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Dvilansky I, Altaras Y, Kamenetsky N, Nachmias D, Elia N. The human AAA-ATPase VPS4A isoform and its co-factor VTA1 have a unique function in regulating mammalian cytokinesis abscission. PLoS Biol 2024; 22:e3002327. [PMID: 38687820 PMCID: PMC11086821 DOI: 10.1371/journal.pbio.3002327] [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: 08/24/2023] [Revised: 05/10/2024] [Accepted: 04/04/2024] [Indexed: 05/02/2024] Open
Abstract
Mutations in the human AAA-ATPase VPS4 isoform, VPS4A, cause severe neurodevelopmental defects and congenital dyserythropoietic anemia (CDA). VPS4 is a crucial component of the endosomal sorting complex required for transport (ESCRT) system, which drives membrane remodeling in numerous cellular processes, including receptor degradation, cell division, and neural pruning. Notably, while most organisms encode for a single VPS4 gene, human cells have 2 VPS4 paralogs, namely VPS4A and VPS4B, but the functional differences between these paralogs is mostly unknown. Here, we set out to investigate the role of the human VPS4 paralogs in cytokinetic abscission using a series of knockout cell lines. We found that VPS4A and VPS4B hold both overlapping and distinct roles in abscission. VPS4A depletion resulted in a more severe abscission delay than VPS4B and was found to be involved in earlier stages of abscission. Moreover, VPS4A and a monomeric-locked VPS4A mutant bound the abscission checkpoint proteins CHMP4C and ANCHR, while VPS4B did not, indicating a regulatory role for the VPS4A isoform in abscission. Depletion of VTA1, a co-factor of VPS4, disrupted VPS4A-ANCHR interactions and accelerated abscission, suggesting that VTA1 is also involved in the abscission regulation. Our findings reveal a dual role for VPS4A in abscission, one that is canonical and can be compensated by VPS4B, and another that is regulatory and may be delivered by its monomeric form. These observations provide a potential mechanistic explanation for the neurodevelopmental defects and other related disorders reported in VPS4A-mutated patients with a fully functional VPS4B paralog.
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Affiliation(s)
- Inbar Dvilansky
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
- National Institute for Biotechnology in the Negev (NIBN), Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Yarin Altaras
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
- National Institute for Biotechnology in the Negev (NIBN), Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Nikita Kamenetsky
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
- National Institute for Biotechnology in the Negev (NIBN), Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Dikla Nachmias
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
- National Institute for Biotechnology in the Negev (NIBN), Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Natalie Elia
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
- National Institute for Biotechnology in the Negev (NIBN), Ben-Gurion University of the Negev, Beer Sheva, Israel
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2
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Rezig IM, Yaduma WG, McInerny CJ. Processes Controlling the Contractile Ring during Cytokinesis in Fission Yeast, Including the Role of ESCRT Proteins. J Fungi (Basel) 2024; 10:154. [PMID: 38392827 PMCID: PMC10890238 DOI: 10.3390/jof10020154] [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: 01/03/2024] [Revised: 02/05/2024] [Accepted: 02/06/2024] [Indexed: 02/24/2024] Open
Abstract
Cytokinesis, as the last stage of the cell division cycle, is a tightly controlled process amongst all eukaryotes, with defective division leading to severe cellular consequences and implicated in serious human diseases and conditions such as cancer. Both mammalian cells and the fission yeast Schizosaccharomyces pombe use binary fission to divide into two equally sized daughter cells. Similar to mammalian cells, in S. pombe, cytokinetic division is driven by the assembly of an actomyosin contractile ring (ACR) at the cell equator between the two cell tips. The ACR is composed of a complex network of membrane scaffold proteins, actin filaments, myosin motors and other cytokinesis regulators. The contraction of the ACR leads to the formation of a cleavage furrow which is severed by the endosomal sorting complex required for transport (ESCRT) proteins, leading to the final cell separation during the last stage of cytokinesis, the abscission. This review describes recent findings defining the two phases of cytokinesis in S. pombe: ACR assembly and constriction, and their coordination with septation. In summary, we provide an overview of the current understanding of the mechanisms regulating ACR-mediated cytokinesis in S. pombe and emphasize a potential role of ESCRT proteins in this process.
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Affiliation(s)
- Imane M Rezig
- School of Molecular Biosciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Davidson Building, Glasgow G12 8QQ, UK
| | - Wandiahyel G Yaduma
- School of Molecular Biosciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Davidson Building, Glasgow G12 8QQ, UK
- Department of Chemistry, School of Sciences, Adamawa State College of Education, Hong 640001, Adamawa State, Nigeria
| | - Christopher J McInerny
- School of Molecular Biosciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Davidson Building, Glasgow G12 8QQ, UK
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3
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Mazzagatti A, Engel JL, Ly P. Boveri and beyond: Chromothripsis and genomic instability from mitotic errors. Mol Cell 2024; 84:55-69. [PMID: 38029753 PMCID: PMC10842135 DOI: 10.1016/j.molcel.2023.11.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 10/30/2023] [Accepted: 11/02/2023] [Indexed: 12/01/2023]
Abstract
Mitotic cell division is tightly monitored by checkpoints that safeguard the genome from instability. Failures in accurate chromosome segregation during mitosis can cause numerical aneuploidy, which was hypothesized by Theodor Boveri over a century ago to promote tumorigenesis. Recent interrogation of pan-cancer genomes has identified unexpected classes of chromosomal abnormalities, including complex rearrangements arising through chromothripsis. This process is driven by mitotic errors that generate abnormal nuclear structures that provoke extensive yet localized shattering of mis-segregated chromosomes. Here, we discuss emerging mechanisms underlying chromothripsis from micronuclei and chromatin bridges, as well as highlight how this mutational cascade converges on the DNA damage response. A fundamental understanding of these catastrophic processes will provide insight into how initial errors in mitosis can precipitate rapid cancer genome evolution.
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Affiliation(s)
- Alice Mazzagatti
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Justin L Engel
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Peter Ly
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Cell Biology, Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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4
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Zhang J, Qiu R, Bieger BD, Oakley CE, Oakley BR, Egan MJ, Xiang X. Aspergillus SUMOylation mutants exhibit chromosome segregation defects including chromatin bridges. Genetics 2023; 225:iyad169. [PMID: 37724751 PMCID: PMC10697819 DOI: 10.1093/genetics/iyad169] [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: 08/01/2023] [Revised: 08/29/2023] [Accepted: 09/07/2023] [Indexed: 09/21/2023] Open
Abstract
Functions of protein SUMOylation remain incompletely understood in different cell types. Via forward genetics, here we identified ubaBQ247*, a loss-of-function mutation in a SUMO activation enzyme UbaB in the filamentous fungus Aspergillus nidulans. The ubaBQ247*, ΔubaB, and ΔsumO mutants all produce abnormal chromatin bridges, indicating the importance of SUMOylation in the completion of chromosome segregation. The bridges are enclosed by nuclear membrane containing peripheral nuclear pore complex proteins that normally get dispersed during mitosis, and the bridges are also surrounded by cytoplasmic microtubules typical of interphase cells. Time-lapse sequences further indicate that most bridges persist through interphase prior to the next mitosis, and anaphase chromosome segregation can produce new bridges that persist into the next interphase. When the first mitosis happens at a higher temperature of 42°C, SUMOylation deficiency produces not only chromatin bridges but also many abnormally shaped single nuclei that fail to divide. UbaB-GFP localizes to interphase nuclei just like the previously studied SumO-GFP, but the nuclear signals disappear during mitosis when the nuclear pores are partially open, and the signals reappear after mitosis. The nuclear localization is consistent with many SUMO targets being nuclear proteins. Finally, although the budding yeast SUMOylation machinery interacts with LIS1, a protein critical for dynein activation, loss of SUMOylation does not cause any obvious defect in dynein-mediated transport of nuclei and early endosomes, indicating that SUMOylation is unnecessary for dynein activation in A. nidulans.
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Affiliation(s)
- Jun Zhang
- Department of Biochemistry and Molecular Biology, The Uniformed Services University of the Health Sciences-F. Edward Hébert School of Medicine, Bethesda, MD 20814, USA
| | - Rongde Qiu
- Department of Biochemistry and Molecular Biology, The Uniformed Services University of the Health Sciences-F. Edward Hébert School of Medicine, Bethesda, MD 20814, USA
| | - Baronger D Bieger
- Department of Entomology and Plant Pathology, University of Arkansas Systems Division of Agriculture, Fayetteville, AR 72701, USA
| | - C Elizabeth Oakley
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66045, USA
| | - Berl R Oakley
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66045, USA
| | - Martin J Egan
- Department of Entomology and Plant Pathology, University of Arkansas Systems Division of Agriculture, Fayetteville, AR 72701, USA
| | - Xin Xiang
- Department of Biochemistry and Molecular Biology, The Uniformed Services University of the Health Sciences-F. Edward Hébert School of Medicine, Bethesda, MD 20814, USA
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5
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Kumar R, Francis V, Ioannou MS, Aguila A, Khan M, Banks E, Kulasekaran G, McPherson PS. DENND2B activates Rab35 at the intercellular bridge, regulating cytokinetic abscission and tetraploidy. Cell Rep 2023; 42:112795. [PMID: 37454296 DOI: 10.1016/j.celrep.2023.112795] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 05/05/2023] [Accepted: 06/26/2023] [Indexed: 07/18/2023] Open
Abstract
Cytokinesis relies on membrane trafficking pathways regulated by Rabs and guanine nucleotide exchange factors (GEFs). During cytokinesis, the intercellular cytokinetic bridge (ICB) connecting daughter cells undergoes abscission, which requires actin depolymerization. Rab35 recruits MICAL1 to oxidize and depolymerize actin filaments. We show that DENND2B, a protein linked to cancer and congenital disorders, functions as a Rab35 GEF, recruiting and activating Rab35 at the ICB. DENND2B's N-terminal region also interacts with an active form of Rab35, suggesting that DENND2B is both a Rab35 GEF and effector. Knockdown of DENND2B delays abscission, leading to multinucleated cells and filamentous actin (F-actin) accumulation at the ICB, impairing recruitment of ESCRT-III at the abscission site. Additionally, F-actin accumulation triggers the formation of a chromatin bridge, activating the NoCut/abscission checkpoint, and DENND2B knockdown activates Aurora B kinase, a hallmark of checkpoint activation. Thus, our study identifies DENND2B as a crucial player in cytokinetic abscission.
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Affiliation(s)
- Rahul Kumar
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada.
| | - Vincent Francis
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Maria S Ioannou
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Adriana Aguila
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Maleeha Khan
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Emily Banks
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Gopinath Kulasekaran
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Peter S McPherson
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada.
