1
|
Deolal P, Scholz J, Ren K, Bragulat-Teixidor H, Otsuka S. Sculpting nuclear envelope identity from the endoplasmic reticulum during the cell cycle. Nucleus 2024; 15:2299632. [PMID: 38238284 PMCID: PMC10802211 DOI: 10.1080/19491034.2023.2299632] [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: 10/18/2023] [Accepted: 12/21/2023] [Indexed: 01/23/2024] Open
Abstract
The nuclear envelope (NE) regulates nuclear functions, including transcription, nucleocytoplasmic transport, and protein quality control. While the outer membrane of the NE is directly continuous with the endoplasmic reticulum (ER), the NE has an overall distinct protein composition from the ER, which is crucial for its functions. During open mitosis in higher eukaryotes, the NE disassembles during mitotic entry and then reforms as a functional territory at the end of mitosis to reestablish nucleocytoplasmic compartmentalization. In this review, we examine the known mechanisms by which the functional NE reconstitutes from the mitotic ER in the continuous ER-NE endomembrane system during open mitosis. Furthermore, based on recent findings indicating that the NE possesses unique lipid metabolism and quality control mechanisms distinct from those of the ER, we explore the maintenance of NE identity and homeostasis during interphase. We also highlight the potential significance of membrane junctions between the ER and NE.
Collapse
Affiliation(s)
- Pallavi Deolal
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Vienna, Austria
- Medical University of Vienna, Center for Medical Biochemistry, Department of Molecular Biology, Vienna, Austria
| | - Julia Scholz
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Vienna, Austria
- Medical University of Vienna, Center for Medical Biochemistry, Department of Molecular Biology, Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Kaike Ren
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Vienna, Austria
- Medical University of Vienna, Center for Medical Biochemistry, Department of Molecular Biology, Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Helena Bragulat-Teixidor
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Vienna, Austria
- Medical University of Vienna, Center for Medical Biochemistry, Department of Molecular Biology, Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Shotaro Otsuka
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Vienna, Austria
- Medical University of Vienna, Center for Medical Biochemistry, Department of Molecular Biology, Vienna, Austria
| |
Collapse
|
2
|
Zych MG, Hatch EM. Small spaces, big problems: The abnormal nucleoplasm of micronuclei and its consequences. Curr Opin Struct Biol 2024; 87:102839. [PMID: 38763098 DOI: 10.1016/j.sbi.2024.102839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 03/29/2024] [Accepted: 04/26/2024] [Indexed: 05/21/2024]
Abstract
Micronuclei (MN) form from missegregated chromatin that recruits its own nuclear envelope during mitotic exit and are a common consequence of chromosomal instability. MN are unstable due to errors in nuclear envelope organization and frequently rupture, leading to loss of compartmentalization, loss of nuclear functions, and major changes in genome stability and gene expression. However, recent work found that, even prior to rupture, nuclear processes can be severely defective in MN, which may contribute to rupture-associated defects and have lasting consequences for chromatin structure and function. In this review we discuss work that highlights nuclear function defects in intact MN, including their mechanisms and consequences, and how biases in chromosome missegregation into MN may affect the penetrance of these defects. Illuminating the nuclear environment of MN demonstrates that MN formation alone has major consequences for both the genome and cell and provides new insight into how nuclear content is regulated.
Collapse
Affiliation(s)
- Molly G Zych
- Molecular and Cellular Biology PhD Program, University of Washington, Seattle, WA, USA; Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA. https://twitter.com/ZychMolly
| | - Emily M Hatch
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA; Human Biology Division, Fred Hutchinson Cancer Center, Seattle, WA, USA.
| |
Collapse
|
3
|
Tollervey F, Rios MU, Zagoriy E, Woodruff JB, Mahamid J. Native molecular architectures of centrosomes in C. elegans embryos. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.03.587742. [PMID: 38617234 PMCID: PMC11014625 DOI: 10.1101/2024.04.03.587742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Centrosomes organize microtubules that are essential for mitotic divisions in animal cells. They consist of centrioles surrounded by Pericentriolar Material (PCM). Questions related to mechanisms of centriole assembly, PCM organization, and microtubule formation remain unanswered, in part due to limited availability of molecular-resolution structural analyses in situ. Here, we use cryo-electron tomography to visualize centrosomes across the cell cycle in cells isolated from C. elegans embryos. We describe a pseudo-timeline of centriole assembly and identify distinct structural features including a cartwheel in daughter centrioles, and incomplete microtubule doublets surrounded by a star-shaped density in mother centrioles. We find that centriole and PCM microtubules differ in protofilament number (13 versus 11) indicating distinct nucleation mechanisms. This difference could be explained by atypical γ-tubulin ring complexes with 11-fold symmetry identified at the minus ends of short PCM microtubules. We further characterize a porous and disordered network that forms the interconnected PCM. Thus, our work builds a three-dimensional structural atlas that helps explain how centrosomes assemble, grow, and achieve function.
