1
|
Kelley ME, Carlini L, Kornakov N, Aher A, Khodjakov A, Kapoor TM. Spastin regulates anaphase chromosome separation distance and microtubule-containing nuclear tunnels. Mol Biol Cell 2024; 35:ar48. [PMID: 38335450 PMCID: PMC11064660 DOI: 10.1091/mbc.e24-01-0031-t] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Accepted: 02/01/2024] [Indexed: 02/12/2024] Open
Abstract
Nuclear envelope reassembly during the final stages of each mitosis depends on disassembling spindle microtubules without disrupting chromosome separation. This process involves the transient recruitment of the ESCRT-III complex and spastin, a microtubule-severing AAA (ATPases associated with diverse cellular activities) mechanoenzyme, to late-anaphase chromosomes. However, dissecting mechanisms underlying these rapid processes, which can be completed within minutes, has been difficult. Here, we combine fast-acting chemical inhibitors with live-cell imaging and find that spindle microtubules, along with spastin activity, regulate the number and lifetimes of spastin foci at anaphase chromosomes. Unexpectedly, spastin inhibition impedes chromosome separation, but does not alter the anaphase localization dynamics of CHMP4B, an ESCRT-III protein, or increase γ-H2AX foci, a DNA damage marker. We show spastin inhibition increases the frequency of lamin-lined nuclear microtunnels that can include microtubules penetrating the nucleus. Our findings suggest failure to sever spindle microtubules impedes chromosome separation, yet reforming nuclear envelopes can topologically accommodate persistent microtubules ensuring nuclear DNA is not damaged or exposed to cytoplasm.
Collapse
Affiliation(s)
- Megan E. Kelley
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY 10065
| | - Lina Carlini
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY 10065
| | - Nikolay Kornakov
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY 10065
| | - Amol Aher
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY 10065
| | - Alexey Khodjakov
- Wadsworth Center, New York State Department of Health, Albany, NY 12237
| | - Tarun M. Kapoor
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY 10065
| |
Collapse
|
2
|
Chen P, Levy DL. Regulation of organelle size and organization during development. Semin Cell Dev Biol 2023; 133:53-64. [PMID: 35148938 PMCID: PMC9357868 DOI: 10.1016/j.semcdb.2022.02.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 01/20/2022] [Accepted: 02/01/2022] [Indexed: 12/11/2022]
Abstract
During early embryogenesis, as cells divide in the developing embryo, the size of intracellular organelles generally decreases to scale with the decrease in overall cell size. Organelle size scaling is thought to be important to establish and maintain proper cellular function, and defective scaling may lead to impaired development and disease. However, how the cell regulates organelle size and organization are largely unanswered questions. In this review, we summarize the process of size scaling at both the cell and organelle levels and discuss recently discovered mechanisms that regulate this process during early embryogenesis. In addition, we describe how some recently developed techniques and Xenopus as an animal model can be used to investigate the underlying mechanisms of size regulation and to uncover the significance of proper organelle size scaling and organization.
Collapse
Affiliation(s)
- Pan Chen
- Institute of Biochemistry and Molecular Biology, School of Medicine, Ningbo University, Ningbo, Zhejiang 315211, China.
| | - Daniel L Levy
- Department of Molecular Biology, University of Wyoming, Laramie, WY 82071, USA.
| |
Collapse
|
3
|
Hubbing the Cancer Cell. Cancers (Basel) 2022; 14:cancers14235924. [PMID: 36497405 PMCID: PMC9738523 DOI: 10.3390/cancers14235924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 11/24/2022] [Accepted: 11/28/2022] [Indexed: 12/02/2022] Open
Abstract
Oncogenic transformation drives adaptive changes in a growing tumor that affect the cellular organization of cancerous cells, resulting in the loss of specialized cellular functions in the polarized compartmentalization of cells. The resulting altered metabolic and morphological patterns are used clinically as diagnostic markers. This review recapitulates the known functions of actin, microtubules and the γ-tubulin meshwork in orchestrating cell metabolism and functional cellular asymmetry.
Collapse
|
4
|
Dynamic cytosolic foci of DPPA4 in human pluripotent stem cells. Tissue Cell 2022; 78:101893. [DOI: 10.1016/j.tice.2022.101893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Revised: 07/28/2022] [Accepted: 08/06/2022] [Indexed: 11/23/2022]
|
5
|
Size regulation of multiple organelles competing for a limiting subunit pool. PLoS Comput Biol 2022; 18:e1010253. [PMID: 35714135 PMCID: PMC9246132 DOI: 10.1371/journal.pcbi.1010253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 06/30/2022] [Accepted: 05/26/2022] [Indexed: 11/20/2022] Open
Abstract
How cells regulate the size of intracellular structures and organelles is a longstanding question. Recent experiments suggest that size control of intracellular structures is achieved through the depletion of a limiting subunit pool in the cytoplasm. While the limiting pool model ensures organelle-to-cell size scaling, it does not provide a mechanism for robust size control of multiple co-existing structures. Here we develop a generalized theory for size-dependent growth of intracellular structures to demonstrate that robust size control of multiple intracellular structures, competing for a limiting subunit pool, is achieved via a negative feedback between the growth rate and the size of the individual structure. This design principle captures size maintenance of a wide variety of subcellular structures, from cytoskeletal filaments to three-dimensional organelles. We identify the feedback motifs for structure size regulation based on known molecular processes, and compare our theory to existing models of size regulation in biological assemblies. Furthermore, we show that positive feedback between structure size and growth rate can lead to bistable size distribution and spontaneous size selection. Organelle size control is essential for the proper physiological functioning of eukaryotic cells, but the underlying mechanisms of size regulation remain poorly understood. By developing a general theory for organelle size control, we show that robust size control of intracellular structures and organelles is achieved via a negative feedback between individual organelle size and their net growth rates. This design principle not only describes size maintenance of single organelles, but also ensures size stability of multiple co-existing organelles that are built from a limiting pool of subunits. Our results delineate the role of limiting pool as a size scaling mechanism rather than a size control mechanism, supporting the idea that negative feedback control of organelle size via depletion of a limiting subunit pool is not sufficient to maintain the size of multiple competing organelles. In the case of positive feedback between organelle size and growth rate, our model reproduces phenomena such as bistability in organelle size distribution and spontaneous emergence of cell polarity.
Collapse
|
6
|
Singh I, Lele TP. Nuclear Morphological Abnormalities in Cancer: A Search for Unifying Mechanisms. Results Probl Cell Differ 2022; 70:443-467. [PMID: 36348118 PMCID: PMC9722227 DOI: 10.1007/978-3-031-06573-6_16] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Irregularities in nuclear shape and/or alterations to nuclear size are a hallmark of malignancy in a broad range of cancer types. Though these abnormalities are commonly used for diagnostic purposes and are often used to assess cancer progression in the clinic, the mechanisms through which they occur are not well understood. Nuclear size alterations in cancer could potentially arise from aneuploidy, changes in osmotic coupling with the cytoplasm, and perturbations to nucleocytoplasmic transport. Nuclear shape changes may occur due to alterations to cell-generated mechanical stresses and/or alterations to nuclear structural components, which balance those stresses, such as the nuclear lamina and chromatin. A better understanding of the mechanisms underlying abnormal nuclear morphology and size may allow the development of new therapeutics to target nuclear aberrations in cancer.
Collapse
Affiliation(s)
- Ishita Singh
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA
| | - Tanmay P. Lele
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA,Department of Chemical Engineering, University of Florida, Gainesville, FL, USA,Department of Translational Medical Sciences, Texas A&M University, Houston, TX, USA
| |
Collapse
|
7
|
Cantwell H, Dey G. Nuclear size and shape control. Semin Cell Dev Biol 2021; 130:90-97. [PMID: 34776332 DOI: 10.1016/j.semcdb.2021.10.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 10/26/2021] [Accepted: 10/29/2021] [Indexed: 11/27/2022]
Abstract
The nucleus displays a wide range of sizes and shapes in different species and cell types, yet its size scaling and many of the key structural constituents that determine its shape are highly conserved. In this review, we discuss the cellular properties and processes that contribute to nuclear size and shape control, drawing examples from across eukaryotes and highlighting conserved themes and pathways. We then outline physiological roles that have been uncovered for specific nuclear morphologies and disease pathologies associated with aberrant nuclear morphology. We argue that a comparative approach, assessing and integrating observations from different systems, will be a powerful way to help us address the open questions surrounding functional roles of nuclear size and shape in cell physiology.