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6
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Elias RD, Zhu Y, Su Q, Ghirlando R, Zhang J, Deshmukh L. Reversible phase separation of ESCRT protein ALIX through tyrosine phosphorylation. SCIENCE ADVANCES 2023; 9:eadg3913. [PMID: 37450591 PMCID: PMC10348681 DOI: 10.1126/sciadv.adg3913] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 06/14/2023] [Indexed: 07/18/2023]
Abstract
Cytokinetic abscission, the last step of cell division, is regulated by the ESCRT machinery. In response to mitotic errors, ESCRT proteins, namely, ALIX, CHMP4B, and CHMP4C, accumulate in the cytosolic compartments termed "abscission checkpoint bodies" (ACBs) to delay abscission and prevent tumorigenesis. ALIX contributes to the biogenesis and stability of ACBs via an unknown mechanism. We show that ALIX phase separates into nondynamic condensates in vitro and in vivo, mediated by the amyloidogenic portion of its proline-rich domain. ALIX condensates confined CHMP4 paralogs in vitro. These condensates dissolved and reformed upon reversible tyrosine phosphorylation of ALIX, mediated by Src kinase and PTP1B, and sequestration of CHMP4C altered their Src-mediated dissolution. NMR analysis revealed how ALIX triggers the activation of CHMP4 proteins, which is required for successful abscission. These results implicate ALIX's phase separation in the modulation of ACBs. This study also highlights how posttranslational modifications can control protein phase separation.
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Affiliation(s)
- Ruben D. Elias
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
| | - Yingqi Zhu
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
| | - Qi Su
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Rodolfo Ghirlando
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jin Zhang
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Lalit Deshmukh
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
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7
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Zhang J, Qiu R, Bieger BD, Oakley CE, Oakley BR, Egan MJ, Xiang X. Aspergillus SUMOylation mutants have normal dynein function but exhibit chromatin bridges. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.16.537086. [PMID: 37131833 PMCID: PMC10153134 DOI: 10.1101/2023.04.16.537086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Functions of protein SUMOylation remain incompletely understood in different cell types. The budding yeast SUMOylation machinery interacts with LIS1, a protein critical for dynein activation, but dynein-pathway components were not identified as SUMO-targets in the filamentous fungus Aspergillus nidulans. Via A. nidulans forward genetics, here we identified ubaBQ247*, a loss-of-function mutation in a SUMO-activation enzyme UbaB. Colonies of the ubaBQ247*, ΔubaB and ΔsumO mutants looked similar and less healthy than the wild-type colony. In these mutants, about 10% of nuclei are connected by abnormal chromatin bridges, indicating the importance of SUMOylation in the completion of chromosome segregation. Nuclei connected by chromatin bridges are mostly in interphase, suggesting that these bridges do not prevent cell-cycle progression. UbaB-GFP localizes to interphase nuclei just like the previously studied SumO-GFP, but the nuclear signals disappear during mitosis when the nuclear pores are partially open, and the signals reappear after mitosis. The nuclear localization is consistent with many SUMO-targets being nuclear proteins, for example, topoisomerase II whose SUMOylation defect gives rise to chromatin bridges in mammalian cells. Unlike in mammalian cells, however, loss of SUMOylation in A. nidulans does not apparently affect the metaphase-to-anaphase transition, further highlighting differences in the requirements of SUMOylation in different cell types. Finally, loss of UbaB or SumO does not affect dynein- and LIS1-mediated early-endosome transport, indicating that SUMOylation is unnecessary for dynein or LIS1 function in A. nidulans.
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Affiliation(s)
- Jun Zhang
- Department of Biochemistry and Molecular Biology, The Uniformed Services University of the Health Sciences- F. Edward Hébert School of Medicine, Bethesda, Maryland 20814, USA
| | - Rongde Qiu
- Department of Biochemistry and Molecular Biology, The Uniformed Services University of the Health Sciences- F. Edward Hébert School of Medicine, Bethesda, Maryland 20814, USA
| | - Baronger D. Bieger
- Department of Entomology and Plant Pathology, University of Arkansas Systems Division of Agriculture, Fayetteville, AR, USA
| | - C. Elizabeth Oakley
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS, USA
| | - Berl R. Oakley
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS, USA
| | - Martin J. Egan
- Department of Entomology and Plant Pathology, University of Arkansas Systems Division of Agriculture, Fayetteville, AR, USA
| | - Xin Xiang
- Department of Biochemistry and Molecular Biology, The Uniformed Services University of the Health Sciences- F. Edward Hébert School of Medicine, Bethesda, Maryland 20814, USA
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8
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Rezig IM, Yaduma WG, Gould GW, McInerny CJ. The role of anillin/Mid1p during medial division and cytokinesis: from fission yeast to cancer cells. Cell Cycle 2023; 22:633-644. [PMID: 36426865 PMCID: PMC9980708 DOI: 10.1080/15384101.2022.2147655] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Cytokinesis is the final stage of cell division cycle when cellular constituents are separated to produce two daughter cells. This process is driven by the formation and constriction of a contractile ring. Progression of these events is controlled by mechanisms and proteins that are evolutionary conserved in eukaryotes from fungi to humans. Genetic and molecular studies in different model organisms identified essential cytokinesis genes, with several conserved proteins, including the anillin/Mid1p proteins, constituting the core cytokinetic machinery. The fission yeast Schizosaccharomyces pombe represents a well-established model organism to study eukaryotic cell cycle regulation. Cytokinesis in fission yeast and mammalian cells depends on the placement, assembly, maturation, and constriction of a medially located actin-myosin contractile ring (ACR). Here, we review aspects of the ACR assembly and cytokinesis process in fission yeast and consider the regulation of such events in mammalian cells. First, we briefly describe the role of anillin during mammalian ACR assembly and cytokinesis. Second, we describe different aspects of the anillin-like protein Mid1p regulation during the S. pombe cell cycle, including its structure, function, and phospho-regulation. Third, we briefly discuss Mid1pindependent ACR assembly in S. pombe. Fourth, we highlight emerging studies demonstrating the roles of anillin in human tumourigenesis introducing anillin as a potential drug target for cancer treatment. Collectively, we provide an overview of the current understanding of medial division and cytokinesis in S. pombe and suggest the implications of these observations in other eukaryotic organisms, including humans.
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Affiliation(s)
- Imane M. Rezig
- School of Molecular Biosciences, College of Medical, Veterinary and Life Sciences, Davidson Building, University of Glasgow, Glasgow, UK
| | - Wandiahyel G. Yaduma
- School of Molecular Biosciences, College of Medical, Veterinary and Life Sciences, Davidson Building, University of Glasgow, Glasgow, UK,Department of Chemistry, School of Sciences, Adamawa State College of Education Hong, Nigeria
| | - Gwyn W. Gould
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Christopher J. McInerny
- School of Molecular Biosciences, College of Medical, Veterinary and Life Sciences, Davidson Building, University of Glasgow, Glasgow, UK,CONTACT Christopher J. McInerny School of Molecular Biosciences, College of Medical, Veterinary and Life Sciences, Davidson Building, University of Glasgow, GlasgowG12 8QQ, UK
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9
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Bayer EM. Divide and connect: divorce by mutual consent, keeping in touch by desideratum. C R Biol 2022; 345:7-14. [PMID: 36847461 DOI: 10.5802/crbiol.79] [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: 06/29/2022] [Accepted: 07/07/2022] [Indexed: 11/24/2022]
Abstract
Cell division is fundamental for living organisms, sustaining their growth and development. During cell division a single mother cell will duplicate its genome and organelles, and give rise to two independent entities that will eventually split apart in a tightly regulated process called abscission or the final-cut. In multicellular organisms, newly born daughter cells split apart while they simultaneously need to maintain contact for intercellular communication. In this mini-review, I discuss this fascinating paradox of how cells across kingdoms combine the need to divide with the need to connect.
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10
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Panagiotou TC, Chen A, Wilde A. An anillin-CIN85-SEPT9 complex promotes intercellular bridge maturation required for successful cytokinesis. Cell Rep 2022; 40:111274. [PMID: 36044846 DOI: 10.1016/j.celrep.2022.111274] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 07/17/2022] [Accepted: 08/05/2022] [Indexed: 11/20/2022] Open
Abstract
Cleavage of one cell into two is the most dramatic event in the life of a cell. Plasma membrane fission occurs within a narrow intercellular bridge (ICB) between the daughter cells, but the mechanisms underlying ICB formation and maturation are poorly understood. Here we identify CIN85 as an ICB assembly factor and demonstrate its requirement for robust and timely cytokinesis. CIN85 interacts directly with the N-terminal region of anillin and SEPT9 and thereby facilitates SEPT9-containing filament localization to the plasma membrane of the ICB. In contrast, the C-terminal pleckstrin homology (PH) domain of anillin binds to septin units lacking SEPT9 but enriched in SEPT11. Anillin's interactions with distinct septin units are required to promote ICB elongation and maturation that, we propose, generate the physical space into which the abscission machinery is recruited to drive the final membrane scission event releasing two independent daughter cells.
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Affiliation(s)
- Thomas C Panagiotou
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1M1, Canada
| | - Anan Chen
- Department of Biochemistry, University of Toronto, Toronto, ON M5S 1M1, Canada
| | - Andrew Wilde
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1M1, Canada; Department of Biochemistry, University of Toronto, Toronto, ON M5S 1M1, Canada.
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11
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The Abscission Checkpoint: A Guardian of Chromosomal Stability. Cells 2021; 10:cells10123350. [PMID: 34943860 PMCID: PMC8699595 DOI: 10.3390/cells10123350] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 11/25/2021] [Accepted: 11/26/2021] [Indexed: 12/11/2022] Open
Abstract
The abscission checkpoint contributes to the fidelity of chromosome segregation by delaying completion of cytokinesis (abscission) when there is chromatin lagging in the intercellular bridge between dividing cells. Although additional triggers of an abscission checkpoint-delay have been described, including nuclear pore defects, replication stress or high intercellular bridge tension, this review will focus only on chromatin bridges. In the presence of such abnormal chromosomal tethers in mammalian cells, the abscission checkpoint requires proper localization and optimal kinase activity of the Chromosomal Passenger Complex (CPC)-catalytic subunit Aurora B at the midbody and culminates in the inhibition of Endosomal Sorting Complex Required for Transport-III (ESCRT-III) components at the abscission site to delay the final cut. Furthermore, cells with an active checkpoint stabilize the narrow cytoplasmic canal that connects the two daughter cells until the chromatin bridges are resolved. Unsuccessful resolution of chromatin bridges in checkpoint-deficient cells or in cells with unstable intercellular canals can lead to chromatin bridge breakage or tetraploidization by regression of the cleavage furrow. In turn, these outcomes can lead to accumulation of DNA damage, chromothripsis, generation of hypermutation clusters and chromosomal instability, which are associated with cancer formation or progression. Recently, many important questions regarding the mechanisms of the abscission checkpoint have been investigated, such as how the presence of chromatin bridges is signaled to the CPC, how Aurora B localization and kinase activity is regulated in late midbodies, the signaling pathways by which Aurora B implements the abscission delay, and how the actin cytoskeleton is remodeled to stabilize intercellular canals with DNA bridges. Here, we review recent progress toward understanding the mechanisms of the abscission checkpoint and its role in guarding genome integrity at the chromosome level, and consider its potential implications for cancer therapy.
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12
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A genetically-encoded crosslinker screen identifies SERBP1 as a PKCε substrate influencing translation and cell division. Nat Commun 2021; 12:6934. [PMID: 34836941 PMCID: PMC8626422 DOI: 10.1038/s41467-021-27189-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 11/08/2021] [Indexed: 01/09/2023] Open
Abstract
The PKCε-regulated genome protective pathway provides transformed cells a failsafe to successfully complete mitosis. Despite the necessary role for Aurora B in this programme, it is unclear whether its requirement is sufficient or if other PKCε cell cycle targets are involved. To address this, we developed a trapping strategy using UV-photocrosslinkable amino acids encoded in the PKCε kinase domain. The validation of the mRNA binding protein SERBP1 as a PKCε substrate revealed a series of mitotic events controlled by the catalytic form of PKCε. PKCε represses protein translation, altering SERBP1 binding to the 40 S ribosomal subunit and promoting the assembly of ribonucleoprotein granules containing SERBP1, termed M-bodies. Independent of Aurora B, SERBP1 is shown to be necessary for chromosome segregation and successful cell division, correlating with M-body formation. This requirement for SERBP1 demonstrates that Aurora B acts in concert with translational regulation in the PKCε-controlled pathway exerting genome protection.
