1
|
Neahring L, Cho NH, He Y, Liu G, Fernandes J, Rux CJ, Nakos K, Subramanian R, Upadhyayula S, Yildiz A, Dumont S. Torques within and outside the human spindle balance twist at anaphase. J Cell Biol 2024; 223:e202312046. [PMID: 38869473 PMCID: PMC11176257 DOI: 10.1083/jcb.202312046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 05/14/2024] [Accepted: 05/30/2024] [Indexed: 06/14/2024] Open
Abstract
At each cell division, nanometer-scale motors and microtubules give rise to the micron-scale spindle. Many mitotic motors step helically around microtubules in vitro, and most are predicted to twist the spindle in a left-handed direction. However, the human spindle exhibits only slight global twist, raising the question of how these molecular torques are balanced. Here, we find that anaphase spindles in the epithelial cell line MCF10A have a high baseline twist, and we identify factors that both increase and decrease this twist. The midzone motors KIF4A and MKLP1 are together required for left-handed twist at anaphase, and we show that KIF4A generates left-handed torque in vitro. The actin cytoskeleton also contributes to left-handed twist, but dynein and its cortical recruitment factor LGN counteract it. Together, our work demonstrates that force generators regulate twist in opposite directions from both within and outside the spindle, preventing strong spindle twist during chromosome segregation.
Collapse
Affiliation(s)
- Lila Neahring
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA, USA
- Developmental and Stem Cell Biology Graduate Program, University of California San Francisco, San Francisco, CA, USA
| | - Nathan H. Cho
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA, USA
- Tetrad Graduate Program, University of California San Francisco, San Francisco, CA, USA
| | - Yifei He
- Department of Chemistry, University of California Berkeley, Berkeley, CA, USA
| | - Gaoxiang Liu
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA, USA
| | - Jonathan Fernandes
- Department of Chemistry, University of California Berkeley, Berkeley, CA, USA
| | - Caleb J. Rux
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA, USA
- UC Berkeley/UC San Francisco Graduate Group in Bioengineering, Berkeley, CA, USA
| | - Konstantinos Nakos
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Radhika Subramanian
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Srigokul Upadhyayula
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA, USA
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Chan Zuckerberg Biohub, San Francisco, CA, USA
| | - Ahmet Yildiz
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA, USA
- Physics Department, University of California Berkeley, Berkeley, CA, USA
| | - Sophie Dumont
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA, USA
- Developmental and Stem Cell Biology Graduate Program, University of California San Francisco, San Francisco, CA, USA
- Tetrad Graduate Program, University of California San Francisco, San Francisco, CA, USA
- UC Berkeley/UC San Francisco Graduate Group in Bioengineering, Berkeley, CA, USA
- Chan Zuckerberg Biohub, San Francisco, CA, USA
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
| |
Collapse
|
2
|
Sacristan C, Samejima K, Ruiz LA, Deb M, Lambers MLA, Buckle A, Brackley CA, Robertson D, Hori T, Webb S, Kiewisz R, Bepler T, van Kwawegen E, Risteski P, Vukušić K, Tolić IM, Müller-Reichert T, Fukagawa T, Gilbert N, Marenduzzo D, Earnshaw WC, Kops GJPL. Vertebrate centromeres in mitosis are functionally bipartite structures stabilized by cohesin. Cell 2024; 187:3006-3023.e26. [PMID: 38744280 PMCID: PMC11164432 DOI: 10.1016/j.cell.2024.04.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 01/30/2024] [Accepted: 04/14/2024] [Indexed: 05/16/2024]
Abstract
Centromeres are scaffolds for the assembly of kinetochores that ensure chromosome segregation during cell division. How vertebrate centromeres obtain a three-dimensional structure to accomplish their primary function is unclear. Using super-resolution imaging, capture-C, and polymer modeling, we show that vertebrate centromeres are partitioned by condensins into two subdomains during mitosis. The bipartite structure is found in human, mouse, and chicken cells and is therefore a fundamental feature of vertebrate centromeres. Super-resolution imaging and electron tomography reveal that bipartite centromeres assemble bipartite kinetochores, with each subdomain binding a distinct microtubule bundle. Cohesin links the centromere subdomains, limiting their separation in response to spindle forces and avoiding merotelic kinetochore-spindle attachments. Lagging chromosomes during cancer cell divisions frequently have merotelic attachments in which the centromere subdomains are separated and bioriented. Our work reveals a fundamental aspect of vertebrate centromere biology with implications for understanding the mechanisms that guarantee faithful chromosome segregation.
Collapse
Affiliation(s)
- Carlos Sacristan
- Oncode Institute, Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW), and University Medical Center Utrecht, Utrecht, the Netherlands.
| | - Kumiko Samejima
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK.
| | - Lorena Andrade Ruiz
- Oncode Institute, Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW), and University Medical Center Utrecht, Utrecht, the Netherlands
| | - Moonmoon Deb
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Maaike L A Lambers
- Oncode Institute, Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW), and University Medical Center Utrecht, Utrecht, the Netherlands
| | - Adam Buckle
- MRC Human Genetics Unit, Institute of Genetics & Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Chris A Brackley
- SUPA School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | - Daniel Robertson
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Tetsuya Hori
- Laboratory of Chromosome Biology, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, Japan
| | - Shaun Webb
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Robert Kiewisz
- Simons Machine Learning Center, New York Structural Biology Center, New York, NY 10027, USA; Biocomputing Unit, Centro Nacional de Biotecnologia (CNB-CSIC), Darwin, 3, Campus Universidad Autonoma, Cantoblanco, Madrid 28049, Spain
| | - Tristan Bepler
- Simons Machine Learning Center, New York Structural Biology Center, New York, NY 10027, USA
| | - Eloïse van Kwawegen
- Oncode Institute, Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW), and University Medical Center Utrecht, Utrecht, the Netherlands
| | | | | | | | - Thomas Müller-Reichert
- Experimental Center, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Tatsuo Fukagawa
- Laboratory of Chromosome Biology, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, Japan
| | - Nick Gilbert
- MRC Human Genetics Unit, Institute of Genetics & Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Davide Marenduzzo
- SUPA School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | - William C Earnshaw
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK.
| | - Geert J P L Kops
- Oncode Institute, Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW), and University Medical Center Utrecht, Utrecht, the Netherlands.
| |
Collapse
|
3
|
Verrillo G, Obeid AM, Genco A, Scrofani J, Orange F, Hanache S, Mignon J, Leyder T, Michaux C, Kempeneers C, Bricmont N, Herkenne S, Vernos I, Martin M, Mottet D. Non-canonical role for the BAF complex subunit DPF3 in mitosis and ciliogenesis. J Cell Sci 2024; 137:jcs261744. [PMID: 38661008 PMCID: PMC11166463 DOI: 10.1242/jcs.261744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 04/04/2024] [Indexed: 04/26/2024] Open
Abstract
DPF3, along with other subunits, is a well-known component of the BAF chromatin remodeling complex, which plays a key role in regulating chromatin remodeling activity and gene expression. Here, we elucidated a non-canonical localization and role for DPF3. We showed that DPF3 dynamically localizes to the centriolar satellites in interphase and to the centrosome, spindle midzone and bridging fiber area, and midbodies during mitosis. Loss of DPF3 causes kinetochore fiber instability, unstable kinetochore-microtubule attachment and defects in chromosome alignment, resulting in altered mitotic progression, cell death and genomic instability. In addition, we also demonstrated that DPF3 localizes to centriolar satellites at the base of primary cilia and is required for ciliogenesis by regulating axoneme extension. Taken together, these findings uncover a moonlighting dual function for DPF3 during mitosis and ciliogenesis.
Collapse
Affiliation(s)
- Giulia Verrillo
- University of Liege, GIGA – Research Institute, Molecular Analysis of Gene Expression (MAGE) Laboratory, B34, Avenue de l'Hôpital, B-4000 Liège, Belgium
| | - Anna Maria Obeid
- University of Liege, GIGA – Research Institute, Molecular Analysis of Gene Expression (MAGE) Laboratory, B34, Avenue de l'Hôpital, B-4000 Liège, Belgium
| | - Alexia Genco
- University of Liege, GIGA – Research Institute, Molecular Analysis of Gene Expression (MAGE) Laboratory, B34, Avenue de l'Hôpital, B-4000 Liège, Belgium
| | - Jacopo Scrofani
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona 08003, Spain
| | - François Orange
- Université Côte d'Azur, Centre Commun de Microscopie Appliquée (CCMA), 06100 Nice, France
| | - Sarah Hanache
- University of Liege, GIGA – Research Institute, Molecular Analysis of Gene Expression (MAGE) Laboratory, B34, Avenue de l'Hôpital, B-4000 Liège, Belgium
| | - Julien Mignon
- University of Namur, Laboratory of Physical Chemistry of Biomolecules, Unité de Chimie Physique Théorique et Structurale (UCPTS), Rue de Bruxelles 61, B-5000 Namur, Belgium
| | - Tanguy Leyder
- University of Namur, Laboratory of Physical Chemistry of Biomolecules, Unité de Chimie Physique Théorique et Structurale (UCPTS), Rue de Bruxelles 61, B-5000 Namur, Belgium
| | - Catherine Michaux
- University of Namur, Laboratory of Physical Chemistry of Biomolecules, Unité de Chimie Physique Théorique et Structurale (UCPTS), Rue de Bruxelles 61, B-5000 Namur, Belgium
| | - Céline Kempeneers
- University of Liege, Pneumology Laboratory, I3 Group, GIGA Research Center, B-4000 Liège, Belgium
- Division of Respirology, Department of Pediatrics, University Hospital Liège, B-4000 Liège, Belgium
| | - Noëmie Bricmont
- University of Liege, Pneumology Laboratory, I3 Group, GIGA Research Center, B-4000 Liège, Belgium
- Division of Respirology, Department of Pediatrics, University Hospital Liège, B-4000 Liège, Belgium
| | - Stephanie Herkenne
- University of Liege, GIGA-Cancer, Laboratory of Mitochondria and Cell Communication, B34, Avenue de l'Hôpital, B-4000 Liège, Belgium
| | - Isabelle Vernos
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona 08003, Spain
- Universitat Pompeu Fabra (UPF), Barcelona 08002, Spain
- ICREA, Pg. Lluis Companys 23, Barcelona 08010, Spain
| | - Maud Martin
- Laboratory of Neurovascular Signaling, Department of Molecular Biology, ULB Neuroscience Institute, Université libre de Bruxelles, B-6041 Gosselies, Belgium
| | - Denis Mottet
- University of Liege, GIGA – Research Institute, Molecular Analysis of Gene Expression (MAGE) Laboratory, B34, Avenue de l'Hôpital, B-4000 Liège, Belgium
| |
Collapse
|
4
|
Zhang JL, Xu MF, Chen J, Wei YL, She ZY. Kinesin-7 CENP-E mediates chromosome alignment and spindle assembly checkpoint in meiosis I. Chromosoma 2024; 133:149-168. [PMID: 38456964 DOI: 10.1007/s00412-024-00818-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 02/05/2024] [Accepted: 02/26/2024] [Indexed: 03/09/2024]
Abstract
In eukaryotes, meiosis is the genetic basis for sexual reproduction, which is important for chromosome stability and species evolution. The defects in meiosis usually lead to chromosome aneuploidy, reduced gamete number, and genetic diseases, but the pathogenic mechanisms are not well clarified. Kinesin-7 CENP-E is a key regulator in chromosome alignment and spindle assembly checkpoint in cell division. However, the functions and mechanisms of CENP-E in male meiosis remain largely unknown. In this study, we have revealed that the CENP-E gene was highly expressed in the rat testis. CENP-E inhibition influences chromosome alignment and spindle organization in metaphase I spermatocytes. We have found that a portion of misaligned homologous chromosomes is located at the spindle poles after CENP-E inhibition, which further activates the spindle assembly checkpoint during the metaphase-to-anaphase transition in rat spermatocytes. Furthermore, CENP-E depletion leads to abnormal spermatogenesis, reduced sperm count, and abnormal sperm head structure. Our findings have elucidated that CENP-E is essential for homologous chromosome alignment and spindle assembly checkpoint in spermatocytes, which further contribute to chromosome stability and sperm cell quality during spermatogenesis.