Collapse
Affiliation(s)
- Helena Cantwell
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720, USA.
| | - Gautam Dey
- Cell Biology and Biophysics, European Molecular Biology Laboratory, Meyerhofstr.1, 69117 Heidelberg, Germany.
| |
Collapse
|
8
|
Orr B, De Sousa F, Gomes AM, Afonso O, Ferreira LT, Figueiredo AC, Maiato H. An anaphase surveillance mechanism prevents micronuclei formation from frequent chromosome segregation errors. Cell Rep 2021; 37:109783. [PMID: 34758324 PMCID: PMC8595644 DOI: 10.1016/j.celrep.2021.109783] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 07/15/2021] [Accepted: 08/26/2021] [Indexed: 12/25/2022] Open
Abstract
Micronuclei are a hallmark of cancer and several other human disorders. Recently, micronuclei were implicated in chromothripsis, a series of massive genomic rearrangements that may drive tumor evolution and progression. Here, we show that Aurora B kinase mediates a surveillance mechanism that integrates error correction during anaphase with spatial control of nuclear envelope reassembly to prevent micronuclei formation. Using high-resolution live-cell imaging of human cancer and non-cancer cells, we uncover that anaphase lagging chromosomes are more frequent than previously anticipated, yet they rarely form micronuclei. Micronuclei formation from anaphase lagging chromosomes is prevented by a midzone-based Aurora B phosphorylation gradient that stabilizes kinetochore-microtubule attachments and assists spindle forces required for anaphase error correction while delaying nuclear envelope reassembly on lagging chromosomes, independently of microtubule density. We propose that a midzone-based Aurora B phosphorylation gradient actively monitors and corrects frequent chromosome segregation errors to prevent micronuclei formation during human cell division. Anaphase lagging chromosomes are frequent but rarely form micronuclei A midzone Aurora B activity gradient prevents micronuclei from segregation errors Midzone Aurora B assists spindle forces at the kinetochores to correct errors Aurora B spatially regulates nuclear envelope reformation on lagging chromosomes
Collapse
Affiliation(s)
- Bernardo Orr
- Chromosome Instability & Dynamics Group, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Filipe De Sousa
- Chromosome Instability & Dynamics Group, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Ana Margarida Gomes
- Chromosome Instability & Dynamics Group, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Olga Afonso
- Chromosome Instability & Dynamics Group, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Luísa T Ferreira
- Chromosome Instability & Dynamics Group, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Ana C Figueiredo
- Chromosome Instability & Dynamics Group, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Helder Maiato
- Chromosome Instability & Dynamics Group, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; Cell Division Group, Department of Biomedicine, Faculdade de Medicina, Universidade do Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal.
| |
Collapse
|
9
|
The Cytoskeleton and Its Roles in Self-Organization Phenomena: Insights from Xenopus Egg Extracts. Cells 2021; 10:cells10092197. [PMID: 34571847 PMCID: PMC8465277 DOI: 10.3390/cells10092197] [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: 07/23/2021] [Revised: 08/18/2021] [Accepted: 08/21/2021] [Indexed: 01/11/2023] Open
Abstract
Self-organization of and by the cytoskeleton is central to the biology of the cell. Since their introduction in the early 1980s, cytoplasmic extracts derived from the eggs of the African clawed-frog, Xenopus laevis, have flourished as a major experimental system to study the various facets of cytoskeleton-dependent self-organization. Over the years, the many investigations that have used these extracts uniquely benefited from their simplified cell cycle, large experimental volumes, biochemical tractability and cell-free nature. Here, we review the contributions of egg extracts to our understanding of the cytoplasmic aspects of self-organization by the microtubule and the actomyosin cytoskeletons as well as the importance of cytoskeletal filaments in organizing nuclear structure and function.
Collapse
|
10
|
Choppakatla P, Dekker B, Cutts EE, Vannini A, Dekker J, Funabiki H. Linker histone H1.8 inhibits chromatin binding of condensins and DNA topoisomerase II to tune chromosome length and individualization. eLife 2021; 10:e68918. [PMID: 34406118 PMCID: PMC8416026 DOI: 10.7554/elife.68918] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 08/13/2021] [Indexed: 12/14/2022] Open
Abstract
DNA loop extrusion by condensins and decatenation by DNA topoisomerase II (topo II) are thought to drive mitotic chromosome compaction and individualization. Here, we reveal that the linker histone H1.8 antagonizes condensins and topo II to shape mitotic chromosome organization. In vitro chromatin reconstitution experiments demonstrate that H1.8 inhibits binding of condensins and topo II to nucleosome arrays. Accordingly, H1.8 depletion in Xenopus egg extracts increased condensins and topo II levels on mitotic chromatin. Chromosome morphology and Hi-C analyses suggest that H1.8 depletion makes chromosomes thinner and longer through shortening the average loop size and reducing the DNA amount in each layer of mitotic loops. Furthermore, excess loading of condensins and topo II to chromosomes by H1.8 depletion causes hyper-chromosome individualization and dispersion. We propose that condensins and topo II are essential for chromosome individualization, but their functions are tuned by the linker histone to keep chromosomes together until anaphase.
Collapse
Affiliation(s)
- Pavan Choppakatla
- Laboratory of Chromosome and Cell Biology, The Rockefeller UniversityNew YorkUnited States
| | - Bastiaan Dekker
- Program in Systems Biology, Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical SchoolWorcesterUnited States
| | - Erin E Cutts
- Division of Structural Biology, The Institute of Cancer ResearchLondonUnited Kingdom
| | - Alessandro Vannini
- Division of Structural Biology, The Institute of Cancer ResearchLondonUnited Kingdom
- Fondazione Human Technopole, Structural Biology Research Centre, 20157MilanItaly
| | - Job Dekker
- Program in Systems Biology, Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical SchoolWorcesterUnited States
- Howard Hughes Medical InstituteChevy ChaseUnited States
| | - Hironori Funabiki
- Laboratory of Chromosome and Cell Biology, The Rockefeller UniversityNew YorkUnited States
| |
Collapse
|
11
|
The γ-tubulin meshwork assists in the recruitment of PCNA to chromatin in mammalian cells. Commun Biol 2021; 4:767. [PMID: 34158617 PMCID: PMC8219688 DOI: 10.1038/s42003-021-02280-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 05/28/2021] [Indexed: 12/27/2022] Open
Abstract
Changes in the location of γ-tubulin ensure cell survival and preserve genome integrity. We investigated whether the nuclear accumulation of γ-tubulin facilitates the transport of proliferating cell nuclear antigen (PCNA) between the cytosolic and the nuclear compartment in mammalian cells. We found that the γ-tubulin meshwork assists in the recruitment of PCNA to chromatin. Also, decreased levels of γ-tubulin reduce the nuclear pool of PCNA. In addition, the γ-tubulin C terminus encodes a PCNA-interacting peptide (PIP) motif, and a γ-tubulin–PIP-mutant affects the nuclear accumulation of PCNA. In a cell-free system, PCNA and γ-tubulin formed a complex. In tumors, there is a significant positive correlation between TUBG1 and PCNA expression. Thus, we report a novel mechanism that constitutes the basis for tumor growth by which the γ-tubulin meshwork maintains indefinite proliferation by acting as an opportune scaffold for the transport of PCNA from the cytosol to the chromatin. Corvaisier et al discover that γ-tubulin and replication protein PCNA forms a complex and that this facilitates recruitment of PCNA to chromatin both during cell division and during the DSB repair response. They identify a PCNA binding motif in γ-tubulin, which when mutated affects replication fork progression, providing insights into the role of the nuclear γ-tubulin meshwork.
Collapse
|
12
|
Shokrollahi M, Mekhail K. Interphase microtubules in nuclear organization and genome maintenance. Trends Cell Biol 2021; 31:721-731. [PMID: 33902985 DOI: 10.1016/j.tcb.2021.03.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 03/10/2021] [Accepted: 03/23/2021] [Indexed: 12/11/2022]
Abstract
Microtubules are major cytoskeletal components mediating fundamental cellular processes, including cell division. Recent evidence suggests that microtubules also regulate the nucleus during the cell cycle's interphase stage. Deciphering such roles of microtubules should uncover direct crosstalk between the nucleus and cytoplasm, impacting genome function and organismal health. Here, we review emerging roles for microtubules in interphase genome regulation. We explore how microtubules exert cytoplasmic forces on the nucleus or transport molecular cargo, including DNA, into or within the nucleus. We also describe how microtubules perform these functions by establishing transient or stable connections with nuclear envelope elements. Lastly, we discuss how the regulation of the nucleus by microtubules impacts genome organization and repair. Together, the literature indicates that interphase microtubules are critical regulators of nuclear structure and genome stability.
Collapse
Affiliation(s)
- Mitra Shokrollahi
- Department of Laboratory Medicine and Pathobiology, MaRS Centre, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Karim Mekhail
- Department of Laboratory Medicine and Pathobiology, MaRS Centre, Faculty of Medicine, University of Toronto, Toronto, ON, Canada; Canada Research Chairs Program, Faculty of Medicine, University of Toronto, Toronto, ON, Canada.
| |
Collapse
|
13
|
Liu S, Pellman D. The coordination of nuclear envelope assembly and chromosome segregation in metazoans. Nucleus 2020; 11:35-52. [PMID: 32208955 PMCID: PMC7289584 DOI: 10.1080/19491034.2020.1742064] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 03/08/2020] [Accepted: 03/10/2020] [Indexed: 01/25/2023] Open
Abstract
The nuclear envelope (NE) is composed of two lipid bilayer membranes that enclose the eukaryotic genome. In interphase, the NE is perforated by thousands of nuclear pore complexes (NPCs), which allow transport in and out of the nucleus. During mitosis in metazoans, the NE is broken down and then reassembled in a manner that enables proper chromosome segregation and the formation of a single nucleus in each daughter cell. Defects in coordinating NE reformation and chromosome segregation can cause aberrant nuclear architecture. This includes the formation of micronuclei, which can trigger a catastrophic mutational process commonly observed in cancers called chromothripsis. Here, we discuss the current understanding of the coordination of NE reformation with chromosome segregation during mitotic exit in metazoans. We review differing models in the field and highlight recent work suggesting that normal NE reformation and chromosome segregation are physically linked through the timing of mitotic spindle disassembly.
