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Na J, Tai C, Wang Z, Yang Z, Chen X, Zhang J, Zheng L, Fan Y. Stiff extracellular matrix drives the differentiation of mesenchymal stem cells toward osteogenesis by the multiscale 3D genome reorganization. Biomaterials 2025; 312:122715. [PMID: 39094522 DOI: 10.1016/j.biomaterials.2024.122715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 07/17/2024] [Accepted: 07/26/2024] [Indexed: 08/04/2024]
Abstract
Extracellular matrix (ECM) stiffness is a major driver of stem cell fate. However, the involvement of the three-dimensional (3D) genomic reorganization in response to ECM stiffness remains unclear. Here, we generated comprehensive 3D chromatin landscapes of mesenchymal stem cells (MSCs) exposed to various ECM stiffness. We found that there were more long-range chromatin interactions, but less compartment A in MSCs cultured on stiff ECM than those cultured on soft ECM. However, the switch from compartment B in MSCs cultured on soft ECM to compartment A in MSCs cultured on stiff ECM included genes encoding proteins primarily enriched in cytoskeleton organization. At the topologically associating domains (TADs) level, stiff ECM tends to have merged TADs on soft ECM. These merged TADs on stiff ECM include upregulated genes encoding proteins enriched in osteogenesis, such as SP1, ETS1, and DCHS1, which were validated by quantitative real-time polymerase chain reaction and found to be consistent with the increase of alkaline phosphatase staining. Knockdown of SP1 or ETS1 led to the downregulation of osteogenic marker genes, including COL1A1, RUNX2, ALP, and OCN in MSCs cultured on stiff ECM. Our study provides an important insight into the stiff ECM-mediated promotion of MSC differentiation towards osteogenesis, emphasizing the influence of mechanical cues on the reorganization of 3D genome architecture and stem cell fate.
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Affiliation(s)
- Jing Na
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China
| | - Chengzheng Tai
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China
| | - Ziyi Wang
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China
| | - Zhijie Yang
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China
| | - Xinyuan Chen
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China
| | - Jing Zhang
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China; Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Engineering Medicine, Beihang University, Beijing, 100083, China.
| | - Lisha Zheng
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China.
| | - Yubo Fan
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China.
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Green NM, Talbot D, Tootle TL. Nuclear actin is a critical regulator of Drosophila female germline stem cell maintenance. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.27.609996. [PMID: 39253513 PMCID: PMC11383290 DOI: 10.1101/2024.08.27.609996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 09/11/2024]
Abstract
Nuclear actin has been implicated in regulating cell fate, differentiation, and cellular reprogramming. However, its roles in development and tissue homeostasis remain largely unknown. Here we uncover the role of nuclear actin in regulating stemness using Drosophila ovarian germline stem cells (GSCs) as a model. We find that the localization and structure of nuclear actin is dynamic in the early germ cells. Nuclear actin recognized by anti-actin C4 is found in both the nucleoplasm and nucleolus of GSCs. The polymeric nucleoplasmic C4 pool is lost after the 2-cell stage, whereas the monomeric nucleolar pool persists to the 8-cell stage, suggesting that polymeric nuclear actin may contribute to stemness. To test this idea, we overexpressed nuclear targeted actin constructs to alter nuclear actin polymerization states in the GSCs and early germ cells. Increasing monomeric nuclear actin, but not polymerizable nuclear actin, causes GSC loss that ultimately results in germline loss. This GSC loss is rescued by simultaneous overexpression of monomeric and polymerizable nuclear actin. Together these data reveal that GSC maintenance requires polymeric nuclear actin. This polymeric nuclear actin likely plays numerous roles in the GSCs, as increasing monomeric nuclear actin disrupts nuclear architecture causing nucleolar hypertrophy, distortion of the nuclear lamina, and heterochromatin reorganization; all factors critical for GSC maintenance and function. These data provide the first evidence that nuclear actin, and in particular, its ability to polymerize, are critical for stem cell function and tissue homeostasis in vivo.
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Affiliation(s)
- Nicole M Green
- Anatomy and Cell Biology, University of Iowa Carver College of Medicine, 51 Newton Rd, 1-500 BSB, Iowa City, IA 52242
- Current affiliation: Biology, Cornell College, 600 First Street SW, Mount Vernon, IA 52314
| | - Danielle Talbot
- Anatomy and Cell Biology, University of Iowa Carver College of Medicine, 51 Newton Rd, 1-500 BSB, Iowa City, IA 52242
- Current affiliation: Biology, University of Iowa, 129 E. Jefferson St, 246 BB, Iowa City, IA 52242
| | - Tina L Tootle
- Anatomy and Cell Biology, University of Iowa Carver College of Medicine, 51 Newton Rd, 1-500 BSB, Iowa City, IA 52242
- Current affiliation: Biology, University of Iowa, 129 E. Jefferson St, 246 BB, Iowa City, IA 52242
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Sundby LJ, Southern WM, Sun J, Patrinostro X, Zhang W, Yong J, Ervasti JM. Deletion of exons 2 and 3 from Actb and cell immortalization lead to widespread, β-actin independent alterations in gene expression associated with cell cycle control. Eur J Cell Biol 2024; 103:151397. [PMID: 38387258 DOI: 10.1016/j.ejcb.2024.151397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Revised: 02/11/2024] [Accepted: 02/12/2024] [Indexed: 02/24/2024] Open
Abstract
The cytoplasmic actin proteins, β- and γ-actin, are 99% identical but thought to perform non-redundant functions. The nucleotide coding regions of cytoplasmic actin genes, Actb and Actg1, are 89% identical. Knockout (KO) of Actb by Cre-mediated deletion of first coding exons 2 and 3 in mice is embryonic lethal and fibroblasts derived from KO embryos (MEFs) fail to proliferate. In contrast, Actg1 KO MEFs display with a much milder defect in cell proliferation and Actg1 KO mice are viable, but present with increased perinatal lethality. Recent studies have identified important protein-independent functions for both Actb and Actg1 and demonstrate that deletions within the Actb nucleotide sequence, and not loss of the β-actin protein, cause the most severe phenotypes in KO mice and cells. Here, we use a multi-omics approach to better understand what drives the phenotypes of Actb KO MEFs. RNA-sequencing and mass spectrometry reveal largescale changes to the transcriptome, proteome, and phosphoproteome in cells lacking Actb but not those only lacking β-actin protein. Pathway analysis of genes and proteins differentially expressed upon Actb KO suggest widespread dysregulation of genes involved in the cell cycle that may explain the severe defect in proliferation.
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Affiliation(s)
- Lauren J Sundby
- Program in Molecular, Cellular, Developmental Biology, and Genetics, University of Minnesota, Minneapolis, MN 55455, USA
| | - William M Southern
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Jiao Sun
- Department of Computer Science, University of Central Florida, Orlando, FL 32816, USA
| | - Xiaobai Patrinostro
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Wei Zhang
- Department of Computer Science, University of Central Florida, Orlando, FL 32816, USA
| | - Jeongsik Yong
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - James M Ervasti
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA.
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4
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Ulferts S, Lopes M, Miyamoto K, Grosse R. Nuclear actin dynamics and functions at a glance. J Cell Sci 2024; 137:jcs261630. [PMID: 38563209 DOI: 10.1242/jcs.261630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2024] Open
Abstract
Actin is well known for its cytoskeletal functions, where it helps to control and maintain cell shape and architecture, as well as regulating cell migration and intracellular cargo transport, among others. However, actin is also prevalent in the nucleus, where genome-regulating roles have been described, including it being part of chromatin-remodeling complexes. More recently, with the help of advances in microscopy techniques and specialized imaging probes, direct visualization of nuclear actin filament dynamics has helped elucidate new roles for nuclear actin, such as in cell cycle regulation, DNA replication and repair, chromatin organization and transcriptional condensate formation. In this Cell Science at a Glance article, we summarize the known signaling events driving the dynamic assembly of actin into filaments of various structures within the nuclear compartment for essential genome functions. Additionally, we highlight the physiological role of nuclear F-actin in meiosis and early embryonic development.