Collapse
Affiliation(s)
- Jing-Lian Zhang
- Department of Cell Biology and Genetics, The School of Basic Medical Sciences, Fujian Medical University, Fuzhou, 350122, Fujian, China
- Key Laboratory of Stem Cell Engineering and Regenerative Medicine, Fujian Province University, Fuzhou, 350122, Fujian, China
| | - Meng-Fei Xu
- Department of Cell Biology and Genetics, The School of Basic Medical Sciences, Fujian Medical University, Fuzhou, 350122, Fujian, China
- Key Laboratory of Stem Cell Engineering and Regenerative Medicine, Fujian Province University, Fuzhou, 350122, Fujian, China
| | - Jie Chen
- Department of Cell Biology and Genetics, The School of Basic Medical Sciences, Fujian Medical University, Fuzhou, 350122, Fujian, China
- Key Laboratory of Stem Cell Engineering and Regenerative Medicine, Fujian Province University, Fuzhou, 350122, Fujian, China
| | - Ya-Lan Wei
- Medical Research Center, Fujian Maternity and Child Health Hospital, Fuzhou, 350001, Fujian, China
- College of Clinical Medicine for Obstetrics & Gynecology and Pediatrics, Fujian Medical University, Fuzhou, 350122, Fujian, China
| | - Zhen-Yu She
- Department of Cell Biology and Genetics, The School of Basic Medical Sciences, Fujian Medical University, Fuzhou, 350122, Fujian, China.
- Key Laboratory of Stem Cell Engineering and Regenerative Medicine, Fujian Province University, Fuzhou, 350122, Fujian, China.
| |
Collapse
|
5
|
de-Carvalho J, Tlili S, Saunders TE, Telley IA. The positioning mechanics of microtubule asters in Drosophila embryo explants. eLife 2024; 12:RP90541. [PMID: 38426416 PMCID: PMC10911390 DOI: 10.7554/elife.90541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2024] Open
Abstract
Microtubule asters are essential in localizing the action of microtubules in processes including mitosis and organelle positioning. In large cells, such as the one-cell sea urchin embryo, aster dynamics are dominated by hydrodynamic pulling forces. However, in systems with more densely positioned nuclei such as the early Drosophila embryo, which packs around 6000 nuclei within the syncytium in a crystalline-like order, it is unclear what processes dominate aster dynamics. Here, we take advantage of a cell cycle regulation Drosophila mutant to generate embryos with multiple asters, independent from nuclei. We use an ex vivo assay to further simplify this biological system to explore the forces generated by and between asters. Through live imaging, drug and optical perturbations, and theoretical modeling, we demonstrate that these asters likely generate an effective pushing force over short distances.
Collapse
Affiliation(s)
- Jorge de-Carvalho
- Instituto Gulbenkian de Ciência, Fundação Calouste GulbenkianOeirasPortugal
| | - Sham Tlili
- Mechanobiology Institute and Department of Biological Sciences, National University of SingaporeSingaporeSingapore
| | - Timothy E Saunders
- Mechanobiology Institute and Department of Biological Sciences, National University of SingaporeSingaporeSingapore
- Institute of Molecular and Cellular Biology, A*Star, ProteosSingaporeSingapore
- Centre for Mechanochemical Cell Biology, Warwick Medical School, University of WarwickWarwickUnited Kingdom
| | - Ivo A Telley
- Instituto Gulbenkian de Ciência, Fundação Calouste GulbenkianOeirasPortugal
| |
Collapse
|
6
|
Wang Y, Liu YR, Wang PY, Xie P. Computational Studies Reveal How Passive Cross-Linkers Regulate Anaphase Spindle Elongation. J Phys Chem B 2024; 128:1194-1204. [PMID: 38287918 DOI: 10.1021/acs.jpcb.3c07655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2024]
Abstract
In eukaryotic cell division, a series of events are organized to produce two daughter cells. The spindle elongation in anaphase B is essential for providing enough space to maintain cell size and distribute sister chromatids properly, which is associated with microtubules and microtubule-associated proteins such as kinesin-5 Eg5 and the Ase1-related protein, PRC1. The available experimental data indicated that after the start of anaphase B more PRC1 proteins can bind to the antiparallel microtubule pairs in the spindle but the excess amount of PRC1 proteins can lead to the failure of cell division, indicating that PRC1 proteins can regulate the spindle elongation in a concentration-dependent manner. However, the underlying mechanism of the PRC1 proteins regulating the spindle elongation has not been explained up to now. Here, we use a simplified model, where only the two important participants (kinesin-5 Eg5 motors and PRC1 proteins) are considered, to study the spindle elongation during anaphase B. We first show that only in the appropriate range of the PRC1 concentration can the spindle elongation complete properly. Furthermore, we explore the underlying mechanism of PRC1 as a regulator for spindle elongation.
Collapse
Affiliation(s)
- Yao Wang
- Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yu-Ru Liu
- Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Peng-Ye Wang
- Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ping Xie
- Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| |
Collapse
|
7
|
Zeng S, Wang Q, Zhou R, Wang D. KIF4A functions as a diagnostic and prognostic biomarker and regulates tumor immune microenvironment in skin cutaneous melanoma. Pathol Res Pract 2024; 254:155166. [PMID: 38286055 DOI: 10.1016/j.prp.2024.155166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 01/06/2024] [Accepted: 01/22/2024] [Indexed: 01/31/2024]
Abstract
BACKGROUND KIF4A is upregulated in various malignancies and serves as an independent risk factor. However, its function in skin cutaneous melanoma (SKCM) and the regulation of the immunological environment remains unknown. METHODS We first explored the mRNA and protein levels of KIF4A in SKCM through public databases. Then, the co-expressed genes with KIF4A in SKCM and their functional enrichment analysis were performed. Moreover, the clinical value, relationship with immune infiltration and tumor microenvironment (TME), as well as the correlation between KIF4A and immunomodulators were evaluated. In addition, we validated the function of KIF4A by in vitro experiments such as CCK-8 assay, clone formation and wound healing assay. RESULTS Our data reveal that the mRNA and protein levels of KIF4A are highly expressed in SKCM. Moreover, functional enrichment analysis of the top 50 co-expressed genes with KIF4A showed significant association with organelle fission, tubulin binding and immune processes. KIF4A can distinguish SKCM from normal tissue and predict a poorer prognosis. A negative association was observed between KIF4A and TME, and KIF4A exhibited a negative correlation with most immunomodulators. Additionally, the knockdown of KIF4A inhibited the proliferation and migration ability of A375 cells. CONCLUSIONS Our findings suggest that KIF4A promotes the progression of SKCM and is negatively associated with immune infiltration and immunomodulators, which indicates a poor prognosis.
Collapse
Affiliation(s)
- Siyi Zeng
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, People's Republic of China
| | - Qirui Wang
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, People's Republic of China.
| | - Renpeng Zhou
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, People's Republic of China
| | - Danru Wang
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, People's Republic of China.
| |
Collapse
|
8
|
Zekušić M, Bujić Mihica M, Skoko M, Vukušić K, Risteski P, Martinčić J, Tolić IM, Bendelja K, Ramić S, Dolenec T, Vrgoč Zimić I, Puljić D, Petric Vicković I, Iveković R, Batarilo I, Prosenc Zmrzljak U, Hoffmeister A, Vučemilo T. New characterization and safety evaluation of human limbal stem cells used in clinical application: fidelity of mitotic process and mitotic spindle morphologies. Stem Cell Res Ther 2023; 14:368. [PMID: 38093301 PMCID: PMC10720168 DOI: 10.1186/s13287-023-03586-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 11/23/2023] [Indexed: 12/17/2023] Open
Abstract
BACKGROUND Limbal stem cells (LSCs) are crucial for the regeneration of the corneal epithelium in patients with limbal stem cell deficiency (LSCD). Thus, LSCs during cultivation in vitro should be in highly homogeneous amounts, while potency and expression of stemness without tumorigenesis would be desirable. Therefore, further characterization and safety evaluation of engineered limbal grafts is required to provide safe and high-quality therapeutic applications. METHODS After in vitro expansion, LSCs undergo laboratory characterization in a single-cell suspension, cell culture, and in limbal grafts before transplantation. Using a clinically applicable protocol, the data collected on LSCs at passage 1 were summarized, including: identity (cell size, morphology); potency (yield, viability, population doubling time, colony-forming efficiency); expression of putative stem cell markers through flow cytometry, immunofluorescence, and immunohistochemistry. Then, mitotic chromosome stability and normal mitotic outcomes were explored by using live-cell imaging. Finally, impurities, bacterial endotoxins and sterility were determined. RESULTS Expression of the stemness marker p63 in single-cell suspension and in cell culture showed high values by different methods. Limbal grafts showed p63-positive cells (78.7 ± 9.4%), Ki67 proliferation (41.7 ± 15.9%), while CK3 was negative. Impurity with 3T3 feeder cells and endotoxins was minimized. We presented mitotic spindles with a length of 11.40 ± 0.54 m and a spindle width of 8.05 ± 0.55 m as new characterization in LSC culture. Additionally, live-cell imaging of LSCs (n = 873) was performed, and only a small fraction < 2.5% of aberrant interphase cells was observed; 2.12 ± 2.10% of mitotic spindles exhibited a multipolar phenotype during metaphase, and 3.84 ± 3.77% of anaphase cells had a DNA signal present within the spindle midzone, indicating a chromosome bridge or lagging chromosome phenotype. CONCLUSION This manuscript provides, for the first time, detailed characterization of the parameters of fidelity of the mitotic process and mitotic spindle morphologies of LSCs used in a direct clinical application. Our data show that p63-positive CK3-negative LSCs grown in vitro for clinical purposes undergo mitotic processes with extremely high fidelity, suggesting high karyotype stability. This finding confirms LSCs as a high-quality and safe therapy for eye regeneration in humans.