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13
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Pangou E, Sumara I. The Multifaceted Regulation of Mitochondrial Dynamics During Mitosis. Front Cell Dev Biol 2021; 9:767221. [PMID: 34805174 PMCID: PMC8595210 DOI: 10.3389/fcell.2021.767221] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 10/15/2021] [Indexed: 12/01/2022] Open
Abstract
Mitosis ensures genome integrity by mediating precise segregation of the duplicated genetic material. Segregation of subcellular organelles during mitosis also needs to be tightly coordinated in order to warrant their proper inheritance and cellular homeostasis. The inheritance of mitochondria, a powerhouse of the cell, is tightly regulated in order to meet the high energy demand to fuel the mitotic machinery. Mitochondria are highly dynamic organelles, which undergo events of fission, fusion and transport during different cell cycle stages. Importantly, during mitosis several kinases phosphorylate the key mitochondrial factors and drive fragmentation of mitochondria to allow for their efficient distribution and inheritance to two daughter cells. Recent evidence suggests that mitochondrial fission can also actively contribute to the regulation of mitotic progression. This review aims at summarizing established and emerging concepts about the complex regulatory networks which couple crucial mitotic factors and events to mitochondrial dynamics and which could be implicated in human disease.
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Affiliation(s)
- Evanthia Pangou
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France.,Centre National de la Recherche Scientifique UMR 7104, Strasbourg, France.,Institut National de la Santé et de la Recherche Médicale U964, Strasbourg, France.,Université de Strasbourg, Strasbourg, France
| | - Izabela Sumara
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France.,Centre National de la Recherche Scientifique UMR 7104, Strasbourg, France.,Institut National de la Santé et de la Recherche Médicale U964, Strasbourg, France.,Université de Strasbourg, Strasbourg, France
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14
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Wiegard A, Kuzin V, Cameron DP, Grosser J, Ceribelli M, Mehmood R, Ballarino R, Valant F, Grochowski R, Karabogdan I, Crosetto N, Lindqvist A, Bizard AH, Kouzine F, Natsume T, Baranello L. Topoisomerase 1 activity during mitotic transcription favors the transition from mitosis to G1. Mol Cell 2021; 81:5007-5024.e9. [PMID: 34767771 DOI: 10.1016/j.molcel.2021.10.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 08/26/2021] [Accepted: 10/15/2021] [Indexed: 12/13/2022]
Abstract
As cells enter mitosis, chromatin compacts to facilitate chromosome segregation yet remains transcribed. Transcription supercoils DNA to levels that can impede further progression of RNA polymerase II (RNAPII) unless it is removed by DNA topoisomerase 1 (TOP1). Using ChIP-seq on mitotic cells, we found that TOP1 is required for RNAPII translocation along genes. The stimulation of TOP1 activity by RNAPII during elongation allowed RNAPII clearance from genes in prometaphase and enabled chromosomal segregation. Disruption of the TOP1-RNAPII interaction impaired RNAPII spiking at promoters and triggered defects in the post-mitotic transcription program. This program includes factors necessary for cell growth, and cells with impaired TOP1-RNAPII interaction are more sensitive to inhibitors of mTOR signaling. We conclude that TOP1 is necessary for assisting transcription during mitosis with consequences for growth and gene expression long after mitosis is completed. In this sense, TOP1 ensures that cellular memory is preserved in subsequent generations.
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Affiliation(s)
- Anika Wiegard
- Department of Cell and Molecular Biology, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Vladislav Kuzin
- Department of Cell and Molecular Biology, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Donald P Cameron
- Department of Cell and Molecular Biology, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Jan Grosser
- Department of Cell and Molecular Biology, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Michele Ceribelli
- Division of Pre-Clinical Innovation, NCATS, National Institutes of Health, Rockville, MD 20850, USA
| | - Rashid Mehmood
- Department of Cell and Molecular Biology, Karolinska Institutet, 17177 Stockholm, Sweden; Department of Software Engineering, University of Kotli, AJ&K, 45320 Kotli Azad Kashmir, Pakistan
| | - Roberto Ballarino
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17165 Stockholm, Sweden
| | - Francesco Valant
- Department of Cell and Molecular Biology, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Radosław Grochowski
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17165 Stockholm, Sweden
| | | | - Nicola Crosetto
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17165 Stockholm, Sweden
| | - Arne Lindqvist
- Department of Cell and Molecular Biology, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Anna Helene Bizard
- Department of Cellular and Molecular Medicine, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Fedor Kouzine
- Laboratory of Pathology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Toyoaki Natsume
- Department of Chromosome Science, National Institute of Genetics, Shizuoka 411-8540, Japan; Research Center for Genome & Medical Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Laura Baranello
- Department of Cell and Molecular Biology, Karolinska Institutet, 17177 Stockholm, Sweden.
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15
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Rheinemann L, Downhour DM, Bredbenner K, Mercenne G, Davenport KA, Schmitt PT, Necessary CR, McCullough J, Schmitt AP, Simon SM, Sundquist WI, Elde NC. RetroCHMP3 blocks budding of enveloped viruses without blocking cytokinesis. Cell 2021; 184:5419-5431.e16. [PMID: 34597582 PMCID: PMC8929533 DOI: 10.1016/j.cell.2021.09.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 05/03/2021] [Accepted: 09/03/2021] [Indexed: 11/26/2022]
Abstract
Many enveloped viruses require the endosomal sorting complexes required for transport (ESCRT) pathway to exit infected cells. This highly conserved pathway mediates essential cellular membrane fission events, which restricts the acquisition of adaptive mutations to counteract viral co-option. Here, we describe duplicated and truncated copies of the ESCRT-III factor CHMP3 that block ESCRT-dependent virus budding and arose independently in New World monkeys and mice. When expressed in human cells, these retroCHMP3 proteins potently inhibit release of retroviruses, paramyxoviruses, and filoviruses. Remarkably, retroCHMP3 proteins have evolved to reduce interactions with other ESCRT-III factors and have little effect on cellular ESCRT processes, revealing routes for decoupling cellular ESCRT functions from viral exploitation. The repurposing of duplicated ESCRT-III proteins thus provides a mechanism to generate broad-spectrum viral budding inhibitors without blocking highly conserved essential cellular ESCRT functions.
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Affiliation(s)
- Lara Rheinemann
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Diane Miller Downhour
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Kate Bredbenner
- Laboratory of Cellular Biophysics, Rockefeller University, New York, NY 10065, USA
| | - Gaelle Mercenne
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Kristen A Davenport
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA; Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Phuong Tieu Schmitt
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA 16802, USA
| | - Christina R Necessary
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - John McCullough
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Anthony P Schmitt
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA 16802, USA
| | - Sanford M Simon
- Laboratory of Cellular Biophysics, Rockefeller University, New York, NY 10065, USA.
| | - Wesley I Sundquist
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA.
| | - Nels C Elde
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112, USA.
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16
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De Marco Zompit M, Stucki M. Mechanisms of genome stability maintenance during cell division. DNA Repair (Amst) 2021; 108:103215. [PMID: 34455186 DOI: 10.1016/j.dnarep.2021.103215] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 08/16/2021] [Accepted: 08/20/2021] [Indexed: 01/12/2023]
Abstract
During mitosis, chromosomes undergo extensive structural changes resulting in the formation of compact cylindrical bodies and in the termination of the bulk of DNA-dependent metabolic activities. Therefore, DNA lesions that interfere with processes such as DNA replication and transcription in interphase are not expected to pose a major threat to genome stability in mitosis. There are, however, a few exceptions. DNA replication and repair intermediates that physically interconnect the sister chromatids jeopardize faithful chromosome segregation and need to be resolved before the onset of anaphase. In addition, dicentric chromosomes can form chromatin bridges and induce breakage-fusion-breakage cycles with dire consequences for genome stability. Finally, chromosome breaks that escape the G2/M DNA damage checkpoint or emerge early in mitosis may result in lagging acentric DNA fragments that mis-segregate and form micronuclei when cells exit from mitosis. Both chromatin bridges and micronuclei are potential sources of a mutational cascade that results in massive chromosomal instability and significantly contributes to genomic complexity. Here, we review recent progress in our understanding of the origins and consequences of chromosome bridges and micronuclei and the mechanisms by which cells suppress them.
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Affiliation(s)
- Mara De Marco Zompit
- Department of Gynecology, University Hospital Zurich, University of Zurich, Wagistrasse 14, CH-8952 Schlieren, Switzerland
| | - Manuel Stucki
- Department of Gynecology, University Hospital Zurich, University of Zurich, Wagistrasse 14, CH-8952 Schlieren, Switzerland.
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17
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Rezig IM, Yaduma WG, Gould GW, McInerny CJ. Anillin/Mid1p interacts with the ESCRT-associated protein Vps4p and mitotic kinases to regulate cytokinesis in fission yeast. Cell Cycle 2021; 20:1845-1860. [PMID: 34382912 PMCID: PMC8525990 DOI: 10.1080/15384101.2021.1962637] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Cytokinesis is the final stage of the cell cycle which separates cellular constituents to produce two daughter cells. Using the fission yeast Schizosaccharomyces pombe we have investigated the role of various classes of proteins involved in this process. Central to these is anillin/Mid1p which forms a ring-like structure at the cell equator that predicts the site of cell separation through septation in fission yeast. Here we demonstrate a direct physical interaction between Mid1p and the endosomal sorting complex required for transport (ESCRT)-associated protein Vps4p, a genetic interaction of the mid1 and vps4 genes essential for cell viability, and a requirement of Vps4p for the correct cellular localization of Mid1p. Furthermore, we show that Mid1p is phosphorylated by aurora kinase, a genetic interaction of the mid1 and the aurora kinase ark1 genes is essential for cell viability, and that Ark1p is also required for the correct cellular localization of Mid1p. We mapped the sites of phosphorylation of Mid1p by human aurora A and the polo kinase Plk1 and assessed their importance in fission yeast by mutational analysis. Such analysis revealed serine residues S332, S523 and S531 to be required for Mid1p function and its interaction with Vps4p, Ark1p and Plo1p. Combined these data suggest a physical interaction between Mid1p and Vps4p important for cytokinesis, and identify phosphorylation of Mid1p by aurora and polo kinases as being significant for this process.