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Affiliation(s)
- Svenja Ulferts
- Institute for Clinical and Experimental Pharmacology and Toxicology I, Medical Faculty, University of Freiburg, 79104 Freiburg, Germany
| | - Massimo Lopes
- Institute of Molecular Cancer Research, University of Zurich, 8057 Zurich, Switzerland
| | - Kei Miyamoto
- Faculty of Biology-Oriented Science and Technology, Kindai University, Wakayama 649-6493, Japan
| | - Robert Grosse
- Institute for Clinical and Experimental Pharmacology and Toxicology I, Medical Faculty, University of Freiburg, 79104 Freiburg, Germany
- Centre for Integrative Biological Signalling Studies (CIBSS), 79104 Freiburg, Germany
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5
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Ferrer P, Upadhyay S, Cai JJ, Clement TM. Novel Nuclear Roles for Testis-Specific ACTL7A and ACTL7B Supported by In Vivo Characterizations and AI Facilitated In Silico Mechanistic Modeling with Implications for Epigenetic Regulation in Spermiogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.29.582797. [PMID: 38464253 PMCID: PMC10925299 DOI: 10.1101/2024.02.29.582797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
A mechanistic role for nuclear function of testis-specific actin related proteins (ARPs) is proposed here through contributions of ARP subunit swapping in canonical chromatin regulatory complexes. This is significant to our understanding of both mechanisms controlling regulation of spermiogenesis, and the expanding functional roles of the ARPs in cell biology. Among these roles, actins and ARPs are pivotal not only in cytoskeletal regulation, but also in intranuclear chromatin organization, influencing gene regulation and nucleosome remodeling. This study focuses on two testis-specific ARPs, ACTL7A and ACTL7B, exploring their intranuclear activities and broader implications utilizing combined in vivo, in vitro, and in silico approaches. ACTL7A and ACTL7B, previously associated with structural roles, are hypothesized here to serve in chromatin regulation during germline development. This study confirms the intranuclear presence of ACTL7B in spermatocytes and round spermatids, revealing a potential role in intranuclear processes, and identifies a putative nuclear localization sequence conserved across mammalian ACTL7B, indicating a potentially unique mode of nuclear transport which differs from conventional actin. Ablation of ACTL7B leads to varied transcriptional changes reported here. Additionally, in the absence of ACTL7A or ACTL7B there is a loss of intranuclear localization of HDAC1 and HDAC3, which are known regulators of epigenetic associated acetylation changes that in turn regulate gene expression. Thus, these HDACs are implicated as contributors to the aberrant gene expression observed in the KO mouse testis transcriptomic analysis. Furthermore, this study employed and confirmed the accuracy of in silico models to predict ARP interactions with Helicase-SANT-associated (HSA) domains, uncovering putative roles for testis-specific ARPs in nucleosome remodeling complexes. In these models, ACTL7A and ACTL7B were found capable of binding to INO80 and SWI/SNF nucleosome remodeler family members in a manner akin to nuclear actin and ACTL6A. These models thus implicate germline-specific ARP subunit swapping within chromatin regulatory complexes as a potential regulatory mechanism for chromatin and associated molecular machinery adaptations in nuclear reorganizations required during spermiogenesis. These results hold implications for male fertility and epigenetic programing in the male-germline that warrant significant future investigation. In summary, this study reveals that ACTL7A and ACTL7B play intranuclear gene regulation roles in male gametogenesis, adding to the multifaceted roles identified also spanning structural, acrosomal, and flagellar stability. ACTL7A and ACTL7B unique nuclear transport, impact on HDAC nuclear associations, impact on transcriptional processes, and proposed mechanism for involvement in nucleosome remodeling complexes supported by AI facilitated in silico modeling contribute to a more comprehensive understanding of the indispensable functions of ARPs broadly in cell biology, and specifically in male fertility.
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Affiliation(s)
- Pierre Ferrer
- Interdisciplinary Faculty of Toxicology Program, Texas A&M University, College Station, TX 77843
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX 77843
| | - Srijana Upadhyay
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX 77843
| | - James J Cai
- Department of Veterinary Integrative Biosciences, School of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843
| | - Tracy M Clement
- Interdisciplinary Faculty of Toxicology Program, Texas A&M University, College Station, TX 77843
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX 77843
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Bogolyubova IO, Sailau ZK, Bogolyubov DS. Nuclear Distribution of the Chromatin-Remodeling Protein ATRX in Mouse Early Embryos during Normal Development and Developmental Arrest In Vitro. Life (Basel) 2023; 14:5. [PMID: 38276254 PMCID: PMC10817635 DOI: 10.3390/life14010005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 12/12/2023] [Accepted: 12/17/2023] [Indexed: 01/27/2024] Open
Abstract
The chromatin-remodeling protein ATRX, which is currently recognized as one of the key genome caretakers, plays an important role in oogenesis and early embryogenesis in mammals. ATRX distribution in the nuclei of mouse embryos developing in vivo and in vitro, including when the embryos are arrested at the two-cell stage-the so-called two-cell block in vitro-was studied using immunofluorescent labeling and FISH. In normally developing two- and four-cell embryos, ATRX was found to be closely colocalized with pericentromeric DNA sequences detected with a probe to the mouse major satellite DNA. The association of ATRX with pericentromeric heterochromatin is mediated by nuclear actin and reduced after the treatment of embryos with latrunculin B. When culturing embryos in vitro, the distribution pattern of ATRX changes, leading to a decrease in the association of this protein with major satellite DNA especially under the two-cell block in vitro. Taken together, our data suggest that the intranuclear distribution of ATRX reflects the viability of mouse embryos and their probability of successful preimplantation development.
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Affiliation(s)
- Irina O. Bogolyubova
- Institute of Cytology of the Russian Academy of Sciences, St. Petersburg 194064, Russia;
| | - Zhuldyz K. Sailau
- PERSONA International Clinical Center for Reproductology, Almaty 050060, Kazakhstan;
| | - Dmitry S. Bogolyubov
- Institute of Cytology of the Russian Academy of Sciences, St. Petersburg 194064, Russia;
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7
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Matsumoto T, Higaki T, Takatsuka H, Kutsuna N, Ogata Y, Hasezawa S, Umeda M, Inada N. Arabidopsis thaliana Subclass I ACTIN DEPOLYMERIZING FACTORs Regulate Nuclear Organization and Gene Expression. PLANT & CELL PHYSIOLOGY 2023; 64:1231-1242. [PMID: 37647615 DOI: 10.1093/pcp/pcad092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 07/28/2023] [Accepted: 08/09/2023] [Indexed: 09/01/2023]
Abstract
ACTIN DEPOLYMERIZING FACTOR (ADF) is a conserved protein that regulates the organization and dynamics of actin microfilaments. Eleven ADFs in the Arabidopsis thaliana genome are grouped into four subclasses, and subclass I ADFs, ADF1-4, are all expressed throughout the plant. Previously, we showed that subclass I ADFs function in the regulation of the response against powdery mildew fungus as well as in the regulation of cell size and endoreplication. Here, we report a new role of subclass I ADFs in the regulation of nuclear organization and gene expression. Through microscopic observation of epidermal cells in mature leaves, we found that the size of chromocenters in both adf4 and transgenic lines where expression of subclass I ADFs is downregulated (ADF1-4Ri) was reduced compared with that of wild-type Col-0. Arabidopsis thaliana possesses eight ACTIN (ACT) genes, among which ACT2, -7 and -8 are expressed in vegetative organs. The chromocenter size in act7, but not in the act2/8 double mutant, was enlarged compared with that in Col-0. Microarray analysis revealed that 1,818 genes were differentially expressed in adf4 and ADF1-4Ri. In particular, expression of 22 nucleotide-binding leucine-rich repeat genes, which are involved in effector-triggered plant immunity, was reduced in adf4 and ADF1-4Ri. qRT-PCR confirmed the altered expressions shown with microarray analysis. Overall, these results suggest that ADF regulates various aspects of plant physiology through its role in regulation of nuclear organization and gene expression. The mechanism how ADF and ACT regulate nuclear organization and gene expression is discussed.