Collapse
Affiliation(s)
- Shiwei Liu
- Howard Hughes Medical Institute, Chevy Chase, MD, USA
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - David Pellman
- Howard Hughes Medical Institute, Chevy Chase, MD, USA
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
| |
Collapse
|
14
|
Kwon M, Leibowitz ML, Lee JH. Small but mighty: the causes and consequences of micronucleus rupture. Exp Mol Med 2020; 52:1777-1786. [PMID: 33230251 PMCID: PMC8080619 DOI: 10.1038/s12276-020-00529-z] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/20/2020] [Accepted: 10/21/2020] [Indexed: 12/20/2022] Open
Abstract
Micronuclei are small DNA-containing nuclear structures that are spatially isolated from the main nucleus. They are frequently found in pathologies, including cancer. It was recently shown that these nuclear structures are not only biomarkers of disease but also play an active role in tumor biology. Many consequences of micronucleus formation on tumor biology are dependent on the frequent and irreversible rupture of their nuclear envelopes, which results in the exposure of their DNA contents to the cytoplasm. In this review, we discuss models of defective nuclear envelope deposition on missegregated chromosomes that lead to nuclear envelope rupture. Furthermore, we expound upon the various downstream consequences of micronucleus nuclear envelope rupture on cells. These consequences include a massive DNA rearrangement phenomenon called chromothripsis and activation of the cGAS-STING innate immune signaling pathway, which can be a double-edged sword with tumorigenesis and tumor prevention functions. Although micronuclei are small structures, the impact they have on cells and their microenvironment is quite large. Micronuclei, which contain faulty chromosomes or chromosome fragments and occur outside the main cellular nucleus, are prone to rupturing, which leads to DNA changes that can drive tumor development. A team led by Mijung Kwon from Ewha Womans University in Seoul and Jae-Ho Lee of Ajou University School of Medicine in Suwon, both in South Korea, review how these micronuclei tend to burst, spilling their contents into the cell with devastating consequences. The chromosomes they contain break into tiny fragments and this broken DNA finds its way into the main nucleus, leading to chromosomal rearrangements that can permanently alter genomic function. The rupture of micronuclei also activates a part of the innate immune system that can promote cancer cell invasion and spread. Drugs targeting these processes could aid in the treatment of cancer.
Collapse
Affiliation(s)
- Mijung Kwon
- Department of Life Science and the Research Center for Cellular Homeostasis, Ewha Womans University, Seoul, 03760, Korea.
| | - Mitchell L Leibowitz
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Jae-Ho Lee
- Department of Biochemistry and Molecular Biology, Suwon, 16499, South Korea. .,Institute of Medical Science, Ajou University School of Medicine, Suwon, 16499, South Korea.
| |
Collapse
|
15
|
Corvaisier M, Alvarado-Kristensson M. Non-Canonical Functions of the Gamma-Tubulin Meshwork in the Regulation of the Nuclear Architecture. Cancers (Basel) 2020; 12:cancers12113102. [PMID: 33114224 PMCID: PMC7690915 DOI: 10.3390/cancers12113102] [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: 10/01/2020] [Revised: 10/17/2020] [Accepted: 10/21/2020] [Indexed: 12/15/2022] Open
Abstract
Simple Summary The appearance of a cell is connected to its function. For example, the fusiform of smooth muscle cells is adapted to facilitate muscle contraction, the lobed nucleus in white blood cells assists with the migratory behavior of these immune cells, and the condensed nucleus in sperm aids in their swimming efficiency. Thus, changes in appearance have been used for decades by doctors as a diagnostic method for human cancers. Here, we summarize our knowledge of how a cell maintains the shape of the nuclear compartment. Specifically, we discuss the role of a novel protein meshwork, the gamma-tubulin meshwork, in the regulation of nuclear morphology and as a therapeutic target against cancer. Abstract The nuclear architecture describes the organization of the various compartments in the nucleus of eukaryotic cells, where a plethora of processes such as nucleocytoplasmic transport, gene expression, and assembly of ribosomal subunits occur in a dynamic manner. During the different phases of the cell cycle, in post-mitotic cells and after oncogenic transformation, rearrangements of the nuclear architecture take place, and, among other things, these alterations result in reorganization of the chromatin and changes in gene expression. A member of the tubulin family, γtubulin, was first identified as part of a multiprotein complex that allows nucleation of microtubules. However, more than a decade ago, γtubulin was also characterized as a nuclear protein that modulates several crucial processes that affect the architecture of the nucleus. This review presents the latest knowledge regarding changes that arise in the nuclear architecture of healthy cells and under pathological conditions and, more specifically, considers the particular involvement of γtubulin in the modulation of the biology of the nuclear compartment.
Collapse
|
16
|
Iwao Y, Kimoto C, Fujimoto A, Suda A, Hara Y. Physiological polyspermy: Selection of a sperm nucleus for the development of diploid genomes in amphibians. Mol Reprod Dev 2020; 87:358-369. [DOI: 10.1002/mrd.23235] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 06/23/2019] [Indexed: 01/04/2023]
Affiliation(s)
- Yasuhiro Iwao
- Laboratory of Reproductive Developmental Biology, Division of Earth Sciences, Biology, and Chemistry, Graduate School of Sciences and Technology for InnovationYamaguchi University Yamaguchi Yamaguchi Japan
| | - Chihiro Kimoto
- Laboratory of Reproductive Developmental Biology, Division of Earth Sciences, Biology, and Chemistry, Graduate School of Sciences and Technology for InnovationYamaguchi University Yamaguchi Yamaguchi Japan
| | - Ayaka Fujimoto
- Laboratory of Reproductive Developmental Biology, Division of Earth Sciences, Biology, and Chemistry, Graduate School of Sciences and Technology for InnovationYamaguchi University Yamaguchi Yamaguchi Japan
| | - Asuka Suda
- Laboratory of Reproductive Developmental Biology, Division of Earth Sciences, Biology, and Chemistry, Graduate School of Sciences and Technology for InnovationYamaguchi University Yamaguchi Yamaguchi Japan
| | - Yuki Hara
- Laboratory of Evolutionary Cell Biology, Department of Biology and Chemistry, Faculty of ScienceYamaguchi University Yamaguchi Yamaguchi Japan
| |
Collapse
|
17
|
Wesley CC, Mishra S, Levy DL. Organelle size scaling over embryonic development. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2020; 9:e376. [PMID: 32003549 DOI: 10.1002/wdev.376] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 12/19/2019] [Accepted: 01/08/2020] [Indexed: 12/13/2022]
Abstract
Cell division without growth results in progressive cell size reductions during early embryonic development. How do the sizes of intracellular structures and organelles scale with cell size and what are the functional implications of such scaling relationships? Model organisms, in particular Caenorhabditis elegans worms, Drosophila melanogaster flies, Xenopus laevis frogs, and Mus musculus mice, have provided insights into developmental size scaling of the nucleus, mitotic spindle, and chromosomes. Nuclear size is regulated by nucleocytoplasmic transport, nuclear envelope proteins, and the cytoskeleton. Regulators of microtubule dynamics and chromatin compaction modulate spindle and mitotic chromosome size scaling, respectively. Developmental scaling relationships for membrane-bound organelles, like the endoplasmic reticulum, Golgi, mitochondria, and lysosomes, have been less studied, although new imaging approaches promise to rectify this deficiency. While models that invoke limiting components and dynamic regulation of assembly and disassembly can account for some size scaling relationships in early embryos, it will be exciting to investigate the contribution of newer concepts in cell biology such as phase separation and interorganellar contacts. With a growing understanding of the underlying mechanisms of organelle size scaling, future studies promise to uncover the significance of proper scaling for cell function and embryonic development, as well as how aberrant scaling contributes to disease. This article is categorized under: Establishment of Spatial and Temporal Patterns > Regulation of Size, Proportion, and Timing Early Embryonic Development > Fertilization to Gastrulation Comparative Development and Evolution > Model Systems.
Collapse
Affiliation(s)
- Chase C Wesley
- Department of Molecular Biology, University of Wyoming, Laramie, Wyoming
| | - Sampada Mishra
- Department of Molecular Biology, University of Wyoming, Laramie, Wyoming
| | - Daniel L Levy
- Department of Molecular Biology, University of Wyoming, Laramie, Wyoming
| |
Collapse
|
18
|
Hoffman LM, Smith MA, Jensen CC, Yoshigi M, Blankman E, Ullman KS, Beckerle MC. Mechanical stress triggers nuclear remodeling and the formation of transmembrane actin nuclear lines with associated nuclear pore complexes. Mol Biol Cell 2020; 31:1774-1787. [PMID: 31967947 PMCID: PMC7521858 DOI: 10.1091/mbc.e19-01-0027] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Mechanical stimulation of fibroblasts induces changes in the actin cytoskeleton including stress fiber (SF) reinforcement and realignment. Here we characterize the nuclear response to mechanical stimulation (uniaxial cyclic stretch). Using fluorescence microscopy and quantitative image analysis we find that stretch-induced nuclear elongation and alignment perpendicular to the stretch vector are dependent on formin-regulated actin polymerization. The mechanosensitive transcription factors Yes-associated protein/Transcriptional coactivator with PDZ domain (YAP/TAZ) and myocardin-related transcription factor (MRTF-A, also known as MKL1 and MAL1) accumulate in the nucleus and activate their target genes in response to uniaxial cyclic stretch. We show that transmembrane actin nuclear (TAN) lines are induced by stretch stimulation and nuclear envelope (NE) proteins including nesprins, SUN2, and lamins form Linkers of the Nucleoskeleton and Cytoskeleton (LINC) complexes aligned with actin SFs. These NE structures are altered by pharmacological treatments (Cytochalasin D and Jasplakinolide) or genetic disruption (zyxin gene deletion) that alter actin, and their persistence requires maintenance of stretch stimulation. Nuclear pore complexes (NPCs) accumulate at TAN lines providing a potential mechanism for linking mechanical cues to NPC function.
Collapse
Affiliation(s)
- Laura M Hoffman
- Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112.,Department of Biology, University of Utah, Salt Lake City, UT 84112
| | - Mark A Smith
- Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112.,Department of Biology, University of Utah, Salt Lake City, UT 84112
| | | | - Masaaki Yoshigi
- Department of Pediatrics, University of Utah, Salt Lake City, UT 84112
| | | | - Katharine S Ullman
- Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112.,Department of Oncological Sciences, University of Utah, Salt Lake City, UT 84112
| | - Mary C Beckerle
- Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112.,Department of Biology, University of Utah, Salt Lake City, UT 84112.,Department of Oncological Sciences, University of Utah, Salt Lake City, UT 84112
| |
Collapse
|
19
|
Wang M, Nagle RB, Knudsen BS, Cress AE, Rogers GC. Centrosome loss results in an unstable genome and malignant prostate tumors. Oncogene 2019; 39:399-413. [PMID: 31477840 DOI: 10.1038/s41388-019-0995-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 08/06/2019] [Accepted: 08/15/2019] [Indexed: 12/14/2022]
Abstract
Localized, nonindolent prostate cancer (PCa) is characterized by large-scale genomic rearrangements, aneuploidy, chromothripsis, and other forms of chromosomal instability (CIN), yet how this occurs remains unclear. A well-established mechanism of CIN is the overproduction of centrosomes, which promotes tumorigenesis in various mouse models. Therefore, we developed a single-cell assay for quantifying centrosomes in human prostate tissue. Surprisingly, centrosome loss-which has not been described in human cancer-was associated with PCa progression. By chemically or genetically inducing centrosome loss in nontumorigenic prostate epithelial cells, mitotic errors ensued, producing aneuploid, and multinucleated cells. Strikingly, transient or chronic centrosome loss transformed prostate epithelial cells, which produced highly proliferative and poorly differentiated malignant tumors in mice. Our findings suggest that centrosome loss could create a cellular crisis with oncogenic potential in prostate epithelial cells.