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Affiliation(s)
- Imane M Rezig
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Wandiahyel G Yaduma
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Gwyn W Gould
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.,Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Christopher J McInerny
- School of Life Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
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18
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McNeely KC, Dwyer ND. Cytokinetic Abscission Regulation in Neural Stem Cells and Tissue Development. CURRENT STEM CELL REPORTS 2021; 7:161-173. [PMID: 36303610 PMCID: PMC9603694 DOI: 10.1007/s40778-021-00193-7] [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] [Indexed: 11/20/2022]
Abstract
Purpose of Review How stem cells balance proliferation with differentiation, giving rise to specific daughter cells during development to build an embryo or tissue, remains an open question. Here, we discuss recent evidence that cytokinetic abscission regulation in stem cells, particularly neural stem cells (NSCs), is part of the answer. Abscission is a multi-step process mediated by the midbody, a microtubule-based structure formed in the intercellular bridge between daughter cells after mitosis. Recent Findings Human mutations and mouse knockouts in abscission genes reveal that subtle disruptions of NSC abscission can cause brain malformations. Experiments in several epithelial systems have shown that midbodies serve as scaffolds for apical junction proteins and are positioned near apical membrane fate determinants. Abscission timing is tightly controlled and developmentally regulated in stem cells, with delayed abscission in early embryos and faster abscission later. Midbody remnants (MBRs) contain over 400 proteins and may influence polarity, fate, and ciliogenesis. Summary As NSCs and other stem cells build tissues, they tightly regulate three aspects of abscission: midbody positioning, duration, and MBR handling. Midbody positioning and remnants establish or maintain cell polarity. MBRs are deposited on the apical membranes of epithelia, can be released or internalized by surrounding cells, and may sequester fate determinants or transfer information between cells. Work in cell lines and simpler systems has shown multiple roles for abscission regulation influencing stem cell polarity, potency, and daughter fates during development. Elucidating how the abscission process influences cell fate and tissue growth is important for our continued understanding of brain development and stem cell biology.
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19
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Record J, Saeed MB, Venit T, Percipalle P, Westerberg LS. Journey to the Center of the Cell: Cytoplasmic and Nuclear Actin in Immune Cell Functions. Front Cell Dev Biol 2021; 9:682294. [PMID: 34422807 PMCID: PMC8375500 DOI: 10.3389/fcell.2021.682294] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 07/06/2021] [Indexed: 12/12/2022] Open
Abstract
Actin cytoskeletal dynamics drive cellular shape changes, linking numerous cell functions to physiological and pathological cues. Mutations in actin regulators that are differentially expressed or enriched in immune cells cause severe human diseases known as primary immunodeficiencies underscoring the importance of efficienct actin remodeling in immune cell homeostasis. Here we discuss recent findings on how immune cells sense the mechanical properties of their environement. Moreover, while the organization and biochemical regulation of cytoplasmic actin have been extensively studied, nuclear actin reorganization is a rapidly emerging field that has only begun to be explored in immune cells. Based on the critical and multifaceted contributions of cytoplasmic actin in immune cell functionality, nuclear actin regulation is anticipated to have a large impact on our understanding of immune cell development and functionality.
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Affiliation(s)
- Julien Record
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institute, Stockholm, Sweden
| | - Mezida B. Saeed
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institute, Stockholm, Sweden
| | - Tomas Venit
- Science Division, Biology Program, New York University Abu Dhabi (NYUAD), Abu Dhabi, United Arab Emirates
| | - Piergiorgio Percipalle
- Science Division, Biology Program, New York University Abu Dhabi (NYUAD), Abu Dhabi, United Arab Emirates
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Lisa S. Westerberg
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institute, Stockholm, Sweden
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20
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Co-ordinated control of the Aurora B abscission checkpoint by PKCε complex assembly, midbody recruitment and retention. Biochem J 2021; 478:2247-2263. [PMID: 34143863 PMCID: PMC8238520 DOI: 10.1042/bcj20210283] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 05/24/2021] [Accepted: 05/26/2021] [Indexed: 11/17/2022]
Abstract
A requirement for PKCε in exiting from the Aurora B dependent abscission checkpoint is associated with events at the midbody, however, the recruitment, retention and action of PKCε in this compartment are poorly understood. Here, the prerequisite for 14-3-3 complex assembly in this pathway is directly linked to the phosphorylation of Aurora B S227 at the midbody. However, while essential for PKCε control of Aurora B, 14-3-3 association is shown to be unnecessary for the activity-dependent enrichment of PKCε at the midbody. This localisation is demonstrated to be an autonomous property of the inactive PKCε D532N mutant, consistent with activity-dependent dissociation. The C1A and C1B domains are necessary for this localisation, while the C2 domain and inter-C1 domain (IC1D) are necessary for retention at the midbody. Furthermore, it is shown that while the IC1D mutant retains 14-3-3 complex proficiency, it does not support Aurora B phosphorylation, nor rescues division failure observed with knockdown of endogenous PKCε. It is concluded that the concerted action of multiple independent events facilitates PKCε phosphorylation of Aurora B at the midbody to control exit from the abscission checkpoint.
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21
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Ikeda Y, Yasutake R, Yuki R, Saito Y, Nakayama Y. Combination Treatment of OSI-906 with Aurora B Inhibitor Reduces Cell Viability via Cyclin B1 Degradation-Induced Mitotic Slippage. Int J Mol Sci 2021; 22:ijms22115706. [PMID: 34071893 PMCID: PMC8197973 DOI: 10.3390/ijms22115706] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/21/2021] [Accepted: 05/25/2021] [Indexed: 01/12/2023] Open
Abstract
Insulin-like growth factor 1 receptor (IGF1R), a receptor-type tyrosine kinase, transduces signals related to cell proliferation, survival, and differentiation. We recently reported that OSI-906, an IGF1R inhibitor, in combination with the Aurora B inhibitor ZM447439 suppresses cell proliferation. However, the mechanism underlying this suppressive effect is yet to be elucidated. In this study, we examined the effects of combination treatment with OSI-906 and ZM447439 on cell division, so as to understand how cell proliferation was suppressed. Morphological analysis showed that the combination treatment generated enlarged cells with aberrant nuclei, whereas neither OSI-906 nor ZM447439 treatment alone caused this morphological change. Flow cytometry analysis indicated that over-replicated cells were generated by the combination treatment, but not by the lone treatment with either inhibitors. Time-lapse imaging showed mitotic slippage following a severe delay in chromosome alignment and cytokinesis failure with furrow regression. Furthermore, in S-trityl-l-cysteine–treated cells, cyclin B1 was precociously degraded. These results suggest that the combination treatment caused severe defect in the chromosome alignment and spindle assembly checkpoint, which resulted in the generation of over-replicated cells. The generation of over-replicated cells with massive aneuploidy may be the cause of reduction of cell viability and cell death. This study provides new possibilities of cancer chemotherapy.
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Affiliation(s)
| | | | | | | | - Yuji Nakayama
- Correspondence: ; Tel.: +81-75-595-4653; Fax: +81-75-595-4758
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22
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Cytokinetic abscission is part of the midblastula transition in early zebrafish embryogenesis. Proc Natl Acad Sci U S A 2021; 118:2021210118. [PMID: 33837152 PMCID: PMC8053991 DOI: 10.1073/pnas.2021210118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
In this work, we show that the last step of cytokinesis, termed abscission, is delayed in early zebrafish embryos. As a result, sibling cells remain connected to one another by a thin membrane bridge for several cycles, forming clusters of interconnected cells. Bridge severing (i.e., abscission) commences at the 10th cell cycle when embryos enter the midblastula transition switch, in which embryonic cells become individualized and exhibit the characteristics of mature cells. Cells connected by intercellular bridges shared similar cellular behaviors, such as transcription onset and cell shape. Our data suggest that cell–cell connectivity is maintained in early embryos through persistent bridge connections that allow cells to coordinate their behavior during embryonic development. Animal cytokinesis ends with the formation of a thin intercellular membrane bridge that connects the two newly formed sibling cells, which is ultimately resolved by abscission. While mitosis is completed within 15 min, the intercellular bridge can persist for hours, maintaining a physical connection between sibling cells and allowing exchange of cytosolic components. Although cell–cell communication is fundamental for development, the role of intercellular bridges during embryogenesis has not been fully elucidated. In this work, we characterized the spatiotemporal characteristics of the intercellular bridge during early zebrafish development. We found that abscission is delayed during the rapid division cycles that occur in the early embryo, giving rise to the formation of interconnected cell clusters. Abscission was accelerated when the embryo entered the midblastula transition (MBT) phase. Components of the ESCRT machinery, which drives abscission, were enriched at intercellular bridges post-MBT and, interfering with ESCRT function, extended abscission beyond MBT. Hallmark features of MBT, including transcription onset and cell shape modulations, were more similar in interconnected sibling cells compared to other neighboring cells. Collectively, our findings suggest that delayed abscission in the early embryo allows clusters of cells to coordinate their behavior during embryonic development.
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23
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Paccosi E, Proietti-De-Santis L. The emerging role of Cockayne group A and B proteins in ubiquitin/proteasome-directed protein degradation. Mech Ageing Dev 2021; 195:111466. [PMID: 33727156 DOI: 10.1016/j.mad.2021.111466] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 02/16/2021] [Accepted: 03/02/2021] [Indexed: 12/18/2022]
Abstract
When mutated, csa and csb genes are responsible of the complex phenotype of the premature aging Cockayne Syndrome (CS). Our working hypothesis is to reconcile the multiple cellular and molecular phenotypes associated to CS within the unifying molecular function of CSA and CSB proteins in the cascade of events leading to ubiquitin/proteasome-directed protein degradation, which occurs in processes as DNA repair, transcription and cell division. This achievement may reasonably explain the plethora of cellular UPS-regulated functions that result impaired when either CSA or CSB are mutated and suggestively explains part of their pleiotropic effect. This review is aimed to solicit the interest of the scientific community in further investigating this aspect, since we believe that the identification of the ubiquitin-proteasome machinery as a new potential therapeutic target, able to comprehensively face the different molecular aspects of CS, whether confirmed and corroborated by in vivo studies, would open a promising avenue to design effective therapeutic intervention.
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Affiliation(s)
- Elena Paccosi
- Unit of Molecular Genetics of Aging, Department of Ecological and Biological Sciences, Università degli Studi della Tuscia, Viterbo, Italy
| | - Luca Proietti-De-Santis
- Unit of Molecular Genetics of Aging, Department of Ecological and Biological Sciences, Università degli Studi della Tuscia, Viterbo, Italy.
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24
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Hadders MA, Lens SM. Delaying the final cut: A close encounter of checkpoint kinases at the midbody. J Cell Biol 2021; 220:e202012130. [PMID: 33404606 PMCID: PMC7791345 DOI: 10.1083/jcb.202012130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
How chromatin bridges are relayed to the chromosomal passenger complex (CPC) during mammalian cell division is unknown. In this issue, Petsalaki and Zachos (2020. J. Cell Biol.https://doi.org/10.1083/jcb.202008029) show that the DNA damage checkpoint kinases ATM and Chk2 signal to the CPC to associate with a pool of cytoskeletal regulators, MKLP2-Cep55, in the midbody center and to delay abscission.
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25
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The Cockayne syndrome group A and B proteins are part of a ubiquitin-proteasome degradation complex regulating cell division. Proc Natl Acad Sci U S A 2020; 117:30498-30508. [PMID: 33199595 DOI: 10.1073/pnas.2006543117] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Cytokinesis is monitored by a molecular machinery that promotes the degradation of the intercellular bridge, a transient protein structure connecting the two daughter cells. Here, we found that CSA and CSB, primarily defined as DNA repair factors, are located at the midbody, a transient structure in the middle of the intercellular bridge, where they recruit CUL4 and MDM2 ubiquitin ligases and the proteasome. As a part of this molecular machinery, CSA and CSB contribute to the ubiquitination and the degradation of proteins such as PRC1, the Protein Regulator of Cytokinesis, to ensure the correct separation of the two daughter cells. Defects in CSA or CSB result in perturbation of the abscission leading to the formation of long intercellular bridges and multinucleated cells, which might explain part of the Cockayne syndrome phenotypes. Our results enlighten the role played by CSA and CSB as part of a ubiquitin/proteasome degradation process involved in transcription, DNA repair, and cell division.
