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Heijo H, Shimogama S, Nakano S, Miyata A, Iwao Y, Hara Y. DNA content contributes to nuclear size control in Xenopus laevis. Mol Biol Cell 2020; 31:2703-2717. [PMID: 32997613 PMCID: PMC7927187 DOI: 10.1091/mbc.e20-02-0113] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 08/28/2020] [Accepted: 09/25/2020] [Indexed: 12/17/2022] Open
Abstract
Cells adapt to drastic changes in genome quantity during evolution and cell division by adjusting the nuclear size to exert genomic functions. However, the mechanism by which DNA content within the nucleus contributes to controlling the nuclear size remains unclear. Here, we experimentally evaluated the effects of DNA content by utilizing cell-free Xenopus egg extracts and imaging of in vivo embryos. Upon manipulation of DNA content while maintaining cytoplasmic effects constant, both plateau size and expansion speed of the nucleus correlated highly with DNA content. We also found that nuclear expansion dynamics was altered when chromatin interaction with the nuclear envelope or chromatin condensation was manipulated while maintaining DNA content constant. Furthermore, excess membrane accumulated on the nuclear surface when the DNA content was low. These results clearly demonstrate that nuclear expansion is determined not only by cytoplasmic membrane supply but also by the physical properties of chromatin, including DNA quantity and chromatin structure within the nucleus, rather than the coding sequences themselves. In controlling the dynamics of nuclear expansion, we propose that chromatin interaction with the nuclear envelope plays a role in transmitting chromatin repulsion forces to the nuclear membrane.
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Affiliation(s)
- Hiroko Heijo
- Evolutionary Cell Biology Laboratory, Faculty of Science, Yamaguchi University, Yoshida 1677-1, Yamaguchi City, 753-8512, Japan
| | - Sora Shimogama
- Evolutionary Cell Biology Laboratory, Faculty of Science, Yamaguchi University, Yoshida 1677-1, Yamaguchi City, 753-8512, Japan
| | - Shuichi Nakano
- Evolutionary Cell Biology Laboratory, Faculty of Science, Yamaguchi University, Yoshida 1677-1, Yamaguchi City, 753-8512, Japan
| | - Anna Miyata
- Evolutionary Cell Biology Laboratory, Faculty of Science, Yamaguchi University, Yoshida 1677-1, Yamaguchi City, 753-8512, Japan
| | - Yasuhiro Iwao
- Laboratory of Molecular Developmental Biology, Department of Biology, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yoshida 1677-1, Yamaguchi City, 753-8512, Japan
| | - Yuki Hara
- Evolutionary Cell Biology Laboratory, Faculty of Science, Yamaguchi University, Yoshida 1677-1, Yamaguchi City, 753-8512, Japan
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Mikulski P, Hohenstatt ML, Farrona S, Smaczniak C, Stahl Y, Kaufmann K, Angenent G, Schubert D. The Chromatin-Associated Protein PWO1 Interacts with Plant Nuclear Lamin-like Components to Regulate Nuclear Size. Plant Cell 2019; 31:1141-1154. [PMID: 30914470 PMCID: PMC6533023 DOI: 10.1105/tpc.18.00663] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 02/27/2019] [Accepted: 03/22/2019] [Indexed: 05/23/2023]
Abstract
Spatial organization of chromatin contributes to gene regulation of many cellular processes and includes a connection of chromatin with the nuclear lamina (NL). The NL is a protein mesh that resides underneath the inner nuclear membrane and consists of lamins and lamina-associated proteins. Chromatin regions associated with lamins in animals are characterized mostly by constitutive heterochromatin, but association with facultative heterochromatin mediated by Polycomb-group (PcG) proteins has been reported as well. In contrast with animals, plant NL components are largely not conserved and NL association with chromatin is poorly explored. Here, we present the connection between the lamin-like protein, CROWDED NUCLEI1 (CRWN1), and the chromatin- and PcG-associated component, PROLINE-TRYPTOPHANE-TRYPTOPHANE-PROLINE INTERACTOR OF POLYCOMBS1, in Arabidopsis (Arabidopsis thaliana). We show that PWO1 and CRWN1 proteins associate physically with each other, act in the same pathway to maintain nuclear morphology, and control expression of a similar set of target genes. Moreover, we demonstrate that transiently expressed PWO1 proteins form foci located partially at the subnuclear periphery. Ultimately, as CRWN1 and PWO1 are plant-specific, our results argue that plants might have developed an equivalent, rather than homologous, mechanism of linking chromatin repression and NL.