Collapse
Affiliation(s)
- Mengdie Wang
- Department of Cellular and Molecular Medicine, University of Arizona Cancer Center, University of Arizona, Tucson, AZ, 85724, USA
| | - Raymond B Nagle
- Department of Pathology, University of Arizona Cancer Center, University of Arizona, Tucson, AZ, 85724, USA
| | - Beatrice S Knudsen
- Department of Pathology and Laboratory Medicine, Cedars Sinai Medical Center, Los Angeles, CA, 90048, USA
| | - Anne E Cress
- Department of Cellular and Molecular Medicine, University of Arizona Cancer Center, University of Arizona, Tucson, AZ, 85724, USA.
| | - Gregory C Rogers
- Department of Cellular and Molecular Medicine, University of Arizona Cancer Center, University of Arizona, Tucson, AZ, 85724, USA.
| |
Collapse
|
20
|
Alvarado-Kristensson M, Rosselló CA. The Biology of the Nuclear Envelope and Its Implications in Cancer Biology. Int J Mol Sci 2019; 20:E2586. [PMID: 31137762 PMCID: PMC6566445 DOI: 10.3390/ijms20102586] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2019] [Revised: 05/07/2019] [Accepted: 05/25/2019] [Indexed: 12/18/2022] Open
Abstract
The formation of the nuclear envelope and the subsequent compartmentalization of the genome is a defining feature of eukaryotes. Traditionally, the nuclear envelope was purely viewed as a physical barrier to preserve genetic material in eukaryotic cells. However, in the last few decades, it has been revealed to be a critical cellular component in controlling gene expression and has been implicated in several human diseases. In cancer, the relevance of the cell nucleus was first reported in the mid-1800s when an altered nuclear morphology was observed in tumor cells. This review aims to give a current and comprehensive view of the role of the nuclear envelope on cancer first by recapitulating the changes of the nuclear envelope during cell division, second, by reviewing the role of the nuclear envelope in cell cycle regulation, signaling, and the regulation of the genome, and finally, by addressing the nuclear envelope link to cell migration and metastasis and its use in cancer prognosis.
Collapse
Affiliation(s)
- Maria Alvarado-Kristensson
- Molecular Pathology, Department of Translational Medicine, Lund University, Skåne University Hospital, 20502 Malmö, Sweden.
| | - Catalina Ana Rosselló
- Laboratory of Molecular Cell Biomedicine, University of the Balearic Islands, 07121 Palma de Mallorca, Spain.
- Lipopharma Therapeutics, Isaac Newton, 07121 Palma de Mallorca, Spain.
| |
Collapse
|
21
|
Ventimiglia LN, Cuesta-Geijo MA, Martinelli N, Caballe A, Macheboeuf P, Miguet N, Parnham IM, Olmos Y, Carlton JG, Weissenhorn W, Martin-Serrano J. CC2D1B Coordinates ESCRT-III Activity during the Mitotic Reformation of the Nuclear Envelope. Dev Cell 2018; 47:547-563.e6. [PMID: 30513301 PMCID: PMC6286407 DOI: 10.1016/j.devcel.2018.11.012] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 08/13/2018] [Accepted: 11/02/2018] [Indexed: 11/29/2022]
Abstract
The coordinated reformation of the nuclear envelope (NE) after mitosis re-establishes the structural integrity and the functionality of the nuclear compartment. The endosomal sorting complex required for transport (ESCRT) machinery, a membrane remodeling pathway that is highly conserved in eukaryotes, has been recently involved in NE resealing by mediating the annular fusion of the nuclear membrane (NM). We show here that CC2D1B, a regulator of ESCRT polymerization, is required to re-establish the nuclear compartmentalization by coordinating endoplasmic reticulum (ER) membrane deposition around chromatin disks with ESCRT-III recruitment to the reforming NE. Accordingly, CC2D1B determines the spatiotemporal distribution of the CHMP7-ESCRT-III axis during NE reformation. Crucially, in CC2D1B-depleted cells, ESCRT activity is uncoupled from Spastin-mediated severing of spindle microtubules, resulting in persisting microtubules that compromise nuclear morphology. Therefore, we reveal CC2D1B as an essential regulatory factor that licenses the formation of ESCRT-III polymers to ensure the orderly reformation of the NE.
Collapse
Affiliation(s)
- Leandro N Ventimiglia
- Department of Infectious Diseases, King's College London, Faculty of Life Sciences & Medicine, London SE1 9RT, UK
| | - Miguel Angel Cuesta-Geijo
- Department of Infectious Diseases, King's College London, Faculty of Life Sciences & Medicine, London SE1 9RT, UK
| | - Nicolas Martinelli
- CNRS, University Grenoble Alpes, CEA, Institut de Biologie Structurale (IBS), 38000 Grenoble, France
| | - Anna Caballe
- Department of Infectious Diseases, King's College London, Faculty of Life Sciences & Medicine, London SE1 9RT, UK
| | - Pauline Macheboeuf
- CNRS, University Grenoble Alpes, CEA, Institut de Biologie Structurale (IBS), 38000 Grenoble, France
| | - Nolwenn Miguet
- CNRS, University Grenoble Alpes, CEA, Institut de Biologie Structurale (IBS), 38000 Grenoble, France
| | - Ian M Parnham
- Department of Infectious Diseases, King's College London, Faculty of Life Sciences & Medicine, London SE1 9RT, UK
| | - Yolanda Olmos
- Division of Cancer Studies, King's College London, London SE1 1UL, UK
| | - Jeremy G Carlton
- Division of Cancer Studies, King's College London, London SE1 1UL, UK
| | - Winfried Weissenhorn
- CNRS, University Grenoble Alpes, CEA, Institut de Biologie Structurale (IBS), 38000 Grenoble, France
| | - Juan Martin-Serrano
- Department of Infectious Diseases, King's College London, Faculty of Life Sciences & Medicine, London SE1 9RT, UK.
| |
Collapse
|
22
|
Rosselló CA, Lindström L, Eklund G, Corvaisier M, Kristensson MA. γ-Tubulin⁻γ-Tubulin Interactions as the Basis for the Formation of a Meshwork. Int J Mol Sci 2018; 19:ijms19103245. [PMID: 30347727 PMCID: PMC6214090 DOI: 10.3390/ijms19103245] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 10/02/2018] [Accepted: 10/16/2018] [Indexed: 12/14/2022] Open
Abstract
In cytoplasm, protein γ-tubulin joins with various γ-tubulin complex proteins (GCPs) to form a heterotetramer γ-tubulin small complex (γ-TuSC) that can grow into a ring-shaped structure called the γ-tubulin ring complex (γ-TuRC). Both γ-TuSC and γ-TuRC are required for microtubule nucleation. Recent knowledge on γ-tubulin with regard to its cellular functions beyond participation in its creation of microtubules suggests that this protein forms a cellular meshwork. The present review summarizes the recognized functions of γ-tubulin and aims to unite the current views on this protein.
Collapse
Affiliation(s)
- Catalina Ana Rosselló
- Molecular Pathology, Department of Translational Medicine, Lund University, Skåne University Hospital, 20502 Malmö, Sweden.
| | - Lisa Lindström
- Molecular Pathology, Department of Translational Medicine, Lund University, Skåne University Hospital, 20502 Malmö, Sweden.
| | - Greta Eklund
- Molecular Pathology, Department of Translational Medicine, Lund University, Skåne University Hospital, 20502 Malmö, Sweden.
| | - Matthieu Corvaisier
- Molecular Pathology, Department of Translational Medicine, Lund University, Skåne University Hospital, 20502 Malmö, Sweden.
| | - Maria Alvarado Kristensson
- Molecular Pathology, Department of Translational Medicine, Lund University, Skåne University Hospital, 20502 Malmö, Sweden.
| |
Collapse
|
23
|
Liu S, Kwon M, Mannino M, Yang N, Renda F, Khodjakov A, Pellman D. Nuclear envelope assembly defects link mitotic errors to chromothripsis. Nature 2018; 561:551-555. [PMID: 30232450 PMCID: PMC6599625 DOI: 10.1038/s41586-018-0534-z] [Citation(s) in RCA: 196] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 08/04/2018] [Indexed: 01/09/2023]
Abstract
Defects in the architecture or integrity of the nuclear envelope (NE) are associated with a variety of human diseases1. Micronuclei, one common nuclear aberration, are an origin for chromothripsis2, a catastrophic mutational process commonly observed in cancer3–5. Chromothripsis occurs after micronuclei spontaneously lose NE integrity, which generates chromosome fragmentation6. NE disruption exposes DNA to the cytoplasm and initiates innate immune proinflammatory signaling7. Despite its importance, the basis for the NE fragility of micronuclei has not been determined. Here, we demonstrate that micronuclei undergo defective NE assembly: Only “core” NE proteins8,9 assemble efficiently on lagging chromosomes whereas “non-core” NE proteins8,9, including nuclear pore complexes (NPCs), do not. Consequently, micronuclei fail to properly import key proteins necessary for NE and genome integrity. We show that spindle microtubules block NPC/non-core NE assembly on lagging chromosomes, causing an irreversible NE assembly defect. Accordingly, experimental manipulations that position missegregated chromosomes away from the spindle correct defective NE assembly, prevent spontaneous NE disruption, and suppress DNA damage in micronuclei. Thus, during mitotic exit in metazoan cells, chromosome segregation and NE assembly are only loosely coordinated by the timing of mitotic spindle disassembly. The absence of precise checkpoint controls may explain why errors during mitotic exit are frequent and often trigger catastrophic genome rearrangements4,5.