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26
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Cancer-driving mutations and variants of components of the membrane trafficking core machinery. Life Sci 2020; 264:118662. [PMID: 33127517 DOI: 10.1016/j.lfs.2020.118662] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 10/17/2020] [Accepted: 10/22/2020] [Indexed: 12/12/2022]
Abstract
The core machinery for vesicular membrane trafficking broadly comprises of coat proteins, RABs, tethering complexes and SNAREs. As cellular membrane traffic modulates key processes of mitogenic signaling, cell migration, cell death and autophagy, its dysregulation could potentially results in increased cell proliferation and survival, or enhanced migration and invasion. Changes in the levels of some components of the core machinery of vesicular membrane trafficking, likely due to gene amplifications and/or alterations in epigenetic factors (such as DNA methylation and micro RNA) have been extensively associated with human cancers. Here, we provide an overview of association of membrane trafficking with cancer, with a focus on mutations and variants of coat proteins, RABs, tethering complex components and SNAREs that have been uncovered in human cancer cells/tissues. The major cellular and molecular cancer-driving or suppression mechanisms associated with these components of the core membrane trafficking machinery shall be discussed.
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27
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Edreira T, Celador R, Manjón E, Sánchez Y. A novel checkpoint pathway controls actomyosin ring constriction trigger in fission yeast. eLife 2020; 9:59333. [PMID: 33103994 PMCID: PMC7661037 DOI: 10.7554/elife.59333] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 10/24/2020] [Indexed: 12/12/2022] Open
Abstract
In fission yeast, the septation initiation network (SIN) ensures temporal coordination between actomyosin ring (CAR) constriction with membrane ingression and septum synthesis. However, questions remain about CAR regulation under stress conditions. We show that Rgf1p (Rho1p GEF), participates in a delay of cytokinesis under cell wall stress (blankophor, BP). BP did not interfere with CAR assembly or the rate of CAR constriction, but did delay the onset of constriction in the wild type cells but not in the rgf1Δ cells. This delay was also abolished in the absence of Pmk1p, the MAPK of the cell integrity pathway (CIP), leading to premature abscission and a multi-septated phenotype. Moreover, cytokinesis delay correlates with maintained SIN signaling and depends on the SIN to be achieved. Thus, we propose that the CIP participates in a checkpoint, capable of triggering a CAR constriction delay through the SIN pathway to ensure that cytokinesis terminates successfully.
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Affiliation(s)
- Tomás Edreira
- Instituto de Biología Funcional y Genómica, CSIC/Universidad de Salamanca and Departamento de Microbiología y Genética, Universidad de Salamanca, Salamanca, Spain
| | - Rubén Celador
- Instituto de Biología Funcional y Genómica, CSIC/Universidad de Salamanca and Departamento de Microbiología y Genética, Universidad de Salamanca, Salamanca, Spain
| | - Elvira Manjón
- Instituto de Biología Funcional y Genómica, CSIC/Universidad de Salamanca and Departamento de Microbiología y Genética, Universidad de Salamanca, Salamanca, Spain
| | - Yolanda Sánchez
- Instituto de Biología Funcional y Genómica, CSIC/Universidad de Salamanca and Departamento de Microbiología y Genética, Universidad de Salamanca, Salamanca, Spain
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28
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Parker PJ, Lockwood N, Davis K, Kelly JR, Soliman TN, Pardo AL, Marshall JJT, Redmond JM, Vitale M, Silvia Martini. A cancer-associated, genome protective programme engaging PKCε. Adv Biol Regul 2020; 78:100759. [PMID: 33039823 PMCID: PMC7689578 DOI: 10.1016/j.jbior.2020.100759] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 09/27/2020] [Accepted: 10/02/2020] [Indexed: 12/21/2022]
Abstract
Associated with their roles as targets for tumour promoters, there has been a long-standing interest in how members of the protein kinase C (PKC) family act to modulate cell growth and division. This has generated a great deal of observational data, but has for the most part not afforded clear mechanistic insights into the control mechanisms at play. Here, we review the roles of PKCε in protecting transformed cells from non-disjunction. In this particular cell cycle context, there is a growing understanding of the pathways involved, affording biomarker and interventional insights and opportunities.
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Affiliation(s)
- Peter J Parker
- Protein Phosphorylation Laboratory, Francis Crick Institute, London, NW1 1AT, UK; School of Cancer and Pharmaceutical Sciences, Guy's Campus, London, SE1 1UL, UK.
| | - Nicola Lockwood
- Protein Phosphorylation Laboratory, Francis Crick Institute, London, NW1 1AT, UK
| | - Khalil Davis
- Protein Phosphorylation Laboratory, Francis Crick Institute, London, NW1 1AT, UK
| | - Joanna R Kelly
- Cancer Research UK, Manchester Institute, Alderley Park, SK10 4TG, UK
| | - Tanya N Soliman
- Barts Cancer Institute, Charterhouse Square, London, EC1M 6BE, UK
| | - Ainara Lopez Pardo
- Protein Phosphorylation Laboratory, Francis Crick Institute, London, NW1 1AT, UK
| | | | | | - Marco Vitale
- Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Silvia Martini
- Protein Phosphorylation Laboratory, Francis Crick Institute, London, NW1 1AT, UK
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29
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Guo X, Dai X, Wu X, Zhou T, Ni J, Xue J, Wang X. Understanding the birth of rupture-prone and irreparable micronuclei. Chromosoma 2020; 129:181-200. [PMID: 32671520 DOI: 10.1007/s00412-020-00741-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 06/30/2020] [Accepted: 07/02/2020] [Indexed: 12/17/2022]
Abstract
Micronuclei are extra-nuclear bodies mainly derived from ana-telophase lagging chromosomes/chromatins (LCs) that are not incorporated into primary nuclei at mitotic exit. Unlike primary nuclei, most micronuclei are enclosed by nuclear envelope (NE) that is highly susceptible to spontaneous and irreparable rupture. Ruptured micronuclei act as triggers of chromothripsis-like chaotic chromosomal rearrangements and cGAS-mediated innate immunity and inflammation, raising the view that micronuclei play active roles in human aging and tumorigenesis. Thus, understanding the ways in which micronuclear envelope (mNE) goes awry acquires increased importance. Here, we review the data to present a general framework for this question. We firstly describe NE reassembly after mitosis and NE repair during interphase. Simultaneously, we briefly discuss how mNE is organized and how mNE rupture controls the fate of micronuclei and micronucleated cells. As a focus of this review, we highlight current knowledge about why mNE is rupture-prone and irreparable. For this, we survey observations from a series of elegant studies to provide a systematic overview. We conclude that the birth of rupture-prone and irreparable micronuclei may be the cumulative effects of their intracellular geographic origins, biophysical properties, and specific mNE features. We propose that DNA damage and immunogenicity in micronuclei increase stepwise from altered mNE components, mNE rupture, and refractory to repair. Throughout our discussion, we note interesting issues in mNE fragility that have yet to be resolved.
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Affiliation(s)
- Xihan Guo
- School of Life Sciences, The Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Yunnan Normal University, Kunming, 650500, Yunnan, China
| | - Xueqin Dai
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650223, Yunnan, China
- Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, 650204, Yunnan, China
- University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Xue Wu
- School of Life Sciences, The Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Yunnan Normal University, Kunming, 650500, Yunnan, China
| | - Tao Zhou
- School of Life Sciences, The Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Yunnan Normal University, Kunming, 650500, Yunnan, China
| | - Juan Ni
- School of Life Sciences, The Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Yunnan Normal University, Kunming, 650500, Yunnan, China
| | - Jinglun Xue
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai, 200433, China
| | - Xu Wang
- School of Life Sciences, The Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Yunnan Normal University, Kunming, 650500, Yunnan, China.
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30
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Al-Jomah N, Mukololo L, Anjum A, Al Madadha M, Patel R. Pds5A and Pds5B Display Non-redundant Functions in Mitosis and Their Loss Triggers Chk1 Activation. Front Cell Dev Biol 2020; 8:531. [PMID: 32760717 PMCID: PMC7372117 DOI: 10.3389/fcell.2020.00531] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 06/05/2020] [Indexed: 12/14/2022] Open
Abstract
Background Pds5 is an abundant HEAT-repeat-containing protein that binds to cohesin and mediates sister chromatid cohesion. In vertebrates, Pds5A and Pds5B are known to protect DNA replication fork, as their loss leads to DNA damage. Pds5 interacts directly with Wapl, to remove cohesin during mitosis. Aim To analyze the effects of the loss of Pds5 proteins-mediated DNA damage on the cell cycle checkpoints and to examine the possibility that Pds5 proteins have an overlapping function. Methods We first analyzed the cell cycle regulation of Pds5 proteins and defects in S-phase; DNA damage was confirmed after Pds5A/B knockdown. The activation of cell cycle checkpoints and apoptosis were examined by the level of p-Chk1S317, MAD2 localization, and the level of pro-apoptotic markers, respectively. Results Pds5 proteins dissociated from chromatin in a stepwise manner, and their loss led to activation of pro-apoptotic markers associated with the phosphorylation of Chk1S317 due to DNA damage. Depletion of either Pds5A or Pds5B alone increased Smc3 acetylation in perturbed cell cycle, while depletion of both proteins severely impaired Smc3 acetylation. Moreover, the loss of Pds5A/Pds5B activated the SAC in an ATR-Chk1-dependent manner and stabilized Wapl on chromatin. The depletion of Chk1 rescued the S-phase delay associated with Pds5 depletion and significantly increased mitotic catastrophe. Conclusion Pds5A and Pds5B display overlapping functions in facilitating Smc3 acetylation. Somewhat paradoxically, they also have non-redundant functions in terms of cohesin removal due to the activated surveillance mechanism that leads to phosphorylation of Chk1S317.
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Affiliation(s)
- Naif Al-Jomah
- Department of Molecular and Cell Biology, University of Leicester, Leicester, United Kingdom.,Molecular Oncology Department, Research Centre, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Lubinda Mukololo
- Department of Molecular and Cell Biology, University of Leicester, Leicester, United Kingdom.,Department of Physiological Sciences, School of Medicine, University of Zambia, Lusaka, Zambia
| | - Awais Anjum
- Department of Molecular and Cell Biology, University of Leicester, Leicester, United Kingdom.,School of Biosciences, University of Nottingham, Loughborough, United Kingdom
| | - Mohammed Al Madadha
- Department of Molecular and Cell Biology, University of Leicester, Leicester, United Kingdom.,Department of Pathology, Microbiology and Forensic Medicine, School of Medicine, The University of Jordan, Amman, Jordan
| | - Raj Patel
- Department of Molecular and Cell Biology, University of Leicester, Leicester, United Kingdom
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31
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Turn RE, East MP, Prekeris R, Kahn RA. The ARF GAP ELMOD2 acts with different GTPases to regulate centrosomal microtubule nucleation and cytokinesis. Mol Biol Cell 2020; 31:2070-2091. [PMID: 32614697 PMCID: PMC7543072 DOI: 10.1091/mbc.e20-01-0012] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
ELMOD2 is a ∼32 kDa protein first purified by its GTPase-activating protein (GAP) activity toward ARL2 and later shown to have uniquely broad specificity toward ARF family GTPases in in vitro assays. To begin the task of defining its functions in cells, we deleted ELMOD2 in immortalized mouse embryonic fibroblasts and discovered a number of cellular defects, which are reversed upon expression of ELMOD2-myc. We show that these defects, resulting from the loss of ELMOD2, are linked to two different pathways and two different GTPases: with ARL2 and TBCD to support microtubule nucleation from centrosomes and with ARF6 in cytokinesis. These data highlight key aspects of signaling by ARF family GAPs that contribute to previously underappreciated sources of complexity, including GAPs acting from multiple sites in cells, working with multiple GTPases, and contributing to the spatial and temporal control of regulatory GTPases by serving as both GAPs and effectors.
