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Kiermaier E, Stötzel I, Schapfl MA, Villunger A. Amplified centrosomes-more than just a threat. EMBO Rep 2024; 25:4153-4167. [PMID: 39285247 PMCID: PMC11467336 DOI: 10.1038/s44319-024-00260-0] [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: 04/19/2024] [Revised: 07/05/2024] [Accepted: 08/28/2024] [Indexed: 09/19/2024] Open
Abstract
Centrosomes are major organizing components of the tubulin-based cytoskeleton. In recent years, we have gained extensive knowledge about their structure, biogenesis, and function from single cells, cell-cell interactions to tissue homeostasis, including their role in human diseases. Centrosome abnormalities are linked to, among others primary microcephaly, birth defects, ciliopathies, and tumorigenesis. Centrosome amplification, a state where two or more centrosomes are present in the G1 phase of the cell cycle, correlates in cancer with karyotype alterations, clinical aggressiveness, and lymph node metastasis. However, amplified centrosomes also appear in healthy tissues and, independent of their established role, in multi-ciliation. One example is the liver where hepatocytes carry amplified centrosomes owing to whole-genome duplication events during organogenesis. More recently, amplified centrosomes have been found in neuronal progenitors and several cell types of hematopoietic origin in which they enhance cellular effector functions. These findings suggest that extra centrosomes do not necessarily pose a risk for genome integrity and are harnessed for physiological processes. Here, we compare established and emerging 'non-canonical functions' of amplified centrosomes in cancerous and somatic cells and discuss their role in cellular physiology.
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Affiliation(s)
- Eva Kiermaier
- Life and Medical Sciences Institute, Immune and Tumor Biology, University of Bonn, Bonn, Germany.
| | - Isabel Stötzel
- Life and Medical Sciences Institute, Immune and Tumor Biology, University of Bonn, Bonn, Germany
| | - Marina A Schapfl
- Institute for Developmental Immunology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Andreas Villunger
- Institute for Developmental Immunology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria.
- The Research Center for Molecular Medicine (CeMM) of the Austrian Academy of Sciences, Lazarettgasse 14, 1090, Vienna, Austria.
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2
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Lau TT, Ma HT, Poon RY. Kinesins regulate the heterogeneity in centrosome clustering after whole-genome duplication. Life Sci Alliance 2024; 7:e202402670. [PMID: 39074902 PMCID: PMC11287020 DOI: 10.26508/lsa.202402670] [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: 02/22/2024] [Revised: 07/20/2024] [Accepted: 07/22/2024] [Indexed: 07/31/2024] Open
Abstract
After whole-genome duplication (WGD), tetraploid cells can undergo multipolar mitosis or pseudo-bipolar mitosis with clustered centrosomes. Kinesins play a crucial role in regulating spindle formation. However, the contribution of kinesin expression levels to the heterogeneity in centrosome clustering observed across different cell lines after WGD remains unclear. We identified two subsets of cell lines: "BP" cells efficiently cluster extra centrosomes for pseudo-bipolar mitosis, and "MP" cells primarily undergo multipolar mitosis after WGD. Diploid MP cells contained higher levels of KIF11 and KIF15 compared with BP cells and showed reduced sensitivity to centrosome clustering induced by KIF11 inhibitors. Moreover, partial inhibition of KIF11 or depletion of KIF15 converted MP cells from multipolar to bipolar mitosis after WGD. Multipolar spindle formation involved microtubules but was independent of kinetochore-microtubule attachment. Silencing KIFC1, but not KIFC3, promoted multipolar mitosis in BP cells, indicating the involvement of specific kinesin-14 family members in counteracting the forces from KIF11/KIF15 after WGD. These findings highlight the collective role of KIF11, KIF15, and KIFC1 in determining the polarity of the mitotic spindle after WGD.
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Affiliation(s)
- Thomas Ty Lau
- https://ror.org/00q4vv597 Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong
| | - Hoi Tang Ma
- Department of Pathology, The University of Hong Kong, Pok Fu Lam, Hong Kong
- State Key Laboratory of Liver Research, The University of Hong Kong, Pok Fu Lam, Hong Kong
| | - Randy Yc Poon
- https://ror.org/00q4vv597 Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong
- https://ror.org/00q4vv597 State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong
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3
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Ryniawec JM, Amoiroglou A, Rogers GC. Generating CRISPR-edited clonal lines of cultured Drosophila S2 cells. Biol Methods Protoc 2024; 9:bpae059. [PMID: 39206452 PMCID: PMC11357795 DOI: 10.1093/biomethods/bpae059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2024] [Revised: 07/26/2024] [Accepted: 08/15/2024] [Indexed: 09/04/2024] Open
Abstract
CRISPR/Cas9 genome editing is a pervasive research tool due to its relative ease of use. However, some systems are not amenable to generating edited clones due to genomic complexity and/or difficulty in establishing clonal lines. For example, Drosophila Schneider 2 (S2) cells possess a segmental aneuploid genome and are challenging to single-cell select. Here, we describe a streamlined CRISPR/Cas9 methodology for knock-in and knock-out experiments in S2 cells, whereby an antibiotic resistance gene is inserted in-frame with the coding region of a gene-of-interest. By using selectable markers, we have improved the ease and efficiency for the positive selection of null cells using antibiotic selection in feeder layers followed by cell expansion to generate clonal lines. Using this method, we generated the first acentrosomal S2 cell lines by knocking-out centriole genes Polo-like Kinase 4/Plk4 or Ana2 as proof of concept. These strategies for generating gene-edited clonal lines will add to the collection of CRISPR tools available for cultured Drosophila cells by making CRISPR more practical and therefore improving gene function studies.
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Affiliation(s)
- John M Ryniawec
- Department of Cellular and Molecular Medicine, University of Arizona Cancer Center, University of Arizona, Tucson, AZ 85724, United States
| | - Anastasia Amoiroglou
- Department of Cellular and Molecular Medicine, University of Arizona Cancer Center, University of Arizona, Tucson, AZ 85724, United States
| | - Gregory C Rogers
- Department of Cellular and Molecular Medicine, University of Arizona Cancer Center, University of Arizona, Tucson, AZ 85724, United States
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Mukherjee A, Andrés Jeske Y, Becam I, Taïeb A, Brooks P, Aouad J, Monguillon C, Conduit PT. γ-TuRCs and the augmin complex are required for the development of highly branched dendritic arbors in Drosophila. J Cell Sci 2024; 137:jcs261534. [PMID: 38606636 PMCID: PMC11128279 DOI: 10.1242/jcs.261534] [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: 08/04/2023] [Accepted: 04/05/2024] [Indexed: 04/13/2024] Open
Abstract
Microtubules are nucleated by γ-tubulin ring complexes (γ-TuRCs) and are essential for neuronal development. Nevertheless, γ-TuRC depletion has been reported to perturb only higher-order branching in elaborated Drosophila larval class IV dendritic arborization (da) neurons. This relatively mild phenotype has been attributed to defects in microtubule nucleation from Golgi outposts, yet most Golgi outposts lack associated γ-TuRCs. By analyzing dendritic arbor regrowth in pupae, we show that γ-TuRCs are also required for the growth and branching of primary and secondary dendrites, as well as for higher-order branching. Moreover, we identify the augmin complex (hereafter augmin), which recruits γ-TuRCs to the sides of pre-existing microtubules, as being required predominantly for higher-order branching. Augmin strongly promotes the anterograde growth of microtubules in terminal dendrites and thus terminal dendrite stability. Consistent with a specific role in higher-order branching, we find that augmin is expressed less strongly and is largely dispensable in larval class I da neurons, which exhibit few higher-order dendrites. Thus, γ-TuRCs are essential for various aspects of complex dendritic arbor development, and they appear to function in higher-order branching via the augmin pathway, which promotes the elaboration of dendritic arbors to help define neuronal morphology.
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Affiliation(s)
- Amrita Mukherjee
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
- MRC Toxicology Unit, Gleeson Building, Tennis Court Road, Cambridge CB2 1QR, UK
| | - Yaiza Andrés Jeske
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
| | - Isabelle Becam
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013 Paris, France
| | - Anaelle Taïeb
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013 Paris, France
| | - Paul Brooks
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
| | - Joanna Aouad
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013 Paris, France
| | | | - Paul T. Conduit
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013 Paris, France
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5
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Baba K, Uemura K, Nakazato R, Ijaz F, Takahashi S, Ikegami K. Δ3-tubulin impairs mitotic spindle morphology and increases nuclear size in pancreatic cancer cells. Med Mol Morphol 2024; 57:59-67. [PMID: 37930423 DOI: 10.1007/s00795-023-00373-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: 07/20/2023] [Accepted: 10/14/2023] [Indexed: 11/07/2023]
Abstract
Cancer cell proliferation is affected by post-translational modifications of tubulin. Especially, overexpression or depletion of enzymes for modifications on the tubulin C-terminal region perturbs dynamic instability of the spindle body. Those modifications include processing of C-terminal amino acids of α-tubulin; detyrosination, and a removal of penultimate glutamic acid (Δ2). We previously found a further removal of the third last glutamic acid, which generates so-called Δ3-tubulin. The effects of Δ3-tubulin on spindle integrities and cell proliferation remain to be elucidated. In this study, we investigated the impacts of forced expression of Δ3-tubulin on the structure of spindle bodies and cell division in a pancreatic cancer cell line, PANC-1. Overexpression of HA-tagged Δ3-tubulin impaired the morphology and orientation of spindle bodies during cell division in PANC-1 cells. In particular, spindle bending was most significantly increased. Expression of EGFP-tagged Δ3-tubulin driven by the endogenous promoter of human TUBA1B also deformed and misoriented spindle bodies. Spindle bending and condensation defects were significantly observed by EGFP-Δ3-tubulin expression. Furthermore, EGFP-Δ3-tubulin expression increased the nuclear size in a dose-dependent manner of EGFP-Δ3-tubulin expression. The expression of EGFP-Δ3-tubulin tended to slow down cell proliferation. Taken together, our results demonstrate that Δ3-tubulin affects the spindle integrity and cell division.
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Affiliation(s)
- Kenta Baba
- Department of Surgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan
- Department of Anatomy and Developmental Biology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan
| | - Kenichiro Uemura
- Department of Surgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan
| | - Ryota Nakazato
- Department of Anatomy and Developmental Biology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan
| | - Faryal Ijaz
- Department of Anatomy and Developmental Biology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan
| | - Shinya Takahashi
- Department of Surgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan
| | - Koji Ikegami
- Department of Anatomy and Developmental Biology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan.
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6
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Gao Z, Huang E, Wang W, Xu L, Xu W, Zheng T, Rui M. Patronin regulates presynaptic microtubule organization and neuromuscular junction development in Drosophila. iScience 2024; 27:108944. [PMID: 38318379 PMCID: PMC10839449 DOI: 10.1016/j.isci.2024.108944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 11/20/2023] [Accepted: 01/15/2024] [Indexed: 02/07/2024] Open
Abstract
Synapses are fundamental components of the animal nervous system. Synaptic cytoskeleton is essential for maintaining proper neuronal development and wiring. Perturbations in neuronal microtubules (MTs) are correlated with numerous neuropsychiatric disorders. Despite discovering multiple synaptic MT regulators, the importance of MT stability, and particularly the polarity of MT in synaptic function, is still under investigation. Here, we identify Patronin, an MT minus-end-binding protein, for its essential role in presynaptic regulation of MT organization and neuromuscular junction (NMJ) development. Analyses indicate that Patronin regulates synaptic development independent of Klp10A. Subsequent research elucidates that it is short stop (Shot), a member of the Spectraplakin family of large cytoskeletal linker molecules, works synergistically with Patronin to govern NMJ development. We further raise the possibility that normal synaptic MT polarity contributes to proper NMJ morphology. Overall, this study demonstrates an unprecedented role of Patronin, and a potential involvement of MT polarity in synaptic development.