Collapse
Affiliation(s)
- Shiwei Liu
- Howard Hughes Medical Institute, Chevy Chase, MD, USA.,Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Mijung Kwon
- Howard Hughes Medical Institute, Chevy Chase, MD, USA.,Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Mark Mannino
- Howard Hughes Medical Institute, Chevy Chase, MD, USA.,Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Nachen Yang
- Wadsworth Center, New York State Department of Health, Albany, NY, USA
| | - Fioranna Renda
- Wadsworth Center, New York State Department of Health, Albany, NY, USA
| | - Alexey Khodjakov
- Wadsworth Center, New York State Department of Health, Albany, NY, USA
| | - David Pellman
- Howard Hughes Medical Institute, Chevy Chase, MD, USA. .,Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA, USA. .,Department of Cell Biology, Harvard Medical School, Boston, MA, USA.
| |
Collapse
|
24
|
Alvarado-Kristensson M. γ-tubulin as a signal-transducing molecule and meshwork with therapeutic potential. Signal Transduct Target Ther 2018; 3:24. [PMID: 30221013 PMCID: PMC6137058 DOI: 10.1038/s41392-018-0021-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 04/23/2018] [Accepted: 05/06/2018] [Indexed: 01/05/2023] Open
Abstract
Knowledge of γ-tubulin is increasing with regard to the cellular functions of this protein beyond its participation in microtubule nucleation. γ-Tubulin expression is altered in various malignancies, and changes in the TUBG1 gene have been found in patients suffering from brain malformations. This review recapitulates the known functions of γ-tubulin in cellular homeostasis and discusses the possible influence of the protein on disease development and cancer.
Collapse
Affiliation(s)
- Maria Alvarado-Kristensson
- Molecular Pathology, Department of Translational Medicine, Lund University, Skåne University Hospital, Malmö, 20502 Sweden
| |
Collapse
|
25
|
Barvitenko N, Lawen A, Aslam M, Pantaleo A, Saldanha C, Skverchinskaya E, Regolini M, Tuszynski JA. Integration of intracellular signaling: Biological analogues of wires, processors and memories organized by a centrosome 3D reference system. Biosystems 2018; 173:191-206. [PMID: 30142359 DOI: 10.1016/j.biosystems.2018.08.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 08/03/2018] [Accepted: 08/20/2018] [Indexed: 02/07/2023]
Abstract
BACKGROUND Myriads of signaling pathways in a single cell function to achieve the highest spatio-temporal integration. Data are accumulating on the role of electromechanical soliton-like waves in signal transduction processes. Theoretical studies strongly suggest feasibility of both classical and quantum computing involving microtubules. AIM A theoretical study of the role of the complex composed of the plasma membrane and the microtubule-based cytoskeleton as a system that transmits, stores and processes information. METHODS Theoretical analysis presented here refers to (i) the Penrose-Hameroff theory of consciousness (Orchestrated Objective Reduction; Orch OR), (ii) the description of the centrosome as a reference system for construction of the 3D map of the cell proposed by Regolini, (iii) the Heimburg-Jackson model of the nerve pulse propagation along axons' lipid bilayer as soliton-like electro-mechanical waves. RESULTS AND CONCLUSION The ideas presented in this paper provide a qualitative model for the decision-making processes in a living cell undergoing a differentiation process. OUTLOOK This paper paves the way for the real-time live-cell observation of information processing by microtubule-based cytoskeleton and cell fate decision making.
Collapse
Affiliation(s)
| | - Alfons Lawen
- Monash University, School of Biomedical Sciences, Department of Biochemistry and Molecular Biology, VIC, 3800, Australia
| | - Muhammad Aslam
- Medical Clininc I, Cardiology/Angiology, University Hospital, Justus-Liebig-University, Giessen, Germany
| | - Antonella Pantaleo
- Department of Biomedical Sciences, University of Sassari, Sassari, Italy
| | - Carlota Saldanha
- Instituto de Medicina Molecular, Instituto de Bioquimica, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | | | - Marco Regolini
- Department of Bioengineering and Mathematical Modeling, AudioLogic, Milan, Italy
| | - Jack A Tuszynski
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada; Department of Physics, University of Alberta, Edmonton, Alberta, Canada; Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, IT-10128, Torino, Italy.
| |
Collapse
|
26
|
Jevtić P, Milunović-Jevtić A, Dilsaver MR, Gatlin JC, Levy DL. Use of Xenopus cell-free extracts to study size regulation of subcellular structures. THE INTERNATIONAL JOURNAL OF DEVELOPMENTAL BIOLOGY 2018; 60:277-288. [PMID: 27759156 DOI: 10.1387/ijdb.160158dl] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Striking size variations are prominent throughout biology, at the organismal, cellular, and subcellular levels. Important fundamental questions concern organelle size regulation and how organelle size is regulated relative to cell size, also known as scaling. Uncovering mechanisms of organelle size regulation will inform the functional significance of size as well as the implications of misregulated size, for instance in the case of nuclear enlargement in cancer. Xenopus egg and embryo extracts are powerful cell-free systems that have been utilized extensively for mechanistic and functional studies of various organelles and subcellular structures. The open biochemical nature of the extract permits facile manipulation of its composition, and in recent years extract approaches have illuminated mechanisms of organelle size regulation. This review largely focuses on in vitro Xenopus studies that have identified regulators of nuclear and spindle size. We also discuss potential relationships between size scaling of the nucleus and spindle, size regulation of other subcellular structures, and extract experiments that have clarified developmental timing mechanisms. We conclude by offering some future prospects, notably the integration of Xenopus extract with microfluidic technology.
Collapse
Affiliation(s)
- Predrag Jevtić
- Department of Molecular Biology, University of Wyoming, Laramie, WY, USA
| | | | | | | | | |
Collapse
|
27
|
Shintomi K, Inoue F, Watanabe H, Ohsumi K, Ohsugi M, Hirano T. Mitotic chromosome assembly despite nucleosome depletion in Xenopus egg extracts. Science 2017; 356:1284-1287. [PMID: 28522692 DOI: 10.1126/science.aam9702] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2017] [Accepted: 05/08/2017] [Indexed: 12/23/2022]
Abstract
The nucleosome is the fundamental structural unit of eukaryotic chromatin. During mitosis, duplicated nucleosome fibers are organized into a pair of rod-shaped structures (chromatids) within a mitotic chromosome. However, it remains unclear whether nucleosome assembly is indeed an essential prerequisite for mitotic chromosome assembly. We combined mouse sperm nuclei and Xenopus cell-free egg extracts depleted of the histone chaperone Asf1 and found that chromatid-like structures could be assembled even in the near absence of nucleosomes. The resultant "nucleosome-depleted" chromatids contained discrete central axes positive for condensins, although they were more fragile than normal nucleosome-containing chromatids. Combinatorial depletion experiments underscored the central importance of condensins in mitotic chromosome assembly, which sheds light on their functional cross-talk with nucleosomes in this process.
Collapse
Affiliation(s)
- Keishi Shintomi
- Chromosome Dynamics Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
| | - Fukashi Inoue
- Department of Life Science, Graduate School of Arts and Sciences, The University of Tokyo, Meguro-ku, Tokyo 153-8902, Japan.,TAK-Circulator Corporation, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hiroshi Watanabe
- Department of Life Science, Graduate School of Arts and Sciences, The University of Tokyo, Meguro-ku, Tokyo 153-8902, Japan
| | - Keita Ohsumi
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Aichi 464-8602, Japan
| | - Miho Ohsugi
- Department of Life Science, Graduate School of Arts and Sciences, The University of Tokyo, Meguro-ku, Tokyo 153-8902, Japan
| | - Tatsuya Hirano
- Chromosome Dynamics Laboratory, RIKEN, Wako, Saitama 351-0198, Japan.
| |
Collapse
|
28
|
Wheelock MS, Wynne DJ, Tseng BS, Funabiki H. Dual recognition of chromatin and microtubules by INCENP is important for mitotic progression. J Cell Biol 2017; 216:925-941. [PMID: 28314740 PMCID: PMC5379950 DOI: 10.1083/jcb.201609061] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 01/11/2017] [Accepted: 02/07/2017] [Indexed: 12/23/2022] Open
Abstract
The chromosomal passenger complex (CPC), composed of inner centromere protein (INCENP), Survivin, Borealin, and the kinase Aurora B, contributes to the activation of the mitotic checkpoint. The regulation of CPC function remains unclear. Here, we reveal that in addition to Survivin and Borealin, the single α-helix (SAH) domain of INCENP supports CPC localization to chromatin and the mitotic checkpoint. The INCENP SAH domain also mediates INCENP's microtubule binding, which is negatively regulated by Cyclin-dependent kinase-mediated phosphorylation of segments flanking the SAH domain. The microtubule-binding capacity of the SAH domain is important for mitotic arrest in conditions of suppressed microtubule dynamics, and the duration of mitotic arrest dictates the probability, but not the timing, of cell death. Although independent targeting of INCENP to microtubules or the kinetochore/centromere promotes the mitotic checkpoint, it is insufficient for a robust mitotic arrest. Altogether, our results demonstrate that dual recognition of chromatin and microtubules by CPC is important for checkpoint maintenance and determination of cell fate in mitosis.