Collapse
Affiliation(s)
- Fergus Tollervey
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
- Collaboration for Joint PhD Degree between EMBL and Heidelberg University, Faculty of Biosciences, Heidelberg, Germany
| | - Manolo U. Rios
- Department of Cell Biology and Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Evgenia Zagoriy
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Jeffrey B. Woodruff
- Department of Cell Biology and Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Julia Mahamid
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
- Cell Biology and Biophysics Unit, EMBL, 69117 Heidelberg, Germany
| |
Collapse
|
4
|
McCafferty CL, Klumpe S, Amaro RE, Kukulski W, Collinson L, Engel BD. Integrating cellular electron microscopy with multimodal data to explore biology across space and time. Cell 2024; 187:563-584. [PMID: 38306982 DOI: 10.1016/j.cell.2024.01.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 01/03/2024] [Accepted: 01/03/2024] [Indexed: 02/04/2024]
Abstract
Biology spans a continuum of length and time scales. Individual experimental methods only glimpse discrete pieces of this spectrum but can be combined to construct a more holistic view. In this Review, we detail the latest advancements in volume electron microscopy (vEM) and cryo-electron tomography (cryo-ET), which together can visualize biological complexity across scales from the organization of cells in large tissues to the molecular details inside native cellular environments. In addition, we discuss emerging methodologies for integrating three-dimensional electron microscopy (3DEM) imaging with multimodal data, including fluorescence microscopy, mass spectrometry, single-particle analysis, and AI-based structure prediction. This multifaceted approach fills gaps in the biological continuum, providing functional context, spatial organization, molecular identity, and native interactions. We conclude with a perspective on incorporating diverse data into computational simulations that further bridge and extend length scales while integrating the dimension of time.
Collapse
Affiliation(s)
| | - Sven Klumpe
- Research Group CryoEM Technology, Max-Planck-Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany.
| | - Rommie E Amaro
- Department of Molecular Biology, University of California, San Diego, La Jolla, CA 92093, USA.
| | - Wanda Kukulski
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28, 3012 Bern, Switzerland.
| | - Lucy Collinson
- Electron Microscopy Science Technology Platform, Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK.
| | - Benjamin D Engel
- Biozentrum, University of Basel, Spitalstrasse 41, 4056 Basel, Switzerland.
| |
Collapse
|
5
|
Camblor-Perujo S, Ozer Yildiz E, Küpper H, Overhoff M, Rastogi S, Bazzi H, Kononenko NL. The AP-2 complex interacts with γ-TuRC and regulates the proliferative capacity of neural progenitors. Life Sci Alliance 2024; 7:e202302029. [PMID: 38086550 PMCID: PMC10716017 DOI: 10.26508/lsa.202302029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 11/23/2023] [Accepted: 11/27/2023] [Indexed: 12/18/2023] Open
Abstract
Centrosomes are organelles that nucleate microtubules via the activity of gamma-tubulin ring complexes (γ-TuRC). In the developing brain, centrosome integrity is central to the progression of the neural progenitor cell cycle, and its loss leads to microcephaly. We show that NPCs maintain centrosome integrity via the endocytic adaptor protein complex-2 (AP-2). NPCs lacking AP-2 exhibit defects in centrosome formation and mitotic progression, accompanied by DNA damage and accumulation of p53. This function of AP-2 in regulating the proliferative capacity of NPCs is independent of its role in clathrin-mediated endocytosis and is coupled to its association with the GCP2, GCP3, and GCP4 components of γ-TuRC. We find that AP-2 maintains γ-TuRC organization and regulates centrosome function at the level of MT nucleation. Taken together, our data reveal a novel, noncanonical function of AP-2 in regulating the proliferative capacity of NPCs and open new avenues for the identification of novel therapeutic strategies for the treatment of neurodevelopmental and neurodegenerative disorders with AP-2 complex dysfunction.