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Affiliation(s)
- Ziyang Gao
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing 210096, China
| | - Erqian Huang
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing 210096, China
| | - Wanting Wang
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing 210096, China
| | - Lizhong Xu
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing 210096, China
| | - Wanyue Xu
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing 210096, China
| | - Ting Zheng
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing 210096, China
| | - Menglong Rui
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing 210096, China
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7
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LaFountain JR, Seaman CE, Cohan CS, Oldenbourg R. Sliding of antiparallel microtubules drives bipolarization of monoastral spindles. Cytoskeleton (Hoboken) 2024; 81:167-183. [PMID: 37812128 PMCID: PMC11172411 DOI: 10.1002/cm.21800] [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: 08/02/2023] [Revised: 09/21/2023] [Accepted: 09/23/2023] [Indexed: 10/10/2023]
Abstract
Time-lapse imaging with liquid crystal polarized light (LC-PolScope) and fluorescent speckle microscopy (FSM) enabled this study of spindle microtubules in monoastral spindles that were produced in crane-fly spermatocytes through flattening-induced centrosome displacement. Monoastral spindles are found in several other contexts: after laser ablation of one of a cell's two centrosomes (in the work of Khodjakov et al.), in Drosophila "urchin" mutants (in the works of Heck et al. and of Wilson et al.), in Sciara males (in the works of Fuge and of Metz), and in RNAi variants of Drosophila S2 cells (in the work of Goshima et al.). In all cases, just one pole has a centrosome (the astral pole); the other lacks a centrosome (the anastral pole). Thus, the question: How is the anastral half-spindle, lacking a centrosome, constructed? We learned that monoastral spindles are assembled in two phases: Phase I assembles the astral half-spindle composed of centrosomal microtubules, and Phase II assembles microtubules of the anastral half through extension of new microtubule polymerization outward from the spindle's equatorial mid-zone. That process uses plus ends of existing centrosomal microtubules as guiding templates to assemble anastral microtubules of opposite polarity. Anastral microtubules slide outward with their minus ends leading, thereby establishing proper bipolarity just like in normal biastral spindles that have two centrosomes.
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Affiliation(s)
- James R LaFountain
- Department of Biological Sciences, University at Buffalo, Buffalo, New York, USA
| | - Catherine E Seaman
- Department of Biological Sciences, University at Buffalo, Buffalo, New York, USA
| | - Christopher S Cohan
- Department of Pathology and Anatomy, University at Buffalo, Buffalo, New York, USA
| | - Rudolf Oldenbourg
- Eugene Bell Center, Marine Biological Laboratory, Woods Hole, Massachusetts, USA
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8
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Kyriacou E, Heun P. Centromere structure and function: lessons from Drosophila. Genetics 2023; 225:iyad170. [PMID: 37931172 PMCID: PMC10697814 DOI: 10.1093/genetics/iyad170] [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: 06/15/2023] [Accepted: 09/01/2023] [Indexed: 11/08/2023] Open
Abstract
The fruit fly Drosophila melanogaster serves as a powerful model organism for advancing our understanding of biological processes, not just by studying its similarities with other organisms including ourselves but also by investigating its differences to unravel the underlying strategies that evolved to achieve a common goal. This is particularly true for centromeres, specialized genomic regions present on all eukaryotic chromosomes that function as the platform for the assembly of kinetochores. These multiprotein structures play an essential role during cell division by connecting chromosomes to spindle microtubules in mitosis and meiosis to mediate accurate chromosome segregation. Here, we will take a historical perspective on the study of fly centromeres, aiming to highlight not only the important similarities but also the differences identified that contributed to advancing centromere biology. We will discuss the current knowledge on the sequence and chromatin organization of fly centromeres together with advances for identification of centromeric proteins. Then, we will describe both the factors and processes involved in centromere organization and how they work together to provide an epigenetic identity to the centromeric locus. Lastly, we will take an evolutionary point of view of centromeres and briefly discuss current views on centromere drive.
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Affiliation(s)
- Eftychia Kyriacou
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Patrick Heun
- Wellcome Centre of Cell Biology, School of Biological Sciences, University of Edinburgh, EH9 3BF Edinburgh, UK
- Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
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9
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Sullenberger C, Kong D, Avazpour P, Luvsanjav D, Loncarek J. Centrosomal organization of Cep152 provides flexibility in Plk4 and procentriole positioning. J Cell Biol 2023; 222:e202301092. [PMID: 37707473 PMCID: PMC10501443 DOI: 10.1083/jcb.202301092] [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: 01/20/2023] [Revised: 06/25/2023] [Accepted: 08/17/2023] [Indexed: 09/15/2023] Open
Abstract
Centriole duplication is a high-fidelity process driven by Polo-like kinase 4 (Plk4) and a few conserved initiators. Dissecting how Plk4 and its receptors organize within centrosomes is critical to understand the centriole duplication process and biochemical and architectural differences between centrosomes of different species. Here, at nanoscale resolution, we dissect centrosomal localization of Plk4 in G1 and S phase in its catalytically active and inhibited state during centriole duplication and amplification. We build a precise distribution map of Plk4 and its receptor Cep152, as well as Cep44, Cep192, and Cep152-anchoring factors Cep57 and Cep63. We find that Cep57, Cep63, Cep44, and Cep192 localize in ninefold symmetry. However, during centriole maturation, Cep152, which we suggest is the major Plk4 receptor, develops a more complex pattern. We propose that the molecular arrangement of Cep152 creates flexibility for Plk4 and procentriole placement during centriole initiation. As a result, procentrioles form at variable positions in relation to the mother centriole microtubule triplets.
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Affiliation(s)
- Catherine Sullenberger
- Cancer Innovation Laboratory, National Institutes of Health, National Cancer Institute, Center for Cancer Research, Frederick, MD, USA
| | - Dong Kong
- Cancer Innovation Laboratory, National Institutes of Health, National Cancer Institute, Center for Cancer Research, Frederick, MD, USA
| | - Pegah Avazpour
- Cancer Innovation Laboratory, National Institutes of Health, National Cancer Institute, Center for Cancer Research, Frederick, MD, USA
| | - Delgermaa Luvsanjav
- Cancer Innovation Laboratory, National Institutes of Health, National Cancer Institute, Center for Cancer Research, Frederick, MD, USA
| | - Jadranka Loncarek
- Cancer Innovation Laboratory, National Institutes of Health, National Cancer Institute, Center for Cancer Research, Frederick, MD, USA
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10
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Sun K, Han Y, Li J, Yu S, Huang Y, Zhang Y, Reilly J, Tu J, Gao P, Jia D, Chen X, Hu H, Ren M, Li P, Luo J, Ren X, Zhang X, Shu X, Liu F, Liu M, Tang Z. The splicing factor DHX38 enables retinal development through safeguarding genome integrity. iScience 2023; 26:108103. [PMID: 37867960 PMCID: PMC10589891 DOI: 10.1016/j.isci.2023.108103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 09/03/2023] [Accepted: 09/27/2023] [Indexed: 10/24/2023] Open
Abstract
DEAH-Box Helicase 38 (DHX38) is a pre-mRNA splicing factor and also a disease-causing gene of autosomal recessive retinitis pigmentosa (arRP). The role of DHX38 in the development and maintenance of the retina remains largely unknown. In this study, by using the dhx38 knockout zebrafish model, we demonstrated that Dhx38 deficiency causes severe differentiation defects and apoptosis of retinal progenitor cells (RPCs) through disrupted mitosis and increased DNA damage. Furthermore, we found a significant accumulation of R-loops in the dhx38-deficient RPCs and human cell lines. Finally, we found that DNA replication stress is the prerequisite for R-loop-induced DNA damage in the DHX38 knockdown cells. Taken together, our study demonstrates a necessary role of DHX38 in the development of retina and reveals a DHX38/R-loop/replication stress/DNA damage regulatory axis that is relatively independent of the known functions of DHX38 in mitosis control.
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Affiliation(s)
- Kui Sun
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, P.R. China
| | - Yunqiao Han
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, P.R. China
| | - Jingzhen Li
- Research Center for Biochemistry and Molecular Biology, Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical University, Xuzhou, Jiangsu 221004, P.R. China
| | - Shanshan Yu
- Institute of Visual Neuroscience and Stem Cell Engineering, College of Life Sciences and Health, Wuhan University of Science and Technology, Wuhan, Hubei 430081, P.R. China
| | - Yuwen Huang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, P.R. China
| | - Yangjun Zhang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, P.R. China
| | - Jamas Reilly
- Department of Life Sciences, Glasgow Caledonian University, Glasgow, Scotland G4 0BA, UK
| | - Jiayi Tu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, P.R. China
| | - Pan Gao
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, P.R. China
| | - Danna Jia
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, P.R. China
| | - Xiang Chen
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, P.R. China
| | - Hualei Hu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, P.R. China
| | - Mengmeng Ren
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, P.R. China
| | - Pei Li
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, P.R. China
| | - Jiong Luo
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, P.R. China
| | - Xiang Ren
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, P.R. China
| | - Xianqin Zhang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, P.R. China
| | - Xinhua Shu
- Department of Life Sciences, Glasgow Caledonian University, Glasgow, Scotland G4 0BA, UK
| | - Fei Liu
- Institute of Hydrobiology, Chinese Academy of Science, Wuhan 430072, P.R. China
| | - Mugen Liu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, P.R. China
| | - Zhaohui Tang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, P.R. China
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11
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Kalbfuss N, Gönczy P. Towards understanding centriole elimination. Open Biol 2023; 13:230222. [PMID: 37963546 PMCID: PMC10645514 DOI: 10.1098/rsob.230222] [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: 07/11/2023] [Accepted: 09/14/2023] [Indexed: 11/16/2023] Open
Abstract
Centrioles are microtubule-based structures crucial for forming flagella, cilia and centrosomes. Through these roles, centrioles are critical notably for proper cell motility, signalling and division. Recent years have advanced significantly our understanding of the mechanisms governing centriole assembly and architecture. Although centrioles are typically very stable organelles, persisting over many cell cycles, they can also be eliminated in some cases. Here, we review instances of centriole elimination in a range of species and cell types. Moreover, we discuss potential mechanisms that enable the switch from a stable organelle to a vanishing one. Further work is expected to provide novel insights into centriole elimination mechanisms in health and disease, thereby also enabling scientists to readily manipulate organelle fate.
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Affiliation(s)
- Nils Kalbfuss
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, Swiss Federal Institute of Technology Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Pierre Gönczy
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, Swiss Federal Institute of Technology Lausanne (EPFL), 1015 Lausanne, Switzerland
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12
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Fellmeth JE, Jang JK, Persaud M, Sturm H, Changela N, Parikh A, McKim KS. A dynamic population of prophase CENP-C is required for meiotic chromosome segregation. PLoS Genet 2023; 19:e1011066. [PMID: 38019881 PMCID: PMC10721191 DOI: 10.1371/journal.pgen.1011066] [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: 07/20/2023] [Revised: 12/14/2023] [Accepted: 11/14/2023] [Indexed: 12/01/2023] Open
Abstract
The centromere is an epigenetic mark that is a loading site for the kinetochore during meiosis and mitosis. This mark is characterized by the H3 variant CENP-A, known as CID in Drosophila. In Drosophila, CENP-C is critical for maintaining CID at the centromeres and directly recruits outer kinetochore proteins after nuclear envelope break down. These two functions, however, happen at different times in the cell cycle. Furthermore, in Drosophila and many other metazoan oocytes, centromere maintenance and kinetochore assembly are separated by an extended prophase. We have investigated the dynamics of function of CENP-C during the extended meiotic prophase of Drosophila oocytes and found that maintaining high levels of CENP-C for metaphase I requires expression during prophase. In contrast, CID is relatively stable and does not need to be expressed during prophase to remain at high levels in metaphase I of meiosis. Expression of CID during prophase can even be deleterious, causing ectopic localization to non-centromeric chromatin, abnormal meiosis and sterility. CENP-C prophase loading is required for multiple meiotic functions. In early meiotic prophase, CENP-C loading is required for sister centromere cohesion and centromere clustering. In late meiotic prophase, CENP-C loading is required to recruit kinetochore proteins. CENP-C is one of the few proteins identified in which expression during prophase is required for meiotic chromosome segregation. An implication of these results is that the failure to maintain recruitment of CENP-C during the extended prophase in oocytes would result in chromosome segregation errors in oocytes.
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Affiliation(s)
- Jessica E. Fellmeth
- Waksman Institute and Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, New Jersey, United States of America
| | - Janet K. Jang
- Waksman Institute and Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, New Jersey, United States of America
| | - Manisha Persaud
- Waksman Institute and Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, New Jersey, United States of America
| | - Hannah Sturm
- Waksman Institute and Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, New Jersey, United States of America
| | - Neha Changela
- Waksman Institute and Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, New Jersey, United States of America
| | - Aashka Parikh
- Waksman Institute and Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, New Jersey, United States of America
| | - Kim S. McKim
- Waksman Institute and Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, New Jersey, United States of America
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13
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Wu X, Li Z, Wang ZQ, Xu X. The neurological and non-neurological roles of the primary microcephaly-associated protein ASPM. Front Neurosci 2023; 17:1242448. [PMID: 37599996 PMCID: PMC10436222 DOI: 10.3389/fnins.2023.1242448] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 07/24/2023] [Indexed: 08/22/2023] Open
Abstract
Primary microcephaly (MCPH), is a neurological disorder characterized by small brain size that results in numerous developmental problems, including intellectual disability, motor and speech delays, and seizures. Hitherto, over 30 MCPH causing genes (MCPHs) have been identified. Among these MCPHs, MCPH5, which encodes abnormal spindle-like microcephaly-associated protein (ASPM), is the most frequently mutated gene. ASPM regulates mitotic events, cell proliferation, replication stress response, DNA repair, and tumorigenesis. Moreover, using a data mining approach, we have confirmed that high levels of expression of ASPM correlate with poor prognosis in several types of tumors. Here, we summarize the neurological and non-neurological functions of ASPM and provide insight into its implications for the diagnosis and treatment of MCPH and cancer.