Collapse
Affiliation(s)
- Michael S Wheelock
- Laboratory of Chromosome and Cell Biology, The Rockefeller University, New York, NY 10065
| | - David J Wynne
- Laboratory of Chromosome and Cell Biology, The Rockefeller University, New York, NY 10065.,Department of Biology, The College of New Jersey, Ewing, NJ 08628
| | - Boo Shan Tseng
- Laboratory of Chromosome and Cell Biology, The Rockefeller University, New York, NY 10065.,The School of Life Sciences, The University of Nevada Las Vegas, Las Vegas, NV 89154
| | - Hironori Funabiki
- Laboratory of Chromosome and Cell Biology, The Rockefeller University, New York, NY 10065
| |
Collapse
|
29
|
LaJoie D, Ullman KS. Coordinated events of nuclear assembly. Curr Opin Cell Biol 2017; 46:39-45. [PMID: 28189102 DOI: 10.1016/j.ceb.2016.12.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 12/22/2016] [Accepted: 12/30/2016] [Indexed: 12/01/2022]
Abstract
Each time a metazoan cell undergoes open mitosis, the nucleus is dismantled in order to partition DNA content to the daughter cells. After chromosomes separate, changes at the chromatin surface usher in reestablishment of nuclear architecture. Proteins destined for the nuclear envelope are attracted to chromatin and concomitantly recruit membrane. As nuclear envelope and protein constituents spread to coat chromatin, distinct regions emerge-some rich in rapid pore formation, others occupied by microtubules that remain attached to kinetochores. Microtubule connections present physical barriers that must be remodeled in order for the nuclear envelope to seal. Regions of the nascent nuclear envelope that are initially characterized by contrasting repertoires of nuclear envelope proteins rapidly coalesce as nuclei expand and enter interphase.
Collapse
Affiliation(s)
- Dollie LaJoie
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112, USA
| | - Katharine S Ullman
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112, USA.
| |
Collapse
|
30
|
Rosselló CA, Lindström L, Glindre J, Eklund G, Alvarado-Kristensson M. Gamma-tubulin coordinates nuclear envelope assembly around chromatin. Heliyon 2016; 2:e00166. [PMID: 27699285 PMCID: PMC5037270 DOI: 10.1016/j.heliyon.2016.e00166] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 07/10/2016] [Accepted: 09/16/2016] [Indexed: 10/29/2022] Open
Abstract
The cytosolic role of γ-tubulin as a microtubule organizer has been studied thoroughly, but its nuclear function is poorly understood. Here, we show that γ-tubulin is located throughout the chromatin of demembranated Xenopus laevis sperm and, as the nucleus is formed, γ-tubulin recruits lamin B3 and nuclear membranes. Immunodepletion of γ-tubulin impairs X. laevis assembly of both the lamina and the nuclear membrane. During nuclear formation in mammalian cell lines, γ-tubulin establishes a cellular protein boundary around chromatin that coordinates nuclear assembly of the daughter nuclei. Furthermore, expression of a γ-tubulin mutant that lacks the DNA-binding domain forms chromatin-empty nuclear like structures and demonstrate that a constant interplay between the chromatin-associated and the cytosolic pools of γ-tubulin is required and, when the balance between pools is impaired, aberrant nuclei are formed. We therefore propose that the nuclear protein meshwork formed by γ-tubulin around chromatin coordinates nuclear formation in eukaryotic cells.
Collapse
Affiliation(s)
- Catalina Ana Rosselló
- Division of Molecular Pathology, Department of Translational Medicine, Lund University, Skåne University Hospital, Malmö, 20502. Sweden
| | - Lisa Lindström
- Division of Molecular Pathology, Department of Translational Medicine, Lund University, Skåne University Hospital, Malmö, 20502. Sweden
| | - Johan Glindre
- Division of Molecular Pathology, Department of Translational Medicine, Lund University, Skåne University Hospital, Malmö, 20502. Sweden
| | - Greta Eklund
- Division of Molecular Pathology, Department of Translational Medicine, Lund University, Skåne University Hospital, Malmö, 20502. Sweden
| | - Maria Alvarado-Kristensson
- Division of Molecular Pathology, Department of Translational Medicine, Lund University, Skåne University Hospital, Malmö, 20502. Sweden
| |
Collapse
|
31
|
Regulation of nuclear shape and size in plants. Curr Opin Cell Biol 2016; 40:114-123. [PMID: 27030912 DOI: 10.1016/j.ceb.2016.03.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 03/03/2016] [Accepted: 03/09/2016] [Indexed: 11/22/2022]
Abstract
Nuclear shape and size changes have long been used by cytopathologists to diagnose, stage, and prognose cancer. However, the underlying causalities and molecular mechanisms are largely unknown. The current eukaryotic tree of life groups eukaryotes into five supergroups, with all organisms between humans and yeast falling into the supergroup Opisthokonta. The emergence of model organisms with strong molecular genetic methodology in the other supergroups has recently facilitated a broader evolutionary approach to pressing biological questions. Here, we review what is known about the control of nuclear shape and size in the Archaeplastidae, the supergroup containing the higher plants. We discuss common themes as well as differences toward a more generalized model of how eukaryotic organisms regulate nuclear morphology.
Collapse
|
32
|
Abstract
Size and shape are important aspects of nuclear structure. While normal cells maintain nuclear size within a defined range, altered nuclear size and shape are associated with a variety of diseases. It is unknown if altered nuclear morphology contributes to pathology, and answering this question requires a better understanding of the mechanisms that control nuclear size and shape. In this review, we discuss recent advances in our understanding of the mechanisms that regulate nuclear morphology, focusing on nucleocytoplasmic transport, nuclear lamins, the endoplasmic reticulum, the cell cycle, and potential links between nuclear size and size regulation of other organelles. We then discuss the functional significance of nuclear morphology in the context of early embryonic development. Looking toward the future, we review new experimental approaches that promise to provide new insights into mechanisms of nuclear size control, in particular microfluidic-based technologies, and discuss how altered nuclear morphology might impact chromatin organization and physiology of diseased cells.
Collapse
Affiliation(s)
- Richik N Mukherjee
- a Department of Molecular Biology , University of Wyoming , Laramie , WY USA
| | - Pan Chen
- a Department of Molecular Biology , University of Wyoming , Laramie , WY USA
| | - Daniel L Levy
- a Department of Molecular Biology , University of Wyoming , Laramie , WY USA
| |
Collapse
|
33
|
Yokoyama H. Chromatin-Binding Proteins Moonlight as Mitotic Microtubule Regulators. Trends Cell Biol 2016; 26:161-164. [PMID: 26786773 DOI: 10.1016/j.tcb.2015.12.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 12/20/2015] [Accepted: 12/21/2015] [Indexed: 10/22/2022]
Abstract
Some microtubule (MT)-associated proteins bind to MTs and chromatin simultaneously to fulfill their mitotic spindle function. By contrast, a growing number of chromatin-binding proteins leave mitotic chromatin and interact with MTs via their chromatin-binding domains. I discuss this switch from chromatin to MT binding as a key regulatory principle of spindle formation.
Collapse
Affiliation(s)
- Hideki Yokoyama
- Friedrich Miescher Laboratory of the Max Planck Society, Spemannstrasse 39, 72076 Tuebingen, Germany.
| |
Collapse
|
34
|
Vuković LD, Jevtić P, Edens LJ, Levy DL. New Insights into Mechanisms and Functions of Nuclear Size Regulation. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 322:1-59. [PMID: 26940517 DOI: 10.1016/bs.ircmb.2015.11.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Nuclear size is generally maintained within a defined range in a given cell type. Changes in cell size that occur during cell growth, development, and differentiation are accompanied by dynamic nuclear size adjustments in order to establish appropriate nuclear-to-cytoplasmic volume relationships. It has long been recognized that aberrations in nuclear size are associated with certain disease states, most notably cancer. Nuclear size and morphology must impact nuclear and cellular functions. Understanding these functional implications requires an understanding of the mechanisms that control nuclear size. In this review, we first provide a general overview of the diverse cellular structures and activities that contribute to nuclear size control, including structural components of the nucleus, effects of DNA amount and chromatin compaction, signaling, and transport pathways that impinge on the nucleus, extranuclear structures, and cell cycle state. We then detail some of the key mechanistic findings about nuclear size regulation that have been gleaned from a variety of model organisms. Lastly, we review studies that have implicated nuclear size in the regulation of cell and nuclear function and speculate on the potential functional significance of nuclear size in chromatin organization, gene expression, nuclear mechanics, and disease. With many fundamental cell biological questions remaining to be answered, the field of nuclear size regulation is still wide open.
Collapse
Affiliation(s)
- Lidija D Vuković
- Department of Molecular Biology, University of Wyoming, Laramie, WY, United States of America
| | - Predrag Jevtić
- Department of Molecular Biology, University of Wyoming, Laramie, WY, United States of America
| | - Lisa J Edens
- Department of Molecular Biology, University of Wyoming, Laramie, WY, United States of America
| | - Daniel L Levy
- Department of Molecular Biology, University of Wyoming, Laramie, WY, United States of America.
| |
Collapse
|
35
|
de Castro IJ, Gokhan E, Vagnarelli P. Resetting a functional G1 nucleus after mitosis. Chromosoma 2016; 125:607-19. [PMID: 26728621 PMCID: PMC5023730 DOI: 10.1007/s00412-015-0561-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 11/13/2015] [Indexed: 12/21/2022]
Abstract
The maintenance of the correct cellular information goes beyond the simple transmission of an intact genetic code from one generation to the next. Epigenetic changes, topological cues and correct protein-protein interactions need to be re-established after each cell division to allow the next cell cycle to resume in the correct regulated manner. This process begins with mitotic exit and re-sets all the changes that occurred during mitosis thus restoring a functional G1 nucleus in preparation for the next cell cycle. Mitotic exit is triggered by inactivation of mitotic kinases and the reversal of their phosphorylation activities on many cellular components, from nuclear lamina to transcription factors and chromatin itself. To reverse all these phosphorylations, phosphatases act during mitotic exit in a timely and spatially controlled manner directing the events that lead to a functional G1 nucleus. In this review, we will summarise the recent developments on the control of phosphatases and their known substrates during mitotic exit, and the key steps that control the restoration of chromatin status, nuclear envelope reassembly and nuclear body re-organisation. Although pivotal work has been conducted in this area in yeast, due to differences between the mitotic exit network between yeast and vertebrates, we will mainly concentrate on the vertebrate system.