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Affiliation(s)
- Rachel E Turn
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322.,Biochemistry, Cell & Developmental Biology Graduate Program, Laney Graduate School, Emory University, Atlanta, GA 30307
| | - Michael P East
- Department of Pharmacology, University of North Carolina Chapel Hill, Chapel Hill, NC 27599
| | - Rytis Prekeris
- Department of Cell and Developmental Biology, University of Colorado, Aurora, CO 80045
| | - Richard A Kahn
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
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32
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Machín F, Ayra-Plasencia J. Are Anaphase Events Really Irreversible? The Endmost Stages of Cell Division and the Paradox of the DNA Double-Strand Break Repair. Bioessays 2020; 42:e2000021. [PMID: 32363600 DOI: 10.1002/bies.202000021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 03/16/2020] [Indexed: 12/25/2022]
Abstract
It has been recently demonstrated that yeast cells are able to partially regress chromosome segregation in telophase as a response to DNA double-strand breaks (DSBs), likely to find a donor sequence for homology-directed repair (HDR). This regression challenges the traditional concept that establishes anaphase events as irreversible, hence opening a new field of research in cell biology. Here, the nature of this new behavior in yeast is summarized and the underlying mechanisms are speculated about. It is also discussed whether it can be reproduced in other eukaryotes. Overall, this work brings forwards the need of understanding how cells attempt to repair DSBs when transiting the latest stages of mitosis, i.e., anaphase and telophase.
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Affiliation(s)
- Félix Machín
- Unidad de Investigación, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, 38010, Spain.,Instituto de Tecnologías Biomédicas, Universidad de La Laguna, Santa Cruz de Tenerife, 38200, Spain.,Universidad Fernando Pessoa Canarias, Las Palmas de Gran Canaria, 35450, Spain
| | - Jessel Ayra-Plasencia
- Unidad de Investigación, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, 38010, Spain.,Instituto de Tecnologías Biomédicas, Universidad de La Laguna, Santa Cruz de Tenerife, 38200, Spain
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33
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McNeely KC, Dwyer ND. Cytokinesis and postabscission midbody remnants are regulated during mammalian brain development. Proc Natl Acad Sci U S A 2020; 117:9584-9593. [PMID: 32273386 PMCID: PMC7197019 DOI: 10.1073/pnas.1919658117] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Building a brain of the proper size and structure requires neural stem cells (NSCs) to divide with tight temporal and spatial control to produce different daughter cell types in proper numbers and sequence. Mammalian NSCs in the embryonic cortex must maintain their polarized epithelial structure as they undergo both early proliferative divisions and later neurogenic divisions. To do this, they undergo a polarized form of cytokinesis at the apical membrane that is not well understood. Here, we investigate whether polarized furrowing and abscission in mouse NSCs are regulated differently at earlier and later stages and in a cytokinesis mutant, Kif20b This mutant was previously shown to have microcephaly and elevated apoptosis of NSCs. We developed methods to live image furrow ingression and midbody abscission in NSCs within cortical explants. We find that polarized furrow ingression occurs at a steady rate and completes in ∼15 min at two different ages. However, ingression is slower in a subset of Kif20b mutant NSCs. Abscission is usually observed on both sides of the midbody and takes 65 to 75 min to complete. Surprisingly, abscission is accelerated in the Kif20b mutant NSCs. Postabscission midbody remnants are observed at the apical membranes of daughter cells and are much more abundant in early-stage cortices. After NSC divisions in vitro, midbody remnants are more often retained on the daughter cells of early proliferative divisions. Altogether, these results suggest that regulation of abscission timing and midbody remnants in embryonic NSCs may influence proper brain growth and structure.
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Affiliation(s)
- Katrina C McNeely
- Department of Cell Biology, University of Virginia School of Medicine, Charlottesville, VA 22908
- Neuroscience Graduate Program, University of Virginia School of Medicine, Charlottesville, VA 22908
| | - Noelle D Dwyer
- Department of Cell Biology, University of Virginia School of Medicine, Charlottesville, VA 22908;
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34
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Nunes VS, Moretti NS, da Silva MS, Elias MC, Janzen CJ, Schenkman S. Trimethylation of histone H3K76 by Dot1B enhances cell cycle progression after mitosis in Trypanosoma cruzi. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1867:118694. [PMID: 32151656 DOI: 10.1016/j.bbamcr.2020.118694] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 03/03/2020] [Accepted: 03/05/2020] [Indexed: 12/11/2022]
Abstract
Dot1 enzymes are histone methyltransferases that mono-, di- and trimethylate lysine 79 of histone H3 to affect several nuclear processes. The functions of these different methylation states are still largely unknown. Trypanosomes, which are flagellated protozoa that cause several parasitic diseases, have two Dot1 homologues. Dot1A catalyzes the mono- and dimethylation of lysine 76 during late G2 and mitosis, and Dot1B catalyzes trimethylation, which is a modification found in all stages of the cell cycle. Here, we generated Trypanosoma cruzi lines lacking Dot1B. Deletion of one allele resulted in parasites with increased levels of mono- and dimethylation and a reduction in H3K76me3. In the full knockout (DKO), no trimethylation was observed. Both the DKO and the single knockout (SKO) showed aberrant morphology and decreased growth due to cell cycle arrest after G2. This phenotype could be rescued by caffeine in the DKO, as caffeine is a checkpoint inhibitor of the cell cycle. The knockouts also phosphorylated γH2A without producing extensive DNA breaks, and Dot1B-depleted cells were more susceptible to general checkpoint kinase inhibitors, suggesting that a lack of H3K76 trimethylation prevents the initiation and/or completion of cytokinesis.
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Affiliation(s)
- Vinicius Santana Nunes
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, 04032-039 São Paulo, SP, Brazil; Centro de Ensino, Pesquisa e Inovação, Hospital Evangélico de Vila Velha, 29118-060 Vila Velha, ES, Brazil
| | - Nilmar Silvio Moretti
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, 04032-039 São Paulo, SP, Brazil
| | | | - Maria Carolina Elias
- Laboratório Especial de Ciclo Celular, Instituto Butantan, São Paulo, SP, Brazil
| | - Christian J Janzen
- Department of Cell & Developmental Biology, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | - Sergio Schenkman
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, 04032-039 São Paulo, SP, Brazil.
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35
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Petsalaki E, Zachos G. DNA damage response proteins regulating mitotic cell division: double agents preserving genome stability. FEBS J 2020; 287:1700-1721. [PMID: 32027459 DOI: 10.1111/febs.15240] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 01/10/2020] [Accepted: 02/04/2020] [Indexed: 12/11/2022]
Abstract
The DNA damage response recognizes DNA lesions and coordinates a cell cycle arrest with the repair of the damaged DNA, or removal of the affected cells to prevent the passage of genetic alterations to the next generation. The mitotic cell division, on the other hand, is a series of processes that aims to accurately segregate the genomic material from the maternal to the two daughter cells. Despite their great importance in safeguarding genomic integrity, the DNA damage response and the mitotic cell division were long viewed as unrelated processes, mainly because animal cells that are irradiated during mitosis continue cell division without repairing the broken chromosomes. However, recent studies have demonstrated that DNA damage proteins play an important role in mitotic cell division. This is performed through regulation of the onset of mitosis, mitotic spindle formation, correction of misattached kinetochore-microtubules, spindle checkpoint signaling, or completion of cytokinesis (abscission), in the absence of DNA damage. In this review, we summarize the roles of DNA damage proteins in unperturbed mitosis, analyze the molecular mechanisms involved, and discuss the potential implications of these findings in cancer therapy.
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Affiliation(s)
- Eleni Petsalaki
- Department of Biology, University of Crete, Heraklion, Greece
| | - George Zachos
- Department of Biology, University of Crete, Heraklion, Greece
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36
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Actin reduction by MsrB2 is a key component of the cytokinetic abscission checkpoint and prevents tetraploidy. Proc Natl Acad Sci U S A 2020; 117:4169-4179. [PMID: 32029597 DOI: 10.1073/pnas.1911629117] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Abscission is the terminal step of cytokinesis leading to the physical separation of the daughter cells. In response to the abnormal presence of lagging chromatin between dividing cells, an evolutionarily conserved abscission/NoCut checkpoint delays abscission and prevents formation of binucleated cells by stabilizing the cytokinetic intercellular bridge (ICB). How this bridge is stably maintained for hours while the checkpoint is activated is poorly understood and has been proposed to rely on F-actin in the bridge region. Here, we show that actin polymerization is indeed essential for stabilizing the ICB when lagging chromatin is present, but not in normal dividing cells. Mechanistically, we found that a cytosolic pool of human methionine sulfoxide reductase B2 (MsrB2) is strongly recruited at the midbody in response to the presence of lagging chromatin and functions within the ICB to promote actin polymerization there. Consistently, in MsrB2-depleted cells, F-actin levels are decreased in ICBs, and dividing cells with lagging chromatin become binucleated as a consequence of unstable bridges. We further demonstrate that MsrB2 selectively reduces oxidized actin monomers and thereby counteracts MICAL1, an enzyme known to depolymerize actin filaments by direct oxidation. Finally, MsrB2 colocalizes and genetically interacts with the checkpoint components Aurora B and ANCHR, and the abscission delay upon checkpoint activation by nuclear pore defects also depends on MsrB2. Altogether, this work reveals that actin reduction by MsrB2 is a key component of the abscission checkpoint that favors F-actin polymerization and limits tetraploidy, a starting point for tumorigenesis.
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37
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Rastegari E, Kajal K, Tan BS, Huang F, Chen RH, Hsieh TS, Hsu HJ. WD40 protein Wuho controls germline homeostasis via TRIM-NHL tumor suppressor Mei-p26 in Drosophila. Development 2020; 147:147/2/dev182063. [PMID: 31941704 DOI: 10.1242/dev.182063] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 12/03/2019] [Indexed: 12/22/2022]
Abstract
WD40 proteins control many cellular processes via protein interactions. Drosophila Wuho (Wh, a WD40 protein) controls fertility, although the involved mechanisms are unclear. Here, we show that Wh promotion of Mei-p26 (a human TRIM32 ortholog) function maintains ovarian germ cell homeostasis. Wh and Mei-p26 are epistatically linked, with wh and mei-p26 mutants showing nearly identical phenotypes, including germline stem cell (GSC) loss, stem-cyst formation due to incomplete cytokinesis between GSCs and daughter cells, and overproliferation of GSC progeny. Mechanistically, Wh interacts with Mei-p26 in different cellular contexts to induce cell type-specific effects. In GSCs, Wh and Mei-p26 promote BMP stemness signaling for proper GSC division and maintenance. In GSC progeny, Wh and Mei-p26 silence nanos translation, downregulate a subset of microRNAs involved in germ cell differentiation and suppress ribosomal biogenesis via dMyc to limit germ cell mitosis. We also found that the human ortholog of Wh (WDR4) interacts with TRIM32 in human cells. Our results show that Wh is a regulator of Mei-p26 in Drosophila germ cells and suggest that the WD40-TRIM interaction may also control tissue homeostasis in other stem cell systems.