Collapse
Affiliation(s)
| | - Ebru Ozer Yildiz
- CECAD Excellence Center, University of Cologne, Cologne, Germany
| | - Hanna Küpper
- CECAD Excellence Center, University of Cologne, Cologne, Germany
| | - Melina Overhoff
- CECAD Excellence Center, University of Cologne, Cologne, Germany
- Center for Physiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Saumya Rastogi
- CECAD Excellence Center, University of Cologne, Cologne, Germany
| | - Hisham Bazzi
- CECAD Excellence Center, University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- Department of Dermatology and Venereology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Natalia L Kononenko
- CECAD Excellence Center, University of Cologne, Cologne, Germany
- Center for Physiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- Institute of Genetics, Natural Faculty, University of Cologne, Cologne, Germany
| |
Collapse
|
6
|
Aljiboury A, Hehnly H. The centrosome - diverse functions in fertilization and development across species. J Cell Sci 2023; 136:jcs261387. [PMID: 38038054 PMCID: PMC10730021 DOI: 10.1242/jcs.261387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2023] Open
Abstract
The centrosome is a non-membrane-bound organelle that is conserved across most animal cells and serves various functions throughout the cell cycle. In dividing cells, the centrosome is known as the spindle pole and nucleates a robust microtubule spindle to separate genetic material equally into two daughter cells. In non-dividing cells, the mother centriole, a substructure of the centrosome, matures into a basal body and nucleates cilia, which acts as a signal-transducing antenna. The functions of centrosomes and their substructures are important for embryonic development and have been studied extensively using in vitro mammalian cell culture or in vivo using invertebrate models. However, there are considerable differences in the composition and functions of centrosomes during different aspects of vertebrate development, and these are less studied. In this Review, we discuss the roles played by centrosomes, highlighting conserved and divergent features across species, particularly during fertilization and embryonic development.
Collapse
Affiliation(s)
- Abrar Aljiboury
- Syracuse University, Department of Biology, 107 College Place, Syracuse, NY 13244, USA
- Syracuse University, BioInspired Institute, Syracuse, NY 13244, USA
| | - Heidi Hehnly
- Syracuse University, Department of Biology, 107 College Place, Syracuse, NY 13244, USA
- Syracuse University, BioInspired Institute, Syracuse, NY 13244, USA
| |
Collapse
|
7
|
Rollins KR, Blankenship JT. Dysregulation of the endoplasmic reticulum blocks recruitment of centrosome-associated proteins resulting in mitotic failure. Development 2023; 150:dev201917. [PMID: 37971218 PMCID: PMC10690056 DOI: 10.1242/dev.201917] [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: 04/24/2023] [Accepted: 10/17/2023] [Indexed: 11/19/2023]
Abstract
The endoplasmic reticulum (ER) undergoes a remarkable transition in morphology during cell division to aid in the proper portioning of the ER. However, whether changes in ER behaviors modulate mitotic events is less clear. Like many animal embryos, the early Drosophila embryo undergoes rapid cleavage cycles in a lipid-rich environment. Here, we show that mitotic spindle formation, centrosomal maturation, and ER condensation occur with similar time frames in the early syncytium. In a screen for Rab family GTPases that display dynamic function at these stages, we identified Rab1. Rab1 disruption led to an enhanced buildup of ER at the spindle poles and produced an intriguing 'mini-spindle' phenotype. ER accumulation around the mitotic space negatively correlates with spindle length/intensity. Importantly, centrosomal maturation is defective in these embryos, as mitotic recruitment of key centrosomal proteins is weakened after Rab1 disruption. Finally, division failures and ER overaccumulation is rescued by Dynein inhibition, demonstrating that Dynein is essential for ER spindle recruitment. These results reveal that ER levels must be carefully tuned during mitotic processes to ensure proper assembly of the division machinery.
Collapse
Affiliation(s)
| | - J. Todd Blankenship
- Department of Biological Sciences, University of Denver, Denver, CO 80208, USA
| |
Collapse
|
8
|
Chen YZ, Zimyanin V, Redemann S. Loss of the mitochondrial protein SPD-3 elevates PLK-1 levels and dysregulates mitotic events. Life Sci Alliance 2023; 6:e202302011. [PMID: 37684042 PMCID: PMC10488725 DOI: 10.26508/lsa.202302011] [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: 02/23/2023] [Revised: 08/28/2023] [Accepted: 08/29/2023] [Indexed: 09/10/2023] Open
Abstract
In metazoans, Polo-like kinase (PLK1) controls several mitotic events including nuclear envelope breakdown, centrosome maturation, spindle assembly and progression through mitosis. Here we show that a mutation in the mitochondria-localized protein SPD-3 affects mitotic events by inducing elevated levels of PLK-1 in early Caenorhabditis elegans embryos. SPD-3 mutant embryos contain abnormally positioned mitotic chromosomes, show a delay in anaphase onset and asymmetrically disassemble the nuclear lamina. We found that more PLK-1 accumulated on centrosomes, nuclear envelope, nucleoplasm, and chromatin before NEBD, suggesting that PLK-1 overexpression is responsible for some of the observed mitotic phenotypes. In agreement with this, the chromosome positioning defects of the spd-3(oj35) mutant could be rescued by reducing PLK-1 levels. Our data suggests that the mitochondrial SPD-3 protein affects chromosome positioning and nuclear envelope integrity by up-regulating the endogenous levels of PLK-1 during early embryogenesis in C. elegans This finding suggests a novel link between mitochondria and nuclear envelope dynamics and chromosome positioning by increasing the amount of a key mitotic regulator, PLK-1, providing a novel link between mitochondria and mitosis.