Collapse
Affiliation(s)
- Ines J de Castro
- College of Health and Life Science, Research Institute of Environment Health and Society, Brunel University London, Uxbridge, UB8 3PH, UK
| | - Ezgi Gokhan
- College of Health and Life Science, Research Institute of Environment Health and Society, Brunel University London, Uxbridge, UB8 3PH, UK
| | - Paola Vagnarelli
- College of Health and Life Science, Research Institute of Environment Health and Society, Brunel University London, Uxbridge, UB8 3PH, UK.
| |
Collapse
|
36
|
Yokoyama H, Koch B, Walczak R, Ciray-Duygu F, González-Sánchez JC, Devos DP, Mattaj IW, Gruss OJ. The nucleoporin MEL-28 promotes RanGTP-dependent γ-tubulin recruitment and microtubule nucleation in mitotic spindle formation. Nat Commun 2015; 5:3270. [PMID: 24509916 DOI: 10.1038/ncomms4270] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Accepted: 01/16/2014] [Indexed: 01/11/2023] Open
Abstract
The GTP-bound form of the Ran GTPase (RanGTP), produced around chromosomes, drives nuclear envelope and nuclear pore complex (NPC) re-assembly after mitosis. The nucleoporin MEL-28/ELYS binds chromatin in a RanGTP-regulated manner and acts to seed NPC assembly. Here we show that, upon mitotic NPC disassembly, MEL-28 dissociates from chromatin and re-localizes to spindle microtubules and kinetochores. MEL-28 directly binds microtubules in a RanGTP-regulated way via its C-terminal chromatin-binding domain. Using Xenopus egg extracts, we demonstrate that MEL-28 is essential for RanGTP-dependent microtubule nucleation and spindle assembly, independent of its function in NPC assembly. Specifically, MEL-28 interacts with the γ-tubulin ring complex and recruits it to microtubule nucleation sites. Our data identify MEL-28 as a RanGTP target that functions throughout the cell cycle. Its cell cycle-dependent binding to chromatin or microtubules discriminates MEL-28 functions in interphase and mitosis, and ensures that spindle assembly occurs only after NPC breakdown.
Collapse
Affiliation(s)
- Hideki Yokoyama
- 1] Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany [2] European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Birgit Koch
- European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Rudolf Walczak
- European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Fulya Ciray-Duygu
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany
| | | | - Damien P Devos
- Centre for Organismal Studies (COS), Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Iain W Mattaj
- European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Oliver J Gruss
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany
| |
Collapse
|
37
|
Schellhaus AK, De Magistris P, Antonin W. Nuclear Reformation at the End of Mitosis. J Mol Biol 2015; 428:1962-85. [PMID: 26423234 DOI: 10.1016/j.jmb.2015.09.016] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 09/17/2015] [Accepted: 09/19/2015] [Indexed: 12/17/2022]
Abstract
Cells have developed highly sophisticated ways to accurately pass on their genetic information to the daughter cells. In animal cells, which undergo open mitosis, the nuclear envelope breaks down at the beginning of mitosis and the chromatin massively condenses to be captured and segregated by the mitotic spindle. These events have to be reverted in order to allow the reformation of a nucleus competent for DNA transcription and replication, as well as all other nuclear processes occurring in interphase. Here, we summarize our current knowledge of how, in animal cells, the highly compacted mitotic chromosomes are decondensed at the end of mitosis and how a nuclear envelope, including functional nuclear pore complexes, reassembles around these decondensing chromosomes.
Collapse
Affiliation(s)
| | - Paola De Magistris
- Friedrich Miescher Laboratory of the Max Planck Society, Spemannstrasse 39, 72076 Tübingen, Germany
| | - Wolfram Antonin
- Friedrich Miescher Laboratory of the Max Planck Society, Spemannstrasse 39, 72076 Tübingen, Germany.
| |
Collapse
|
38
|
Abstract
Chromosomes are not only carriers of the genetic material, but also actively regulate the assembly of complex intracellular architectures. During mitosis, chromosome-induced microtubule polymerisation ensures spindle assembly in cells without centrosomes and plays a supportive role in centrosome-containing cells. Chromosomal signals also mediate post-mitotic nuclear envelope (NE) re-formation. Recent studies using novel approaches to manipulate histones in oocytes, where functions can be analysed in the absence of transcription, have established that nucleosomes, but not DNA alone, mediate the chromosomal regulation of spindle assembly and NE formation. Both processes require the generation of RanGTP by RCC1 recruited to nucleosomes but nucleosomes also acquire cell cycle stage specific regulators, Aurora B in mitosis and ELYS, the initiator of nuclear pore complex assembly, at mitotic exit. Here, we review the mechanisms by which nucleosomes control assembly and functions of the spindle and the NE, and discuss their implications for genome maintenance.
Collapse
Affiliation(s)
- Christian Zierhut
- Laboratory of Chromosome and Cell Biology, Rockefeller University, New York, NY, USA
| | - Hironori Funabiki
- Laboratory of Chromosome and Cell Biology, Rockefeller University, New York, NY, USA
| |
Collapse
|
39
|
Hara Y, Merten CA. Dynein-Based Accumulation of Membranes Regulates Nuclear Expansion in Xenopus laevis Egg Extracts. Dev Cell 2015; 33:562-75. [PMID: 26004509 DOI: 10.1016/j.devcel.2015.04.016] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 03/02/2015] [Accepted: 04/22/2015] [Indexed: 10/23/2022]
Abstract
Nuclear size changes dynamically during development and has long been observed to correlate with the space surrounding the nucleus, as well as with the volume of the cell. Here we combine an in vitro cell-free system of Xenopus laevis egg extract with microfluidic devices to systematically analyze the effect of spatial constraints. The speed of nuclear expansion depended on the available space surrounding the nucleus up to a threshold volume in the nanoliter range, herein referred to as the nuclear domain. Under spatial constraints smaller than this nuclear domain, the size of microtubule-occupied space surrounding the nucleus turned out to be limiting for the accumulation of membranes around the nucleus via the motor protein dynein, therefore determining the speed of nuclear expansion. This mechanism explains how spatial information surrounding the nucleus, such as the positioning of the nucleus inside the cell, can control nuclear expansion.
Collapse
Affiliation(s)
- Yuki Hara
- Genome Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany.
| | - Christoph A Merten
- Genome Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany.
| |
Collapse
|
40
|
Tessaro I, Modina SC, Crotti G, Franciosi F, Colleoni S, Lodde V, Galli C, Lazzari G, Luciano AM. Transferability and inter-laboratory variability assessment of the in vitro bovine oocyte fertilization test. Reprod Toxicol 2015; 51:106-13. [PMID: 25625651 DOI: 10.1016/j.reprotox.2015.01.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 12/16/2014] [Accepted: 01/06/2015] [Indexed: 11/28/2022]
Abstract
The dramatic increase in the number of animals required for reproductive toxicity testing imposes the validation of alternative methods to reduce the use of laboratory animals. As we previously demonstrated for in vitro maturation test of bovine oocytes, the present study describes the transferability assessment and the inter-laboratory variability of an in vitro test able to identify chemical effects during the process of bovine oocyte fertilization. Eight chemicals with well-known toxic properties (benzo[a]pyrene, busulfan, cadmium chloride, cycloheximide, diethylstilbestrol, ketoconazole, methylacetoacetate, mifepristone/RU-486) were tested in two well-trained laboratories. The statistical analysis demonstrated no differences in the EC50 values for each chemical in within (inter-runs) and in between-laboratory variability of the proposed test. We therefore conclude that the bovine in vitro fertilization test could advance toward the validation process as alternative in vitro method and become part of an integrated testing strategy in order to predict chemical hazards on mammalian fertility.
Collapse
Affiliation(s)
- Irene Tessaro
- Reproductive and Developmental Biology Laboratory, Department of Health, Animal Science and Food Safety, University of Milan, 20133 Milan, Italy
| | - Silvia C Modina
- Reproductive and Developmental Biology Laboratory, Department of Health, Animal Science and Food Safety, University of Milan, 20133 Milan, Italy; Interdepartmental Research Centre for the Study of Biological Effects of Nano-Concentrations (CREBION), University of Milan, 20133 Milan, Italy
| | - Gabriella Crotti
- Avantea, Laboratory of Reproductive Technologies, 26100 Cremona, Italy
| | - Federica Franciosi
- Reproductive and Developmental Biology Laboratory, Department of Health, Animal Science and Food Safety, University of Milan, 20133 Milan, Italy
| | - Silvia Colleoni
- Avantea, Laboratory of Reproductive Technologies, 26100 Cremona, Italy
| | - Valentina Lodde
- Reproductive and Developmental Biology Laboratory, Department of Health, Animal Science and Food Safety, University of Milan, 20133 Milan, Italy
| | - Cesare Galli
- Avantea, Laboratory of Reproductive Technologies, 26100 Cremona, Italy; Dipartimento di Scienze Mediche Veterinarie, Università di Bologna, 40064 Bologna, Italy; Fondazione Avantea, Cremona, Italy
| | - Giovanna Lazzari
- Avantea, Laboratory of Reproductive Technologies, 26100 Cremona, Italy; Fondazione Avantea, Cremona, Italy
| | - Alberto M Luciano
- Reproductive and Developmental Biology Laboratory, Department of Health, Animal Science and Food Safety, University of Milan, 20133 Milan, Italy; Interdepartmental Research Centre for the Study of Biological Effects of Nano-Concentrations (CREBION), University of Milan, 20133 Milan, Italy.
