kinetochores and increases the tension between them. Using laser ablation to isolate kinetochores bound to polymerizing versus depolymerizing microtubules, we show that without SKAP, kinetochores move slower on both polymerizing and depolymerizing microtubules and that more force is needed to rescue microtubules to polymerize. Thus, in contrast to the previously described kinetochore proteins that increase the grip on microtubules under force, Astrin-SKAP reduces the grip, increasing attachment dynamics and force responsiveness and reducing friction. Together, our findings suggest a model where the Astrin-SKAP complex effectively "lubricates" correct, bioriented attachments to help preserve them.
    Keywords:  Astrin-SKAP; dynamics; force; friction; grip; kinetochore; mammal; mechanics; microtubule; spindle
    DOI:  https://doi.org/10.1016/j.cub.2022.04.061
  5. Ann Bot. 2022 May 16. pii: mcac063. [Epub ahead of print]
    Kinetochore size scales with chromosome size in bimodal karyotypes of Agavoideae.
    Klára Plačková, František Zedek, Veit Schubert, Andreas Houben, Petr Bureš.
      BACKGROUND AND AIMS: In eukaryotes, the total kinetochore size (defined as a chromosomal region containing CENH3-positive nucleosomes) per nucleus strongly correlates with genome size, a relationship that has been hypothesized to stem from general intracellular scaling principles. However, it could also come from the mechanics of the cell division, if larger chromosomes within a karyotype required larger kinetochores to move properly.METHODS: We selected seven species of the plant subfamily Agavoideae whose karyotypes are characterized by the presence of small and very large chromosomes. We visualized the kinetochore regions and chromosomes by immunolabeling with an anti-CENH3 antibody and DAPI staining. Then, we employed 2D widefield and 3D super-resolution microscopy to measure chromosome and kinetochore areas and volumes, respectively. To assess the scaling relationship of kinetochore size to chromosome size inside a karyotype, we log-transformed the data and analyzed them with linear mixed models which allowed us to control for the inherent hierarchical structure of the dataset (metaphases within slides and species).
    KEY RESULTS: We found a positive intra-karyotype relationship between kinetochore and chromosome size. The slope of the regression line of the observed relationship (0.277 for areas, 0.247 for volumes) was very close to the theoretical slope of 0.25 for chromosome width based on the expected physics of chromosome passage through the cytoplasm during cell division. We obtained similar results by reanalyzing available data from human and maize.
    CONCLUSIONS: Our findings suggest that the total kinetochore size to genome size scaling observed across eukaryotes may also originate from the cell division mechanics. Moreover, the potential causal link between kinetochore and chromosome size indicates that evolutionary mechanisms capable of leading kinetochore size changes to fixation, such as centromere drive, could promote the size evolution of entire chromosomes and genomes.
    Keywords:  Asparagaceae; cell division; centromere; chromosome size evolution; genome size evolution; intracellular scaling; linear mixed models; structured illumination microscopy
    DOI:  https://doi.org/10.1093/aob/mcac063
  6. Mol Biol Cell. 2022 May 20. mbcE22020056
    Acentrosomal spindle assembly and maintenance in C. elegans oocytes requires a kinesin-12 non-motor microtubule interaction domain.
    Ian D Wolff, Jeremy A Hollis, Sarah M Wignall.
      During the meiotic divisions in oocytes, microtubules are sorted and organized by motor proteins to generate a bipolar spindle in the absence of centrosomes. In most organisms, kinesin-5 family members crosslink and slide microtubules to generate outward force that promotes acentrosomal spindle bipolarity. However, the mechanistic basis for how other kinesin families act on acentrosomal spindles has not been explored. We investigated this question in C. elegans oocytes, where kinesin-5 is not required to generate outward force and the kinesin-12 family motor KLP-18 instead performs this function. Here we use a combination of in vitro biochemical assays and in vivo mutant analysis to provide insight into the mechanism by which KLP-18 promotes acentrosomal spindle assembly. We identify a microtubule binding site on the C-terminal stalk of KLP-18 and demonstrate that a direct interaction between the KLP-18 stalk and its adaptor protein MESP-1 activates non-motor microtubule binding. We also provide evidence that this C-terminal domain is required for KLP-18 activity during spindle assembly and show that KLP-18 is continuously required to maintain spindle bipolarity. This study thus provides new insight into the construction and maintenance of the oocyte acentrosomal spindle as well as into kinesin-12 mechanism and regulation. [Media: see text] [Media: see text].
    DOI:  https://doi.org/10.1091/mbc.E22-05-0153
  7. Front Genet. 2022 ;13 852049
    Prognostic Biomarker KIF18A and Its Correlations With Immune Infiltrates and Mitosis in Glioma.
    Bing-Yan Tao, Yu-Yang Liu, Hong-Yu Liu, Ze-Han Zhang, Yun-Qian Guan, Hui Wang, Ying Shi, Jun Zhang.