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Affiliation(s)
- Tomoko Matsumoto
- Graduate School of Agriculture, Osaka Metropolitan University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8531 Japan
| | - Takumi Higaki
- Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuou-ku, Kumamoto, 860-8555 Japan
- International Research Organization for Advanced Science and Technology (IROAST), Kumamoto University, 2-39-1 Kurokami, Chuou-ku, Kumamoto, 860-8555 Japan
| | | | | | - Yoshiyuki Ogata
- Graduate School of Agriculture, Osaka Metropolitan University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8531 Japan
| | - Seiichiro Hasezawa
- Graduate School of Science and Engineering, Hosei University, Kajino-cho 3-7-2 Koganei, Tokyo, 184-8584 Japan
| | - Masaaki Umeda
- Graduate School of Science and Technology, Nara Institute of Science and Technology, Takayama-cho 8916-5 Ikoma, Nara, 630-0192 Japan
| | - Noriko Inada
- Graduate School of Agriculture, Osaka Metropolitan University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8531 Japan
- Graduate School of Science and Technology, Nara Institute of Science and Technology, Takayama-cho 8916-5 Ikoma, Nara, 630-0192 Japan
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8
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Jeruzalska E, Mazur AJ. The Role of non-muscle actin paralogs in cell cycle progression and proliferation. Eur J Cell Biol 2023; 102:151315. [PMID: 37099935 DOI: 10.1016/j.ejcb.2023.151315] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 04/14/2023] [Accepted: 04/17/2023] [Indexed: 04/28/2023] Open
Abstract
Uncontrolled cell proliferation leads to several pathologies, including cancer. Thus, this process must be tightly regulated. The cell cycle accounts for cell proliferation, and its progression is coordinated with changes in cell shape, for which cytoskeleton reorganization is responsible. Rearrangement of the cytoskeleton allows for its participation in the precise division of genetic material and cytokinesis. One of the main cytoskeletal components is filamentous actin-based structures. Mammalian cells have at least six actin paralogs, four of which are muscle-specific, while two, named β- and γ-actin, are abundantly present in all types of cells. This review summarizes the findings that establish the role of non-muscle actin paralogs in regulating cell cycle progression and proliferation. We discuss studies showing that the level of a given non-muscle actin paralog in a cell influences the cell's ability to progress through the cell cycle and, thus, proliferation. Moreover, we elaborate on the non-muscle actins' role in regulating gene transcription, interactions of actin paralogs with proteins involved in controlling cell proliferation, and the contribution of non-muscle actins to different structures in a dividing cell. The data cited in this review show that non-muscle actins regulate the cell cycle and proliferation through varying mechanisms. We point to the need for further studies addressing these mechanisms.
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Affiliation(s)
- Estera Jeruzalska
- Department of Cell Pathology, Faculty of Biotechnology, University of Wroclaw, Poland
| | - Antonina J Mazur
- Department of Cell Pathology, Faculty of Biotechnology, University of Wroclaw, Poland.
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Mahmood SR, Said NHE, Gunsalus KC, Percipalle P. β-actin mediated H3K27ac changes demonstrate the link between compartment switching and enhancer-dependent transcriptional regulation. Genome Biol 2023; 24:18. [PMID: 36698204 PMCID: PMC9875490 DOI: 10.1186/s13059-023-02853-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 01/09/2023] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND Recent work has demonstrated that three-dimensional genome organization is directly affected by changes in the levels of nuclear cytoskeletal proteins such as β-actin. The mechanisms which translate changes in 3D genome structure into changes in transcription, however, are not fully understood. Here, we use a comprehensive genomic analysis of cells lacking nuclear β-actin to investigate the mechanistic links between compartment organization, enhancer activity, and gene expression. RESULTS Using HiC-Seq, ATAC-Seq, and RNA-Seq, we first demonstrate that transcriptional and chromatin accessibility changes observed upon β-actin loss are highly enriched in compartment-switching regions. Accessibility changes within compartment switching genes, however, are mainly observed in non-promoter regions which potentially represent distal regulatory elements. Our results also show that β-actin loss induces widespread accumulation of the enhancer-specific epigenetic mark H3K27ac. Using the ABC model of enhancer annotation, we then establish that these epigenetic changes have a direct impact on enhancer activity and underlie transcriptional changes observed upon compartment switching. A complementary analysis of fibroblasts undergoing reprogramming into pluripotent stem cells further confirms that this relationship between compartment switching and enhancer-dependent transcriptional change is not specific to β-actin knockout cells but represents a general mechanism linking compartment-level genome organization to gene expression. CONCLUSIONS We demonstrate that enhancer-dependent transcriptional regulation plays a crucial role in driving gene expression changes observed upon compartment-switching. Our results also reveal a novel function of nuclear β-actin in regulating enhancer function by influencing H3K27 acetylation levels.
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Affiliation(s)
- Syed Raza Mahmood
- grid.440573.10000 0004 1755 5934Center for Genomics and Systems Biology, New York University Abu Dhabi (NYUAD), P.O. Box 129188, Abu Dhabi, United Arab Emirates ,grid.137628.90000 0004 1936 8753Department of Biology, New York University, New York, NY 10003 USA
| | - Nadine Hosny El Said
- grid.440573.10000 0004 1755 5934Program in Biology, Division of Science and Mathematics, New York University Abu Dhabi (NYUAD), P.O. Box 129188, Abu Dhabi, United Arab Emirates
| | - Kristin C. Gunsalus
- grid.440573.10000 0004 1755 5934Center for Genomics and Systems Biology, New York University Abu Dhabi (NYUAD), P.O. Box 129188, Abu Dhabi, United Arab Emirates ,grid.137628.90000 0004 1936 8753Department of Biology, Center for Genomics and Systems Biology, New York University, New York, NY 10003 USA
| | - Piergiorgio Percipalle
- grid.440573.10000 0004 1755 5934Center for Genomics and Systems Biology, New York University Abu Dhabi (NYUAD), P.O. Box 129188, Abu Dhabi, United Arab Emirates ,grid.440573.10000 0004 1755 5934Program in Biology, Division of Science and Mathematics, New York University Abu Dhabi (NYUAD), P.O. Box 129188, Abu Dhabi, United Arab Emirates ,grid.10548.380000 0004 1936 9377Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 106 91 Stockholm, Sweden
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Niu W, Cao W, Wu F, Liang C. SUV39H1 Inhibits Angiogenesis in Limb Ischemia of Mice. Cell Transplant 2023; 32:9636897231198167. [PMID: 37811706 PMCID: PMC10563463 DOI: 10.1177/09636897231198167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 08/07/2023] [Accepted: 08/15/2023] [Indexed: 10/10/2023] Open
Abstract
Peripheral arterial disease (PAD), characterized by atherosclerosis of the peripheral arteries or even amputation, has threatened public life and health. However, the underlying mechanism remains largely obscure. SUV39H1, a histone methyltransferase, could specifically methylate lysine 9 of histone H3 and act as a repressor in transcriptional activity. The study aimed to investigate the role of SUV39H1 in limb ischemia. C57BL/6 male mice were randomly divided into Sham or Model groups to investigate the expression of SUV39H1 in the ischemic limbs. Then, pharmaceutical inhibition or genetic deletion of SUV39H1 in the limb ischemia mice model was performed to confirm its effect on limb ischemia. The blood perfusion was quantified by laser speckle contrast imaging (LSCI). Capillary density and muscle edema were measured by CD31 immunohistochemical staining and HE staining. The expressions of SUV39H1 and Catalase were confirmed by western blot. Transcriptome sequencing of siSUV39H1 in human umbilical vein endothelial cells (HUVECs) was used to explore the regulation mechanism of SUV39H1 on angiogenesis. The results showed that SUV39H1 was highly expressed in the ischemic muscle tissue of the mice. Pharmaceutical inhibition or genetic deletion of SUV39H1 significantly improved blood perfusion, capillary density, and angiogenesis in ischemic muscle tissue. Cell experiments showed that SUV39H1 knockdown promoted cell migration, tube formation, and mitochondrial membrane potential in endothelial cells under oxidative stress. The transcriptome sequencing results unmasked mechanisms of the regulation of angiogenesis induced by SUV39H1. Finally, Salvianolic acid B and Astragaloside IV were identified as potential drug candidates for the improvement of endothelial function by repressing SUV39H1. Our study reveals a new mechanism in limb ischemia. Targeting SUV39H1 could improve endothelial dysfunction and thus prevent limb ischemia.