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Affiliation(s)
- Xingxuan Wu
- Guangdong Key Laboratory for Genome Stability and Disease Prevention and Marshall Laboratory of Biomedical Engineering, Shenzhen University Medical School, Shenzhen, Guangdong, China
- Shenzhen University-Friedrich Schiller Universität Jena Joint PhD Program in Biomedical Sciences, Shenzhen University School of Medicine, Shenzhen, Guangdong, China
- Laboratory of Genome Stability, Leibniz Institute on Aging-Fritz Lipmann Institute, Jena, Germany
| | - Zheng Li
- Guangdong Key Laboratory for Genome Stability and Disease Prevention and Marshall Laboratory of Biomedical Engineering, Shenzhen University Medical School, Shenzhen, Guangdong, China
| | - Zhao-Qi Wang
- Shenzhen University-Friedrich Schiller Universität Jena Joint PhD Program in Biomedical Sciences, Shenzhen University School of Medicine, Shenzhen, Guangdong, China
- Laboratory of Genome Stability, Leibniz Institute on Aging-Fritz Lipmann Institute, Jena, Germany
| | - Xingzhi Xu
- Guangdong Key Laboratory for Genome Stability and Disease Prevention and Marshall Laboratory of Biomedical Engineering, Shenzhen University Medical School, Shenzhen, Guangdong, China
- Shenzhen University-Friedrich Schiller Universität Jena Joint PhD Program in Biomedical Sciences, Shenzhen University School of Medicine, Shenzhen, Guangdong, China
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14
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O'Neill RS, Sodeinde AK, Welsh FC, Fagerstrom CJ, Galletta BJ, Rusan NM. Spd-2 gene duplication reveals cell-type-specific pericentriolar material regulation. Curr Biol 2023; 33:3031-3040.e6. [PMID: 37379844 DOI: 10.1016/j.cub.2023.06.020] [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: 02/07/2022] [Revised: 04/25/2023] [Accepted: 06/07/2023] [Indexed: 06/30/2023]
Abstract
Centrosomes are multi-protein organelles that function as microtubule (MT) organizing centers (MTOCs), ensuring spindle formation and chromosome segregation during cell division.1,2,3 Centrosome structure includes core centrioles that recruit pericentriolar material (PCM) that anchors γ-tubulin to nucleate MTs.1,2 In Drosophila melanogaster, PCM organization depends on proper regulation of proteins like Spd-2, which dynamically localizes to centrosomes and is required for PCM, γ-tubulin, and MTOC activity in brain neuroblast (NB) mitosis and male spermatocyte (SC) meiosis.4,5,6,7,8 Some cells have distinct requirements for MTOC activity due to differences in characteristics like cell size9,10 or whether they are mitotic or meiotic.11,12 How centrosome proteins achieve cell-type-specific functional differences is poorly understood. Previous work identified alternative splicing13 and binding partners14 as contributors to cell-type-specific differences in centrosome function. Gene duplication, which can generate paralogs with specialized functions,15,16 is also implicated in centrosome gene evolution,17 including cell-type-specific centrosome genes.18,19 To gain insight into cell-type-specific differences in centrosome protein function and regulation, we investigated a duplication of Spd-2 in Drosophila willistoni, which has Spd-2A (ancestral) and Spd-2B (derived). We find that Spd-2A functions in NB mitosis, whereas Spd-2B functions in SC meiosis. Ectopically expressed Spd-2B accumulates and functions in mitotic NBs, but ectopically expressed Spd-2A failed to accumulate in meiotic SCs, suggesting cell-type-specific differences in translation or protein stability. We mapped this failure to accumulate and function in meiosis to the C-terminal tail domain of Spd-2A, revealing a novel regulatory mechanism that can potentially achieve differences in PCM function across cell types.
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Affiliation(s)
- Ryan S O'Neill
- Cell and Developmental Biology Center, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Afeez K Sodeinde
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, CT 06510, USA
| | - Frances C Welsh
- Basic Sciences Division and Computational Biology Program, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA; Molecular and Cellular Biology Graduate Program, University of Washington and Fred Hutchinson Cancer Research Center, Seattle, WA 98195, USA
| | - Carey J Fagerstrom
- Cell and Developmental Biology Center, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Brian J Galletta
- Cell and Developmental Biology Center, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Nasser M Rusan
- Cell and Developmental Biology Center, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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15
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Guan C, Hua S, Jiang K. The CEP170B-KIF2A complex destabilizes microtubule minus ends to generate polarized microtubule network. EMBO J 2023; 42:e112953. [PMID: 37014312 PMCID: PMC10233374 DOI: 10.15252/embj.2022112953] [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: 10/28/2022] [Revised: 03/16/2023] [Accepted: 03/22/2023] [Indexed: 04/05/2023] Open
Abstract
Microtubule (MT) minus ends are stabilized by CAMSAP family proteins at noncentrosomal MT-organizing centers. Despite progress in identifying diverse positive regulators, knowledge on the negative regulation of the MT minus-end distribution is lacking. Here, we identify CEP170B as a MT minus-end-binding protein that colocalizes with the microtubule-stabilizing complex at the cortical patches. CEP170B depends on the scaffold protein liprin-α1 for its cortical targeting and requires liprin-α1-bound PP2A phosphatase for its MT localization. CEP170B excludes CAMSAPs-stabilized MT minus ends from the cell periphery in HeLa cells and the basal cortex in human epithelial cells and is required for directional vesicle trafficking and cyst formation in 3D culture. Reconstitution experiments demonstrate that CEP170B autonomously tracks growing MT minus ends and blocks minus-end growth. Furthermore, CEP170B in a complex with the kinesin KIF2A acts as a potent MT minus-end depolymerase capable of antagonizing the stabilizing effect of CAMSAPs. Our study uncovers an antagonistic mechanism for controlling the spatial distribution of MT minus ends, which contributes to the establishment of polarized MT network and cell polarity.
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Affiliation(s)
- Cuirong Guan
- The State Key Laboratory Breeding Base of Basic Science of Stomatology & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Medical Research InstituteWuhan UniversityWuhanChina
- Frontier Science Center for Immunology and MetabolismWuhan UniversityWuhanChina
| | - Shasha Hua
- The State Key Laboratory Breeding Base of Basic Science of Stomatology & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Medical Research InstituteWuhan UniversityWuhanChina
- Frontier Science Center for Immunology and MetabolismWuhan UniversityWuhanChina
| | - Kai Jiang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Medical Research InstituteWuhan UniversityWuhanChina
- Frontier Science Center for Immunology and MetabolismWuhan UniversityWuhanChina
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16
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Lau TY, Poon RY. Whole-Genome Duplication and Genome Instability in Cancer Cells: Double the Trouble. Int J Mol Sci 2023; 24:ijms24043733. [PMID: 36835147 PMCID: PMC9959281 DOI: 10.3390/ijms24043733] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 02/04/2023] [Accepted: 02/08/2023] [Indexed: 02/15/2023] Open
Abstract
Whole-genome duplication (WGD) is one of the most common genomic abnormalities in cancers. WGD can provide a source of redundant genes to buffer the deleterious effect of somatic alterations and facilitate clonal evolution in cancer cells. The extra DNA and centrosome burden after WGD is associated with an elevation of genome instability. Causes of genome instability are multifaceted and occur throughout the cell cycle. Among these are DNA damage caused by the abortive mitosis that initially triggers tetraploidization, replication stress and DNA damage associated with an enlarged genome, and chromosomal instability during the subsequent mitosis in the presence of extra centrosomes and altered spindle morphology. Here, we chronicle the events after WGD, from tetraploidization instigated by abortive mitosis including mitotic slippage and cytokinesis failure to the replication of the tetraploid genome, and finally, to the mitosis in the presence of supernumerary centrosomes. A recurring theme is the ability of some cancer cells to overcome the obstacles in place for preventing WGD. The underlying mechanisms range from the attenuation of the p53-dependent G1 checkpoint to enabling pseudobipolar spindle formation via the clustering of supernumerary centrosomes. These survival tactics and the resulting genome instability confer a subset of polyploid cancer cells proliferative advantage over their diploid counterparts and the development of therapeutic resistance.
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Affiliation(s)
- Tsz Yin Lau
- Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Randy Y.C. Poon
- Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
- State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
- Correspondence: ; Tel.: +852-2358-8718
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17
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Zhang W, Yang C, Hu Y, Yi K, Xiao W, Xu X, Chen Z. Comprehensive analysis of the correlation of the pan-cancer gene HAUS5 with prognosis and immune infiltration in liver cancer. Sci Rep 2023; 13:2409. [PMID: 36765148 PMCID: PMC9918732 DOI: 10.1038/s41598-023-28653-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 01/23/2023] [Indexed: 02/12/2023] Open
Abstract
Liver hepatocellular carcinoma (LIHC) is one of the most common malignancies and places a heavy burden on patients worldwide. HAUS augmin-like complex subunit 5 (HAUS5) is involved in the occurrence and development of various cancers. However, the functional role and significance of HAUS5 in LIHC remain unclear. The Cancer Genome Atlas (TCGA), Genotype-Tissue Expression (GTEx), Cancer Cell Line Encyclopedia (CCLE) and Gene Expression Omnibus (GEO) databases were used to analyze the mRNA expression of HAUS5. The value of HAUS5 in predicting LIHC prognosis and the relationship between HAUS5 and clinicopathological features were assessed by the Kaplan-Meier plotter and UALCAN databases. Functional enrichment analyses and nomogram prediction model construction were performed with the R packages. The LinkedOmics database was searched to reveal co-expressed genes associated with HAUS5. The relationship between HAUS5 expression and immune infiltration was explored by searching the TISIDB database and single-sample gene set enrichment analysis (ssGSEA). The Clinical Proteomic Tumor Analysis Consortium (CPTAC) and the Human Protein Atlas (HPA) databases were used to evaluate HAUS5 protein expression. Finally, the effect of HAUS5 on the proliferation of hepatoma cells was verified by CCK-8, colony formation and EdU assays. HAUS5 is aberrantly expressed and associated with a poor prognosis in most tumors, including LIHC. The expression of HAUS5 is significantly correlated with clinicopathological indicators in patients with LIHC. Functional enrichment analysis showed that HAUS5 was closely related to DNA replication, cell cycle and p53 signaling pathway. HAUS5 may serve as an independent risk factor for LIHC prognosis. The nomogram based on HAUS5 had area under the curve (AUC) values of 0.74 and 0.77 for predicting the 3-year and 5-year overall survival (OS) of LIHC patients. Immune correlation analysis showed that HAUS5 was significantly associated with immune infiltration. Finally, the results of in vitro experiments showed that when HAUS5 was knocked down, the proliferation of hepatoma cells was significantly decreased. The pan-oncogene HAUS5 is a positive regulator of LIHC progression and is closely associated with a poor prognosis in LIHC. Moreover, HAUS5 is involved in immune infiltration in LIHC. HAUS5 may be a new prognostic marker and therapeutic target for LIHC patients.
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Affiliation(s)
- Wenbing Zhang
- Suzhou Medical College of Soochow University, Suzhou, Jiangsu, China
- Department of General Surgery, The First People's Hospital of Taicang, Taicang Affiliated Hospital of Soochow University, No. 58 Changsheng South Road, Taicang, Suzhou, 215400, Jiangsu, People's Republic of China
| | - Chi Yang
- Suzhou Medical College of Soochow University, Suzhou, Jiangsu, China
- Department of General Surgery, The First People's Hospital of Taicang, Taicang Affiliated Hospital of Soochow University, No. 58 Changsheng South Road, Taicang, Suzhou, 215400, Jiangsu, People's Republic of China
| | - Yan Hu
- Central Laboratory, The First People's Hospital of Taicang, Taicang Affiliated Hospital of Soochow University, No. 58 Changsheng South Road, Taicang, Suzhou, 215400, Jiangsu, People's Republic of China
| | - Ke Yi
- Central Laboratory, The First People's Hospital of Taicang, Taicang Affiliated Hospital of Soochow University, No. 58 Changsheng South Road, Taicang, Suzhou, 215400, Jiangsu, People's Republic of China
| | - Wangwen Xiao
- Central Laboratory, The First People's Hospital of Taicang, Taicang Affiliated Hospital of Soochow University, No. 58 Changsheng South Road, Taicang, Suzhou, 215400, Jiangsu, People's Republic of China
| | - Xiaohui Xu
- Suzhou Medical College of Soochow University, Suzhou, Jiangsu, China.
- Department of General Surgery, The First People's Hospital of Taicang, Taicang Affiliated Hospital of Soochow University, No. 58 Changsheng South Road, Taicang, Suzhou, 215400, Jiangsu, People's Republic of China.