Collapse
Affiliation(s)
- Marija Zekušić
- Department of Transfusion and Regenerative Medicine, Sestre milosrdnice University Hospital Center, Zagreb, Croatia
| | - Marina Bujić Mihica
- Department of Transfusion and Regenerative Medicine, Sestre milosrdnice University Hospital Center, Zagreb, Croatia.
| | - Marija Skoko
- Department of Transfusion and Regenerative Medicine, Sestre milosrdnice University Hospital Center, Zagreb, Croatia
| | - Kruno Vukušić
- Division of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| | - Patrik Risteski
- Division of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| | - Jelena Martinčić
- Division of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| | - Iva M Tolić
- Division of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| | - Krešo Bendelja
- Center for Research and Knowledge Transfer in Biotechnology, Laboratory of Immunology, University of Zagreb, Zagreb, Croatia
| | - Snježana Ramić
- Department of Oncological Pathology and Clinical Cytology 'Ljudevit Jurak', University Hospital Center Sestre Milosrdnice, Zagreb, Croatia
| | - Tamara Dolenec
- Department of Transfusion and Regenerative Medicine, Sestre milosrdnice University Hospital Center, Zagreb, Croatia
| | - Ivana Vrgoč Zimić
- Department of Transfusion and Regenerative Medicine, Sestre milosrdnice University Hospital Center, Zagreb, Croatia
| | - Dominik Puljić
- Department of Transfusion and Regenerative Medicine, Sestre milosrdnice University Hospital Center, Zagreb, Croatia
| | - Ivanka Petric Vicković
- Clinical Department of Ophthalmology, Sestre milosrdnice University Hospital Center, Zagreb, Croatia
| | - Renata Iveković
- Clinical Department of Ophthalmology, Sestre milosrdnice University Hospital Center, Zagreb, Croatia
| | - Ivanka Batarilo
- Department of Microbiology, Croatian Institute of Transfusion Medicine, Zagreb, Croatia
| | - Uršula Prosenc Zmrzljak
- Molecular Biology Department, BIA Separations CRO, Labena d.O.O, Ljubljana, Slovenia
- Labena d.o.o, Zagreb, Croatia
| | | | - Tiha Vučemilo
- Department of Transfusion and Regenerative Medicine, Sestre milosrdnice University Hospital Center, Zagreb, Croatia
| |
Collapse
|
9
|
Neahring L, He Y, Cho NH, Liu G, Fernandes J, Rux CJ, Nakos K, Subramanian R, Upadhyayula S, Yildiz A, Dumont S. Torques within and outside the human spindle balance twist at anaphase. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.10.570990. [PMID: 38405786 PMCID: PMC10888964 DOI: 10.1101/2023.12.10.570990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
At each cell division, nanometer-scale motors and microtubules give rise to the micron-scale spindle. Many mitotic motors step helically around microtubules in vitro, and most are predicted to twist the spindle in a left-handed direction. However, the human spindle exhibits only slight global twist, raising the question of how these molecular torques are balanced. Here, using lattice light sheet microscopy, we find that anaphase spindles in the epithelial cell line MCF10A have a high baseline twist, and we identify factors that both increase and decrease this twist. The midzone motors KIF4A and MKLP1 are redundantly required for left-handed twist at anaphase, and we show that KIF4A generates left-handed torque in vitro. The actin cytoskeleton also contributes to left-handed twist, but dynein and its cortical recruitment factor LGN counteract it. Together, our work demonstrates that force generators regulate twist in opposite directions from both within and outside the spindle, preventing strong spindle twist during chromosome segregation.
Collapse
Affiliation(s)
- Lila Neahring
- Department of Bioengineering & Therapeutic Sciences, University of California San Francisco, San Francisco, CA, USA
- Developmental & Stem Cell Biology Graduate Program, University of California San Francisco, San Francisco, CA, USA
| | - Yifei He
- Department of Chemistry, University of California Berkeley, Berkeley, CA, USA
| | - Nathan H. Cho
- Department of Bioengineering & Therapeutic Sciences, University of California San Francisco, San Francisco, CA, USA
- Tetrad Graduate Program, University of California San Francisco, San Francisco, CA, USA
| | - Gaoxiang Liu
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA, USA
| | - Jonathan Fernandes
- Department of Chemistry, University of California Berkeley, Berkeley, CA, USA
| | - Caleb J. Rux
- Department of Bioengineering & Therapeutic Sciences, University of California San Francisco, San Francisco, CA, USA
- UC Berkeley/UC San Francisco Graduate Group in Bioengineering, Berkeley, CA, USA
| | - Konstantinos Nakos
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Radhika Subramanian
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Srigokul Upadhyayula
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA, USA
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Chan Zuckerberg Biohub, San Francisco, CA, USA
| | - Ahmet Yildiz
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA, USA
- Physics Department, University of California Berkeley, Berkeley, CA, USA
| | - Sophie Dumont
- Department of Bioengineering & Therapeutic Sciences, University of California San Francisco, San Francisco, CA, USA
- Developmental & Stem Cell Biology Graduate Program, University of California San Francisco, San Francisco, CA, USA
- Tetrad Graduate Program, University of California San Francisco, San Francisco, CA, USA
- UC Berkeley/UC San Francisco Graduate Group in Bioengineering, Berkeley, CA, USA
- Chan Zuckerberg Biohub, San Francisco, CA, USA
- Department of Biochemistry & Biophysics, University of California San Francisco, San Francisco, CA, USA
| |
Collapse
|
10
|
Li W, Crellin HA, Cheerambathur D, McNally FJ. Redundant microtubule crosslinkers prevent meiotic spindle bending to ensure diploid offspring in C. elegans. PLoS Genet 2023; 19:e1011090. [PMID: 38150489 PMCID: PMC10775986 DOI: 10.1371/journal.pgen.1011090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 01/09/2024] [Accepted: 12/05/2023] [Indexed: 12/29/2023] Open
Abstract
Oocyte meiotic spindles mediate the expulsion of ¾ of the genome into polar bodies to generate diploid zygotes in nearly all animal species. Failures in this process result in aneuploid or polyploid offspring that are typically inviable. Accurate meiotic chromosome segregation and polar body extrusion require the spindle to elongate while maintaining its structural integrity. Previous studies have implicated three hypothetical activities during this process, including microtubule crosslinking, microtubule sliding and microtubule polymerization. However, how these activities regulate spindle rigidity and elongation as well as the exact proteins involved in the activities remain unclear. We discovered that C. elegans meiotic anaphase spindle integrity is maintained through redundant microtubule crosslinking activities of the Kinesin-5 family motor BMK-1, the microtubule bundling protein SPD-1/PRC1, and the Kinesin-4 family motor, KLP-19. Using time-lapse imaging, we found that single depletion of KLP-19KIF4A, SPD-1PRC1 or BMK-1Eg5 had minimal effects on anaphase B spindle elongation velocity. In contrast, double depletion of SPD-1PRC1 and BMK-1Eg5 or double depletion of KLP-19KIF4A and BMK-1Eg5 resulted in spindles that elongated faster, bent in a myosin-dependent manner, and had a high rate of polar body extrusion errors. Bending spindles frequently extruded both sets of segregating chromosomes into two separate polar bodies. Normal anaphase B velocity was observed after double depletion of KLP-19KIF4A and SPD-1PRC1. These results suggest that KLP-19KIF4A and SPD-1PRC1 act in different pathways, each redundant with a separate BMK-1Eg5 pathway in regulating meiotic spindle elongation. Depletion of ZYG-8, a doublecortin-related microtubule binding protein, led to slower anaphase B spindle elongation. We found that ZYG-8DCLK1 acts by excluding SPD-1PRC1 from the spindle. Thus, three mechanistically distinct microtubule regulation modules, two based on crosslinking, and one based on exclusion of crosslinkers, power the mechanism that drives spindle elongation and structural integrity during anaphase B of C.elegans female meiosis.
Collapse
Affiliation(s)
- Wenzhe Li
- Department of Molecular and Cellular Biology, University of California, Davis, California, United States of America
| | - Helena A. Crellin
- Wellcome Centre for Cell Biology & Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Dhanya Cheerambathur
- Wellcome Centre for Cell Biology & Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Francis J. McNally
- Department of Molecular and Cellular Biology, University of California, Davis, California, United States of America
| |
Collapse
|
11
|
Gluszek‐Kustusz A, Craske B, Legal T, McHugh T, Welburn JPI. Phosphorylation controls spatial and temporal activities of motor-PRC1 complexes to complete mitosis. EMBO J 2023; 42:e113647. [PMID: 37592895 PMCID: PMC10620760 DOI: 10.15252/embj.2023113647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 06/30/2023] [Accepted: 07/25/2023] [Indexed: 08/19/2023] Open
Abstract
During mitosis, spindle architecture alters as chromosomes segregate into daughter cells. The microtubule crosslinker protein regulator of cytokinesis 1 (PRC1) is essential for spindle stability, chromosome segregation and completion of cytokinesis, but how it recruits motors to the central spindle to coordinate the segregation of chromosomes is unknown. Here, we combine structural and cell biology approaches to show that the human CENP-E motor, which is essential for chromosome capture and alignment by microtubules, binds to PRC1 through a conserved hydrophobic motif. This binding mechanism is also used by Kinesin-4 Kif4A:PRC1. Using in vitro reconstitution, we demonstrate that CENP-E slides antiparallel PRC1-crosslinked microtubules. We find that the regulation of CENP-E -PRC1 interaction is spatially and temporally coupled with relocalization to overlapping microtubules in anaphase. Finally, we demonstrate that the PRC1-microtubule motor interaction is essential in anaphase to control chromosome partitioning, retain central spindle integrity and ensure cytokinesis. Taken together our findings reveal the molecular basis for the cell cycle regulation of motor-PRC1 complexes to couple chromosome segregation and cytokinesis.