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Affiliation(s)
- Wenhao Niu
- Department of Cardiology, Shanghai Changzheng Hospital, Naval Medical University, Shanghai, China
| | - Wenyue Cao
- Department of Ultrasonography, Shanghai Chest Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Feng Wu
- Department of Cardiology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Chun Liang
- Department of Cardiology, Shanghai Changzheng Hospital, Naval Medical University, Shanghai, China
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11
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Rubin J, van Wijnen AJ, Uzer G. Architectural control of mesenchymal stem cell phenotype through nuclear actin. Nucleus 2022; 13:35-48. [PMID: 35133922 PMCID: PMC8837231 DOI: 10.1080/19491034.2022.2029297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 01/10/2022] [Accepted: 01/11/2022] [Indexed: 11/18/2022] Open
Abstract
There is growing appreciation that architectural components of the nucleus regulate gene accessibility by altering chromatin organization. While nuclear membrane connector proteins link the mechanosensitive actin cytoskeleton to the nucleoskeleton, actin's contribution to the inner architecture of the nucleus remains enigmatic. Control of actin transport into the nucleus, plus the presence of proteins that control actin structure (the actin tool-box) within the nucleus, suggests that nuclear actin may support biomechanical regulation of gene expression. Cellular actin structure is mechanoresponsive: actin cables generated through forces experienced at the plasma membrane transmit force into the nucleus. We posit that dynamic actin remodeling in response to such biomechanical cues provides a novel level of structural control over the epigenetic landscape. We here propose to bring awareness to the fact that mechanical forces can promote actin transfer into the nucleus and control structural arrangements as illustrated in mesenchymal stem cells, thereby modulating lineage commitment.
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Affiliation(s)
- Janet Rubin
- Department of Medicine, University of North Carolina, Chapel Hill, NC, USA
| | - Andre J. van Wijnen
- Department of Biochemistry, University of Vermont Medical School, Burlington, Vt, USA
| | - Gunes Uzer
- Department of Mechanical & Biomedical Engineering, Boise State University, Boise, ID, USA
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12
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Zhu C, Iwase M, Li Z, Wang F, Quinet A, Vindigni A, Shao J. Profilin-1 regulates DNA replication forks in a context-dependent fashion by interacting with SNF2H and BOD1L. Nat Commun 2022; 13:6531. [PMID: 36319634 PMCID: PMC9626489 DOI: 10.1038/s41467-022-34310-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Accepted: 10/21/2022] [Indexed: 12/04/2022] Open
Abstract
DNA replication forks are tightly controlled by a large protein network consisting of well-known core regulators and many accessory factors which remain functionally undefined. In this study, we report previously unknown nuclear functions of the actin-binding factor profilin-1 (PFN1) in DNA replication, which occur in a context-dependent fashion and require its binding to poly-L-proline (PLP)-containing proteins instead of actin. In unperturbed cells, PFN1 increases DNA replication initiation and accelerates fork progression by binding and stimulating the PLP-containing nucleosome remodeler SNF2H. Under replication stress, PFN1/SNF2H increases fork stalling and functionally collaborates with fork reversal enzymes to enable the over-resection of unprotected forks. In addition, PFN1 binds and functionally attenuates the PLP-containing fork protector BODL1 to increase the resection of a subset of stressed forks. Accordingly, raising nuclear PFN1 level decreases genome stability and cell survival during replication stress. Thus, PFN1 is a multi-functional regulator of DNA replication with exploitable anticancer potential.
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Affiliation(s)
- Cuige Zhu
- Divison of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Mari Iwase
- Divison of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Ziqian Li
- Divison of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
- Department of Microbial and Biochemical Pharmacy, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
| | - Faliang Wang
- Divison of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Annabel Quinet
- Divison of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
- UMR Genetic Stability Stem Cells and Radiation, University of Paris and University of Paris-Saclay, INSERM, iRCM/IBFJ CEA, Fontenay-aux-Roses, France
| | - Alessandro Vindigni
- Divison of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
- Siteman Cancer Center, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Jieya Shao
- Divison of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA.
- Siteman Cancer Center, Washington University School of Medicine, St. Louis, MO, 63110, USA.
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13
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Tomikawa J, Miyamoto K. Structural alteration of the nucleus for the reprogramming of gene expression. FEBS J 2022; 289:7221-7233. [PMID: 33891358 DOI: 10.1111/febs.15894] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 04/06/2021] [Accepted: 04/19/2021] [Indexed: 01/13/2023]
Abstract
The regulation of gene expression is a critical process for establishing and maintaining cellular identity. Gene expression is controlled through a chromatin-based mechanism in the nucleus of eukaryotic cells. Recent studies suggest that chromatin accessibility and the higher-order structure of chromatin affect transcriptional outcome. This is especially evident when cells change their fate during development and nuclear reprogramming. Furthermore, non-chromosomal contents of the cell nucleus, namely nucleoskeleton proteins, can also affect chromatin and nuclear structures, resulting in transcriptional alterations. Here, we review our current mechanistic understanding about how chromatin and nuclear structures impact transcription in the course of embryonic development, cellular differentiation and nuclear reprogramming, and also discuss unresolved questions that remain to be addressed in the field.
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Affiliation(s)
- Junko Tomikawa
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Wakayama, Japan
| | - Kei Miyamoto
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Wakayama, Japan
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14
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Dupont S, Wickström SA. Mechanical regulation of chromatin and transcription. Nat Rev Genet 2022; 23:624-643. [DOI: 10.1038/s41576-022-00493-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/21/2022] [Indexed: 01/14/2023]
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15
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Horníková L, Bruštíková K, Huérfano S, Forstová J. Nuclear Cytoskeleton in Virus Infection. Int J Mol Sci 2022; 23:ijms23010578. [PMID: 35009004 PMCID: PMC8745530 DOI: 10.3390/ijms23010578] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 12/30/2021] [Accepted: 01/03/2022] [Indexed: 02/04/2023] Open
Abstract
The nuclear lamina is the main component of the nuclear cytoskeleton that maintains the integrity of the nucleus. However, it represents a natural barrier for viruses replicating in the cell nucleus. The lamina blocks viruses from being trafficked to the nucleus for replication, but it also impedes the nuclear egress of the progeny of viral particles. Thus, viruses have evolved mechanisms to overcome this obstacle. Large viruses induce the assembly of multiprotein complexes that are anchored to the inner nuclear membrane. Important components of these complexes are the viral and cellular kinases phosphorylating the lamina and promoting its disaggregation, therefore allowing virus egress. Small viruses also use cellular kinases to induce lamina phosphorylation and the subsequent disruption in order to facilitate the import of viral particles during the early stages of infection or during their nuclear egress. Another component of the nuclear cytoskeleton, nuclear actin, is exploited by viruses for the intranuclear movement of their particles from the replication sites to the nuclear periphery. This study focuses on exploitation of the nuclear cytoskeleton by viruses, although this is just the beginning for many viruses, and promises to reveal the mechanisms and dynamic of physiological and pathological processes in the nucleus.