- Central Laboratory, The First People's Hospital of Taicang, Taicang Affiliated Hospital of Soochow University, No. 58 Changsheng South Road, Taicang, Suzhou, 215400, Jiangsu, People's Republic of China.
| | - Zhihua Chen
- Suzhou Medical College of Soochow University, Suzhou, Jiangsu, China.
- Department of General Surgery, The First People's Hospital of Taicang, Taicang Affiliated Hospital of Soochow University, No. 58 Changsheng South Road, Taicang, Suzhou, 215400, Jiangsu, People's Republic of China.
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18
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Funk L, Su KC, Ly J, Feldman D, Singh A, Moodie B, Blainey PC, Cheeseman IM. The phenotypic landscape of essential human genes. Cell 2022; 185:4634-4653.e22. [PMID: 36347254 PMCID: PMC10482496 DOI: 10.1016/j.cell.2022.10.017] [Citation(s) in RCA: 45] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 09/01/2022] [Accepted: 10/14/2022] [Indexed: 11/09/2022]
Abstract
Understanding the basis for cellular growth, proliferation, and function requires determining the roles of essential genes in diverse cellular processes, including visualizing their contributions to cellular organization and morphology. Here, we combined pooled CRISPR-Cas9-based functional screening of 5,072 fitness-conferring genes in human HeLa cells with microscopy-based imaging of DNA, the DNA damage response, actin, and microtubules. Analysis of >31 million individual cells identified measurable phenotypes for >90% of gene knockouts, implicating gene targets in specific cellular processes. Clustering of phenotypic similarities based on hundreds of quantitative parameters further revealed co-functional genes across diverse cellular activities, providing predictions for gene functions and associations. By conducting pooled live-cell screening of ∼450,000 cell division events for 239 genes, we additionally identified diverse genes with functional contributions to chromosome segregation. Our work establishes a resource detailing the consequences of disrupting core cellular processes that represents the functional landscape of essential human genes.
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Affiliation(s)
- Luke Funk
- Broad Institute of MIT and Harvard, 415 Main St., Cambridge, MA 02142, USA; Harvard-MIT Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Kuan-Chung Su
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Jimmy Ly
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - David Feldman
- Broad Institute of MIT and Harvard, 415 Main St., Cambridge, MA 02142, USA
| | - Avtar Singh
- Broad Institute of MIT and Harvard, 415 Main St., Cambridge, MA 02142, USA
| | - Brittania Moodie
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Paul C Blainey
- Broad Institute of MIT and Harvard, 415 Main St., Cambridge, MA 02142, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02142, USA; Koch Institute for Integrative Cancer Research at MIT, Cambridge, MA 02142, USA.
| | - Iain M Cheeseman
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.
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19
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Morphological growth dynamics, mechanical stability, and active microtubule mechanics underlying spindle self-organization. Proc Natl Acad Sci U S A 2022; 119:e2209053119. [PMID: 36282919 PMCID: PMC9636915 DOI: 10.1073/pnas.2209053119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The spindle is a dynamic intracellular structure self-organized from microtubules and microtubule-associated proteins. The spindle’s bipolar morphology is essential for the faithful segregation of chromosomes during cell division, and it is robustly maintained by multifaceted mechanisms. However, abnormally shaped spindles, such as multipolar spindles, can stochastically arise in a cell population and cause chromosome segregation errors. The physical basis of how microtubules fail in bipolarization and occasionally favor nonbipolar assembly is poorly understood. Here, using live fluorescence imaging and quantitative shape analysis in
Xenopus
egg extracts, we find that spindles of varied shape morphologies emerge through nonrandom, bistable self-organization paths, one leading to a bipolar and the other leading to a multipolar phenotype. The bistability defines the spindle’s unique morphological growth dynamics linked to each shape phenotype and can be promoted by a locally distorted microtubule flow that arises within premature structures. We also find that bipolar and multipolar spindles are stable at the steady-state in bulk but can infrequently switch between the two phenotypes. Our microneedle-based physical manipulation further demonstrates that a transient force perturbation applied near the assembled pole can trigger the phenotypic switching, revealing the mechanical plasticity of the spindle. Together with molecular perturbation of kinesin-5 and augmin, our data propose the physical and molecular bases underlying the emergence of spindle-shape variation, which influences chromosome segregation fidelity during cell division.
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20
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Štimac V, Koprivec I, Manenica M, Simunić J, Tolić IM. Augmin prevents merotelic attachments by promoting proper arrangement of bridging and kinetochore fibers. eLife 2022; 11:e83287. [PMID: 36269126 PMCID: PMC9640188 DOI: 10.7554/elife.83287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 09/26/2022] [Indexed: 11/18/2022] Open
Abstract
The human mitotic spindle is made of microtubules nucleated at centrosomes, at kinetochores, and from pre-existing microtubules by the augmin complex. However, it is unknown how the augmin-mediated nucleation affects distinct microtubule classes and thereby mitotic fidelity. Here, we use superresolution microscopy to analyze the previously indistinguishable microtubule arrangements within the crowded metaphase plate area and demonstrate that augmin is vital for the formation of uniformly arranged parallel units consisting of sister kinetochore fibers connected by a bridging fiber. This ordered geometry helps both prevent and resolve merotelic attachments. Whereas augmin-nucleated bridging fibers prevent merotelic attachments by creating a nearly parallel and highly bundled microtubule arrangement unfavorable for creating additional attachments, augmin-nucleated k-fibers produce robust force required to resolve errors during anaphase. STED microscopy revealed that bridging fibers were impaired twice as much as k-fibers following augmin depletion. The complete absence of bridging fibers from a significant portion of kinetochore pairs, especially in the inner part of the spindle, resulted in the specific reduction of the interkinetochore distance. Taken together, we propose a model where augmin promotes mitotic fidelity by generating assemblies consisting of bridging and kinetochore fibers that align sister kinetochores to face opposite poles, thereby preventing erroneous attachments.
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Affiliation(s)
- Valentina Štimac
- Division of Molecular Biology, Ruđer Bošković InstituteZagrebCroatia
| | - Isabella Koprivec
- Division of Molecular Biology, Ruđer Bošković InstituteZagrebCroatia
| | - Martina Manenica
- Division of Molecular Biology, Ruđer Bošković InstituteZagrebCroatia
| | - Juraj Simunić
- Division of Molecular Biology, Ruđer Bošković InstituteZagrebCroatia
| | - Iva M Tolić
- Division of Molecular Biology, Ruđer Bošković InstituteZagrebCroatia
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21
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The Green Valley of Drosophila melanogaster Constitutive Heterochromatin: Protein-Coding Genes Involved in Cell Division Control. Cells 2022; 11:cells11193058. [PMID: 36231024 PMCID: PMC9563267 DOI: 10.3390/cells11193058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 09/22/2022] [Accepted: 09/23/2022] [Indexed: 11/25/2022] Open
Abstract
Constitutive heterochromatin represents a significant fraction of eukaryotic genomes (10% in Arabidopsis, 20% in humans, 30% in D. melanogaster, and up to 85% in certain nematodes) and shares similar genetic and molecular properties in animal and plant species. Studies conducted over the last few years on D. melanogaster and other organisms led to the discovery of several functions associated with constitutive heterochromatin. This made it possible to revise the concept that this ubiquitous genomic territory is incompatible with gene expression. The aim of this review is to focus the attention on a group of protein-coding genes resident in D. melanogaster constitutive of heterochromatin, which are implicated in different steps of cell division.
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22
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The augmin complex architecture reveals structural insights into microtubule branching. Nat Commun 2022; 13:5635. [PMID: 36163468 PMCID: PMC9512787 DOI: 10.1038/s41467-022-33228-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 09/05/2022] [Indexed: 11/24/2022] Open
Abstract
In mitosis, the augmin complex binds to spindle microtubules to recruit the γ-tubulin ring complex (γ-TuRC), the principal microtubule nucleator, for the formation of branched microtubules. Our understanding of augmin-mediated microtubule branching is hampered by the lack of structural information on the augmin complex. Here, we elucidate the molecular architecture and conformational plasticity of the augmin complex using an integrative structural biology approach. The elongated structure of the augmin complex is characterised by extensive coiled-coil segments and comprises two structural elements with distinct but complementary functions in γ-TuRC and microtubule binding, linked by a flexible hinge. The augmin complex is recruited to microtubules via a composite microtubule binding site comprising a positively charged unordered extension and two calponin homology domains. Our study provides the structural basis for augmin function in branched microtubule formation, decisively fostering our understanding of spindle formation in mitosis. The formation of branched microtubule networks in mitotic spindles depends on the augmin complex. Zupa, Würtz et al. elucidate the molecular architecture and conformational plasticity of the augmin complex using integrative structural biology, providing structural insights into microtubule branching.
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23
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Gabel CA, Li Z, DeMarco AG, Zhang Z, Yang J, Hall MC, Barford D, Chang L. Molecular architecture of the augmin complex. Nat Commun 2022; 13:5449. [PMID: 36114186 PMCID: PMC9481612 DOI: 10.1038/s41467-022-33227-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 09/05/2022] [Indexed: 12/21/2022] Open
Abstract
Accurate segregation of chromosomes during mitosis depends on the correct assembly of the mitotic spindle, a bipolar structure composed mainly of microtubules. The augmin complex, or homologous to augmin subunits (HAUS) complex, is an eight-subunit protein complex required for building robust mitotic spindles in metazoa. Augmin increases microtubule density within the spindle by recruiting the γ-tubulin ring complex (γ-TuRC) to pre-existing microtubules and nucleating branching microtubules. Here, we elucidate the molecular architecture of augmin by single particle cryo-electron microscopy (cryo-EM), computational methods, and crosslinking mass spectrometry (CLMS). Augmin's highly flexible structure contains a V-shaped head and a filamentous tail, with the head existing in either extended or contracted conformational states. Our work highlights how cryo-EM, complemented by computational advances and CLMS, can elucidate the structure of a challenging protein complex and provides insights into the function of augmin in mediating microtubule branching nucleation.
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Affiliation(s)
- Clinton A Gabel
- Department of Biological Sciences, Purdue University, West Lafayette, IN, 47907, USA
- Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN, 47907, USA
| | - Zhuang Li
- Department of Biological Sciences, Purdue University, West Lafayette, IN, 47907, USA
- Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN, 47907, USA
| | - Andrew G DeMarco
- Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN, 47907, USA
- Department of Biochemistry, Purdue University, West Lafayette, IN, 47907, USA
| | - Ziguo Zhang
- MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK
| | - Jing Yang
- MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK
| | - Mark C Hall
- Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN, 47907, USA
- Department of Biochemistry, Purdue University, West Lafayette, IN, 47907, USA
| | - David Barford
- MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK
| | - Leifu Chang
- Department of Biological Sciences, Purdue University, West Lafayette, IN, 47907, USA.
- Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN, 47907, USA.
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24
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Batman U, Deretic J, Firat-Karalar EN. The ciliopathy protein CCDC66 controls mitotic progression and cytokinesis by promoting microtubule nucleation and organization. PLoS Biol 2022; 20:e3001708. [PMID: 35849559 PMCID: PMC9333452 DOI: 10.1371/journal.pbio.3001708] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 07/28/2022] [Accepted: 06/14/2022] [Indexed: 11/23/2022] Open
Abstract
Precise spatiotemporal control of microtubule nucleation and organization is critical for faithful segregation of cytoplasmic and genetic material during cell division and signaling via the primary cilium in quiescent cells. Microtubule-associated proteins (MAPs) govern assembly, maintenance, and remodeling of diverse microtubule arrays. While a set of conserved MAPs are only active during cell division, an emerging group of MAPs acts as dual regulators in dividing and nondividing cells. Here, we elucidated the nonciliary functions and molecular mechanism of action of the ciliopathy-linked protein CCDC66, which we previously characterized as a regulator of ciliogenesis in quiescent cells. We showed that CCDC66 dynamically localizes to the centrosomes, the bipolar spindle, the spindle midzone, the central spindle, and the midbody in dividing cells and interacts with the core machinery of centrosome maturation and MAPs involved in cell division. Loss-of-function experiments revealed its functions during mitotic progression and cytokinesis. Specifically, CCDC66 depletion resulted in defective spindle assembly and orientation, kinetochore fiber stability, chromosome alignment in metaphase as well as central spindle and midbody assembly and organization in anaphase and cytokinesis. Notably, CCDC66 regulates mitotic microtubule nucleation via noncentrosomal and centrosomal pathways via recruitment of gamma-tubulin to the centrosomes and the spindle. Additionally, CCDC66 bundles microtubules in vitro and in cells by its C-terminal microtubule-binding domain. Phenotypic rescue experiments showed that the microtubule and centrosome-associated pools of CCDC66 individually or cooperatively mediate its mitotic and cytokinetic functions. Collectively, our findings identify CCDC66 as a multifaceted regulator of the nucleation and organization of the diverse mitotic and cytokinetic microtubule arrays and provide new insight into nonciliary defects that underlie ciliopathies. The ciliopathy-linked protein CCDC66 is only known for its ciliary functions. This study reveals that CCDC66 also has extensive non-ciliary functions, localizing to the spindle poles, spindle midzone, central spindle and midbody throughout cell division, where it regulates mitosis and cytokinesis by promoting microtubule nucleation and organization.