Collapse
Affiliation(s)
- Agata Gluszek‐Kustusz
- Wellcome Centre for Cell Biology, School of Biological SciencesUniversity of EdinburghEdinburghUK
| | - Benjamin Craske
- Wellcome Centre for Cell Biology, School of Biological SciencesUniversity of EdinburghEdinburghUK
| | - Thibault Legal
- Wellcome Centre for Cell Biology, School of Biological SciencesUniversity of EdinburghEdinburghUK
- McGill UniversityMontrealQCCanada
| | - Toni McHugh
- Wellcome Centre for Cell Biology, School of Biological SciencesUniversity of EdinburghEdinburghUK
| | - Julie PI Welburn
- Wellcome Centre for Cell Biology, School of Biological SciencesUniversity of EdinburghEdinburghUK
| |
Collapse
|
12
|
Du L, Wu Y, Jia Q, Li J, Li Y, Ma H, Fan Z, Guo X, Li L, Peng Y, Li J, Fang Z, Zhang X. Autophagy Suppresses Ferroptosis by Degrading TFR1 to Alleviate Cognitive Dysfunction in Mice with SAE. Cell Mol Neurobiol 2023; 43:3605-3622. [PMID: 37341832 DOI: 10.1007/s10571-023-01370-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 05/30/2023] [Indexed: 06/22/2023]
Abstract
Sepsis-associated encephalopathy (SAE) is a serious complication of sepsis that is characterized by long-term cognitive impairment, which imposes a heavy burden on families and society. However, its pathological mechanism has not been elucidated. Ferroptosis is a novel form of programmed cell death that is involved in multiple neurodegenerative diseases. In the current study, we found that ferroptosis also participated in the pathological process of cognitive dysfunction in SAE, while Liproxstatin-1 (Lip-1) effectively inhibited ferroptosis and alleviated cognitive impairment. Additionally, since an increasing number of studies have suggested the crosstalk between autophagy and ferroptosis, we further proved the essential role of autophagy in this process and demonstrated the key molecular mechanism of the autophagy-ferroptosis interaction. Currently, we showed that autophagy in the hippocampus was downregulated within 3 days of lipopolysaccharide injection into the lateral ventricle. Moreover, enhancing autophagy ameliorated cognitive dysfunction. Importantly, we found that autophagy suppressed ferroptosis by downregulating transferrin receptor 1 (TFR1) in the hippocampus, thereby alleviating cognitive impairment in mice with SAE. In conclusion, our findings indicated that hippocampal neuronal ferroptosis is associated with cognitive impairment. In addition, enhancing autophagy can inhibit ferroptosis via degradation of TFR1 to ameliorate cognitive impairment in SAE, which shed new light on the prevention and therapy for SAE.
Collapse
Affiliation(s)
- Lixia Du
- Department of Anesthesiology and Perioperative Medicine and Department of Intensive Care Unit, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, Shaanxi, China
- College of Life Sciences, Northwest University, Xi'an, 710069, Shaanxi, China
| | - You Wu
- Department of Anesthesiology and Perioperative Medicine and Department of Intensive Care Unit, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, Shaanxi, China
| | - Qi Jia
- Department of Anesthesiology and Perioperative Medicine and Department of Intensive Care Unit, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, Shaanxi, China
| | - Jin Li
- Department of Anesthesiology and Perioperative Medicine and Department of Intensive Care Unit, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, Shaanxi, China
| | - Yi Li
- Department of Anesthesiology and Perioperative Medicine and Department of Intensive Care Unit, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, Shaanxi, China
| | - Hongwei Ma
- Department of Anesthesiology and Perioperative Medicine and Department of Intensive Care Unit, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, Shaanxi, China
| | - Zhongmin Fan
- Department of Anesthesiology and Perioperative Medicine and Department of Intensive Care Unit, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, Shaanxi, China
| | - Xiaofeng Guo
- Department of Anesthesiology and Perioperative Medicine and Department of Intensive Care Unit, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, Shaanxi, China
| | - Ling Li
- Department of Anesthesiology and Perioperative Medicine and Department of Intensive Care Unit, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, Shaanxi, China
| | - Yuliang Peng
- Department of Anesthesiology and Perioperative Medicine and Department of Intensive Care Unit, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, Shaanxi, China
| | - Jing Li
- Department of Anesthesiology and Perioperative Medicine and Department of Intensive Care Unit, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, Shaanxi, China
| | - Zongping Fang
- Department of Anesthesiology and Perioperative Medicine and Department of Intensive Care Unit, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, Shaanxi, China.
- Translational Research Institute of Brain and Brain-Like Intelligence, School of Medicine, Shanghai Fourth People's Hospital, Tongji University, Shanghai, 200434, China.
| | - Xijing Zhang
- Department of Anesthesiology and Perioperative Medicine and Department of Intensive Care Unit, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, Shaanxi, China.
| |
Collapse
|
13
|
do Rosário CF, Zhang Y, Stadnicki J, Ross JL, Wadsworth P. Lateral and longitudinal compaction of PRC1 overlap zones drives stabilization of interzonal microtubules. Mol Biol Cell 2023; 34:ar100. [PMID: 37467037 PMCID: PMC10551706 DOI: 10.1091/mbc.e23-02-0049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 06/20/2023] [Accepted: 07/04/2023] [Indexed: 07/20/2023] Open
Abstract
During anaphase, antiparallel-overlapping midzone microtubules elongate and form bundles, contributing to chromosome segregation and the location of contractile ring formation. Midzone microtubules are dynamic in early but not late anaphase; however, the kinetics and mechanisms of stabilization are incompletely understood. Using photoactivation of cells expressing PA-EGFP-α-tubulin we find that immediately after anaphase onset, a single highly dynamic population of midzone microtubules is present; as anaphase progresses, both dynamic and stable populations of midzone microtubules coexist. By mid-cytokinesis, only static, non-dynamic microtubules are detected. The velocity of microtubule sliding also decreases as anaphase progresses, becoming undetectable by late anaphase. Following depletion of PRC1, midzone microtubules remain highly dynamic in anaphase and fail to form static arrays in telophase despite furrowing. Cells depleted of Kif4a contain elongated PRC1 overlap zones and fail to form static arrays in telophase. Cells blocked in cytokinesis form short PRC1 overlap zones that do not coalesce laterally; these cells also fail to form static arrays in telophase. Together, our results demonstrate that dynamic turnover and sliding of midzone microtubules is gradually reduced during anaphase and that the final transition to a static array in telophase requires both lateral and longitudinal compaction of PRC1 containing overlap zones.
Collapse
Affiliation(s)
- Carline Fermino do Rosário
- Department of Biology, University of Massachusetts Amherst, Amherst MA 01003
- Program in Molecular and Cellular Biology, University of Massachusetts Amherst, Amherst MA 01003
| | - Ying Zhang
- Department of Biology, University of Massachusetts Amherst, Amherst MA 01003
| | - Jennifer Stadnicki
- Department of Biology, University of Massachusetts Amherst, Amherst MA 01003
- Program in Molecular and Cellular Biology, University of Massachusetts Amherst, Amherst MA 01003
| | | | - Patricia Wadsworth
- Department of Biology, University of Massachusetts Amherst, Amherst MA 01003
- Program in Molecular and Cellular Biology, University of Massachusetts Amherst, Amherst MA 01003
| |
Collapse
|
14
|
Bracey KM, Noguchi P, Edwards C, Cario A, Gu G, Kaverina I. Glucose-stimulated KIF5B-driven microtubule sliding organizes microtubule networks in pancreatic beta cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.25.546468. [PMID: 37425827 PMCID: PMC10327020 DOI: 10.1101/2023.06.25.546468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
In pancreatic islet beta cells, molecular motors use cytoskeletal polymers microtubules as tracks for intracellular transport of insulin secretory granules. Beta-cell microtubule network has a complex architecture and is non-directional, which provide insulin granules at the cell periphery for rapid secretion response, yet to avoid over-secretion and subsequent hypoglycemia. We have previously characterized a peripheral sub-membrane microtubule array, which is critical for withdrawal of excessive insulin granules from the secretion sites. Microtubules in beta cells originate at the Golgi in the cell interior, and how the peripheral array is formed is unknown. Using real-time imaging and photo-kinetics approaches in clonal mouse pancreatic beta cells MIN6, we now demonstrate that kinesin KIF5B, a motor protein with a capacity to transport microtubules as cargos, slides existing microtubules to the cell periphery and aligns them to each other along the plasma membrane. Moreover, like many physiological beta-cell features, microtubule sliding is facilitated by a high glucose stimulus. These new data, together with our previous report that in high glucose sub-membrane MT array is destabilized to allow for robust secretion, indicate that MT sliding is another integral part of glucose-triggered microtubule remodeling, likely replacing destabilized peripheral microtubules to prevent their loss over time and beta-cell malfunction.
Collapse
Affiliation(s)
- Kai M Bracey
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37235, USA
| | - Pi'illani Noguchi
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37235, USA
| | - Courtney Edwards
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Alisa Cario
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37235, USA
| | - Guoqiang Gu
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37235, USA
- Program of Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA. Corresponding author: Irina Kaverina
| | - Irina Kaverina
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37235, USA
- Program of Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA
| |
Collapse
|
15
|
Moreno-Andrés D, Holl K, Antonin W. The second half of mitosis and its implications in cancer biology. Semin Cancer Biol 2023; 88:1-17. [PMID: 36436712 DOI: 10.1016/j.semcancer.2022.11.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 11/16/2022] [Accepted: 11/21/2022] [Indexed: 11/26/2022]
Abstract
The nucleus undergoes dramatic structural and functional changes during cell division. With the entry into mitosis, in human cells the nuclear envelope breaks down, chromosomes rearrange into rod-like structures which are collected and segregated by the spindle apparatus. While these processes in the first half of mitosis have been intensively studied, much less is known about the second half of mitosis, when a functional nucleus reforms in each of the emerging cells. Here we review our current understanding of mitotic exit and nuclear reformation with spotlights on the links to cancer biology.
Collapse
Affiliation(s)
- Daniel Moreno-Andrés
- Institute of Biochemistry and Molecular Cell Biology, Medical School, RWTH Aachen University, Aachen, Germany.
| | - Kristin Holl
- Institute of Biochemistry and Molecular Cell Biology, Medical School, RWTH Aachen University, Aachen, Germany
| | - Wolfram Antonin
- Institute of Biochemistry and Molecular Cell Biology, Medical School, RWTH Aachen University, Aachen, Germany
| |
Collapse
|
16
|
Matković J, Ghosh S, Ćosić M, Eibes S, Barišić M, Pavin N, Tolić IM. Kinetochore- and chromosome-driven transition of microtubules into bundles promotes spindle assembly. Nat Commun 2022; 13:7307. [PMID: 36435852 PMCID: PMC9701229 DOI: 10.1038/s41467-022-34957-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 11/11/2022] [Indexed: 11/28/2022] Open
Abstract
Mitotic spindle assembly is crucial for chromosome segregation and relies on bundles of microtubules that extend from the poles and overlap in the middle. However, how these structures form remains poorly understood. Here we show that overlap bundles arise through a network-to-bundles transition driven by kinetochores and chromosomes. STED super-resolution microscopy reveals that PRC1-crosslinked microtubules initially form loose arrays, which become rearranged into bundles. Kinetochores promote microtubule bundling by lateral binding via CENP-E/kinesin-7 in an Aurora B-regulated manner. Steric interactions between the bundle-associated chromosomes at the spindle midplane drive bundle separation and spindle widening. In agreement with experiments, theoretical modeling suggests that bundles arise through competing attractive and repulsive mechanisms. Finally, perturbation of overlap bundles leads to inefficient correction of erroneous kinetochore-microtubule attachments. Thus, kinetochores and chromosomes drive coarsening of a uniform microtubule array into overlap bundles, which promote not only spindle formation but also chromosome segregation fidelity.