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16
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Abstract
Actin is a highly conserved protein in mammals. The actin dynamics is regulated by actin-binding proteins and actin-related proteins. Nuclear actin and these regulatory proteins participate in multiple nuclear processes, including chromosome architecture organization, chromatin remodeling, transcription machinery regulation, and DNA repair. It is well known that the dysfunctions of these processes contribute to the development of cancer. Moreover, emerging evidence has shown that the deregulated actin dynamics is also related to cancer. This chapter discusses how the deregulation of nuclear actin dynamics contributes to tumorigenesis via such various nuclear events.
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Affiliation(s)
- Yuanjian Huang
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Department of General Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Shengzhe Zhang
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Jae-Il Park
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
- Graduate School of Biomedical Sciences, The University of Texas MD Anderson Cancer Center and Health Science Center, Houston, TX, USA.
- Program in Genetics and Epigenetics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
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17
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Mahmood SR, El Said NH, Percipalle P. The Role of Nuclear Actin in Genome Organization and Gene Expression Regulation During Differentiation. Results Probl Cell Differ 2022; 70:607-624. [PMID: 36348124 DOI: 10.1007/978-3-031-06573-6_22] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
In the cell nucleus, actin participates in numerous essential processes. Actin is involved in chromatin as part of specific ATP-dependent chromatin remodeling complexes and associates with the RNA polymerase machinery to regulate transcription at multiple levels. Emerging evidence has also shown that the nuclear actin pool controls the architecture of the mammalian genome playing an important role in its hierarchical organization into transcriptionally active and repressed compartments, contributing to the clustering of RNA polymerase II into transcriptional hubs. Here, we review the most recent literature and discuss how actin involvement in genome organization impacts the regulation of gene programs that are activated or repressed during differentiation and development. As in the cytoplasm, we propose that nuclear actin is involved in key nuclear tasks in complex with different types of actin-binding proteins that regulate actin function and bridge interactions between actin and various nuclear components.
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Affiliation(s)
- Syed Raza Mahmood
- Center for Genomics and Systems Biology, New York University Abu Dhabi (NYUAD), Abu Dhabi, United Arab Emirates
- Department of Biology, New York University, New York, NY, USA
| | - Nadine Hosny El Said
- Program in Biology, Division of Science and Mathematics, New York University Abu Dhabi (NYUAD), Abu Dhabi, United Arab Emirates
| | - Piergiorgio Percipalle
- Center for Genomics and Systems Biology, New York University Abu Dhabi (NYUAD), Abu Dhabi, United Arab Emirates.
- Department of Biology, New York University, New York, NY, USA.
- Program in Biology, Division of Science and Mathematics, New York University Abu Dhabi (NYUAD), Abu Dhabi, United Arab Emirates.
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18
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Napoletano F, Ferrari Bravo G, Voto IAP, Santin A, Celora L, Campaner E, Dezi C, Bertossi A, Valentino E, Santorsola M, Rustighi A, Fajner V, Maspero E, Ansaloni F, Cancila V, Valenti CF, Santo M, Artimagnella OB, Finaurini S, Gioia U, Polo S, Sanges R, Tripodo C, Mallamaci A, Gustincich S, d'Adda di Fagagna F, Mantovani F, Specchia V, Del Sal G. The prolyl-isomerase PIN1 is essential for nuclear Lamin-B structure and function and protects heterochromatin under mechanical stress. Cell Rep 2021; 36:109694. [PMID: 34525372 DOI: 10.1016/j.celrep.2021.109694] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 06/29/2021] [Accepted: 08/19/2021] [Indexed: 01/24/2023] Open
Abstract
Chromatin organization plays a crucial role in tissue homeostasis. Heterochromatin relaxation and consequent unscheduled mobilization of transposable elements (TEs) are emerging as key contributors of aging and aging-related pathologies, including Alzheimer's disease (AD) and cancer. However, the mechanisms governing heterochromatin maintenance or its relaxation in pathological conditions remain poorly understood. Here we show that PIN1, the only phosphorylation-specific cis/trans prolyl isomerase, whose loss is associated with premature aging and AD, is essential to preserve heterochromatin. We demonstrate that this PIN1 function is conserved from Drosophila to humans and prevents TE mobilization-dependent neurodegeneration and cognitive defects. Mechanistically, PIN1 maintains nuclear type-B Lamin structure and anchoring function for heterochromatin protein 1α (HP1α). This mechanism prevents nuclear envelope alterations and heterochromatin relaxation under mechanical stress, which is a key contributor to aging-related pathologies.
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Affiliation(s)
- Francesco Napoletano
- Laboratorio Nazionale CIB (LNCIB), Area Science Park, Padriciano 99, 34149 Trieste, Italy; Department of Life Sciences (DSV), University of Trieste, 34127 Trieste, Italy.