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Affiliation(s)
- Umut Batman
- Department of Molecular Biology and Genetics, Koç University, Istanbul, Turkey
| | - Jovana Deretic
- Department of Molecular Biology and Genetics, Koç University, Istanbul, Turkey
| | - Elif Nur Firat-Karalar
- Department of Molecular Biology and Genetics, Koç University, Istanbul, Turkey
- Koç University School of Medicine, Istanbul, Turkey
- * E-mail:
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25
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Popova JV, Pavlova GA, Razuvaeva AV, Yarinich LA, Andreyeva EN, Anders AF, Galimova YA, Renda F, Somma MP, Pindyurin AV, Gatti M. Genetic Control of Kinetochore-Driven Microtubule Growth in Drosophila Mitosis. Cells 2022; 11:cells11142127. [PMID: 35883570 PMCID: PMC9323100 DOI: 10.3390/cells11142127] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 06/28/2022] [Accepted: 06/29/2022] [Indexed: 01/08/2023] Open
Abstract
Centrosome-containing cells assemble their spindles exploiting three main classes of microtubules (MTs): MTs nucleated by the centrosomes, MTs generated near the chromosomes/kinetochores, and MTs nucleated within the spindle by the augmin-dependent pathway. Mammalian and Drosophila cells lacking the centrosomes generate MTs at kinetochores and eventually form functional bipolar spindles. However, the mechanisms underlying kinetochore-driven MT formation are poorly understood. One of the ways to elucidate these mechanisms is the analysis of spindle reassembly following MT depolymerization. Here, we used an RNA interference (RNAi)-based reverse genetics approach to dissect the process of kinetochore-driven MT regrowth (KDMTR) after colcemid-induced MT depolymerization. This MT depolymerization procedure allows a clear assessment of KDMTR, as colcemid disrupts centrosome-driven MT regrowth but not KDMTR. We examined KDMTR in normal Drosophila S2 cells and in S2 cells subjected to RNAi against conserved genes involved in mitotic spindle assembly: mast/orbit/chb (CLASP1), mei-38 (TPX2), mars (HURP), dgt6 (HAUS6), Eb1 (MAPRE1/EB1), Patronin (CAMSAP2), asp (ASPM), and Klp10A (KIF2A). RNAi-mediated depletion of Mast/Orbit, Mei-38, Mars, Dgt6, and Eb1 caused a significant delay in KDMTR, while loss of Patronin had a milder negative effect on this process. In contrast, Asp or Klp10A deficiency increased the rate of KDMTR. These results coupled with the analysis of GFP-tagged proteins (Mast/Orbit, Mei-38, Mars, Eb1, Patronin, and Asp) localization during KDMTR suggested a model for kinetochore-dependent spindle reassembly. We propose that kinetochores capture the plus ends of MTs nucleated in their vicinity and that these MTs elongate at kinetochores through the action of Mast/Orbit. The Asp protein binds the MT minus ends since the beginning of KDMTR, preventing excessive and disorganized MT regrowth. Mei-38, Mars, Dgt6, Eb1, and Patronin positively regulate polymerization, bundling, and stabilization of regrowing MTs until a bipolar spindle is reformed.
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Affiliation(s)
- Julia V. Popova
- Institute of Molecular and Cellular Biology, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia; (J.V.P.); (G.A.P.); (A.V.R.); (L.A.Y.); (E.N.A.); (A.F.A.); (Y.A.G.)
- Laboratory of Bioengineering, Novosibirsk State Agrarian University, 630039 Novosibirsk, Russia
| | - Gera A. Pavlova
- Institute of Molecular and Cellular Biology, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia; (J.V.P.); (G.A.P.); (A.V.R.); (L.A.Y.); (E.N.A.); (A.F.A.); (Y.A.G.)
- Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Alyona V. Razuvaeva
- Institute of Molecular and Cellular Biology, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia; (J.V.P.); (G.A.P.); (A.V.R.); (L.A.Y.); (E.N.A.); (A.F.A.); (Y.A.G.)
- Institute of Cytology and Genetics, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia
| | - Lyubov A. Yarinich
- Institute of Molecular and Cellular Biology, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia; (J.V.P.); (G.A.P.); (A.V.R.); (L.A.Y.); (E.N.A.); (A.F.A.); (Y.A.G.)
- Faculty of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Evgeniya N. Andreyeva
- Institute of Molecular and Cellular Biology, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia; (J.V.P.); (G.A.P.); (A.V.R.); (L.A.Y.); (E.N.A.); (A.F.A.); (Y.A.G.)
| | - Alina F. Anders
- Institute of Molecular and Cellular Biology, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia; (J.V.P.); (G.A.P.); (A.V.R.); (L.A.Y.); (E.N.A.); (A.F.A.); (Y.A.G.)
| | - Yuliya A. Galimova
- Institute of Molecular and Cellular Biology, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia; (J.V.P.); (G.A.P.); (A.V.R.); (L.A.Y.); (E.N.A.); (A.F.A.); (Y.A.G.)
| | - Fioranna Renda
- Institute of Molecular Biology and Pathology (IBPM), National Research Council (CNR), c/o Department of Biology and Biotechnology, Sapienza University of Rome, 00185 Rome, Italy; (F.R.); (M.P.S.)
| | - Maria Patrizia Somma
- Institute of Molecular Biology and Pathology (IBPM), National Research Council (CNR), c/o Department of Biology and Biotechnology, Sapienza University of Rome, 00185 Rome, Italy; (F.R.); (M.P.S.)
| | - Alexey V. Pindyurin
- Institute of Molecular and Cellular Biology, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia; (J.V.P.); (G.A.P.); (A.V.R.); (L.A.Y.); (E.N.A.); (A.F.A.); (Y.A.G.)
- Correspondence: (A.V.P.); (M.G.)
| | - Maurizio Gatti
- Institute of Molecular and Cellular Biology, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia; (J.V.P.); (G.A.P.); (A.V.R.); (L.A.Y.); (E.N.A.); (A.F.A.); (Y.A.G.)
- Institute of Molecular Biology and Pathology (IBPM), National Research Council (CNR), c/o Department of Biology and Biotechnology, Sapienza University of Rome, 00185 Rome, Italy; (F.R.); (M.P.S.)
- Correspondence: (A.V.P.); (M.G.)
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26
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Zhang Y, Hong X, Hua S, Jiang K. Reconstitution and mechanistic dissection of the human microtubule branching machinery. J Cell Biol 2022; 221:e202109053. [PMID: 35604367 PMCID: PMC9129923 DOI: 10.1083/jcb.202109053] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 03/07/2022] [Accepted: 05/02/2022] [Indexed: 01/07/2023] Open
Abstract
Branching microtubule (MT) nucleation is mediated by the augmin complex and γ-tubulin ring complex (γ-TuRC). However, how these two complexes work together to promote this process remains elusive. Here, using purified components from native and recombinant sources, we demonstrate that human augmin and γ-TuRC are sufficient to reconstitute the minimal MT branching machinery, in which NEDD1 bridges between augmin holo complex and GCP3/MZT1 subcomplex of γ-TuRC. The single-molecule experiment suggests that oligomerization of augmin may activate the branching machinery. We provide direct biochemical evidence that CDK1- and PLK1-dependent phosphorylation are crucial for NEDD1 binding to augmin, for their synergistic MT-binding activities, and hence for branching MT nucleation. In addition, we unveil that NEDD1 possesses an unanticipated intrinsic affinity for MTs via its WD40 domain, which also plays a pivotal role in the branching process. In summary, our study provides a comprehensive understanding of the underlying mechanisms of branching MT nucleation in human cells.
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Affiliation(s)
- Yaqian Zhang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Wuhan University, Wuhan, China
| | - Xing Hong
- The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Wuhan University, Wuhan, China
| | - Shasha Hua
- The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Wuhan University, Wuhan, China
| | - Kai Jiang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Wuhan University, Wuhan, China
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27
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Sridhar S, Fukagawa T. Kinetochore Architecture Employs Diverse Linker Strategies Across Evolution. Front Cell Dev Biol 2022; 10:862637. [PMID: 35800888 PMCID: PMC9252888 DOI: 10.3389/fcell.2022.862637] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 05/23/2022] [Indexed: 01/09/2023] Open
Abstract
The assembly of a functional kinetochore on centromeric chromatin is necessary to connect chromosomes to the mitotic spindle, ensuring accurate chromosome segregation. This connecting function of the kinetochore presents multiple internal and external structural challenges. A microtubule interacting outer kinetochore and centromeric chromatin interacting inner kinetochore effectively confront forces from the external spindle and centromere, respectively. While internally, special inner kinetochore proteins, defined as "linkers," simultaneously interact with centromeric chromatin and the outer kinetochore to enable association with the mitotic spindle. With the ability to simultaneously interact with outer kinetochore components and centromeric chromatin, linker proteins such as centromere protein (CENP)-C or CENP-T in vertebrates and, additionally CENP-QOkp1-UAme1 in yeasts, also perform the function of force propagation within the kinetochore. Recent efforts have revealed an array of linker pathways strategies to effectively recruit the largely conserved outer kinetochore. In this review, we examine these linkages used to propagate force and recruit the outer kinetochore across evolution. Further, we look at their known regulatory pathways and implications on kinetochore structural diversity and plasticity.
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Affiliation(s)
- Shreyas Sridhar
- Laboratory of Chromosome Biology, Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - Tatsuo Fukagawa
- Laboratory of Chromosome Biology, Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
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28
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Almeida AC, Soares-de-Oliveira J, Drpic D, Cheeseman LP, Damas J, Lewin HA, Larkin DM, Aguiar P, Pereira AJ, Maiato H. Augmin-dependent microtubule self-organization drives kinetochore fiber maturation in mammals. Cell Rep 2022; 39:110610. [PMID: 35385739 PMCID: PMC8994134 DOI: 10.1016/j.celrep.2022.110610] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 01/07/2022] [Accepted: 03/11/2022] [Indexed: 11/29/2022] Open
Abstract
Chromosome segregation in mammals relies on the maturation of a thick bundle of kinetochore-attached microtubules known as k-fiber. How k-fibers mature from initial kinetochore microtubule attachments remains a fundamental question. By combining molecular perturbations and phenotypic analyses in Indian muntjac fibroblasts containing the lowest known diploid chromosome number in mammals (2N = 6) and distinctively large kinetochores, with fixed/live-cell super-resolution coherent-hybrid stimulated emission depletion (CH-STED) nanoscopy and laser microsurgery, we demonstrate a key role for augmin in kinetochore microtubule self-organization and maturation, regardless of pioneer centrosomal microtubules. In doing so, augmin promotes kinetochore and interpolar microtubule turnover and poleward flux. Tracking of microtubule growth events within individual k-fibers reveals a wide angular dispersion, consistent with augmin-mediated branched microtubule nucleation. Augmin depletion reduces the frequency of kinetochore microtubule growth events and hampers efficient repair after acute k-fiber injury by laser microsurgery. Together, these findings underscore the contribution of augmin-mediated microtubule amplification for k-fiber self-organization and maturation in mammals.
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Affiliation(s)
- Ana C Almeida
- Instituto de Investigação e Inovação em Saúde (i3S), 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
| | - Joana Soares-de-Oliveira
- Instituto de Investigação e Inovação em Saúde (i3S), 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
| | - Danica Drpic
- Instituto de Investigação e Inovação em Saúde (i3S), 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
| | - Liam P Cheeseman
- Instituto de Investigação e Inovação em Saúde (i3S), 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
| | - Joana Damas
- Department of Comparative Biomedical Sciences, Royal Veterinary College, University of London, London NW1 0TU, UK; Department of Evolution and Ecology, University of California, Davis, CA 95616, USA
| | - Harris A Lewin
- Department of Evolution and Ecology, University of California, Davis, CA 95616, USA
| | - Denis M Larkin
- Department of Comparative Biomedical Sciences, Royal Veterinary College, University of London, London NW1 0TU, UK
| | - Paulo Aguiar
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; Instituto Nacional de Engenharia Biomédica (INEB), Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - António J Pereira
- Instituto de Investigação e Inovação em Saúde (i3S), 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
- Instituto de Investigação e Inovação em Saúde (i3S), 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 Professor Hernâni Monteiro, 4200-319 Porto, Portugal.