Collapse
Affiliation(s)
- Yu-Zen Chen
- https://ror.org/0153tk833 Center for Membrane and Cell Physiology, School of Medicine, University of Virginia, Charlottesville, VA, USA
- https://ror.org/0153tk833 Department of Molecular Physiology and Biological Physics, School of Medicine, University of Virginia, Charlottesville, VA, USA
| | - Vitaly Zimyanin
- https://ror.org/0153tk833 Center for Membrane and Cell Physiology, School of Medicine, University of Virginia, Charlottesville, VA, USA
- https://ror.org/0153tk833 Department of Molecular Physiology and Biological Physics, School of Medicine, University of Virginia, Charlottesville, VA, USA
| | - Stefanie Redemann
- https://ror.org/0153tk833 Center for Membrane and Cell Physiology, School of Medicine, University of Virginia, Charlottesville, VA, USA
- https://ror.org/0153tk833 Department of Molecular Physiology and Biological Physics, School of Medicine, University of Virginia, Charlottesville, VA, USA
- https://ror.org/0153tk833 Department of Cell Biology, School of Medicine, University of Virginia, Charlottesville, VA, USA
| |
Collapse
|
9
|
Sperling AL, Fabian DK, Garrison E, Glover DM. A genetic basis for facultative parthenogenesis in Drosophila. Curr Biol 2023; 33:3545-3560.e13. [PMID: 37516115 PMCID: PMC11044649 DOI: 10.1016/j.cub.2023.07.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 06/04/2023] [Accepted: 07/05/2023] [Indexed: 07/31/2023]
Abstract
Facultative parthenogenesis enables sexually reproducing organisms to switch between sexual and asexual parthenogenetic reproduction. To gain insights into this phenomenon, we sequenced the genomes of sexually reproducing and parthenogenetic strains of Drosophila mercatorum and identified differences in the gene expression in their eggs. We then tested whether manipulating the expression of candidate gene homologs identified in Drosophila mercatorum could lead to facultative parthenogenesis in the non-parthenogenetic species Drosophila melanogaster. This identified a polygenic system whereby increased expression of the mitotic protein kinase polo and decreased expression of a desaturase, Desat2, caused facultative parthenogenesis in the non-parthenogenetic species that was enhanced by increased expression of Myc. The genetically induced parthenogenetic Drosophila melanogaster eggs exhibit de novo centrosome formation, fusion of the meiotic products, and the onset of development to generate predominantly triploid offspring. Thus, we demonstrate a genetic basis for sporadic facultative parthenogenesis in an animal.
Collapse
Affiliation(s)
- Alexis L Sperling
- University of Cambridge, Department of Genetics, Downing Street, Cambridge CB2 3EH, UK.
| | - Daniel K Fabian
- University of Cambridge, Department of Genetics, Downing Street, Cambridge CB2 3EH, UK
| | - Erik Garrison
- University of Tennessee Health Science Center, S Manassas Street, Memphis, TN 38103, USA
| | - David M Glover
- University of Cambridge, Department of Genetics, Downing Street, Cambridge CB2 3EH, UK; Division of Biology and Biological Engineering, California Institute of Technology, East California Boulevard, Pasadena, CA 91125, USA.