Collapse
Affiliation(s)
- Jurica Matković
- grid.4905.80000 0004 0635 7705Division of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| | - Subhadip Ghosh
- grid.4808.40000 0001 0657 4636Department of Physics, Faculty of Science, University of Zagreb, Zagreb, Croatia
| | - Mateja Ćosić
- grid.4905.80000 0004 0635 7705Division of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| | - Susana Eibes
- grid.417390.80000 0001 2175 6024Cell Division and Cytoskeleton, Danish Cancer Society Research Center, Copenhagen, Denmark
| | - Marin Barišić
- grid.417390.80000 0001 2175 6024Cell Division and Cytoskeleton, Danish Cancer Society Research Center, Copenhagen, Denmark ,grid.5254.60000 0001 0674 042XDepartment of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Nenad Pavin
- grid.4808.40000 0001 0657 4636Department of Physics, Faculty of Science, University of Zagreb, Zagreb, Croatia
| | - Iva M. Tolić
- grid.4905.80000 0004 0635 7705Division of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| |
Collapse
|
17
|
Carlier-Grynkorn F, Fachinetti D, Tran PT. Kinesin-14 HSET may not oppose kinesin-5 Eg5 activity in RPE-1 cells. MICROPUBLICATION BIOLOGY 2022; 2022:10.17912/micropub.biology.000623. [PMID: 36004005 PMCID: PMC9393730 DOI: 10.17912/micropub.biology.000623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 08/03/2022] [Accepted: 08/06/2022] [Indexed: 11/13/2022]
Abstract
Human retinal pigment epithelium RPE-1 cells are immortalized diploid wild-type cells. RPE-1 is increasingly used for studies of spindle assembly dynamics and chromosome segregation. Here, we imaged living RPE-1 cells using the spinning disk confocal microscope and report their complete spindle assembly dynamic parameters. Live-cell experiments enabled ascribing precise timing of function of the kinesin-5 Eg5 and kinesin-14 HSET throughout different phases of mitosis. Eg5 functions at prophase and metaphase, to assemble and maintain spindle bipolarity, respectively. Eg5 inhibition results in spindle collapse during prophase and metaphase, resulting in monoastral/monopolar spindles. HSET functions throughout mitosis to maintain spindle length. HSET degradation results in shorter spindles through all phases of mitosis. Double-inhibition of Eg5 and HSET produces only monoastral/monopolar spindles, indicating that Eg5 and HSET may not be antagonistic in wild-type RPE-1 cells, contrary to previous studies using cancer cells. In the context of spindle assembly, our results highlight potential important differences between RPE-1 and other cancer-derived cell lines.
Collapse
Affiliation(s)
| | - Daniele Fachinetti
- Institut Curie, PSL Université, Sorbonne Université, CNRS UMR144, Paris, France
| | - Phong T. Tran
- Institut Curie, PSL Université, Sorbonne Université, CNRS UMR144, Paris, France
,
University of Pennsylvania, Department of Cell and Developmental Biology, Philadelphia, PA, United States
,
Correspondence to: Phong T. Tran (
)
| |
Collapse
|
18
|
Tan F, Xu J. Validation of the solution structure of dimerization domain of PRC1. PLoS One 2022; 17:e0270572. [PMID: 35930764 PMCID: PMC9355583 DOI: 10.1371/journal.pone.0270572] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 06/13/2022] [Indexed: 11/18/2022] Open
Abstract
Cell-cycle dependent proteins are indispensible for the accurate division of cells, a group of proteins called Microtubule-associated proteins (MAPs) are important to cell division as it bind microtubules and participate with other co-factors to form the spindle midbody, which works as the workhorse of cell-division. PRC1 is a distinguishing member of MAPs, as it is a human MAP and works as the key in mediating daughter cell segregation in ana-phase and telo-phase. The physiological significance of PRC1 calls for a high resolution three-dimensional structure. The crystal structure of PRC1 was published but has low resolution (>3 Å) and incomplete sidechains, placing hurdles to understanding the structure-function relationships of PRC1, therefore, we determined the high-resolution solution structure of PRC1’s dimerization domain using NMR spectroscopy. Significant differences between the crystal structure and the solution structure can be observed, the main differences center around the N terminus and the end of the alpha-Helix H2. Furthermore, detailed structure analyses revealed that the hydrophobic core packing of the solution and crystal structures are also different. To validate the solution structure, we used Hydrogen-deuterium exchange experiments that address the structural discrepancies between the crystal and solution structure; we also generated mutants that are key to the differences in the crystal and solution structures, measuring its structural or thermal stability by NMR spectroscopy and Fluorescence Thermal Shift Assays. These results suggest that N terminal residues are key to the integrity of the whole protein, and the solution structure of the dimerization domain better reflects the conformation PRC1 adopted in solution conditions.
Collapse
Affiliation(s)
- Fei Tan
- Peking University, Beijing, China
- * E-mail:
| | - Jin Xu
- Peking University, Beijing, China
| |
Collapse
|
19
|
Risteski P, Božan D, Jagrić M, Bosilj A, Pavin N, Tolić IM. Length-dependent poleward flux of sister kinetochore fibers promotes chromosome alignment. Cell Rep 2022; 40:111169. [PMID: 35926461 PMCID: PMC9364240 DOI: 10.1016/j.celrep.2022.111169] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 04/20/2022] [Accepted: 07/14/2022] [Indexed: 11/25/2022] Open
Abstract
Chromosome alignment at the spindle equator promotes proper chromosome segregation and depends on pulling forces exerted at kinetochore fiber tips together with polar ejection forces. However, kinetochore fibers are also subjected to forces driving their poleward flux. Here we introduce a flux-driven centering model that relies on flux generated by forces within the overlaps of bridging and kinetochore fibers. This centering mechanism works so that the longer kinetochore fiber fluxes faster than the shorter one, moving the kinetochores toward the center. We develop speckle microscopy in human spindles and confirm the key prediction that kinetochore fiber flux is length dependent. Kinetochores are better centered when overlaps are shorter and the kinetochore fiber flux slower than the bridging fiber flux. We identify Kif18A and Kif4A as overlap and flux regulators and NuMA as a fiber coupler. Thus, length-dependent sliding forces exerted by the bridging fiber onto kinetochore fibers support chromosome alignment. A flux-driven centering model explains chromosome alignment at the spindle equator Kinetochore fiber poleward flux is driven by overlap microtubules Kinetochore centering requires faster flux of the longer sister kinetochore fiber Chromosome alignment depends on the overlap length of bridging microtubules
Collapse
Affiliation(s)
- Patrik Risteski
- Division of Molecular Biology, Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia
| | - Domagoj Božan
- Department of Physics, Faculty of Science, University of Zagreb, Bijenička cesta 32, 10000 Zagreb, Croatia
| | - Mihaela Jagrić
- Division of Molecular Biology, Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia
| | - Agneza Bosilj
- Department of Physics, Faculty of Science, University of Zagreb, Bijenička cesta 32, 10000 Zagreb, Croatia
| | - Nenad Pavin
- Department of Physics, Faculty of Science, University of Zagreb, Bijenička cesta 32, 10000 Zagreb, Croatia.
| | - Iva M Tolić
- Division of Molecular Biology, Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia.
| |
Collapse
|
20
|
Klaasen SJ, Truong MA, van Jaarsveld RH, Koprivec I, Štimac V, de Vries SG, Risteski P, Kodba S, Vukušić K, de Luca KL, Marques JF, Gerrits EM, Bakker B, Foijer F, Kind J, Tolić IM, Lens SMA, Kops GJPL. Nuclear chromosome locations dictate segregation error frequencies. Nature 2022; 607:604-609. [PMID: 35831506 PMCID: PMC9300461 DOI: 10.1038/s41586-022-04938-0] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 06/07/2022] [Indexed: 12/25/2022]
Abstract
Chromosome segregation errors during cell divisions generate aneuploidies and micronuclei, which can undergo extensive chromosomal rearrangements such as chromothripsis1-5. Selective pressures then shape distinct aneuploidy and rearrangement patterns-for example, in cancer6,7-but it is unknown whether initial biases in segregation errors and micronucleation exist for particular chromosomes. Using single-cell DNA sequencing8 after an error-prone mitosis in untransformed, diploid cell lines and organoids, we show that chromosomes have different segregation error frequencies that result in non-random aneuploidy landscapes. Isolation and sequencing of single micronuclei from these cells showed that mis-segregating chromosomes frequently also preferentially become entrapped in micronuclei. A similar bias was found in naturally occurring micronuclei of two cancer cell lines. We find that segregation error frequencies of individual chromosomes correlate with their location in the interphase nucleus, and show that this is highest for peripheral chromosomes behind spindle poles. Randomization of chromosome positions, Cas9-mediated live tracking and forced repositioning of individual chromosomes showed that a greater distance from the nuclear centre directly increases the propensity to mis-segregate. Accordingly, chromothripsis in cancer genomes9 and aneuploidies in early development10 occur more frequently for larger chromosomes, which are preferentially located near the nuclear periphery. Our findings reveal a direct link between nuclear chromosome positions, segregation error frequencies and micronucleus content, with implications for our understanding of tumour genome evolution and the origins of specific aneuploidies during development.