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29
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Osadska M, Selicky T, Kretova M, Jurcik J, Sivakova B, Cipakova I, Cipak L. The Interplay of Cohesin and RNA Processing Factors: The Impact of Their Alterations on Genome Stability. Int J Mol Sci 2022; 23:3939. [PMID: 35409298 PMCID: PMC8999970 DOI: 10.3390/ijms23073939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 03/28/2022] [Accepted: 03/31/2022] [Indexed: 12/01/2022] Open
Abstract
Cohesin, a multi-subunit protein complex, plays important roles in sister chromatid cohesion, DNA replication, chromatin organization, gene expression, transcription regulation, and the recombination or repair of DNA damage. Recently, several studies suggested that the functions of cohesin rely not only on cohesin-related protein-protein interactions, their post-translational modifications or specific DNA modifications, but that some RNA processing factors also play an important role in the regulation of cohesin functions. Therefore, the mutations and changes in the expression of cohesin subunits or alterations in the interactions between cohesin and RNA processing factors have been shown to have an impact on cohesion, the fidelity of chromosome segregation and, ultimately, on genome stability. In this review, we provide an overview of the cohesin complex and its role in chromosome segregation, highlight the causes and consequences of mutations and changes in the expression of cohesin subunits, and discuss the RNA processing factors that participate in the regulation of the processes involved in chromosome segregation. Overall, an understanding of the molecular determinants of the interplay between cohesin and RNA processing factors might help us to better understand the molecular mechanisms ensuring the integrity of the genome.
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Affiliation(s)
- Michaela Osadska
- Cancer Research Institute, Biomedical Research Center, Slovak Academy of Sciences, Dubravska cesta 9, 845 05 Bratislava, Slovakia; (M.O.); (T.S.); (M.K.); (J.J.)
| | - Tomas Selicky
- Cancer Research Institute, Biomedical Research Center, Slovak Academy of Sciences, Dubravska cesta 9, 845 05 Bratislava, Slovakia; (M.O.); (T.S.); (M.K.); (J.J.)
| | - Miroslava Kretova
- Cancer Research Institute, Biomedical Research Center, Slovak Academy of Sciences, Dubravska cesta 9, 845 05 Bratislava, Slovakia; (M.O.); (T.S.); (M.K.); (J.J.)
| | - Jan Jurcik
- Cancer Research Institute, Biomedical Research Center, Slovak Academy of Sciences, Dubravska cesta 9, 845 05 Bratislava, Slovakia; (M.O.); (T.S.); (M.K.); (J.J.)
| | - Barbara Sivakova
- Institute of Chemistry, Slovak Academy of Sciences, Dubravska Cesta 9, 845 38 Bratislava, Slovakia;
| | - Ingrid Cipakova
- Cancer Research Institute, Biomedical Research Center, Slovak Academy of Sciences, Dubravska cesta 9, 845 05 Bratislava, Slovakia; (M.O.); (T.S.); (M.K.); (J.J.)
| | - Lubos Cipak
- Cancer Research Institute, Biomedical Research Center, Slovak Academy of Sciences, Dubravska cesta 9, 845 05 Bratislava, Slovakia; (M.O.); (T.S.); (M.K.); (J.J.)
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30
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Microtubule and Actin Cytoskeletal Dynamics in Male Meiotic Cells of Drosophila melanogaster. Cells 2022; 11:cells11040695. [PMID: 35203341 PMCID: PMC8870657 DOI: 10.3390/cells11040695] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Revised: 02/11/2022] [Accepted: 02/14/2022] [Indexed: 01/12/2023] Open
Abstract
Drosophila dividing spermatocytes offer a highly suitable cell system in which to investigate the coordinated reorganization of microtubule and actin cytoskeleton systems during cell division of animal cells. Like male germ cells of mammals, Drosophila spermatogonia and spermatocytes undergo cleavage furrow ingression during cytokinesis, but abscission does not take place. Thus, clusters of primary and secondary spermatocytes undergo meiotic divisions in synchrony, resulting in cysts of 32 secondary spermatocytes and then 64 spermatids connected by specialized structures called ring canals. The meiotic spindles in Drosophila males are substantially larger than the spindles of mammalian somatic cells and exhibit prominent central spindles and contractile rings during cytokinesis. These characteristics make male meiotic cells particularly amenable to immunofluorescence and live imaging analysis of the spindle microtubules and the actomyosin apparatus during meiotic divisions. Moreover, because the spindle assembly checkpoint is not robust in spermatocytes, Drosophila male meiosis allows investigating of whether gene products required for chromosome segregation play additional roles during cytokinesis. Here, we will review how the research studies on Drosophila male meiotic cells have contributed to our knowledge of the conserved molecular pathways that regulate spindle microtubules and cytokinesis with important implications for the comprehension of cancer and other diseases.
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31
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Verma V, Maresca TJ. A celebration of the 25th anniversary of chromatin-mediated spindle assembly. Mol Biol Cell 2022; 33:rt1. [PMID: 35076260 PMCID: PMC9236140 DOI: 10.1091/mbc.e21-08-0400] [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] [Indexed: 11/30/2022] Open
Abstract
Formation of a bipolar spindle is required for the faithful segregation of chromosomes during cell division. Twenty-five years ago, a transformative insight into how bipolarity is achieved was provided by Rebecca Heald, Eric Karsenti, and colleagues in their landmark publication characterizing a chromatin-mediated spindle assembly pathway in which centrosomes and kinetochores were dispensable. The discovery revealed that bipolar spindle assembly is a self-organizing process where microtubules, which possess an intrinsic polarity, polymerize around chromatin and become sorted by mitotic motors into a bipolar structure. On the 25th anniversary of this seminal paper, we discuss what was known before, what we have learned since, and what may lie ahead in understanding the bipolar spindle.
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Affiliation(s)
- Vikash Verma
- Biology Department, University of Massachusetts, Amherst, Amherst, MA 01003
| | - Thomas J Maresca
- Biology Department, University of Massachusetts, Amherst, Amherst, MA 01003.,Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, Amherst, MA 01003
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32
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Tian Y, Yan Y, Fu J. Nine-fold symmetry of centriole: The joint efforts of its core proteins. Bioessays 2022; 44:e2100262. [PMID: 34997615 DOI: 10.1002/bies.202100262] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 12/22/2021] [Accepted: 12/30/2021] [Indexed: 12/14/2022]
Abstract
The centriole is a widely conserved organelle required for the assembly of centrosomes, cilia, and flagella. Its striking feature - the nine-fold symmetrical structure, was discovered over 70 years ago by transmission electron microscopy, and since elaborated mostly by cryo-electron microscopy and super-resolution microscopy. Here, we review the discoveries that led to the current understanding of how the nine-fold symmetrical structure is built. We focus on the recent findings of the centriole structure in high resolution, its assembly pathways, and its nine-fold distributed components. We propose a model that the assembly of the nine-fold symmetrical centriole depends on the concerted efforts of its core proteins.
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Affiliation(s)
- Yuan Tian
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Yuxuan Yan
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Jingyan Fu
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
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Strunov A, Boldyreva LV, Pindyurin AV, Gatti M, Kiseleva E. TEM Imaging of Membrane Choreography During Mitosis of Drosophila Tissue Culture Cells. Methods Mol Biol 2022; 2502:407-415. [PMID: 35412253 DOI: 10.1007/978-1-0716-2337-4_26] [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] [Indexed: 06/14/2023]
Abstract
Schneider 2 (S2) cells are one of the most widely used Drosophila cell lines, and are specifically suitable for genetic dissection of biological processes by RNA interference. We have recently developed a method that allows an easy preparation of samples for transmission electron microscopy (TEM) analysis of S2 cells. This method is based on the collection and pelleting of the cells in test tubes, followed by fixation and staining of pellets in the same tubes. Pellets are then embedded in resin and used to prepare ultrathin sections for TEM observation. Our Method allows clear visualization of the complex membrane transformations that characterize mitosis in S2 cells. It also allows precise analysis of microtubule behavior during the different mitotic phases. Although the method was specifically developed for S2 cells, our preliminary results indicate that it can be successfully applied to other types of Drosophila tissue culture cells.
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Affiliation(s)
- Anton Strunov
- Institute of Cytology and Genetics (ICG), Siberian Branch of Russian Academy of Sciences (SB RAS), Novosibirsk, Russia
- Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Lidiya V Boldyreva
- Institute of Molecular and Cellular Biology (IMCB), SB RAS, Novosibirsk, Russia
| | - Alexey V Pindyurin
- Institute of Molecular and Cellular Biology (IMCB), SB RAS, Novosibirsk, Russia
| | - Maurizio Gatti
- IBPM CNR and Department of Biology and Biotechnology, Sapienza University of Rome, Rome, Italy
| | - Elena Kiseleva
- Institute of Cytology and Genetics (ICG), Siberian Branch of Russian Academy of Sciences (SB RAS), Novosibirsk, Russia.
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SF3B14 is involved in the centrosome regulation trough splicing of TUBGCP6 pre-mRNA. Biochem Biophys Res Commun 2021; 588:133-139. [PMID: 34954520 DOI: 10.1016/j.bbrc.2021.12.059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 12/16/2021] [Indexed: 11/20/2022]
Abstract
Splicing precursor messenger RNA (pre-mRNA) is a critical step to produce physiologically functional protein. Splicing failure not only gives rise to dysfunctional proteins but also generates abnormal protein function, which causes several diseases. Several pre-mRNA splicing factors are reported to regulate mitosis directly at mitotic structures and/or indirectly through controlling the pre-mRNA splicing for mitotic proteins. In this study, we described the mitotic functions of SF3B14, a component of the spliceosomal U2 small nuclear ribonucleoprotein (snRNP), which we identified as a candidate involved in mitosis based on the large-scale RNA interference (RNAi) screen of the nucleolar proteome database. We observed that SF3B14 depletion caused prolonged mitosis and several mitotic defects, such as monopolar spindle and chromosome misalignment during metaphase. Although SF3B14 was found in the nucleolar proteome database, our immunofluorescent stainings demonstrated that SF3B14 was predominantly localized in the nucleoplasm and excluded from the nucleolus during interphase. In addition, SF3B14 did not colocalize with specific mitotic structures during mitosis, which is not in line with its direct mitotic function. Notably, we found that the SF3B14 depletion reduced protein levels of TUBGCP6, required for centrosome regulation, and increased the unspliced/spliced ratio of its mRNA. Taken together, we propose that the pre-mRNA of TUBGCP6 is one of the targets for SF3B14 splicing through which SF3B14 controls mitotic chromosome behavior.
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35
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Berloco MF, Minervini CF, Moschetti R, Palazzo A, Viggiano L, Marsano RM. Evidence of the Physical Interaction between Rpl22 and the Transposable Element Doc5, a Heterochromatic Transposon of Drosophila melanogaster. Genes (Basel) 2021; 12:1997. [PMID: 34946947 PMCID: PMC8701128 DOI: 10.3390/genes12121997] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Revised: 12/06/2021] [Accepted: 12/12/2021] [Indexed: 11/16/2022] Open
Abstract
Chromatin is a highly dynamic biological entity that allows for both the control of gene expression and the stabilization of chromosomal domains. Given the high degree of plasticity observed in model and non-model organisms, it is not surprising that new chromatin components are frequently described. In this work, we tested the hypothesis that the remnants of the Doc5 transposable element, which retains a heterochromatin insertion pattern in the melanogaster species complex, can be bound by chromatin proteins, and thus be involved in the organization of heterochromatic domains. Using the Yeast One Hybrid approach, we found Rpl22 as a potential interacting protein of Doc5. We further tested in vitro the observed interaction through Electrophoretic Mobility Shift Assay, uncovering that the N-terminal portion of the protein is sufficient to interact with Doc5. However, in situ localization of the native protein failed to detect Rpl22 association with chromatin. The results obtained are discussed in the light of the current knowledge on the extra-ribosomal role of ribosomal protein in eukaryotes, which suggests a possible role of Rpl22 in the determination of the heterochromatin in Drosophila.
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Affiliation(s)
- Maria Francesca Berloco
- Department of Biology, University of Bari “Aldo Moro”, 70126 Bari, Italy; (M.F.B.); (R.M.); (A.P.)
| | - Crescenzio Francesco Minervini
- Department of Emergency and Organ Transplantation (D.E.T.O.), Hematology and Stem Cell Transplantation Unit, University of Bari “Aldo Moro”, 70124 Bari, Italy;
| | - Roberta Moschetti
- Department of Biology, University of Bari “Aldo Moro”, 70126 Bari, Italy; (M.F.B.); (R.M.); (A.P.)
| | - Antonio Palazzo
- Department of Biology, University of Bari “Aldo Moro”, 70126 Bari, Italy; (M.F.B.); (R.M.); (A.P.)
| | - Luigi Viggiano
- Department of Biology, University of Bari “Aldo Moro”, 70126 Bari, Italy; (M.F.B.); (R.M.); (A.P.)