| |
Collapse
|
10
|
Nkombo Nkoula S, Velez-Aguilera G, Ossareh-Nazari B, Van Hove L, Ayuso C, Legros V, Chevreux G, Thomas L, Seydoux G, Askjaer P, Pintard L. Mechanisms of nuclear pore complex disassembly by the mitotic Polo-like kinase 1 (PLK-1) in C. elegans embryos. SCIENCE ADVANCES 2023; 9:eadf7826. [PMID: 37467327 PMCID: PMC10355831 DOI: 10.1126/sciadv.adf7826] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 06/16/2023] [Indexed: 07/21/2023]
Abstract
The nuclear envelope, which protects and organizes the genome, is dismantled during mitosis. In the Caenorhabditis elegans zygote, nuclear envelope breakdown (NEBD) of the parental pronuclei is spatially and temporally regulated during mitosis to promote the unification of the maternal and paternal genomes. Nuclear pore complex (NPC) disassembly is a decisive step of NEBD, essential for nuclear permeabilization. By combining live imaging, biochemistry, and phosphoproteomics, we show that NPC disassembly is a stepwise process that involves Polo-like kinase 1 (PLK-1)-dependent and -independent steps. PLK-1 targets multiple NPC subcomplexes, including the cytoplasmic filaments, central channel, and inner ring. PLK-1 is recruited to and phosphorylates intrinsically disordered regions (IDRs) of several multivalent linker nucleoporins. Notably, although the phosphosites are not conserved between human and C. elegans nucleoporins, they are located in IDRs in both species. Our results suggest that targeting IDRs of multivalent linker nucleoporins is an evolutionarily conserved driver of NPC disassembly during mitosis.
Collapse
Affiliation(s)
- Sylvia Nkombo Nkoula
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013 Paris, France
- Programme Équipe Labellisée Ligue contre le Cancer, Paris, France
| | - Griselda Velez-Aguilera
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013 Paris, France
- Programme Équipe Labellisée Ligue contre le Cancer, Paris, France
| | - Batool Ossareh-Nazari
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013 Paris, France
- Programme Équipe Labellisée Ligue contre le Cancer, Paris, France
| | - Lucie Van Hove
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013 Paris, France
- Programme Équipe Labellisée Ligue contre le Cancer, Paris, France
| | - Cristina Ayuso
- Andalusian Center for Developmental Biology (CABD), CSIC/JA/Universidad Pablo de Olavide, Seville, Spain
| | - Véronique Legros
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013 Paris, France
| | - Guillaume Chevreux
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013 Paris, France
| | - Laura Thomas
- HHMI and Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Géraldine Seydoux
- HHMI and Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Peter Askjaer
- Andalusian Center for Developmental Biology (CABD), CSIC/JA/Universidad Pablo de Olavide, Seville, Spain
| | - Lionel Pintard
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013 Paris, France
- Programme Équipe Labellisée Ligue contre le Cancer, Paris, France
| |
Collapse
|
11
|
Lüders J. Microtubule cytoskeleton: The centrosome gains a membrane. Curr Biol 2023; 33:R180-R182. [PMID: 36917938 DOI: 10.1016/j.cub.2023.02.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
Abstract
Identification of a membrane structure, termed the 'centriculum', in Caenorhabditis elegans embryos challenges the textbook view of the centrosome - a major microtubule organizing center in animal cells - as an organelle that lacks a surrounding membrane.
Collapse
Affiliation(s)
- Jens Lüders
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain.
| |
Collapse
|
12
|
Nkoula SN, Velez-Aguilera G, Ossareh-Nazari B, Hove LV, Ayuso C, Legros V, Chevreux G, Thomas L, Seydoux G, Askjaer P, Pintard L. Mechanisms of Nuclear Pore Complex disassembly by the mitotic Polo-Like Kinase 1 (PLK-1) in C. elegans embryos. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.21.528438. [PMID: 36865292 PMCID: PMC9980100 DOI: 10.1101/2023.02.21.528438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
The nuclear envelope, which protects and organizes the interphase genome, is dismantled during mitosis. In the C. elegans zygote, nuclear envelope breakdown (NEBD) of the parental pronuclei is spatially and temporally regulated during mitosis to promote the unification of the parental genomes. During NEBD, Nuclear Pore Complex (NPC) disassembly is critical for rupturing the nuclear permeability barrier and removing the NPCs from the membranes near the centrosomes and between the juxtaposed pronuclei. By combining live imaging, biochemistry, and phosphoproteomics, we characterized NPC disassembly and unveiled the exact role of the mitotic kinase PLK-1 in this process. We show that PLK-1 disassembles the NPC by targeting multiple NPC sub-complexes, including the cytoplasmic filaments, the central channel, and the inner ring. Notably, PLK-1 is recruited to and phosphorylates intrinsically disordered regions of several multivalent linker nucleoporins, a mechanism that appears to be an evolutionarily conserved driver of NPC disassembly during mitosis. (149/150 words). One-Sentence Summary PLK-1 targets intrinsically disordered regions of multiple multivalent nucleoporins to dismantle the nuclear pore complexes in the C. elegans zygote.
Collapse
|