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Affiliation(s)
- Pawel Mikulski
- Institute for Biology, Freie Universität Berlin, Berlin 14195, Germany
- Institute for Biology, Heinrich-Heine-University Düsseldorf, Düsseldorf 40225, Germany
| | - Mareike L Hohenstatt
- Institute for Biology, Heinrich-Heine-University Düsseldorf, Düsseldorf 40225, Germany
| | - Sara Farrona
- Institute for Biology, Heinrich-Heine-University Düsseldorf, Düsseldorf 40225, Germany
| | - Cezary Smaczniak
- Institute for Biology, Humboldt-University Berlin, Berlin 10115, Germany
- Laboratory of Molecular Biology, Wageningen University, Wageningen 6700 AP, The Netherlands
| | - Yvonne Stahl
- Institute for Biology, Heinrich-Heine-University Düsseldorf, Düsseldorf 40225, Germany
| | - Kerstin Kaufmann
- Institute for Biology, Humboldt-University Berlin, Berlin 10115, Germany
- Laboratory of Molecular Biology, Wageningen University, Wageningen 6700 AP, The Netherlands
| | - Gerco Angenent
- Laboratory of Molecular Biology, Wageningen University, Wageningen 6700 AP, The Netherlands
| | - Daniel Schubert
- Institute for Biology, Freie Universität Berlin, Berlin 14195, Germany
- Institute for Biology, Heinrich-Heine-University Düsseldorf, Düsseldorf 40225, Germany
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Snoek BL, Pavlova P, Tessadori F, Peeters AJM, Bourbousse C, Barneche F, de Jong H, Fransz PF, van Zanten M. Genetic Dissection of Morphometric Traits Reveals That Phytochrome B Affects Nucleus Size and Heterochromatin Organization in Arabidopsis thaliana. G3 (Bethesda) 2017; 7:2519-2531. [PMID: 28592555 PMCID: PMC5555459 DOI: 10.1534/g3.117.043539] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 05/31/2017] [Indexed: 02/05/2023]
Abstract
Microscopically visible chromatin is partitioned into two major components in Arabidopsis thaliana nuclei. On one hand, chromocenters are conspicuous foci of highly condensed "heterochromatic" domains that contain mostly repeated sequences. On the other hand, less condensed and gene-rich "euchromatin" emanates from these chromocenters. This differentiation, together with the dynamic nature of chromatin compaction in response to developmental and environmental stimuli, makes Arabidopsis a powerful system for studying chromatin organization and dynamics. Heterochromatin dynamics can be monitored by measuring the Heterochromatin Index, i.e., the proportion of nuclei displaying well-defined chromocenters, or the DNA fraction of chromocenters (relative heterochromatin fraction). Both measures are composite traits, thus their values represent the sum of effects of various underlying morphometric properties. We exploited genetic variation between natural occurring accessions to determine the genetic basis of individual nucleus and chromocenter morphometric parameters (area, perimeter, density, roundness, and heterogeneity) that together determine chromatin compaction. Our novel reductionist genetic approach revealed quantitative trait loci (QTL) for all measured traits. Genomic colocalization among QTL was limited, which suggests a complex genetic regulation of chromatin compaction. Yet genomic intervals of QTL for nucleus size (area and perimeter) both overlap with a known QTL for heterochromatin compaction that is explained by natural polymorphism in the red/far-red light and temperature receptor Phytochrome B. Mutant analyses and genetic complementation assays show that Phytochrome B is a negative regulator of nucleus size, revealing that perception of climatic conditions by a Phytochrome-mediated hub is a major determinant for coordinating nucleus size and heterochromatin compaction.