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Ryniawec JM, Rogers GC. Centrosome instability: when good centrosomes go bad. Cell Mol Life Sci 2021; 78:6775-6795. [PMID: 34476544 PMCID: PMC8560572 DOI: 10.1007/s00018-021-03928-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Revised: 08/10/2021] [Accepted: 08/26/2021] [Indexed: 02/06/2023]
Abstract
The centrosome is a tiny cytoplasmic organelle that organizes and constructs massive molecular machines to coordinate diverse cellular processes. Due to its many roles during both interphase and mitosis, maintaining centrosome homeostasis is essential to normal health and development. Centrosome instability, divergence from normal centrosome number and structure, is a common pathognomonic cellular state tightly associated with cancers and other genetic diseases. As novel connections are investigated linking the centrosome to disease, it is critical to understand the breadth of centrosome functions to inspire discovery. In this review, we provide an introduction to normal centrosome function and highlight recent discoveries that link centrosome instability to specific disease states.
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Affiliation(s)
- John M Ryniawec
- University of Arizona Cancer Center, University of Arizona, 1515 N. Campbell Ave., Tucson, AZ, 85724, USA
| | - Gregory C Rogers
- University of Arizona Cancer Center, University of Arizona, 1515 N. Campbell Ave., Tucson, AZ, 85724, USA.
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Tian Y, Wei C, He J, Yan Y, Pang N, Fang X, Liang X, Fu J. Superresolution characterization of core centriole architecture. J Cell Biol 2021; 220:211748. [PMID: 33533934 PMCID: PMC7863704 DOI: 10.1083/jcb.202005103] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 11/29/2020] [Accepted: 01/06/2021] [Indexed: 12/31/2022] Open
Abstract
The centrosome is the main microtubule-organizing center in animal cells. It comprises of two centrioles and the surrounding pericentriolar material. Protein organization at the outer layer of the centriole and outward has been studied extensively; however, an overall picture of the protein architecture at the centriole core has been missing. Here we report a direct view of Drosophila centriolar proteins at ∼50-nm resolution. This reveals a Sas6 ring at the C-terminus, where it overlaps with the C-terminus of Cep135. The ninefold symmetrical pattern of Cep135 is further conveyed through Ana1-Asterless axes that extend past the microtubule wall from between the blades. Ana3 and Rcd4, whose termini are close to Cep135, are arranged in ninefold symmetry that does not match the above axes. During centriole biogenesis, Ana3 and Rcd4 are sequentially loaded on the newly formed centriole and are required for centriole-to-centrosome conversion through recruiting the Cep135-Ana1-Asterless complex. Together, our results provide a spatiotemporal map of the centriole core and implications of how the structure might be built.
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Affiliation(s)
- Yuan Tian
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Chenxi Wei
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Jianfeng He
- Tsinghua-Peking Joint Center for Life Sciences and Max Planck Partner Group, School of Life Sciences, Tsinghua University, Beijing, China
| | - Yuxuan Yan
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Nan Pang
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Xiaomin Fang
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Xin Liang
- Tsinghua-Peking Joint Center for Life Sciences and Max Planck Partner Group, School of Life Sciences, Tsinghua University, Beijing, China
| | - Jingyan Fu
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
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The Cilioprotist Cytoskeleton , a Model for Understanding How Cell Architecture and Pattern Are Specified: Recent Discoveries from Ciliates and Comparable Model Systems. Methods Mol Biol 2021; 2364:251-295. [PMID: 34542858 DOI: 10.1007/978-1-0716-1661-1_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
Abstract
The cytoskeletons of eukaryotic, cilioprotist microorganisms are complex, highly patterned, and diverse, reflecting the varied and elaborate swimming, feeding, reproductive, and sensory behaviors of the multitude of cilioprotist species that inhabit the aquatic environment. In the past 10-20 years, many new discoveries and technologies have helped to advance our understanding of how cytoskeletal organelles are assembled in many different eukaryotic model systems, in relation to the construction and modification of overall cellular architecture and function. Microtubule organizing centers, particularly basal bodies and centrioles, have continued to reveal their central roles in architectural engineering of the eukaryotic cell, including in the cilioprotists. This review calls attention to (1) published resources that illuminate what is known of the cilioprotist cytoskeleton; (2) recent studies on cilioprotists and other model organisms that raise specific questions regarding whether basal body- and centriole-associated nucleic acids, both DNA and RNA, should continue to be considered when seeking to employ cilioprotists as model systems for cytoskeletal research; and (3) new, mainly imaging, technologies that have already proven useful for, but also promise to enhance, future cytoskeletal research on cilioprotists.
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Aromolaran O, Beder T, Adedeji E, Ajamma Y, Oyelade J, Adebiyi E, Koenig R. Predicting host dependency factors of pathogens in Drosophila melanogaster using machine learning. Comput Struct Biotechnol J 2021; 19:4581-4592. [PMID: 34471501 PMCID: PMC8385402 DOI: 10.1016/j.csbj.2021.08.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 08/06/2021] [Accepted: 08/06/2021] [Indexed: 11/25/2022] Open
Abstract
Pathogens causing infections, and particularly when invading the host cells, require the host cell machinery for efficient regeneration and proliferation during infection. For their life cycle, host proteins are needed and these Host Dependency Factors (HDF) may serve as therapeutic targets. Several attempts have approached screening for HDF producing large lists of potential HDF with, however, only marginal overlap. To get consistency into the data of these experimental studies, we developed a machine learning pipeline. As a case study, we used publicly available lists of experimentally derived HDF from twelve different screening studies based on gene perturbation in Drosophila melanogaster cells or in vivo upon bacterial or protozoan infection. A total of 50,334 gene features were generated from diverse categories including their functional annotations, topology attributes in protein interaction networks, nucleotide and protein sequence features, homology properties and subcellular localization. Cross-validation revealed an excellent prediction performance. All feature categories contributed to the model. Predicted and experimentally derived HDF showed a good consistency when investigating their common cellular processes and function. Cellular processes and molecular function of these genes were highly enriched in membrane trafficking, particularly in the trans-Golgi network, cell cycle and the Rab GTPase binding family. Using our machine learning approach, we show that HDF in organisms can be predicted with high accuracy evidencing their common investigated characteristics. We elucidated cellular processes which are utilized by invading pathogens during infection. Finally, we provide a list of 208 novel HDF proposed for future experimental studies.
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Affiliation(s)
- Olufemi Aromolaran
- Department of Computer & Information Sciences, Covenant University, Ota, Ogun State, Nigeria
- Integrated Research and Treatment Center, Center for Sepsis Control and Care (CSCC), Jena University Hospital, Am Klinikum 1, 07747 Jena, Germany
- Covenant University Bioinformatics Research (CUBRe), Covenant University, Ota, Ogun State, Nigeria
| | - Thomas Beder
- Integrated Research and Treatment Center, Center for Sepsis Control and Care (CSCC), Jena University Hospital, Am Klinikum 1, 07747 Jena, Germany
- Institute of Infectious Diseases and Infection Control, Jena University Hospital, Am Klinikum 1, 07747 Jena, Germany
| | - Eunice Adedeji
- Covenant University Bioinformatics Research (CUBRe), Covenant University, Ota, Ogun State, Nigeria
- Department of Biochemistry, Covenant University, Ota, Ogun State, Nigeria
| | - Yvonne Ajamma
- Covenant University Bioinformatics Research (CUBRe), Covenant University, Ota, Ogun State, Nigeria
| | - Jelili Oyelade
- Department of Computer & Information Sciences, Covenant University, Ota, Ogun State, Nigeria
- Integrated Research and Treatment Center, Center for Sepsis Control and Care (CSCC), Jena University Hospital, Am Klinikum 1, 07747 Jena, Germany
- Covenant University Bioinformatics Research (CUBRe), Covenant University, Ota, Ogun State, Nigeria
| | - Ezekiel Adebiyi
- Department of Computer & Information Sciences, Covenant University, Ota, Ogun State, Nigeria
- Covenant University Bioinformatics Research (CUBRe), Covenant University, Ota, Ogun State, Nigeria
| | - Rainer Koenig
- Integrated Research and Treatment Center, Center for Sepsis Control and Care (CSCC), Jena University Hospital, Am Klinikum 1, 07747 Jena, Germany
- Institute of Infectious Diseases and Infection Control, Jena University Hospital, Am Klinikum 1, 07747 Jena, Germany
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Szikora S, Görög P, Kozma C, Mihály J. Drosophila Models Rediscovered with Super-Resolution Microscopy. Cells 2021; 10:1924. [PMID: 34440693 PMCID: PMC8391832 DOI: 10.3390/cells10081924] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 07/22/2021] [Accepted: 07/27/2021] [Indexed: 11/25/2022] Open
Abstract
With the advent of super-resolution microscopy, we gained a powerful toolbox to bridge the gap between the cellular- and molecular-level analysis of living organisms. Although nanoscopy is broadly applicable, classical model organisms, such as fruit flies, worms and mice, remained the leading subjects because combining the strength of sophisticated genetics, biochemistry and electrophysiology with the unparalleled resolution provided by super-resolution imaging appears as one of the most efficient approaches to understanding the basic cell biological questions and the molecular complexity of life. Here, we summarize the major nanoscopic techniques and illustrate how these approaches were used in Drosophila model systems to revisit a series of well-known cell biological phenomena. These investigations clearly demonstrate that instead of simply achieving an improvement in image quality, nanoscopy goes far beyond with its immense potential to discover novel structural and mechanistic aspects. With the examples of synaptic active zones, centrosomes and sarcomeres, we will explain the instrumental role of super-resolution imaging pioneered in Drosophila in understanding fundamental subcellular constituents.
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Affiliation(s)
- Szilárd Szikora
- Institute of Genetics, Biological Research Centre, Temesvári krt. 62, H-6726 Szeged, Hungary;
| | - Péter Görög
- Institute of Genetics, Biological Research Centre, Temesvári krt. 62, H-6726 Szeged, Hungary;
- Doctoral School of Multidisciplinary Medical Science, Faculty of Medicine, University of Szeged, H-6725 Szeged, Hungary
| | - Csaba Kozma
- Foundation for the Future of Biomedical Sciences in Szeged, Szeged Scientists Academy, Pálfy u. 52/d, H-6725 Szeged, Hungary;
| | - József Mihály
- Institute of Genetics, Biological Research Centre, Temesvári krt. 62, H-6726 Szeged, Hungary;
- Department of Genetics, University of Szeged, H-6726 Szeged, Hungary
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Abstract
As one of four filament types, microtubules are a core component of the cytoskeleton and are essential for cell function. Yet how microtubules are nucleated from their building blocks, the αβ-tubulin heterodimer, has remained a fundamental open question since the discovery of tubulin 50 years ago. Recent structural studies have shed light on how γ-tubulin and the γ-tubulin complex proteins (GCPs) GCP2 to GCP6 form the γ-tubulin ring complex (γ-TuRC). In parallel, functional and single-molecule studies have informed on how the γ-TuRC nucleates microtubules in real time, how this process is regulated in the cell and how it compares to other modes of nucleation. Another recent surprise has been the identification of a second essential nucleation factor, which turns out to be the well-characterized microtubule polymerase XMAP215 (also known as CKAP5, a homolog of chTOG, Stu2 and Alp14). This discovery helps to explain why the observed nucleation activity of the γ-TuRC in vitro is relatively low. Taken together, research in recent years has afforded important insight into how microtubules are made in the cell and provides a basis for an exciting era in the cytoskeleton field.
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Affiliation(s)
- Akanksha Thawani
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, Berkeley, CA 94720, USA
| | - Sabine Petry
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
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42
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Jiang X, Ho DBT, Mahe K, Mia J, Sepulveda G, Antkowiak M, Jiang L, Yamada S, Jao LE. Condensation of pericentrin proteins in human cells illuminates phase separation in centrosome assembly. J Cell Sci 2021; 134:jcs258897. [PMID: 34308971 PMCID: PMC8349556 DOI: 10.1242/jcs.258897] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 06/08/2021] [Indexed: 11/24/2022] Open
Abstract
At the onset of mitosis, centrosomes expand the pericentriolar material (PCM) to maximize their microtubule-organizing activity. This step, termed centrosome maturation, ensures proper spindle organization and faithful chromosome segregation. However, as the centrosome expands, how PCM proteins are recruited and held together without membrane enclosure remains elusive. We found that endogenously expressed pericentrin (PCNT), a conserved PCM scaffold protein, condenses into dynamic granules during late G2/early mitosis before incorporating into mitotic centrosomes. Furthermore, the N-terminal portion of PCNT, enriched with conserved coiled-coils (CCs) and low-complexity regions (LCRs), phase separates into dynamic condensates that selectively recruit PCM proteins and nucleate microtubules in cells. We propose that CCs and LCRs, two prevalent sequence features in the centrosomal proteome, are preserved under evolutionary pressure in part to mediate liquid-liquid phase separation, a process that bestows upon the centrosome distinct properties critical for its assembly and functions.