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Affiliation(s)
- Elham Rastegari
- Molecular and Cell Biology, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan, R.O.C.,Graduate Institute of Life Science, National Defense Medical Center, Taipei 11490, Taiwan, R.O.C.,Institute of Cellular and Organismic Biology, Sinica, Taipei 11529, Taiwan, R.O.C
| | - Kreeti Kajal
- Institute of Cellular and Organismic Biology, Sinica, Taipei 11529, Taiwan, R.O.C.,Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, National Chung Hsing University and Academia Sinica, Taipei 11529, Taiwan, R.O.C.,Graduate Institute of Biotechnology, National Chung Hsing University, Taichung 40227, Taiwan, R.O.C
| | - Boon-Shing Tan
- Institute of Biological Chemistry, Sinica, Taipei 11529, Taiwan, R.O.C
| | - Fu Huang
- Institute of Biological Chemistry, Sinica, Taipei 11529, Taiwan, R.O.C
| | - Ruey-Hwa Chen
- Institute of Biological Chemistry, Sinica, Taipei 11529, Taiwan, R.O.C
| | - Tao-Shieh Hsieh
- Molecular and Cell Biology, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan, R.O.C.,Graduate Institute of Life Science, National Defense Medical Center, Taipei 11490, Taiwan, R.O.C.,Institute of Cellular and Organismic Biology, Sinica, Taipei 11529, Taiwan, R.O.C
| | - Hwei-Jan Hsu
- Molecular and Cell Biology, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan, R.O.C .,Graduate Institute of Life Science, National Defense Medical Center, Taipei 11490, Taiwan, R.O.C.,Institute of Cellular and Organismic Biology, Sinica, Taipei 11529, Taiwan, R.O.C.,Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, National Chung Hsing University and Academia Sinica, Taipei 11529, Taiwan, R.O.C.,Graduate Institute of Biotechnology, National Chung Hsing University, Taichung 40227, Taiwan, R.O.C
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38
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Bates M, Furlong F, Gallagher MF, Spillane CD, McCann A, O'Toole S, O'Leary JJ. Too MAD or not MAD enough: The duplicitous role of the spindle assembly checkpoint protein MAD2 in cancer. Cancer Lett 2020; 469:11-21. [DOI: 10.1016/j.canlet.2019.10.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 09/26/2019] [Accepted: 10/01/2019] [Indexed: 12/11/2022]
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39
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Petsalaki E, Zachos G. Building bridges between chromosomes: novel insights into the abscission checkpoint. Cell Mol Life Sci 2019; 76:4291-4307. [PMID: 31302750 PMCID: PMC11105294 DOI: 10.1007/s00018-019-03224-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 06/19/2019] [Accepted: 07/05/2019] [Indexed: 12/20/2022]
Abstract
In the presence of chromatin bridges, mammalian cells delay completion of cytokinesis (abscission) to prevent chromatin breakage or tetraploidization by regression of the cleavage furrow. This abscission delay is called "the abscission checkpoint" and is dependent on Aurora B kinase. Furthermore, cells stabilize the narrow cytoplasmic canal between the two daughter cells until the DNA bridges are resolved. Impaired abscission checkpoint signaling or unstable intercellular canals can lead to accumulation of DNA damage, aneuploidy, or generation of polyploid cells which are associated with tumourigenesis. However, the molecular mechanisms involved have only recently started to emerge. In this review, we focus on the molecular pathways of the abscission checkpoint and describe newly identified triggers, Aurora B-regulators and effector proteins in abscission checkpoint signaling. We also describe mechanisms that control intercellular bridge stabilization, DNA bridge resolution, or abscission checkpoint silencing upon satisfaction, and discuss how abscission checkpoint proteins can be targeted to potentially improve cancer therapy.
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Affiliation(s)
- Eleni Petsalaki
- Department of Biology, University of Crete, Vassilika Vouton, 70013, Heraklion, Greece
| | - George Zachos
- Department of Biology, University of Crete, Vassilika Vouton, 70013, Heraklion, Greece.
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40
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Renshaw MJ, Panagiotou TC, Lavoie BD, Wilde A. CDK11 p58-cyclin L1β regulates abscission site assembly. J Biol Chem 2019; 294:18639-18649. [PMID: 31653703 DOI: 10.1074/jbc.ra119.009107] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Revised: 10/10/2019] [Indexed: 01/22/2023] Open
Abstract
Rigorous spatiotemporal regulation of cell division is required to maintain genome stability. The final stage in cell division, when the cells physically separate (abscission), is tightly regulated to ensure that it occurs after cytokinetic events such as chromosome segregation. A key regulator of abscission timing is Aurora B kinase activity, which inhibits abscission and forms the major activity of the abscission checkpoint. This checkpoint prevents abscission until chromosomes have been cleared from the cytokinetic machinery. Here we demonstrate that the mitosis-specific CDK11p58 kinase specifically forms a complex with cyclin L1β that, in late cytokinesis, localizes to the stem body, a structure in the middle of the intercellular bridge that forms between two dividing cells. Depletion of CDK11 inhibits abscission, and rescue of this phenotype requires CDK11p58 kinase activity or inhibition of Aurora B kinase activity. Furthermore, CDK11p58 kinase activity is required for formation of endosomal sorting complex required for transport III filaments at the site of abscission. Combined, these data suggest that CDK11p58 kinase activity opposes Aurora B activity to enable abscission to proceed and result in successful completion of cytokinesis.
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Affiliation(s)
- Matthew J Renshaw
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5G 1M1, Canada
| | - Thomas C Panagiotou
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5G 1M1, Canada
| | - Brigitte D Lavoie
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5G 1M1, Canada
| | - Andrew Wilde
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5G 1M1, Canada; Department of Biochemistry, University of Toronto, Toronto, Ontario M5G 1M1, Canada.
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Gatta AT, Carlton JG. The ESCRT-machinery: closing holes and expanding roles. Curr Opin Cell Biol 2019; 59:121-132. [DOI: 10.1016/j.ceb.2019.04.005] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 04/10/2019] [Accepted: 04/15/2019] [Indexed: 01/08/2023]
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HIPK2 Phosphorylates the Microtubule-Severing Enzyme Spastin at S268 for Abscission. Cells 2019; 8:cells8070684. [PMID: 31284535 PMCID: PMC6678495 DOI: 10.3390/cells8070684] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 07/02/2019] [Accepted: 07/03/2019] [Indexed: 12/27/2022] Open
Abstract
Abscission is the final step of cell division, mediating the physical separation of the two daughter cells. A key player in this process is the microtubule-severing enzyme spastin that localizes at the midbody where its activity is crucial to cut microtubules and culminate the cytokinesis. Recently, we demonstrated that HIPK2, a multifunctional kinase involved in several cellular pathways, contributes to abscission and prevents tetraploidization. Here, we show that HIPK2 binds and phosphorylates spastin at serine 268. During cytokinesis, the midbody-localized spastin is phosphorylated at S268 in HIPK2-proficient cells. In contrast, no spastin is detectable at the midbody in HIPK2-depleted cells. The non-phosphorylatable spastin-S268A mutant does not localize at the midbody and cannot rescue HIPK2-depleted cells from abscission defects. In contrast, the phosphomimetic spastin-S268D mutant localizes at the midbody and restores successful abscission in the HIPK2-depleted cells. These results show that spastin is a novel target of HIPK2 and that HIPK2-mediated phosphorylation of spastin contributes to its midbody localization for successful abscission.
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43
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Karasmanis EP, Hwang D, Nakos K, Bowen JR, Angelis D, Spiliotis ET. A Septin Double Ring Controls the Spatiotemporal Organization of the ESCRT Machinery in Cytokinetic Abscission. Curr Biol 2019; 29:2174-2182.e7. [PMID: 31204162 DOI: 10.1016/j.cub.2019.05.050] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 03/29/2019] [Accepted: 05/20/2019] [Indexed: 01/01/2023]
Abstract
Abscission is the terminal step of mitosis that physically separates two daughter cells [1, 2]. Abscission requires the endocytic sorting complex required for transport (ESCRT), a molecular machinery of multiple subcomplexes (ESCRT-I/II/III) that promotes membrane remodeling and scission [3-5]. Recruitment of ESCRT-I/II complexes to the midbody of telophase cells initiates ESCRT-III assembly into two rings, which subsequently expand into helices and spirals that narrow down to the incipient site of abscission [6-8]. ESCRT-III assembly is highly dynamic and spatiotemporally ordered, but the underlying mechanisms are poorly understood. Here, we report that, after cleavage furrow closure, septins form a membrane-bound double ring that controls the organization and function of ESCRT-III. The septin double ring demarcates the sites of ESCRT-III assembly into rings and disassembles before ESCRT-III rings expand into helices and spirals. We show that septin 9 (SEPT9) depletion, which abrogates abscission, impairs recruitment of VPS25 (ESCRT-II) and CHMP6 (ESCRT-III). Strikingly, ESCRT-III subunits (CHMP4B and CHMP2A/B) accumulate to the midbody, but they are highly disorganized, failing to form symmetric rings and to expand laterally into the cone-shaped helices and spirals of abscission. We found that SEPT9 interacts directly with the ubiquitin E2 variant (UEV) domain of ESCRT-I protein TSG101 through two N-terminal PTAP motifs, which are required for the recruitment of VPS25 and CHMP6, and the spatial organization of ESCRT-III (CHMP4B and CHMP2B) into functional rings. These results reveal that septins function in the ESCRT-I-ESCRT-II-CHMP6 pathway of ESCRT-III assembly and provide a framework for the spatiotemporal control of the ESCRT machinery of cytokinetic abscission.
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Affiliation(s)
- Eva P Karasmanis
- Department of Biology, Drexel University, Philadelphia, PA 19104, USA
| | - Daniel Hwang
- Department of Biology, Drexel University, Philadelphia, PA 19104, USA
| | | | - Jonathan R Bowen
- Department of Biology, Drexel University, Philadelphia, PA 19104, USA
| | - Dimitrios Angelis
- Department of Biology, Drexel University, Philadelphia, PA 19104, USA
| | - Elias T Spiliotis
- Department of Biology, Drexel University, Philadelphia, PA 19104, USA.