      Background: Glioma is globally recognised as one of the most frequently occurring primary malignant brain tumours, making the identification of glioma biomarkers critically significant. The protein KIF18A (Kinesin Family Member 18A) is a member of the kinesin superfamily of microtubule-associated molecular motors and has been shown to participate in cell cycle and mitotic metaphase and anaphase. This is the first investigation into the expression of KIF18A and its prognostic value, potential biological functions, and effects on the immune system and mitosis in glioma patients. Methods: Gene expression and clinicopathological analysis, enrichment analysis, and immune infiltration analysis were based on data obtained from The Cancer Genome Atlas (TCGA), with additional bioinformatics analyses performed. Statistical analysis was conducted in R software. Clinical samples were used to evaluate the expression of KIF18A via immunohistochemical staining. In addition, the expression level of KIF18A was validated on U87 cell line. Results: Our results highlighted that KIF18A plays a key role as an independent prognostic factor in patients with glioma. KIF18A was highly expressed in glioma tissues, and KIF18A expression was associated with age, World Health Organization grade, isocitrate dehydrogenase (IDH) status, 1p/19q codeletion, primary therapy outcome, and overall survival (OS). Enrichment analysis revealed that KIF18A is closely correlated with the cell cycle and mitosis. Single sample gene set enrichment analysis (ssGSEA) analysis revealed that KIF18A expression was related to the immune microenvironment. The increased expression of KIF18A in glioma was verified in clinical samples and U87 cell line. Conclusion: The identification of KIF18A as a new biomarker for glioma could help elucidate how changes in the glioma cell and immune microenvironment promote glioma malignancy. With further analysis, KIF18A may serve as an independent prognostic indicator for human glioma.
    Keywords:  Kif18A; bioinformatics; glioma; immune infiltrates; prognostic biomarker
    DOI:  https://doi.org/10.3389/fgene.2022.852049
  8. Front Cell Infect Microbiol. 2022 ;12 864819
    Apicoplast Dynamics During Plasmodium Cell Cycle.
    Arwa Elaagip, Sabrina Absalon, Anat Florentin.
      The deadly malaria parasite, Plasmodium falciparum, contains a unique subcellular organelle termed the apicoplast, which is a clinically-proven antimalarial drug target. The apicoplast is a plastid with essential metabolic functions that evolved via secondary endosymbiosis. As an ancient endosymbiont, the apicoplast retained its own genome and it must be inherited by daughter cells during cell division. During the asexual replication of P. falciparum inside human red blood cells, both the parasite, and the apicoplast inside it, undergo massive morphological changes, including DNA replication and division. The apicoplast is an integral part of the cell and thus its development is tightly synchronized with the cell cycle. At the same time, certain aspects of its dynamics are independent of nuclear division, representing a degree of autonomy in organelle biogenesis. Here, we review the different aspects of organelle dynamics during P. falciparum intraerythrocytic replication, summarize our current understanding of these processes, and describe the many open questions in this area of parasite basic cell biology.
    Keywords:  apicoplast; cell cycle; malaria; organelle dynamics; plasmodium; schizogony
    DOI:  https://doi.org/10.3389/fcimb.2022.864819
  9. Science. 2022 May 20. 376(6595): 818-823
    The deubiquitinase USP8 targets ESCRT-III to promote incomplete cell division.
    Juliette Mathieu, Pascale Michel-Hissier, Virginie Boucherit, Jean-René Huynh.
      In many vertebrate and invertebrate organisms, gametes develop within groups of interconnected cells called germline cysts formed by several rounds of incomplete divisions. We found that loss of the deubiquitinase USP8 gene in Drosophila can transform incomplete divisions of germline cells into complete divisions. Conversely, overexpression of USP8 in germline stem cells is sufficient for the reverse transformation from complete to incomplete cytokinesis. The ESCRT-III proteins CHMP2B and Shrub/CHMP4 are targets of USP8 deubiquitinating activity. In Usp8 mutant sister cells, ectopic recruitment of ESCRT proteins at intercellular bridges causes cysts to break apart. A Shrub/CHMP4 variant that cannot be ubiquitinated does not localize at abscission bridges and cannot complete abscission. Our results uncover ubiquitination of ESCRT-III as a major switch between two types of cell division.
    DOI:  https://doi.org/10.1126/science.abg2653
  10. Plant Cell. 2022 May 17. pii: koac147. [Epub ahead of print]
    MOR1/MAP215 acts synergistically with katanin to control cell division and anisotropic cell elongation in Arabidopsis.
    Yu Chen, Xiayan Liu, Wenjing Zhang, Jie Li, Haofeng Liu, Lan Yang, Pei Lei, Hongchang Zhang, Fei Yu.
      The MAP215 family of microtubule (MT) polymerase/nucleation factors and the MT severing enzyme katanin are widely conserved microtubule-associated proteins (MAPs) across the plant and animal kingdoms. However, how these two essential MAPs coordinate to regulate plant MT dynamics and development remains unknown. Here, we identified novel hypomorphic alleles of MICROTUBULE ORGANIZATION 1 (MOR1), encoding the Arabidopsis thaliana homolog of MAP215, in genetic screens for mutants oversensitive to the MT-destabilizing drug propyzamide. Live imaging in planta revealed that MOR1-green fluorescent protein (GFP) predominantly tracks the plus-ends of cortical MTs in interphase cells and labels preprophase band, spindle and phragmoplast MT arrays in diving cells. Remarkably, MOR1 and KATANIN 1 (KTN1), the p60 subunit of Arabidopsis katanin, act synergistically to control the proper formation of plant-specific MT arrays, and consequently, cell division and anisotropic cell expansion. Moreover, MOR1 physically interacts with KTN1 and promotes KTN1-mediated severing of cortical MTs. Our work establishes the Arabidopsis MOR1-KTN1 interaction as a central functional node dictating MT dynamics and plant growth and development.
    DOI:  https://doi.org/10.1093/plcell/koac147
This page is being maintained by Thomas Krichel. It was last updated on 2022‒06‒06 at 15:07:04.