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Affiliation(s)
- Xueer Jiang
- Department of Cell Biology and Human Anatomy, University of California, Davis, School of Medicine, Davis, CA 95616, USA
| | - Dac Bang Tam Ho
- Department of Cell Biology and Human Anatomy, University of California, Davis, School of Medicine, Davis, CA 95616, USA
| | - Karan Mahe
- Department of Cell Biology and Human Anatomy, University of California, Davis, School of Medicine, Davis, CA 95616, USA
| | - Jennielee Mia
- Department of Cell Biology and Human Anatomy, University of California, Davis, School of Medicine, Davis, CA 95616, USA
| | - Guadalupe Sepulveda
- Department of Cell Biology and Human Anatomy, University of California, Davis, School of Medicine, Davis, CA 95616, USA
| | - Mark Antkowiak
- Department of Cell Biology and Human Anatomy, University of California, Davis, School of Medicine, Davis, CA 95616, USA
| | - Linhao Jiang
- Department of Cell Biology and Human Anatomy, University of California, Davis, School of Medicine, Davis, CA 95616, USA
| | - Soichiro Yamada
- Department of Biomedical Engineering, University of California, Davis, Davis, CA 95616, USA
| | - Li-En Jao
- Department of Cell Biology and Human Anatomy, University of California, Davis, School of Medicine, Davis, CA 95616, USA
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Maiato H. Mitosis under the macroscope. Semin Cell Dev Biol 2021; 117:1-5. [PMID: 34172396 DOI: 10.1016/j.semcdb.2021.06.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- 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, Experimental Biology Unit, Department of Biomedicine, Faculdade de Medicina, Universidade do Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal.
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44
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Ferreira LT, Maiato H. Prometaphase. Semin Cell Dev Biol 2021; 117:52-61. [PMID: 34127384 DOI: 10.1016/j.semcdb.2021.06.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/31/2021] [Accepted: 06/02/2021] [Indexed: 11/28/2022]
Abstract
The establishment of a metaphase plate in which all chromosomes are attached to mitotic spindle microtubules and aligned at the cell equator is required for faithful chromosome segregation in metazoans. The achievement of this configuration relies on the precise coordination between several concurrent mechanisms that start upon nuclear envelope breakdown, mediate chromosome capture at their kinetochores during mitotic spindle assembly and culminate with the congression of all chromosomes to the spindle equator. This period is called 'prometaphase'. Because the nature of chromosome capture by mitotic spindle microtubules is error prone, the cell is provided of error correction mechanisms that sense and correct most erroneous kinetochore-microtubule attachments before committing to separate sister chromatids in anaphase. In this review, aimed for newcomers in the field, more than providing an exhaustive mechanistic coverage of each and every concurrent mechanism taking place during prometaphase, we provide an integrative overview of these processes that ultimately promote the subsequent faithful segregation of chromosomes during mitosis.
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Affiliation(s)
- 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
| | - 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, Experimental Biology Unit, Department of Biomedicine, Faculdade de Medicina, Universidade do Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal.
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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.
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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
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Carty BL, Dattoli AA, Dunleavy EM. CENP-C functions in centromere assembly, the maintenance of CENP-A asymmetry and epigenetic age in Drosophila germline stem cells. PLoS Genet 2021; 17:e1009247. [PMID: 34014920 PMCID: PMC8136707 DOI: 10.1371/journal.pgen.1009247] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 04/16/2021] [Indexed: 01/08/2023] Open
Abstract
Germline stem cells divide asymmetrically to produce one new daughter stem cell and one daughter cell that will subsequently undergo meiosis and differentiate to generate the mature gamete. The silent sister hypothesis proposes that in asymmetric divisions, the selective inheritance of sister chromatids carrying specific epigenetic marks between stem and daughter cells impacts cell fate. To facilitate this selective inheritance, the hypothesis specifically proposes that the centromeric region of each sister chromatid is distinct. In Drosophila germ line stem cells (GSCs), it has recently been shown that the centromeric histone CENP-A (called CID in flies)—the epigenetic determinant of centromere identity—is asymmetrically distributed between sister chromatids. In these cells, CID deposition occurs in G2 phase such that sister chromatids destined to end up in the stem cell harbour more CENP-A, assemble more kinetochore proteins and capture more spindle microtubules. These results suggest a potential mechanism of ‘mitotic drive’ that might bias chromosome segregation. Here we report that the inner kinetochore protein CENP-C, is required for the assembly of CID in G2 phase in GSCs. Moreover, CENP-C is required to maintain a normal asymmetric distribution of CID between stem and daughter cells. In addition, we find that CID is lost from centromeres in aged GSCs and that a reduction in CENP-C accelerates this loss. Finally, we show that CENP-C depletion in GSCs disrupts the balance of stem and daughter cells in the ovary, shifting GSCs toward a self-renewal tendency. Ultimately, we provide evidence that centromere assembly and maintenance via CENP-C is required to sustain asymmetric divisions in female Drosophila GSCs. Stem cells can divide in an asymmetric fashion giving rise to two daughter cells with different fates. One daughter remains a stem cell, while the other can differentiate and adopt a new cell fate. Germline stem cells in the testes and ovaries give rise to differentiating daughter cells that eventually form the gametes, eggs and sperm. Here we investigate mechanisms controlling germline stem cell divisions occurring in the ovary of the fruit fly Drosophila melanogaster. Centromeres are epigenetically specified loci on chromosomes that make essential connections to the cell division machinery. Our study is focused on the centromere component CENP-C. We show that CENP-C is critical for the correct assembly of centromeres that occurs prior to cell division in germline stem cells. In addition, we find that CENP-C is asymmetrically distributed between stem and daughter cells, with more CENP-C at stem cell centromeres. Finally, we show that CENP-C depletion in germline stem cells disrupts the balance of stem and daughter cells in the developing ovary, impacting on cell fate. Taken together, we propose that CENP-C level and function at centromeres plays an important role in determining cell fate upon asymmetric division occurring in stem cells.
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Affiliation(s)
- Ben L. Carty
- Centre for Chromosome Biology, Biomedical Sciences, National University of Ireland Galway, Galway, Ireland
| | - Anna A. Dattoli
- Centre for Chromosome Biology, Biomedical Sciences, National University of Ireland Galway, Galway, Ireland
| | - Elaine M. Dunleavy
- Centre for Chromosome Biology, Biomedical Sciences, National University of Ireland Galway, Galway, Ireland
- * E-mail:
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Cutillas V, Johnston CA. Mud binds the kinesin-14 Ncd in Drosophila. Biochem Biophys Rep 2021; 26:101016. [PMID: 34027137 PMCID: PMC8134030 DOI: 10.1016/j.bbrep.2021.101016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 04/13/2021] [Accepted: 05/05/2021] [Indexed: 11/03/2022] Open
Abstract
Maintenance of proper mitotic spindle structure is necessary for error-free chromosome segregation and cell division. Spindle assembly is controlled by force-generating kinesin motors that contribute to its geometry and bipolarity, and balancing motor-dependent forces between opposing kinesins is critical to the integrity of this process. Non-claret dysjunctional (Ncd), a Drosophila kinesin-14 member, crosslinks and slides microtubule minus-ends to focus spindle poles and sustain bipolarity. However, mechanisms that regulate Ncd activity during mitosis are underappreciated. Here, we identify Mushroom body defect (Mud), the fly ortholog of human NuMA, as a direct Ncd binding partner. We demonstrate this interaction involves a short coiled-coil domain within Mud (MudCC) binding the N-terminal, non-motor microtubule-binding domain of Ncd (NcdnMBD). We further show that the C-terminal ATPase motor domain of Ncd (NcdCTm) directly interacts with NcdnMBD as well. Mud binding competes against this self-association and also increases NcdnMBD microtubule binding in vitro. Our results describe an interaction between two spindle-associated proteins and suggest a potentially new mode of minus-end motor protein regulation at mitotic spindle poles.
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Affiliation(s)
- Vincent Cutillas
- Department of Biology, University of New Mexico, Albuquerque, NM, USA
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Li J, Liu F, Lv Y, Sun K, Zhao Y, Reilly J, Zhang Y, Tu J, Yu S, Liu X, Qin Y, Huang Y, Gao P, Jia D, Chen X, Han Y, Shu X, Luo D, Tang Z, Liu M. Prpf31 is essential for the survival and differentiation of retinal progenitor cells by modulating alternative splicing. Nucleic Acids Res 2021; 49:2027-2043. [PMID: 33476374 PMCID: PMC7913766 DOI: 10.1093/nar/gkab003] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 01/01/2021] [Accepted: 01/05/2021] [Indexed: 12/23/2022] Open
Abstract
Dysfunction of splicing factors often result in abnormal cell differentiation and apoptosis, especially in neural tissues. Mutations in pre-mRNAs processing factor 31 (PRPF31) cause autosomal dominant retinitis pigmentosa, a progressive retinal degeneration disease. The transcriptome-wide splicing events specifically regulated by PRPF31 and their biological roles in the development and maintenance of retina are still unclear. Here, we showed that the differentiation and viability of retinal progenitor cells (RPCs) are severely perturbed in prpf31 knockout zebrafish when compared with other tissues at an early embryonic stage. At the cellular level, significant mitotic arrest and DNA damage were observed. These defects could be rescued by the wild-type human PRPF31 rather than the disease-associated mutants. Further bioinformatic analysis and experimental verification uncovered that Prpf31 deletion predominantly causes the skipping of exons with a weak 5′ splicing site. Moreover, genes necessary for DNA repair and mitotic progression are most enriched among the differentially spliced events, which may explain the cellular and tissular defects in prpf31 mutant retinas. This is the first time that Prpf31 is demonstrated to be essential for the survival and differentiation of RPCs during retinal neurogenesis by specifically modulating the alternative splicing of genes involved in DNA repair and mitosis.
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Affiliation(s)
- Jingzhen Li
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Fei Liu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Yuexia Lv
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Kui Sun
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Yuntong Zhao
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Innovation Academy for Seed Design, Chinese Academy of Science, Wuhan 430072, PR China
| | - Jamas Reilly
- Department of Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, Scotland, UK
| | - Yangjun Zhang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Jiayi Tu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Shanshan Yu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Xiliang Liu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Yayun Qin
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Yuwen Huang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Pan Gao
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Danna Jia
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Xiang Chen
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Yunqiao Han
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Xinhua Shu
- Department of Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, Scotland, UK
| | - Daji Luo
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Innovation Academy for Seed Design, Chinese Academy of Science, Wuhan 430072, PR China
| | - Zhaohui Tang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Mugen Liu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
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Spindle scaling mechanisms. Essays Biochem 2021; 64:383-396. [PMID: 32501481 DOI: 10.1042/ebc20190064] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 05/11/2020] [Accepted: 05/12/2020] [Indexed: 02/02/2023]
Abstract
The mitotic spindle robustly scales with cell size in a plethora of different organisms. During development and throughout evolution, the spindle adjusts to cell size in metazoans and yeast in order to ensure faithful chromosome separation. Spindle adjustment to cell size occurs by the scaling of spindle length, spindle shape and the velocity of spindle assembly and elongation. Different mechanisms, depending on spindle structure and organism, account for these scaling relationships. The limited availability of critical spindle components, protein gradients, sequestration of spindle components, or post-translational modification and differential expression levels have been implicated in the regulation of spindle length and the spindle assembly/elongation velocity in a cell size-dependent manner. In this review, we will discuss the phenomenon and mechanisms of spindle length, spindle shape and spindle elongation velocity scaling with cell size.
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50
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Higaki T, Akita K, Katoh K. Coefficient of variation as an image-intensity metric for cytoskeleton bundling. Sci Rep 2020; 10:22187. [PMID: 33349642 PMCID: PMC7752905 DOI: 10.1038/s41598-020-79136-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 11/27/2020] [Indexed: 12/17/2022] Open
Abstract
The evaluation of cytoskeletal bundling is a fundamental experimental method in the field of cell biology. Although the skewness of the pixel intensity distribution derived from fluorescently-labeled cytoskeletons has been widely used as a metric to evaluate the degree of bundling in digital microscopy images, its versatility has not been fully validated. Here, we applied the coefficient of variation (CV) of intensity values as an alternative metric, and compared its performance with skewness. In synthetic images representing extremely bundled conditions, the CV successfully detected degrees of bundling that could not be distinguished by skewness. On actual microscopy images, CV was better than skewness, especially on variable-angle epifluorescence microscopic images or stimulated emission depletion and confocal microscopy images of very small areas of around 1 μm2. When blur or noise was added to synthetic images, CV was found to be robust to blur but deleteriously affected by noise, whereas skewness was robust to noise but deleteriously affected by blur. For confocal images, CV and skewness showed similar sensitivity to noise, possibly because optical blurring is often present in microscopy images. Therefore, in practical use with actual microscopy images, CV may be more appropriate than skewness, unless the image is extremely noisy.
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Affiliation(s)
- Takumi Higaki
- International Research Organization for Advanced Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuo-ku, Kumamoto, Japan.
| | - Kae Akita
- Department of Chemical Biological Science, Faculty of Science, Japan Women's University, 2-8-1 Mejirodai, Bunkyo-ku, Tokyo, Japan
| | - Kaoru Katoh
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
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