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44
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Zuck M, Hybiske K. The Chlamydia trachomatis Extrusion Exit Mechanism Is Regulated by Host Abscission Proteins. Microorganisms 2019; 7:microorganisms7050149. [PMID: 31130662 PMCID: PMC6560402 DOI: 10.3390/microorganisms7050149] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 05/21/2019] [Accepted: 05/22/2019] [Indexed: 12/13/2022] Open
Abstract
The cellular exit strategies of intracellular pathogens have a direct impact on microbial dissemination, transmission, and engagement of immune responses of the host. Chlamydia exit their host via a budding mechanism called extrusion, which offers protective benefits to Chlamydia as they navigate their extracellular environment. Many intracellular pathogens co-opt cellular abscission machinery to facilitate cell exit, which is utilized to perform scission of two newly formed daughter cells following mitosis. Similar to viral budding exit strategies, we hypothesize that an abscission-like mechanism is required to physically sever the chlamydial extrusion from the host cell, co-opting the membrane fission activities of the endosomal sorting complex required for transport (ESCRT) family of proteins that are necessary for cellular scission events, including abscission. To test this, C. trachomatis L2-infected HeLa cells were depleted of key abscission machinery proteins charged multivesicle body protein 4b (CHMP4B), ALIX, centrosome protein 55 (CEP55), or vacuolar protein sorting-associated protein 4A (VPS4A), using RNA interference (RNAi). Over 50% reduction in extrusion formation was achieved by depletion of CHMP4B, VPS4A, and ALIX, but no effect on extrusion was observed with CEP55 depletion. These results demonstrate a role for abscission machinery in C. trachomatis extrusion from the host cell, with ALIX, VPS4A and CHMP4B playing key functional roles in optimal extrusion release.
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Affiliation(s)
- Meghan Zuck
- Department of Medicine, Division of Allergy and Infectious Diseases, Center for Emerging and Reemerging Infectious Disease (CERID), University of Washington, Seattle, WA 98109, USA.
- Division of Infectious Diseases and Immunity, School of Public Health, University of California, Berkeley, CA 94720, USA.
| | - Kevin Hybiske
- Department of Medicine, Division of Allergy and Infectious Diseases, Center for Emerging and Reemerging Infectious Disease (CERID), University of Washington, Seattle, WA 98109, USA.
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45
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Brace JL, Doerfler MD, Weiss EL. A cell separation checkpoint that enforces the proper order of late cytokinetic events. J Cell Biol 2019; 218:150-170. [PMID: 30455324 PMCID: PMC6314563 DOI: 10.1083/jcb.201805100] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 08/28/2018] [Accepted: 10/05/2018] [Indexed: 01/28/2023] Open
Abstract
Eukaryotic cell division requires dependency relationships in which late processes commence only after early ones are appropriately completed. We have discovered a system that blocks late events of cytokinesis until early ones are successfully accomplished. In budding yeast, cytokinetic actomyosin ring contraction and membrane ingression are coupled with deposition of an extracellular septum that is selectively degraded in its primary septum immediately after its completion by secreted enzymes. We find this secretion event is linked to septum completion and forestalled when the process is slowed. Delay of septum degradation requires Fir1, an intrinsically disordered protein localized to the cytokinesis site that is degraded upon septum completion but stabilized when septation is aberrant. Fir1 protects cytokinesis in part by inhibiting a separation-specific exocytosis function of the NDR/LATS kinase Cbk1, a key component of "hippo" signaling that induces mother-daughter separation. We term this system enforcement of cytokinesis order, a checkpoint ensuring proper temporal sequence of mechanistically incompatible processes of cytokinesis.
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Affiliation(s)
- Jennifer L Brace
- Department of Molecular Biosciences, Northwestern University, Evanston, IL
| | - Matthew D Doerfler
- Department of Molecular Biosciences, Northwestern University, Evanston, IL
| | - Eric L Weiss
- Department of Molecular Biosciences, Northwestern University, Evanston, IL
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46
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Abstract
Budding yeast Saccharomyces cerevisiae is an ideal model organism to study membrane trafficking pathways. The ESCRT (endosomal sorting complexes required for transport) pathway was first identified in this organism. Upon recognition of endocytosed ubiquitinated membrane proteins at endosomes, ESCRTs assemble at these organelles to catalyze the biogenesis of multivesicular bodies (MVBs). Formation of MVBs leads to the trafficking of these membrane proteins to vacuoles for degradation. Here, we describe genetic and biochemical approaches to study ESCRT function. We outline in vivo endocytosis assays using two model cargoes in Saccharomyces cerevisiae and also describe an in vitro approach to analyze ESCRT-III polymerization on lipid monolayers.
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Affiliation(s)
- Sudeep Banjade
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, USA
| | - Shaogeng Tang
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, USA
- Department of Biochemistry, Stanford University, Stanford, CA, USA
| | - Scott D Emr
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, USA.
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47
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O’Shaughnessy B, Thiyagarajan S. Mechanisms of contractile ring tension production and constriction. Biophys Rev 2018; 10:1667-1681. [PMID: 30456601 PMCID: PMC6297097 DOI: 10.1007/s12551-018-0476-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 10/23/2018] [Indexed: 12/24/2022] Open
Abstract
The contractile ring is a remarkable tension-generating cellular machine that constricts and divides cells into two during cytokinesis, the final stage of the cell cycle. Since the ring's discovery, the parallels with muscle have been emphasized. Both are contractile actomyosin machineries, and long ago, a muscle-like sliding filament mechanism was proposed for the ring. This review focuses on the mechanisms that generate ring tension and constrict contractile rings. The emphasis is on fission yeast, whose contractile ring is sufficiently well characterized that realistic mathematical models are feasible, and possible lessons from fission yeast that may apply to animal cells are discussed. Recent discoveries relevant to the organization in fission yeast rings suggest a stochastic steady-state version of the classic sliding filament mechanism for tension. The importance of different modes of anchoring for tension production and for organizational stability of constricting rings is discussed. Possible mechanisms are discussed that set the constriction rate and enable the contractile ring to meet the technical challenge of maintaining structural integrity and tension-generating capacity while continuously disassembling throughout constriction.
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Affiliation(s)
- Ben O’Shaughnessy
- Department of Chemical Engineering, Columbia University, New York, NY 10027 USA
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48
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CHMP4C: A novel regulator of the mitotic spindle checkpoint. Mol Cell Oncol 2018; 5:e1445944. [PMID: 30250900 DOI: 10.1080/23723556.2018.1445944] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 02/22/2018] [Accepted: 02/22/2018] [Indexed: 12/12/2022]
Abstract
The mitotic spindle checkpoint delays anaphase onset until all chromosomes have achieved stable kinetochore-microtubule attachments. Here, we discuss recent findings showing that CHMP4C, a component of the endosomal sorting complex required for transport (ESCRT) machinery, protects human cells against chromosome missegregation by promoting localisation of the ROD-ZW10-ZWILCH (RZZ) spindle checkpoint complex to unattached kinetochores.
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49
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Sadler JBA, Wenzel DM, Strohacker LK, Guindo-Martínez M, Alam SL, Mercader JM, Torrents D, Ullman KS, Sundquist WI, Martin-Serrano J. A cancer-associated polymorphism in ESCRT-III disrupts the abscission checkpoint and promotes genome instability. Proc Natl Acad Sci U S A 2018; 115:E8900-E8908. [PMID: 30181294 PMCID: PMC6156662 DOI: 10.1073/pnas.1805504115] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Cytokinetic abscission facilitates the irreversible separation of daughter cells. This process requires the endosomal-sorting complexes required for transport (ESCRT) machinery and is tightly regulated by charged multivesicular body protein 4C (CHMP4C), an ESCRT-III subunit that engages the abscission checkpoint (NoCut) in response to mitotic problems such as persisting chromatin bridges within the midbody. Importantly, a human polymorphism in CHMP4C (rs35094336, CHMP4CT232) increases cancer susceptibility. Here, we explain the structural and functional basis for this cancer association: The CHMP4CT232 allele unwinds the C-terminal helix of CHMP4C, impairs binding to the early-acting ESCRT factor ALIX, and disrupts the abscission checkpoint. Cells expressing CHMP4CT232 exhibit increased levels of DNA damage and are sensitized to several conditions that increase chromosome missegregation, including DNA replication stress, inhibition of the mitotic checkpoint, and loss of p53. Our data demonstrate the biological importance of the abscission checkpoint and suggest that dysregulation of abscission by CHMP4CT232 may synergize with oncogene-induced mitotic stress to promote genomic instability and tumorigenesis.
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Affiliation(s)
- Jessica B A Sadler
- Department of Infectious Diseases, Faculty of Life Sciences and Medicine, King's College London, SE1 9RT London, United Kingdom
| | - Dawn M Wenzel
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112
| | - Lauren K Strohacker
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112
| | - Marta Guindo-Martínez
- Joint Barcelona Supercomputing Center-Centre for Genomic Regulation-Institute for Research in Biomedicine Research Program in Computational Biology, Barcelona Supercomputing Center, 08034 Barcelona, Spain
| | - Steven L Alam
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112
| | - Josep M Mercader
- Joint Barcelona Supercomputing Center-Centre for Genomic Regulation-Institute for Research in Biomedicine Research Program in Computational Biology, Barcelona Supercomputing Center, 08034 Barcelona, Spain
- Program in Metabolism, Broad Institute of Harvard and MIT, Cambridge, MA 02142
- Program in Medical and Population Genetics, Broad Institute of Harvard and MIT, Cambridge, MA 02142
- Diabetes Unit, Massachusetts General Hospital, Boston, MA 02114
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114
| | - David Torrents
- Joint Barcelona Supercomputing Center-Centre for Genomic Regulation-Institute for Research in Biomedicine Research Program in Computational Biology, Barcelona Supercomputing Center, 08034 Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats, 08010 Barcelona, Spain
| | - Katharine S Ullman
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112
| | - Wesley I Sundquist
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112;
| | - Juan Martin-Serrano
- Department of Infectious Diseases, Faculty of Life Sciences and Medicine, King's College London, SE1 9RT London, United Kingdom;
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50
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Dandoulaki M, Petsalaki E, Sumpton D, Zanivan S, Zachos G. Src activation by Chk1 promotes actin patch formation and prevents chromatin bridge breakage in cytokinesis. J Cell Biol 2018; 217:3071-3089. [PMID: 29954829 PMCID: PMC6122982 DOI: 10.1083/jcb.201802102] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Revised: 04/16/2018] [Accepted: 06/03/2018] [Indexed: 12/23/2022] Open
Abstract
In cytokinesis with chromatin bridges, cells delay abscission and retain actin patches at the intercellular canal to prevent chromosome breakage. In this study, we show that inhibition of Src, a protein-tyrosine kinase that regulates actin dynamics, or Chk1 kinase correlates with chromatin breakage and impaired formation of actin patches but not with abscission in the presence of chromatin bridges. Chk1 is required for optimal localization and complete activation of Src. Furthermore, Chk1 phosphorylates human Src at serine 51, and phosphorylated Src localizes to actin patches, the cell membrane, or the nucleus. Nonphosphorylatable mutation of S51 to alanine reduces Src catalytic activity and impairs formation of actin patches, whereas expression of a phosphomimicking Src-S51D protein rescues actin patches and prevents chromatin breakage in Chk1-deficient cells. We propose that Chk1 phosphorylates Src-S51 to fully induce Src kinase activity and that phosphorylated Src promotes formation of actin patches and stabilizes chromatin bridges. These results identify proteins that regulate formation of actin patches in cytokinesis.
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Affiliation(s)
| | - Eleni Petsalaki
- Department of Biology, University of Crete, Heraklion, Greece
| | - David Sumpton
- Cancer Research UK Beatson Institute, Glasgow, Scotland, UK
| | - Sara Zanivan
- Cancer Research UK Beatson Institute, Glasgow, Scotland, UK
- Institute of Cancer Sciences, Wolfson Wohl Cancer Research Centre, University of Glasgow, Glasgow, Scotland, UK
| | - George Zachos
- Department of Biology, University of Crete, Heraklion, Greece
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