Collapse
Affiliation(s)
- Sjoerd J Klaasen
- Oncode Institute, Hubrecht Institute-KNAW (Royal Academy of Arts and Sciences) and University Medical Centre Utrecht, Utrecht, the Netherlands
| | - My Anh Truong
- Oncode Institute, Centre for Molecular Medicine, University Medical Centre Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Richard H van Jaarsveld
- Oncode Institute, Hubrecht Institute-KNAW (Royal Academy of Arts and Sciences) and University Medical Centre Utrecht, Utrecht, the Netherlands
| | | | | | - Sippe G de Vries
- Oncode Institute, Centre for Molecular Medicine, University Medical Centre Utrecht, Utrecht University, Utrecht, The Netherlands
| | | | | | | | - Kim L de Luca
- Oncode Institute, Hubrecht Institute-KNAW (Royal Academy of Arts and Sciences) and University Medical Centre Utrecht, Utrecht, the Netherlands
| | - Joana F Marques
- Oncode Institute, Hubrecht Institute-KNAW (Royal Academy of Arts and Sciences) and University Medical Centre Utrecht, Utrecht, the Netherlands
| | - Elianne M Gerrits
- Oncode Institute, Hubrecht Institute-KNAW (Royal Academy of Arts and Sciences) and University Medical Centre Utrecht, Utrecht, the Netherlands
| | - Bjorn Bakker
- Department of Ageing Biology/ERIBA, University of Groningen, University Medical Centre Groningen, Groningen, the Netherlands
| | - Floris Foijer
- Department of Ageing Biology/ERIBA, University of Groningen, University Medical Centre Groningen, Groningen, the Netherlands
| | - Jop Kind
- Oncode Institute, Hubrecht Institute-KNAW (Royal Academy of Arts and Sciences) and University Medical Centre Utrecht, Utrecht, the Netherlands.,Department of Molecular Biology, Faculty of Science, Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, Nijmegen, The Netherlands
| | | | - Susanne M A Lens
- Oncode Institute, Centre for Molecular Medicine, University Medical Centre Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Geert J P L Kops
- Oncode Institute, Hubrecht Institute-KNAW (Royal Academy of Arts and Sciences) and University Medical Centre Utrecht, Utrecht, the Netherlands.
| |
Collapse
|
21
|
Moreno-Andrés D, Bhattacharyya A, Scheufen A, Stegmaier J. LiveCellMiner: A new tool to analyze mitotic progression. PLoS One 2022; 17:e0270923. [PMID: 35797385 PMCID: PMC9262191 DOI: 10.1371/journal.pone.0270923] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 06/17/2022] [Indexed: 11/21/2022] Open
Abstract
Live-cell imaging has become state of the art to accurately identify the nature of mitotic and cell cycle defects. Low- and high-throughput microscopy setups have yield huge data amounts of cells recorded in different experimental and pathological conditions. Tailored semi-automated and automated image analysis approaches allow the analysis of high-content screening data sets, saving time and avoiding bias. However, they were mostly designed for very specific experimental setups, which restricts their flexibility and usability. The general need for dedicated experiment-specific user-annotated training sets and experiment-specific user-defined segmentation parameters remains a major bottleneck for fully automating the analysis process. In this work we present LiveCellMiner, a highly flexible open-source software tool to automatically extract, analyze and visualize both aggregated and time-resolved image features with potential biological relevance. The software tool allows analysis across high-content data sets obtained in different platforms, in a quantitative and unbiased manner. As proof of principle application, we analyze here the dynamic chromatin and tubulin cytoskeleton features in human cells passing through mitosis highlighting the versatile and flexible potential of this tool set.
Collapse
Affiliation(s)
- Daniel Moreno-Andrés
- Institute of Biochemistry and Molecular Cell Biology, Medical School, RWTH Aachen University, Aachen, Germany
- * E-mail: (DMA), (JS)
| | - Anuk Bhattacharyya
- Institute of Imaging and Computer Vision, RWTH Aachen University, Aachen, Germany
| | - Anja Scheufen
- Institute of Biochemistry and Molecular Cell Biology, Medical School, RWTH Aachen University, Aachen, Germany
| | - Johannes Stegmaier
- Institute of Imaging and Computer Vision, RWTH Aachen University, Aachen, Germany
- * E-mail: (DMA), (JS)
| |
Collapse
|
22
|
Thompson AF, Blackburn PR, Arons NS, Stevens SN, Babovic-Vuksanovic D, Lian JB, Klee EW, Stumpff J. Pathogenic mutations in the chromokinesin KIF22 disrupt anaphase chromosome segregation. eLife 2022; 11:78653. [PMID: 35730929 PMCID: PMC9302971 DOI: 10.7554/elife.78653] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 06/21/2022] [Indexed: 11/22/2022] Open
Abstract
The chromokinesin KIF22 generates forces that contribute to mitotic chromosome congression and alignment. Mutations in the α2 helix of the motor domain of KIF22 have been identified in patients with abnormal skeletal development, and we report the identification of a patient with a novel mutation in the KIF22 tail. We demonstrate that pathogenic mutations do not result in a loss of KIF22’s functions in early mitosis. Instead, mutations disrupt chromosome segregation in anaphase, resulting in reduced proliferation, abnormal daughter cell nuclear morphology, and, in a subset of cells, cytokinesis failure. This phenotype could be explained by a failure of KIF22 to inactivate in anaphase. Consistent with this model, constitutive activation of the motor via a known site of phosphoregulation in the tail phenocopied the effects of pathogenic mutations. These results suggest that the motor domain α2 helix may be an important site for regulation of KIF22 activity at the metaphase to anaphase transition. In support of this conclusion, mimicking phosphorylation of α2 helix residue T158 also prevents inactivation of KIF22 in anaphase. These findings demonstrate the importance of both the head and tail of the motor in regulating the activity of KIF22 and offer insight into the cellular consequences of preventing KIF22 inactivation and disrupting force balance in anaphase.
Collapse
Affiliation(s)
- Alex F Thompson
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, United States
| | | | - Noah S Arons
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, United States
| | - Sarah N Stevens
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, United States
| | | | - Jane B Lian
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, United States
| | - Eric W Klee
- Biomedical Informatics, Mayo Clinic, Rochester, United States
| | - Jason Stumpff
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, United States
| |
Collapse
|
23
|
Palumbo J, Tai E, Forth S. Directly Measuring Forces within Reconstituted Active Microtubule Bundles. J Vis Exp 2022:10.3791/63819. [PMID: 35635475 PMCID: PMC10790399 DOI: 10.3791/63819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2023] Open
Abstract
Microtubule networks are employed in cells to accomplish a wide range of tasks, ranging from acting as tracks for vesicle transport to working as specialized arrays during mitosis to regulate chromosome segregation. Proteins that interact with microtubules include motors such as kinesins and dynein, which can generate active forces and directional motion, as well as non-motor proteins that crosslink filaments into higher-order networks or regulate filament dynamics. To date, biophysical studies of microtubule-associated proteins have overwhelmingly focused on the role of single motor proteins needed for vesicle transport, and significant progress has been made in elucidating the force-generating properties and mechanochemical regulation of kinesins and dyneins. However, for processes in which microtubules act both as cargo and track, such as during filament sliding within the mitotic spindle, much less is understood about the biophysical regulation of ensembles of the crosslinking proteins involved. Here, we detail our methodology for directly probing force generation and response within crosslinked microtubule minimal networks reconstituted from purified microtubules and mitotic proteins. Microtubule pairs are crosslinked by proteins of interest, one microtubule is immobilized to a microscope coverslip, and the second microtubule is manipulated by an optical trap. Simultaneous total internal reflection fluorescence microscopy allows for multichannel visualization of all the components of this microtubule network as the filaments slide apart to generate force. We also demonstrate how these techniques can be used to probe pushing forces exerted by kinesin-5 ensembles and how viscous braking forces arise between sliding microtubule pairs crosslinked by the mitotic MAP PRC1. These assays provide insights into the mechanisms of spindle assembly and function and can be more broadly adapted to study dense microtubule network mechanics in diverse contexts, such as the axon and dendrites of neurons and polar epithelial cells.
Collapse
Affiliation(s)
- Jacob Palumbo
- Department of Biological Sciences and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute
| | - Ellinor Tai
- Department of Biological Sciences and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute
| | - Scott Forth
- Department of Biological Sciences and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute;
| |
Collapse
|
24
|
Vukušić K, Tolić IM. Polar Chromosomes—Challenges of a Risky Path. Cells 2022; 11:cells11091531. [PMID: 35563837 PMCID: PMC9101661 DOI: 10.3390/cells11091531] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 04/28/2022] [Accepted: 04/30/2022] [Indexed: 12/29/2022] Open
Abstract
The process of chromosome congression and alignment is at the core of mitotic fidelity. In this review, we discuss distinct spatial routes that the chromosomes take to align during prometaphase, which are characterized by distinct biomolecular requirements. Peripheral polar chromosomes are an intriguing case as their alignment depends on the activity of kinetochore motors, polar ejection forces, and a transition from lateral to end-on attachments to microtubules, all of which can result in the delayed alignment of these chromosomes. Due to their undesirable position close to and often behind the spindle pole, these chromosomes may be particularly prone to the formation of erroneous kinetochore-microtubule interactions, such as merotelic attachments. To prevent such errors, the cell employs intricate mechanisms to preposition the spindle poles with respect to chromosomes, ensure the formation of end-on attachments in restricted spindle regions, repair faulty attachments by error correction mechanisms, and delay segregation by the spindle assembly checkpoint. Despite this protective machinery, there are several ways in which polar chromosomes can fail in alignment, mis-segregate, and lead to aneuploidy. In agreement with this, polar chromosomes are present in certain tumors and may even be involved in the process of tumorigenesis.
Collapse
|
25
|
The chirality of the mitotic spindle provides a mechanical response to forces and depends on microtubule motors and augmin. Curr Biol 2022; 32:2480-2493.e6. [PMID: 35537456 PMCID: PMC9235856 DOI: 10.1016/j.cub.2022.04.035] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 02/17/2022] [Accepted: 04/13/2022] [Indexed: 12/24/2022]
Abstract
Forces produced by motor proteins and microtubule dynamics within the mitotic spindle are crucial for proper chromosome segregation. In addition to linear forces, rotational forces or torques are present in the spindle, which are reflected in the left-handed twisted shapes of microtubule bundles that make the spindle chiral. However, the biological role and molecular origins of spindle chirality are unknown. By developing methods for measuring the spindle twist, we show that spindles are most chiral near the metaphase-to-anaphase transition. To assess the role of chirality in spindle mechanics, we compressed the spindles along their axis. This resulted in a stronger left-handed twist, suggesting that the twisted shape allows for a mechanical response to forces. Inhibition or depletion of motor proteins that perform chiral stepping, Eg5/kinesin-5, Kif18A/kinesin-8, MKLP1/kinesin-6, and dynein, decreased the left-handed twist or led to right-handed twist, implying that these motors regulate the twist by rotating microtubules within their antiparallel overlaps or at the spindle pole. A right-handed twist was also observed after the depletion of the microtubule nucleator augmin, indicating its contribution to the twist through the nucleation of antiparallel bridging microtubules. The uncovered switch from left-handed to right-handed twist reveals the existence of competing mechanisms that promote twisting in opposite directions. As round spindles are more twisted than the elongated ones are, we infer that bending and twisting moments are generated by similar molecular mechanisms and propose a physiological role for spindle chirality in allowing the spindle to absorb mechanical load. Video abstract
Spindle twist depends on torque-generating motors Eg5, Kif18A, MKLP1, and dynein Without the microtubule nucleator augmin, spindles show right-handed twist Compression of the spindle along the axis increases the left-handed twist Rounder spindles are more twisted than elongated ones are
Collapse
|
26
|
N-Terminus-Mediated Solution Structure of Dimerization Domain of PRC1. Curr Issues Mol Biol 2022; 44:1626-1645. [PMID: 35723369 PMCID: PMC9164050 DOI: 10.3390/cimb44040111] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 04/01/2022] [Accepted: 04/06/2022] [Indexed: 11/30/2022] Open
Abstract
Microtubule-associated proteins (MAPs) are essential for the accurate division of a cell into two daughter cells. These proteins target specific microtubules to be incorporated into the spindle midzone, which comprises a special array of microtubules that initiate cytokinesis during anaphase. A representative member of the MAPs is Protein Regulator of Cytokinesis 1 (PRC1), which self-multimerizes to cross-link microtubules, the malfunction of which might result in cancerous cells. The importance of PRC1 multimerization makes it a popular target for structural studies. The available crystal structure of PRC1 has low resolution (>3 Å) and accuracy, limiting a better understanding of the structure-related functions of PRC1. Therefore, we used NMR spectroscopy to better determine the structure of the dimerization domain of PRC1. The NMR structure shows that the PRC1 N terminus is crucial to the overall structure integrity, but the crystal structure bespeaks otherwise. We systematically addressed the role of the N terminus by generating a series of mutants in which N-terminal residues methionine (Met1) and arginine (Arg2) were either deleted, extended or substituted with other rationally selected amino acids. Each mutant was subsequently analyzed by NMR spectroscopy or fluorescence thermal shift assays for its structural or thermal stability; we found that N-terminal perturbations indeed affected the overall protein structure and that the solution structure better reflects the conformation of PRC1 under solution conditions. These results reveal that the structure of PRC1 is governed by its N terminus through hydrophobic interactions with other core residues, such hitherto unidentified N-terminal conformations might shed light on the structure−function relationships of PRC1 or other proteins. Therefore, our study is of major importance in terms of identifying a novel structural feature and can further the progress of protein folding and protein engineering.