| | - Gloria Ferrari Bravo
- Laboratorio Nazionale CIB (LNCIB), Area Science Park, Padriciano 99, 34149 Trieste, Italy; Department of Life Sciences (DSV), University of Trieste, 34127 Trieste, Italy
| | - Ilaria Anna Pia Voto
- Laboratorio Nazionale CIB (LNCIB), Area Science Park, Padriciano 99, 34149 Trieste, Italy
| | - Aurora Santin
- Laboratorio Nazionale CIB (LNCIB), Area Science Park, Padriciano 99, 34149 Trieste, Italy
| | - Lucia Celora
- Laboratorio Nazionale CIB (LNCIB), Area Science Park, Padriciano 99, 34149 Trieste, Italy
| | - Elena Campaner
- Laboratorio Nazionale CIB (LNCIB), Area Science Park, Padriciano 99, 34149 Trieste, Italy; Department of Life Sciences (DSV), University of Trieste, 34127 Trieste, Italy
| | - Clara Dezi
- Department of Life Sciences (DSV), University of Trieste, 34127 Trieste, Italy
| | - Arianna Bertossi
- Laboratorio Nazionale CIB (LNCIB), Area Science Park, Padriciano 99, 34149 Trieste, Italy; Department of Life Sciences (DSV), University of Trieste, 34127 Trieste, Italy
| | - Elena Valentino
- Laboratorio Nazionale CIB (LNCIB), Area Science Park, Padriciano 99, 34149 Trieste, Italy
| | - Mariangela Santorsola
- Laboratorio Nazionale CIB (LNCIB), Area Science Park, Padriciano 99, 34149 Trieste, Italy; Department of Life Sciences (DSV), University of Trieste, 34127 Trieste, Italy
| | - Alessandra Rustighi
- Laboratorio Nazionale CIB (LNCIB), Area Science Park, Padriciano 99, 34149 Trieste, Italy; Department of Life Sciences (DSV), University of Trieste, 34127 Trieste, Italy
| | | | - Elena Maspero
- FIRC Institute of Molecular Oncology (IFOM), 20139 Milan, Italy
| | - Federico Ansaloni
- Area of Neuroscience, International School for Advanced Studies (SISSA), 34146 Trieste, Italy
| | - Valeria Cancila
- Tumor Immunology Unit, Department of Health Science, Human Pathology Section, School of Medicine, University of Palermo, 90133 Palermo, Italy
| | - Cesare Fabio Valenti
- Tumor Immunology Unit, Department of Health Science, Human Pathology Section, School of Medicine, University of Palermo, 90133 Palermo, Italy
| | - Manuela Santo
- Area of Neuroscience, International School for Advanced Studies (SISSA), 34146 Trieste, Italy
| | | | - Sara Finaurini
- Area of Neuroscience, International School for Advanced Studies (SISSA), 34146 Trieste, Italy
| | - Ubaldo Gioia
- FIRC Institute of Molecular Oncology (IFOM), 20139 Milan, Italy
| | - Simona Polo
- FIRC Institute of Molecular Oncology (IFOM), 20139 Milan, Italy
| | - Remo Sanges
- Area of Neuroscience, International School for Advanced Studies (SISSA), 34146 Trieste, Italy
| | - Claudio Tripodo
- FIRC Institute of Molecular Oncology (IFOM), 20139 Milan, Italy; Tumor Immunology Unit, Department of Health Science, Human Pathology Section, School of Medicine, University of Palermo, 90133 Palermo, Italy
| | - Antonello Mallamaci
- Area of Neuroscience, International School for Advanced Studies (SISSA), 34146 Trieste, Italy
| | - Stefano Gustincich
- Area of Neuroscience, International School for Advanced Studies (SISSA), 34146 Trieste, Italy; Central RNA Laboratory, Italian Institute of Technology, 16163 Genova, Italy
| | - Fabrizio d'Adda di Fagagna
- FIRC Institute of Molecular Oncology (IFOM), 20139 Milan, Italy; Institute of Molecular Genetics, National Research Institute (CNR), Pavia, Italy
| | - Fiamma Mantovani
- Laboratorio Nazionale CIB (LNCIB), Area Science Park, Padriciano 99, 34149 Trieste, Italy; Department of Life Sciences (DSV), University of Trieste, 34127 Trieste, Italy
| | - Valeria Specchia
- Department of Biological and Environmental Sciences and Technologies (DiSTeBA), University of Salento, 73100 Lecce, Italy
| | - Giannino Del Sal
- Laboratorio Nazionale CIB (LNCIB), Area Science Park, Padriciano 99, 34149 Trieste, Italy; Department of Life Sciences (DSV), University of Trieste, 34127 Trieste, Italy; FIRC Institute of Molecular Oncology (IFOM), 20139 Milan, Italy.
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19
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β-actin dependent chromatin remodeling mediates compartment level changes in 3D genome architecture. Nat Commun 2021; 12:5240. [PMID: 34475390 PMCID: PMC8413440 DOI: 10.1038/s41467-021-25596-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 08/18/2021] [Indexed: 02/07/2023] Open
Abstract
β-actin is a crucial component of several chromatin remodeling complexes that control chromatin structure and accessibility. The mammalian Brahma-associated factor (BAF) is one such complex that plays essential roles in development and differentiation by regulating the chromatin state of critical genes and opposing the repressive activity of polycomb repressive complexes (PRCs). While previous work has shown that β-actin loss can lead to extensive changes in gene expression and heterochromatin organization, it is not known if changes in β-actin levels can directly influence chromatin remodeling activities of BAF and polycomb proteins. Here we conduct a comprehensive genomic analysis of β-actin knockout mouse embryonic fibroblasts (MEFs) using ATAC-Seq, HiC-seq, RNA-Seq and ChIP-Seq of various epigenetic marks. We demonstrate that β-actin levels can induce changes in chromatin structure by affecting the complex interplay between chromatin remodelers such as BAF/BRG1 and EZH2. Our results show that changes in β-actin levels and associated chromatin remodeling activities can not only impact local chromatin accessibility but also induce reversible changes in 3D genome architecture. Our findings reveal that β-actin-dependent chromatin remodeling plays a role in shaping the chromatin landscape and influences the regulation of genes involved in development and differentiation.
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20
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Lapeña-Luzón T, Rodríguez LR, Beltran-Beltran V, Benetó N, Pallardó FV, Gonzalez-Cabo P. Cofilin and Neurodegeneration: New Functions for an Old but Gold Protein. Brain Sci 2021; 11:brainsci11070954. [PMID: 34356188 PMCID: PMC8303701 DOI: 10.3390/brainsci11070954] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/12/2021] [Accepted: 07/16/2021] [Indexed: 12/11/2022] Open
Abstract
Cofilin is an actin-binding protein that plays a major role in the regulation of actin dynamics, an essential cellular process. This protein has emerged as a crucial molecule for functions of the nervous system including motility and guidance of the neuronal growth cone, dendritic spine organization, axonal branching, and synaptic signalling. Recently, other important functions in cell biology such as apoptosis or the control of mitochondrial function have been attributed to cofilin. Moreover, novel mechanisms of cofilin function regulation have also been described. The activity of cofilin is controlled by complex regulatory mechanisms, with phosphorylation being the most important, since the addition of a phosphate group to cofilin renders it inactive. Due to its participation in a wide variety of key processes in the cell, cofilin has been related to a great variety of pathologies, among which neurodegenerative diseases have attracted great interest. In this review, we summarized the functions of cofilin and its regulation, emphasizing how defects in these processes have been related to different neurodegenerative diseases.
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Affiliation(s)
- Tamara Lapeña-Luzón
- Department of Physiology, Faculty of Medicine and Dentistry, University of Valencia, 46010 Valencia, Spain; (T.L.-L.); (L.R.R.); (V.B.-B.); (N.B.); (F.V.P.)
- Biomedical Research Institute INCLIVA, 46010 Valencia, Spain
- CIBER de Enfermedades Raras (CIBERER), 46010 Valencia, Spain
| | - Laura R. Rodríguez
- Department of Physiology, Faculty of Medicine and Dentistry, University of Valencia, 46010 Valencia, Spain; (T.L.-L.); (L.R.R.); (V.B.-B.); (N.B.); (F.V.P.)
- Biomedical Research Institute INCLIVA, 46010 Valencia, Spain
- CIBER de Enfermedades Raras (CIBERER), 46010 Valencia, Spain
| | - Vicent Beltran-Beltran
- Department of Physiology, Faculty of Medicine and Dentistry, University of Valencia, 46010 Valencia, Spain; (T.L.-L.); (L.R.R.); (V.B.-B.); (N.B.); (F.V.P.)
| | - Noelia Benetó
- Department of Physiology, Faculty of Medicine and Dentistry, University of Valencia, 46010 Valencia, Spain; (T.L.-L.); (L.R.R.); (V.B.-B.); (N.B.); (F.V.P.)
- Biomedical Research Institute INCLIVA, 46010 Valencia, Spain
- CIBER de Enfermedades Raras (CIBERER), 46010 Valencia, Spain
| | - Federico V. Pallardó
- Department of Physiology, Faculty of Medicine and Dentistry, University of Valencia, 46010 Valencia, Spain; (T.L.-L.); (L.R.R.); (V.B.-B.); (N.B.); (F.V.P.)
- Biomedical Research Institute INCLIVA, 46010 Valencia, Spain
- CIBER de Enfermedades Raras (CIBERER), 46010 Valencia, Spain
| | - Pilar Gonzalez-Cabo
- Department of Physiology, Faculty of Medicine and Dentistry, University of Valencia, 46010 Valencia, Spain; (T.L.-L.); (L.R.R.); (V.B.-B.); (N.B.); (F.V.P.)