| |
Collapse
|
41
|
Lian HY, Jiao GZ, Wang HL, Tan XW, Wang TY, Zheng LL, Kong QQ, Tan JH. Role of cytoskeleton in regulating fusion of nucleoli: a study using the activated mouse oocyte model. Biol Reprod 2014; 91:56. [PMID: 25061094 DOI: 10.1095/biolreprod.114.120188] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Although fusion of nucleoli was observed during pronuclear development of zygotes and the behavior of nucleoli in pronuclei has been suggested as an indicator of embryonic developmental potential, the mechanism for nucleolar fusion is unclear. Although both cytoskeleton and the nucleolus are important cellular entities, there are no special reports on the relationship between the two. Role of cytoskeleton in regulating fusion of nucleoli was studied using the activated mouse oocyte model. Mouse oocytes were cultured for 6 h in activating medium (Ca²⁺-free CZB medium containing 10 mM SrCl₂) supplemented with or without inhibitors for cytoskeleton or protein synthesis before pronuclear formation, nucleolar fusion, and the activity of maturation-promoting factor (MPF) were examined. Whereas treatment with microfilament inhibitor cytochalasin D or B or intermediate filament inhibitor acrylamide suppressed nucleolar fusion efficiently, treatment with microtubule inhibitor demecolcine or nocodazole or protein synthesis inhibitor cycloheximide had no effect. The cytochalasin D- or acrylamide-sensitive temporal window coincided well with the reported temporal window for nucleolar fusion in activated oocytes. Whereas a continuous incubation with demecolcine prevented pronuclear formation, pronuclei formed normally when demecolcine was excluded during the first hour of activation treatment when the MPF activity dropped dramatically. The results suggest that 1) microfilaments and intermediate filaments but not microtubules support nucleolar fusion, 2) proteins required for nucleolar fusion including microfilaments and intermediate filaments are not de novo synthesized, and 3) microtubule disruption prevents pronuclear formation by activating MPF.
Collapse
Affiliation(s)
- Hua-Yu Lian
- College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai-an City, P.R. China
| | - Guang-Zhong Jiao
- College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai-an City, P.R. China
| | - Hui-Li Wang
- College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai-an City, P.R. China
| | - Xiu-Wen Tan
- College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai-an City, P.R. China
| | - Tian-Yang Wang
- College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai-an City, P.R. China
| | - Liang-Liang Zheng
- College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai-an City, P.R. China
| | - Qiao-Qiao Kong
- College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai-an City, P.R. China
| | - Jing-He Tan
- College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai-an City, P.R. China
| |
Collapse
|
42
|
Zierhut C, Jenness C, Kimura H, Funabiki H. Nucleosomal regulation of chromatin composition and nuclear assembly revealed by histone depletion. Nat Struct Mol Biol 2014; 21:617-25. [PMID: 24952593 PMCID: PMC4082469 DOI: 10.1038/nsmb.2845] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Accepted: 05/23/2014] [Indexed: 12/13/2022]
Abstract
Nucleosomes are the fundamental unit of chromatin, but analysis of transcription-independent nucleosome functions has been complicated by the gene-expression changes resulting from histone manipulation. Here we solve this dilemma by developing Xenopus laevis egg extracts deficient for nucleosome formation and by analyzing the proteomic landscape and behavior of nucleosomal chromatin and nucleosome-free DNA. We show that although nucleosome-free DNA can recruit nuclear-envelope membranes, nucleosomes are required for spindle assembly and for formation of the lamina and of nuclear pore complexes (NPCs). We show that, in addition to the Ran G-nucleotide exchange factor RCC1, ELYS, the initiator of NPC formation, fails to associate with naked DNA but directly binds histone H2A-H2B dimers and nucleosomes. Tethering ELYS and RCC1 to DNA bypasses the requirement for nucleosomes in NPC formation in a synergistic manner. Thus, the minimal essential function of nucleosomes in NPC formation is to recruit RCC1 and ELYS.
Collapse
Affiliation(s)
- Christian Zierhut
- Laboratory of Chromosome and Cell Biology, Rockefeller University, New York, New York, USA
| | - Christopher Jenness
- Laboratory of Chromosome and Cell Biology, Rockefeller University, New York, New York, USA
| | - Hiroshi Kimura
- 1] Graduate School of Frontier Biosciences, Osaka University, Suita, Japan. [2] Japan Science and Technology Agency, Core Research for Evolutional Science and Technology, Suita, Japan
| | - Hironori Funabiki
- Laboratory of Chromosome and Cell Biology, Rockefeller University, New York, New York, USA
| |
Collapse
|
43
|
Schlaitz AL. Microtubules as key coordinators of nuclear envelope and endoplasmic reticulum dynamics during mitosis. Bioessays 2014; 36:665-71. [PMID: 24848719 DOI: 10.1002/bies.201400022] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
During mitosis, cells comprehensively restructure their interior to promote the faithful inheritance of DNA and cytoplasmic contents. In metazoans, this restructuring entails disassembly of the nuclear envelope, redistribution of its components into the endoplasmic reticulum (ER) and eventually nuclear envelope reassembly around the segregated chromosomes. The microtubule cytoskeleton has recently emerged as a critical regulator of mitotic nuclear envelope and ER dynamics. Microtubules and associated molecular motors tear open the nuclear envelope in prophase and remove nuclear envelope remnants from chromatin. Additionally, two distinct mechanisms of microtubule-based regulation of ER dynamics operate later in mitosis. First, association of the ER with microtubules is reduced, preventing invasion of ER into the spindle area, and second, organelle membrane is actively cleared from metaphase chromosomes. However, we are only beginning to understand the role of microtubules in shaping and distributing ER and other organelles during mitosis.
Collapse
Affiliation(s)
- Anne-Lore Schlaitz
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), Heidelberg, Germany
| |
Collapse
|
44
|
Abstract
Maintenance of nuclear architecture is crucial for gene regulation, cell proliferation and tissue development. However, during every open mitosis and meiosis, chromosomes are exposed to cytoskeletal forces until they are fully reassembled into mature nuclei. Here we discuss our recent study of nuclear assembly in Xenopus egg extracts, where we showed that the DNA binding protein Developmental pluripotency associated 2 (Dppa2) directly inhibits microtubule polymerization during nuclear formation, and that this is essential for normal nuclear shape and replication. We explore mechanisms by which microtubule dynamics could regulate nuclear formation and morphology, and discuss the importance of both spatial and temporal regulation of microtubules in this process. Moreover, expression of Dppa2 is limited to the early embryo and pluripotent tissues, and we highlight the specific demands of mitosis in these often rapidly dividing cells, in which telophase nuclear assembly must be expedited and may facilitate developmental changes in nuclear architecture.
Collapse
Affiliation(s)
- John Z Xue
- Laboratory of Chromosome and Cell Biology; The Rockefeller University; New York, NY USA
| | - Hironori Funabiki
- Laboratory of Chromosome and Cell Biology; The Rockefeller University; New York, NY USA
| |
Collapse
|
45
|
Batzenschlager M, Herzog E, Houlné G, Schmit AC, Chabouté ME. GIP/MZT1 proteins orchestrate nuclear shaping. FRONTIERS IN PLANT SCIENCE 2014; 5:29. [PMID: 24570680 PMCID: PMC3916773 DOI: 10.3389/fpls.2014.00029] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Accepted: 01/22/2014] [Indexed: 05/28/2023]
Abstract
The functional organization of the nuclear envelope (NE) is only just emerging in plants with the recent characterization of NE protein complexes and their molecular links to the actin cytoskeleton. The NE also plays a role in microtubule nucleation by recruiting γ-Tubulin Complexes (γ-TuCs) which contribute to the establishment of a robust mitotic spindle. γ-tubulin Complex Protein 3 (GCP3)-interacting proteins (GIPs) have been identified recently as integral components of γ-TuCs. GIPs have been conserved throughout evolution and are also named MZT1 (mitotic-spindle organizing protein 1). This review focuses on recent data investigating the role of GIP/MZT1 at the NE, including insights from the study of GIP partners. It also uncovers new functions for GIP/MZT1 during interphase and highlights a current view of NE-associated components which are critical for nuclear shaping during both cell division and differentiation.
Collapse
Affiliation(s)
| | | | | | - Anne-Catherine Schmit
- *Correspondence: Anne-Catherine Schmit, Institut de Biologie Moléculaire des Plantes, Centre National de la Recherche Scientifique, UPR 2357, 12 rue du Gl Zimmer, 67084 Strasbourg, France e-mail:
| | | |
Collapse
|
46
|
Sizing and shaping the nucleus: mechanisms and significance. Curr Opin Cell Biol 2014; 28:16-27. [PMID: 24503411 DOI: 10.1016/j.ceb.2014.01.003] [Citation(s) in RCA: 116] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Revised: 01/07/2014] [Accepted: 01/11/2014] [Indexed: 01/14/2023]
Abstract
The size and shape of the nucleus are tightly regulated, indicating the physiological significance of proper nuclear morphology, yet the mechanisms and functions of nuclear size and shape regulation remain poorly understood. Correlations between altered nuclear morphology and certain disease states have long been observed, most notably many cancers are diagnosed and staged based on graded increases in nuclear size. Here we review recent studies investigating the mechanisms regulating nuclear size and shape, how mitotic events influence nuclear morphology, and the role of nuclear size and shape in subnuclear chromatin organization and cancer progression.
Collapse
|
47
|
Abstract
How nuclear morphology is regulated during development and disease remains poorly understood. In this issue of Developmental Cell, using a pronuclear assembly assay, Xue et al. (2013) demonstrate that Dppa2, a chromatin-bound microtubule regulator, controls both the morphology and function of the pronucleus by fine-tuning microtubule dynamics.
Collapse
Affiliation(s)
- Yuxuan Guo
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA; Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA
| | | |
Collapse
|
48
|
Schuldt A. Nuclear organization: Microtubule shaping of the nucleus. Nat Rev Mol Cell Biol 2013; 14:752. [PMID: 24169857 DOI: 10.1038/nrm3698] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|