Collapse
|
27
|
Lera-Ramirez M, Nédélec FJ, Tran PT. Microtubule rescue at midzone edges promotes overlap stability and prevents spindle collapse during anaphase B. eLife 2022; 11:72630. [PMID: 35293864 PMCID: PMC9018073 DOI: 10.7554/elife.72630] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 03/15/2022] [Indexed: 11/14/2022] Open
Abstract
During anaphase B, molecular motors slide interpolar microtubules to elongate the mitotic spindle, contributing to the separation of chromosomes. However, sliding of antiparallel microtubules reduces their overlap, which may lead to spindle breakage, unless microtubules grow to compensate sliding. How sliding and growth are coordinated is still poorly understood. In this study, we have used the fission yeast S. pombe to measure microtubule dynamics during anaphase B. We report that the coordination of microtubule growth and sliding relies on promoting rescues at the midzone edges. This makes microtubules stable from pole to midzone, while their distal parts including the plus ends alternate between assembly and disassembly. Consequently, the midzone keeps a constant length throughout anaphase, enabling sustained sliding without the need for a precise regulation of microtubule growth speed. Additionally, we found that in S. pombe, which undergoes closed mitosis, microtubule growth speed decreases when the nuclear membrane wraps around the spindle midzone.
Collapse
|
28
|
Dema A, van Haren J, Wittmann T. Optogenetic EB1 inactivation shortens metaphase spindles by disrupting cortical force-producing interactions with astral microtubules. Curr Biol 2022; 32:1197-1205.e4. [PMID: 35090591 PMCID: PMC8930524 DOI: 10.1016/j.cub.2022.01.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 12/09/2021] [Accepted: 01/07/2022] [Indexed: 10/19/2022]
Abstract
Chromosome segregation is accomplished by the mitotic spindle, a bipolar micromachine built primarily from microtubules. Different microtubule populations contribute to spindle function: kinetochore microtubules attach and transmit forces to chromosomes, antiparallel interpolar microtubules support spindle structure, and astral microtubules connect spindle poles to the cell cortex.1,2 In mammalian cells, end-binding (EB) proteins associate with all growing microtubule plus ends throughout the cell cycle and serve as adaptors for diverse +TIPs that control microtubule dynamics and interactions with other intracellular structures.3 Because binding of many +TIPs to EB1 and thus microtubule-end association is switched off by mitotic phosphorylation,4-6 the mitotic function of EBs remains poorly understood. To analyze how EB1 and associated +TIPs on different spindle microtubule populations contribute to mitotic spindle dynamics, we use a light-sensitive EB1 variant, π-EB1, that allows local, acute, and reversible inactivation of +TIP association with growing microtubule ends in live cells.7 We find that acute π-EB1 photoinactivation results in rapid and reversible metaphase spindle shortening and transient relaxation of tension across the central spindle. However, in contrast to interphase, π-EB1 photoinactivation does not inhibit microtubule growth in metaphase but instead increases astral microtubule length and number. Yet in the absence of EB1 activity, astral microtubules fail to engage the cortical dynein/dynactin machinery, and spindle poles move away from regions of π-EB1 photoinactivation. In conclusion, our optogenetic approach reveals mitotic EB1 functions that remain hidden in genetic experiments, likely due to compensatory molecular systems regulating vertebrate spindle dynamics.
Collapse
Affiliation(s)
- Alessandro Dema
- Department of Cell & Tissue Biology, University of California, San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA
| | | | - Torsten Wittmann
- Department of Cell & Tissue Biology, University of California, San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA.
| |
Collapse
|
29
|
Microtubule Organization Is Essential for Maintaining Cellular Morphology and Function. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:1623181. [PMID: 35295719 PMCID: PMC8920689 DOI: 10.1155/2022/1623181] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 01/10/2022] [Accepted: 02/26/2022] [Indexed: 12/12/2022]
Abstract
Microtubules (MTs) are highly dynamic polymers essential for a wide range of cellular physiologies, such as acting as directional railways for intracellular transport and position, guiding chromosome segregation during cell division, and controlling cell polarity and morphogenesis. Evidence has established that maintaining microtubule (MT) stability in neurons is vital for fundamental cellular and developmental processes, such as neurodevelopment, degeneration, and regeneration. To fulfill these diverse functions, the nervous system employs an arsenal of microtubule-associated proteins (MAPs) to control MT organization and function. Subsequent studies have identified that the disruption of MT function in neurons is one of the most prevalent and important pathological features of traumatic nerve damage and neurodegenerative diseases and that this disruption manifests as a reduction in MT polymerization and concomitant deregulation of the MT cytoskeleton, as well as downregulation of microtubule-associated protein (MAP) expression. A variety of MT-targeting agents that reverse this pathological condition, which is regarded as a therapeutic opportunity to intervene the onset and development of these nervous system abnormalities, is currently under development. Here, we provide an overview of the MT-intrinsic organization process and how MAPs interact with the MT cytoskeleton to promote MT polymerization, stabilization, and bundling. We also highlight recent advances in MT-targeting therapeutic agents applied to various neurological disorders. Together, these findings increase our current understanding of the function and regulation of MT organization in nerve growth and regeneration.
Collapse
|
30
|
Velle KB, Kennard AS, Trupinić M, Ivec A, Swafford AJM, Nolton E, Rice LM, Tolić IM, Fritz-Laylin LK, Wadsworth P. Naegleria’s mitotic spindles are built from unique tubulins and highlight core spindle features. Curr Biol 2022; 32:1247-1261.e6. [PMID: 35139359 PMCID: PMC9036621 DOI: 10.1016/j.cub.2022.01.034] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 11/02/2021] [Accepted: 01/12/2022] [Indexed: 12/30/2022]
Abstract
Naegleria gruberi is a unicellular eukaryote whose evolutionary distance from animals and fungi has made it useful for developing hypotheses about the last common eukaryotic ancestor. Naegleria amoebae lack a cytoplasmic microtubule cytoskeleton and assemble microtubules only during mitosis and thus represent a unique system for studying the evolution and functional specificity of mitotic tubulins and the spindles they assemble. Previous studies show that Naegleria amoebae express a divergent α-tubulin during mitosis, and we now show that Naegleria amoebae express a second mitotic α- and two mitotic β-tubulins. The mitotic tubulins are evolutionarily divergent relative to typical α- and β-tubulins and contain residues that suggest distinct microtubule properties. These distinct residues are conserved in mitotic tubulin homologs of the “brain-eating amoeba” Naegleria fowleri, making them potential drug targets. Using quantitative light microscopy, we find that Naegleria’s mitotic spindle is a distinctive barrel-like structure built from a ring of microtubule bundles. Similar to those of other species, Naegleria’s spindle is twisted, and its length increases during mitosis, suggesting that these aspects of mitosis are ancestral features. Because bundle numbers change during metaphase, we hypothesize that the initial bundles represent kinetochore fibers and secondary bundles function as bridging fibers. Naegleria amoebae are profoundly different from other eukaryotes as they lack interphase microtubules. During cell division, Velle et al. show that Naegleria express α- and β-tubulins that are highly divergent at key structural positions. These tubulins form spindles with an unusual architecture: a ring of twisted microtubule bundles.
Collapse
Affiliation(s)
- Katrina B Velle
- Department of Biology, University of Massachusetts, 611 N. Pleasant Street, Amherst, MA 01003, USA
| | - Andrew S Kennard
- Department of Biology, University of Massachusetts, 611 N. Pleasant Street, Amherst, MA 01003, USA
| | - Monika Trupinić
- Division of Molecular Biology, Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia
| | - Arian Ivec
- Department of Physics, Faculty of Science, University of Zagreb, Bijenička cesta 32, 10000 Zagreb, Croatia
| | - Andrew J M Swafford
- Department of Biology, University of Massachusetts, 611 N. Pleasant Street, Amherst, MA 01003, USA
| | - Emily Nolton
- Department of Biology, University of Massachusetts, 611 N. Pleasant Street, Amherst, MA 01003, USA
| | - Luke M Rice
- Departments of Biophysics and Biochemistry, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Iva M Tolić
- Division of Molecular Biology, Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia
| | - Lillian K Fritz-Laylin
- Department of Biology, University of Massachusetts, 611 N. Pleasant Street, Amherst, MA 01003, USA.
| | - Patricia Wadsworth
- Department of Biology, University of Massachusetts, 611 N. Pleasant Street, Amherst, MA 01003, USA.
| |
Collapse
|
31
|
Deshpande O, de-Carvalho J, Vieira DV, Telley IA. Astral microtubule cross-linking safeguards uniform nuclear distribution in the Drosophila syncytium. J Cell Biol 2022; 221:212810. [PMID: 34766978 PMCID: PMC8594625 DOI: 10.1083/jcb.202007209] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/24/2021] [Accepted: 10/20/2021] [Indexed: 12/16/2022] Open
Abstract
The early insect embryo develops as a multinucleated cell distributing the genome uniformly to the cell cortex. Mechanistic insight for nuclear positioning beyond cytoskeletal requirements is missing. Contemporary hypotheses propose actomyosin-driven cytoplasmic movement transporting nuclei or repulsion of neighbor nuclei driven by microtubule motors. Here, we show that microtubule cross-linking by Feo and Klp3A is essential for nuclear distribution and internuclear distance maintenance in Drosophila. Germline knockdown causes irregular, less-dense nuclear delivery to the cell cortex and smaller distribution in ex vivo embryo explants. A minimal internuclear distance is maintained in explants from control embryos but not from Feo-inhibited embryos, following micromanipulation-assisted repositioning. A dimerization-deficient Feo abolishes nuclear separation in embryo explants, while the full-length protein rescues the genetic knockdown. We conclude that Feo and Klp3A cross-linking of antiparallel microtubule overlap generates a length-regulated mechanical link between neighboring microtubule asters. Enabled by a novel experimental approach, our study illuminates an essential process of embryonic multicellularity.