- Biomedical Research Institute INCLIVA, 46010 Valencia, Spain
- CIBER de Enfermedades Raras (CIBERER), 46010 Valencia, Spain
- Correspondence:
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21
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Venit T, El Said NH, Mahmood SR, Percipalle P. A dynamic actin-dependent nucleoskeleton and cell identity. J Biochem 2021; 169:243-257. [PMID: 33351909 DOI: 10.1093/jb/mvaa133] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Accepted: 10/27/2020] [Indexed: 12/19/2022] Open
Abstract
Actin is an essential regulator of cellular functions. In the eukaryotic cell nucleus, actin regulates chromatin as a bona fide component of chromatin remodelling complexes, it associates with nuclear RNA polymerases to regulate transcription and is involved in co-transcriptional assembly of nascent RNAs into ribonucleoprotein complexes. Actin dynamics are, therefore, emerging as a major regulatory factor affecting diverse cellular processes. Importantly, the involvement of actin dynamics in nuclear functions is redefining the concept of nucleoskeleton from a rigid scaffold to a dynamic entity that is likely linked to the three-dimensional organization of the nuclear genome. In this review, we discuss how nuclear actin, by regulating chromatin structure through phase separation may contribute to the architecture of the nuclear genome during cell differentiation and facilitate the expression of specific gene programs. We focus specifically on mitochondrial genes and how their dysregulation in the absence of actin raises important questions about the role of cytoskeletal proteins in regulating chromatin structure. The discovery of a novel pool of mitochondrial actin that serves as 'mitoskeleton' to facilitate organization of mtDNA supports a general role for actin in genome architecture and a possible function of distinct actin pools in the communication between nucleus and mitochondria.
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Affiliation(s)
- Tomas Venit
- Science Division, Biology Program, New York University Abu Dhabi (NYUAD), PO Box 129188, Abu Dhabi United Arab Emirates
| | - Nadine Hosny El Said
- Science Division, Biology Program, New York University Abu Dhabi (NYUAD), PO Box 129188, Abu Dhabi United Arab Emirates
| | - Syed Raza Mahmood
- Science Division, Biology Program, New York University Abu Dhabi (NYUAD), PO Box 129188, Abu Dhabi United Arab Emirates.,Department of Biology, New York University, 100 Washington Square East, 1009 Silver Center, New York, NY 10003, USA
| | - Piergiorgio Percipalle
- Science Division, Biology Program, New York University Abu Dhabi (NYUAD), PO Box 129188, Abu Dhabi United Arab Emirates.,Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrhenius väg 20C, 114 18 Stockholm, Sweden
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22
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Machida N, Takahashi D, Ueno Y, Nakama Y, Gubeli RJ, Bertoldo D, Harata M. Modulating dynamics and function of nuclear actin with synthetic bicyclic peptides. J Biochem 2021; 169:295-302. [PMID: 33169153 DOI: 10.1093/jb/mvaa130] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 10/26/2020] [Indexed: 12/27/2022] Open
Abstract
Actin exists in monomeric globular (G-) and polymerized filamentous (F-) forms and the dynamics of its polymerization/depolymerization are tightly regulated in both the cytoplasm and the nucleus. Various essential functions of nuclear actin have been identified including regulation of gene expression and involvement in the repair of DNA double-strand breaks (DSB). Small G-actin-binding molecules affect F-actin formation and can be utilized for analysis and manipulation of actin in living cells. However, these G-actin-binding molecules are obtained by extraction from natural sources or through complex chemical synthesis procedures, and therefore, the generation of their derivatives for analytical tools is underdeveloped. In addition, their effects on nuclear actin cannot be separately evaluated from those on cytoplasmic actin. Previously, we have generated synthetic bicyclic peptides, consisting of two macrocyclic rings, which bind to G-actin but not to F-actin. Here, we describe the introduction of these bicyclic peptides into living cells. Furthermore, by conjugation to a nuclear localization signal (NLS), the bicyclic peptides accumulated in the nucleus. The NLS-bicyclic peptides repress the formation of nuclear F-actin, and impair transcriptional regulation and DSB repair. These observations highlight a potential role for NLS-linked bicyclic peptides in the manipulation of dynamics and functions of nuclear actin.
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Affiliation(s)
- Nanako Machida
- Laboratory of Molecular Biology, Division of Life Science, Graduate School of Agricultural Science, Tohoku University, 468-1, Aramaki Aza Aoba, Aoba-ku, Sendai 980-0845, Japan
| | - Daisuke Takahashi
- Laboratory of Molecular Biology, Division of Life Science, Graduate School of Agricultural Science, Tohoku University, 468-1, Aramaki Aza Aoba, Aoba-ku, Sendai 980-0845, Japan
| | - Yuya Ueno
- Laboratory of Molecular Biology, Division of Life Science, Graduate School of Agricultural Science, Tohoku University, 468-1, Aramaki Aza Aoba, Aoba-ku, Sendai 980-0845, Japan
| | - Yoshihiro Nakama
- Laboratory of Molecular Biology, Division of Life Science, Graduate School of Agricultural Science, Tohoku University, 468-1, Aramaki Aza Aoba, Aoba-ku, Sendai 980-0845, Japan
| | - Raphael J Gubeli
- Institute of Chemical Sciences and Engineering, School of Basic Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Davide Bertoldo
- Institute of Chemical Sciences and Engineering, School of Basic Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Masahiko Harata
- Laboratory of Molecular Biology, Division of Life Science, Graduate School of Agricultural Science, Tohoku University, 468-1, Aramaki Aza Aoba, Aoba-ku, Sendai 980-0845, Japan
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23
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Miyamoto K, Harata M. Nucleoskeleton proteins for nuclear dynamics. J Biochem 2021; 169:237-241. [PMID: 33479767 DOI: 10.1093/jb/mvab006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 12/29/2020] [Indexed: 12/12/2022] Open
Abstract
The eukaryotic nucleus shows organized structures of chromosomes, transcriptional components and their associated proteins. It has been believed that such a dense nuclear environment prevents the formation of a cytoskeleton-like network of protein filaments. However, accumulating evidence suggests that the cell nucleus also possesses structural filamentous components to support nuclear organization and compartments, which are referred to as nucleoskeleton proteins. Nucleoskeleton proteins including lamins and actin influence nuclear dynamics including transcriptional regulation, chromatin organization and DNA damage responses. Furthermore, these nucleoskeleton proteins play a pivotal role in cellular differentiation and animal development. In this commentary, we discuss how nucleoskeleton-based regulatory mechanisms orchestrate nuclear dynamics.
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Affiliation(s)
- Kei Miyamoto
- Graduate School of Biology-Oriented Science and Technology, Kindai University, 930 Nishimitani, Kinokawa-shi, Wakayama 649-6493, Japan
| | - Masahiko Harata
- Laboratory of Molecular Biology, Graduate School of Agricultural Science, Tohoku University, Aramaki Aza-Aoba 468-1, Aoba-ku, Sendai 980-0845, Japan
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24
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Takahashi Y, Hiratsuka S, Machida N, Takahashi D, Matsushita J, Hozak P, Misteli T, Miyamoto K, Harata M. Impairment of nuclear F-actin formation and its relevance to cellular phenotypes in Hutchinson-Gilford progeria syndrome. Nucleus 2021; 11:250-263. [PMID: 32954953 PMCID: PMC7529414 DOI: 10.1080/19491034.2020.1815395] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Hutchinson-Gilford progeria syndrome (HGPS) is a premature aging disorder caused by a mutation of lamin A, which contributes to nuclear architecture and the spatial organization of chromatin in the nucleus. The expression of a lamin A mutant, named progerin, leads to functional and structural disruption of nuclear organization. Since progerin lacks a part of the actin-binding site of lamin A, we hypothesized that nuclear actin dynamics and function are altered in HGPS cells. Nuclear F-actin is required for the organization of nuclear shape, transcriptional regulation, DNA damage repair, and activation of Wnt/β-catenin signaling. Here we show that the expression of progerin decreases nuclear F-actin and impairs F-actin-regulated transcription. When nuclear F-actin levels are increased by overexpression of nuclear-targeted actin or by using jasplakinolide, a compound that stabilizes F-actin, the irregularity of nuclear shape and defects in gene expression can be reversed. These observations provide evidence for a novel relationship between nuclear actin and the etiology of HGPS.