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Affiliation(s)
- Basten L Snoek
- Laboratory of Nematology, Wageningen University, 6708 PB, The Netherlands
- Theoretical Biology and Bioinformatics, Institute of Biodynamics and Biocomplexity
| | - Penka Pavlova
- Laboratory of Genetics, Wageningen University, 6708 PB, The Netherlands
- Plant Development and (Epi)Genetics, Swammerdam Institute for Life Sciences, University of Amsterdam, 1098 SM, The Netherlands
| | - Federico Tessadori
- Plant Development and (Epi)Genetics, Swammerdam Institute for Life Sciences, University of Amsterdam, 1098 SM, The Netherlands
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences, University Medical Center Utrecht, 3584 CT, The Netherlands
| | - Anton J M Peeters
- Department of Biology, Institute of Education, Utrecht University, 3584 CH, The Netherlands
| | - Clara Bourbousse
- Institut de Biologie de l'Ecole Normale Supérieure, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8197, Institut National de la Santé et de la Recherche Médicale U1024, Ecole Normale Supérieure, Paris Sciences et Lettres Research University, F-75005, France
| | - Fredy Barneche
- Institut de Biologie de l'Ecole Normale Supérieure, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8197, Institut National de la Santé et de la Recherche Médicale U1024, Ecole Normale Supérieure, Paris Sciences et Lettres Research University, F-75005, France
| | - Hans de Jong
- Laboratory of Genetics, Wageningen University, 6708 PB, The Netherlands
| | - Paul F Fransz
- Plant Development and (Epi)Genetics, Swammerdam Institute for Life Sciences, University of Amsterdam, 1098 SM, The Netherlands
| | - Martijn van Zanten
- Molecular Plant Physiology, Institute of Environmental Biology, Utrecht University, 3584 CH, The Netherlands
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Sikkema WKA, Strikwerda A, Sharma M, Assi K, Salh B, Cox ME, Mills J. Regulation of mitotic cytoskeleton dynamics and cytokinesis by integrin-linked kinase in retinoblastoma cells. PLoS One 2014; 9:e98838. [PMID: 24911651 PMCID: PMC4049663 DOI: 10.1371/journal.pone.0098838] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2013] [Accepted: 05/07/2014] [Indexed: 12/31/2022] Open
Abstract
During cell division integrin-linked kinase (ILK) has been shown to regulate microtubule dynamics and centrosome clustering, processes involved in cell cycle progression, and malignant transformation. In this study, we examine the effects of downregulating ILK on mitotic function in human retinoblastoma cell lines. These retinal cancer cells, caused by the loss of function of two gene alleles (Rb1) that encode the retinoblastoma tumour suppressor, have elevated expression of ILK. Here we show that inhibition of ILK activity results in a concentration-dependent increase in nuclear area and multinucleated cells. Moreover, inhibition of ILK activity and expression increased the accumulation of multinucleated cells over time. In these cells, aberrant cytokinesis and karyokinesis correlate with altered mitotic spindle organization, decreased levels of cortical F-actin and centrosome de-clustering. Centrosome de-clustering, induced by ILK siRNA, was rescued in FLAG-ILK expressing Y79 cells as compared to those expressing FLAG-tag alone. Inhibition of ILK increased the proportion of cells exhibiting mitotic spindles and caused a significant G2/M arrest as early as 24 hours after exposure to QLT-0267. Live cell analysis indicate ILK downregulation causes an increase in multipolar anaphases and failed cytokinesis (bipolar and multipolar) of viable cells. These studies extend those indicating a critical function for ILK in mitotic cytoskeletal organization and describe a novel role for ILK in cytokinesis of Rb deficient cells.
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Affiliation(s)
- William K. A. Sikkema
- Department of Biology, Trinity Western University, Langley, British Columbia, Canada
| | - Arend Strikwerda
- Department of Biology, Trinity Western University, Langley, British Columbia, Canada
| | - Manju Sharma
- Vancouver Prostate Centre, Vancouver Coastal Health Research Institute, Vancouver, British Columbia, Canada
| | - Kiran Assi
- Division of Gastroenterology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Baljinder Salh
- Division of Gastroenterology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Michael E. Cox
- Vancouver Prostate Centre, Vancouver Coastal Health Research Institute, Vancouver, British Columbia, Canada
| | - Julia Mills
- Department of Biology, Trinity Western University, Langley, British Columbia, Canada
- Adjunct, Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada
- External Associate Member, Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
- * E-mail:
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