Collapse
Affiliation(s)
- Ojas Deshpande
- Instituto Gulbenkian de Ciência, Fundação Calouste Gulbenkian, Oeiras, Portugal
| | - Jorge de-Carvalho
- Instituto Gulbenkian de Ciência, Fundação Calouste Gulbenkian, Oeiras, Portugal
| | - Diana V Vieira
- Instituto Gulbenkian de Ciência, Fundação Calouste Gulbenkian, Oeiras, Portugal
| | - Ivo A Telley
- Instituto Gulbenkian de Ciência, Fundação Calouste Gulbenkian, Oeiras, Portugal
| |
Collapse
|
32
|
Orr B, De Sousa F, Gomes AM, Afonso O, Ferreira LT, Figueiredo AC, Maiato H. An anaphase surveillance mechanism prevents micronuclei formation from frequent chromosome segregation errors. Cell Rep 2021; 37:109783. [PMID: 34758324 PMCID: PMC8595644 DOI: 10.1016/j.celrep.2021.109783] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 07/15/2021] [Accepted: 08/26/2021] [Indexed: 12/25/2022] Open
Abstract
Micronuclei are a hallmark of cancer and several other human disorders. Recently, micronuclei were implicated in chromothripsis, a series of massive genomic rearrangements that may drive tumor evolution and progression. Here, we show that Aurora B kinase mediates a surveillance mechanism that integrates error correction during anaphase with spatial control of nuclear envelope reassembly to prevent micronuclei formation. Using high-resolution live-cell imaging of human cancer and non-cancer cells, we uncover that anaphase lagging chromosomes are more frequent than previously anticipated, yet they rarely form micronuclei. Micronuclei formation from anaphase lagging chromosomes is prevented by a midzone-based Aurora B phosphorylation gradient that stabilizes kinetochore-microtubule attachments and assists spindle forces required for anaphase error correction while delaying nuclear envelope reassembly on lagging chromosomes, independently of microtubule density. We propose that a midzone-based Aurora B phosphorylation gradient actively monitors and corrects frequent chromosome segregation errors to prevent micronuclei formation during human cell division. Anaphase lagging chromosomes are frequent but rarely form micronuclei A midzone Aurora B activity gradient prevents micronuclei from segregation errors Midzone Aurora B assists spindle forces at the kinetochores to correct errors Aurora B spatially regulates nuclear envelope reformation on lagging chromosomes
Collapse
Affiliation(s)
- Bernardo Orr
- Chromosome Instability & Dynamics Group, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Filipe De Sousa
- Chromosome Instability & Dynamics Group, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Ana Margarida Gomes
- Chromosome Instability & Dynamics Group, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Olga Afonso
- Chromosome Instability & Dynamics Group, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Luísa T Ferreira
- Chromosome Instability & Dynamics Group, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Ana C Figueiredo
- Chromosome Instability & Dynamics Group, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Helder Maiato
- Chromosome Instability & Dynamics Group, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; Cell Division Group, Department of Biomedicine, Faculdade de Medicina, Universidade do Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal.
| |
Collapse
|
33
|
Neahring L, Cho NH, Dumont S. Opposing motors provide mechanical and functional robustness in the human spindle. Dev Cell 2021; 56:3006-3018.e5. [PMID: 34614397 DOI: 10.1016/j.devcel.2021.09.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 07/27/2021] [Accepted: 09/13/2021] [Indexed: 11/30/2022]
Abstract
At each cell division, the spindle self-organizes from microtubules and motors. In human spindles, the motors dynein and Eg5 generate contractile and extensile stress, respectively. Inhibiting dynein or its targeting factor NuMA leads to unfocused, turbulent spindles, and inhibiting Eg5 leads to monopoles; yet, bipolar spindles form when both are inhibited together. What, then, are the roles of these opposing motors? Here, we generate NuMA/dynein- and Eg5-doubly inhibited spindles that not only attain a typical metaphase shape and size but also undergo anaphase. However, these spindles have reduced microtubule dynamics and are mechanically fragile, fracturing under force. Furthermore, they exhibit lagging chromosomes and a dramatic left-handed twist at anaphase. Thus, although these opposing motors are not required for spindle shape, they are essential to its mechanical and functional robustness. This work suggests a design principle whereby opposing active stresses provide robustness to force-generating cellular structures.
Collapse
Affiliation(s)
- Lila Neahring
- Department of Bioengineering & Therapeutic Sciences, UCSF, San Francisco, CA 94158, USA; Developmental & Stem Cell Biology Graduate Program, UCSF, San Francisco, CA 94143, USA.
| | - Nathan H Cho
- Department of Bioengineering & Therapeutic Sciences, UCSF, San Francisco, CA 94158, USA; Tetrad Graduate Program, UCSF, San Francisco, CA 94158, USA
| | - Sophie Dumont
- Department of Bioengineering & Therapeutic Sciences, UCSF, San Francisco, CA 94158, USA; Developmental & Stem Cell Biology Graduate Program, UCSF, San Francisco, CA 94143, USA; Tetrad Graduate Program, UCSF, San Francisco, CA 94158, USA; Department of Biochemistry & Biophysics, UCSF, San Francisco, CA 94158, USA; Chan Zuckerberg Biohub, San Francisco, CA 94158, USA.
| |
Collapse
|
34
|
Vukušić K, Tolić IM. Anaphase B: Long-standing models meet new concepts. Semin Cell Dev Biol 2021; 117:127-139. [PMID: 33849764 PMCID: PMC8406420 DOI: 10.1016/j.semcdb.2021.03.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 03/26/2021] [Accepted: 03/28/2021] [Indexed: 12/16/2022]
Abstract
Mitotic cell divisions ensure stable transmission of genetic information from a mother to daughter cells in a series of generations. To ensure this crucial task is accomplished, the cell forms a bipolar structure called the mitotic spindle that divides sister chromatids to the opposite sides of the dividing mother cell. After successful establishment of stable attachments of microtubules to chromosomes and inspection of connections between them, at the heart of mitosis, the cell starts the process of segregation. This spectacular moment in the life of a cell is termed anaphase, and it involves two distinct processes: depolymerization of microtubules bound to chromosomes, which is also known as anaphase A, and elongation of the spindle or anaphase B. Both processes ensure physical separation of disjointed sister chromatids. In this chapter, we review the mechanisms of anaphase B spindle elongation primarily in mammalian systems, combining different pioneering ideas and concepts with more recent findings that shed new light on the force generation and regulation of biochemical modules operating during spindle elongation. Finally, we present a comprehensive model of spindle elongation that includes structural, biophysical, and molecular aspects of anaphase B.
Collapse
Affiliation(s)
- Kruno Vukušić
- Division of Molecular Biology, Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia.
| | - Iva M Tolić
- Division of Molecular Biology, Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia.
| |
Collapse
|
35
|
Barisic M, Rajendraprasad G, Steblyanko Y. The metaphase spindle at steady state - Mechanism and functions of microtubule poleward flux. Semin Cell Dev Biol 2021; 117:99-117. [PMID: 34053864 DOI: 10.1016/j.semcdb.2021.05.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 05/13/2021] [Accepted: 05/13/2021] [Indexed: 11/24/2022]
Abstract
The mitotic spindle is a bipolar cellular structure, built from tubulin polymers, called microtubules, and interacting proteins. This macromolecular machine orchestrates chromosome segregation, thereby ensuring accurate distribution of genetic material into the two daughter cells during cell division. Powered by GTP hydrolysis upon tubulin polymerization, the microtubule ends exhibit a metastable behavior known as the dynamic instability, during which they stochastically switch between the growth and shrinkage phases. In the context of the mitotic spindle, dynamic instability is furthermore regulated by microtubule-associated proteins and motor proteins, which enables the spindle to undergo profound changes during mitosis. This highly dynamic behavior is essential for chromosome capture and congression in prometaphase, as well as for chromosome alignment to the spindle equator in metaphase and their segregation in anaphase. In this review we focus on the mechanisms underlying microtubule dynamics and sliding and their importance for the maintenance of shape, structure and dynamics of the metaphase spindle. We discuss how these spindle properties are related to the phenomenon of microtubule poleward flux, highlighting its highly cooperative molecular basis and role in keeping the metaphase spindle at a steady state.
Collapse
Affiliation(s)
- Marin Barisic
- Cell Division and Cytoskeleton, Danish Cancer Society Research Center (DCRC), Strandboulevarden 49, 2100 Copenhagen, Denmark; Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark.
| | - Girish Rajendraprasad
- Cell Division and Cytoskeleton, Danish Cancer Society Research Center (DCRC), Strandboulevarden 49, 2100 Copenhagen, Denmark
| | - Yulia Steblyanko
- Cell Division and Cytoskeleton, Danish Cancer Society Research Center (DCRC), Strandboulevarden 49, 2100 Copenhagen, Denmark
| |
Collapse
|
36
|
Abstract
During anaphase, a microtubule-containing structure called the midzone forms between the segregating chromosomes. The midzone is composed of an antiparallel array of microtubules and numerous microtubule-associated proteins that contribute to midzone formation and function. In many cells, the midzone is an important source of signals that specify the location of contractile ring assembly and constriction. The midzone also contributes to the events of anaphase by generating forces that impact chromosome segregation and spindle elongation; some midzone components contribute to both processes. The results of recent experiments have increased our understanding of the importance of the midzone, a microtubule array that has often been overlooked. This Journal of Cell Science at a Glance article will review, and illustrate on the accompanying poster, the organization, formation and dynamics of the midzone, and discuss open questions for future research.
Collapse
Affiliation(s)
- Patricia Wadsworth
- Department of Biology, Morrill Science Center, University of Massachusetts, 611 N. Pleasant Street, Amherst 01003, USA
| |
Collapse
|