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Affiliation(s)
- Yuto Takahashi
- Laboratory of Molecular Biology, Graduate School of Agricultural Science, Tohoku University , Sendai, Japan
| | - Shogo Hiratsuka
- Laboratory of Molecular Biology, Graduate School of Agricultural Science, Tohoku University , Sendai, Japan
| | - Nanako Machida
- Laboratory of Molecular Biology, Graduate School of Agricultural Science, Tohoku University , Sendai, Japan
| | - Daisuke Takahashi
- Laboratory of Molecular Biology, Graduate School of Agricultural Science, Tohoku University , Sendai, Japan
| | - Junpei Matsushita
- Laboratory of Molecular Biology, Graduate School of Agricultural Science, Tohoku University , Sendai, Japan
| | - Pavel Hozak
- Institute of Molecular Genetics of the Czech Academy of Sciences , Prague, Czech Republic
| | - Tom Misteli
- National Cancer Institute, National Institutes of Health , Bethesda, MD, USA
| | - Kei Miyamoto
- Laboratory of Molecular Developmental Biology, Faculty of Biology-Oriented Science and Technology, Kindai University , Wakayama, Japan
| | - Masahiko Harata
- Laboratory of Molecular Biology, Graduate School of Agricultural Science, Tohoku University , Sendai, Japan
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25
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Okuno T, Li WY, Hatano Y, Takasu A, Sakamoto Y, Yamamoto M, Ikeda Z, Shindo T, Plessner M, Morita K, Matsumoto K, Yamagata K, Grosse R, Miyamoto K. Zygotic Nuclear F-Actin Safeguards Embryonic Development. Cell Rep 2021; 31:107824. [PMID: 32610125 DOI: 10.1016/j.celrep.2020.107824] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 02/27/2020] [Accepted: 06/04/2020] [Indexed: 12/20/2022] Open
Abstract
After fertilization, sperm and oocyte nuclei are rapidly remodeled to form swollen pronuclei (PN) in mammalian zygotes, and the proper formation and function of PN are key to producing totipotent zygotes. However, how mature PN are formed has been unclear. We find that filamentous actin (F-actin) assembles in the PN of mouse zygotes and is required for fully functional PN. The perturbation of nuclear actin dynamics in zygotes results in the misregulation of genes related to genome integrity and abnormal development of mouse embryos. We show that nuclear F-actin ensures DNA damage repair, thus preventing the activation of a zygotic checkpoint. Furthermore, optogenetic control of cofilin nuclear localization reveals the dynamically regulated F-actin nucleoskeleton in zygotes, and its timely disassembly is needed for developmental progression. Nuclear F-actin is a hallmark of totipotent zygotic PN, and the temporal regulation of its polymerized state is necessary for normal embryonic development.
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Affiliation(s)
- Tomomi Okuno
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Kinokawa-shi, Wakayama 649-6493, Japan
| | - Wayne Yang Li
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Kinokawa-shi, Wakayama 649-6493, Japan
| | - Yu Hatano
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Kinokawa-shi, Wakayama 649-6493, Japan
| | - Atsushi Takasu
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Kinokawa-shi, Wakayama 649-6493, Japan
| | - Yuko Sakamoto
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Kinokawa-shi, Wakayama 649-6493, Japan
| | - Mari Yamamoto
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Kinokawa-shi, Wakayama 649-6493, Japan
| | - Zenki Ikeda
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Kinokawa-shi, Wakayama 649-6493, Japan
| | - Taiki Shindo
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Kinokawa-shi, Wakayama 649-6493, Japan
| | - Matthias Plessner
- Institute of Experimental and Clinical Pharmacology and Toxicology, Albert-Ludwigs-University Freiburg, Albertstrasse 25, 79104 Freiburg, Germany
| | - Kohtaro Morita
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Kinokawa-shi, Wakayama 649-6493, Japan
| | - Kazuya Matsumoto
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Kinokawa-shi, Wakayama 649-6493, Japan
| | - Kazuo Yamagata
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Kinokawa-shi, Wakayama 649-6493, Japan
| | - Robert Grosse
- Institute of Experimental and Clinical Pharmacology and Toxicology, Albert-Ludwigs-University Freiburg, Albertstrasse 25, 79104 Freiburg, Germany; CIBSS-Centre for Integrative Biological Signalling Studies, Albert-Ludwigs-University Freiburg, Schänzlestr. 18, 79104 Freiburg, Germany
| | - Kei Miyamoto
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Kinokawa-shi, Wakayama 649-6493, Japan.
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26
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Ulferts S, Prajapati B, Grosse R, Vartiainen MK. Emerging Properties and Functions of Actin and Actin Filaments Inside the Nucleus. Cold Spring Harb Perspect Biol 2021; 13:cshperspect.a040121. [PMID: 33288541 PMCID: PMC7919393 DOI: 10.1101/cshperspect.a040121] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Recent years have provided considerable insights into the dynamic nature of the cell nucleus, which is constantly reorganizing its genome, controlling its size and shape, as well as spatiotemporally orchestrating chromatin remodeling and transcription. Remarkably, it has become clear that the ancient and highly conserved cytoskeletal protein actin plays a crucial part in these processes. However, the underlying mechanisms, regulations, and properties of actin functions inside the nucleus are still not well understood. Here we summarize the diverse and distinct roles of monomeric and filamentous actin as well as the emerging roles for actin dynamics inside the nuclear compartment for genome organization and nuclear architecture.
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Affiliation(s)
- Svenja Ulferts
- Institute for Clinical and Experimental Pharmacology and Toxicology I, University of Freiburg, 79104 Freiburg, Germany
| | - Bina Prajapati
- Institute of Biotechnology, Helsinki Institute for Life Science, University of Helsinki, 00014 Helsinki, Finland
| | - Robert Grosse
- Institute for Clinical and Experimental Pharmacology and Toxicology I, University of Freiburg, 79104 Freiburg, Germany,Centre for Integrative Biological Signalling Studies (CIBSS), 79104 Freiburg, Germany
| | - Maria K. Vartiainen
- Institute of Biotechnology, Helsinki Institute for Life Science, University of Helsinki, 00014 Helsinki, Finland
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27
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Xie X, Mahmood SR, Gjorgjieva T, Percipalle P. Emerging roles of cytoskeletal proteins in regulating gene expression and genome organization during differentiation. Nucleus 2020; 11:53-65. [PMID: 32212905 PMCID: PMC7289583 DOI: 10.1080/19491034.2020.1742066] [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] [Indexed: 02/06/2023] Open
Abstract
In the eukaryotic cell nucleus, cytoskeletal proteins are emerging as essential players in nuclear function. In particular, actin regulates chromatin as part of ATP-dependent chromatin remodeling complexes, it modulates transcription and it is incorporated into nascent ribonucleoprotein complexes, accompanying them from the site of transcription to polyribosomes. The nuclear actin pool is undistinguishable from the cytoplasmic one in terms of its ability to undergo polymerization and it has also been implicated in the dynamics of chromatin, regulating heterochromatin segregation at the nuclear lamina and maintaining heterochromatin levels in the nuclear interiors. One of the next frontiers is, therefore, to determine a possible involvement of nuclear actin in the functional architecture of the cell nucleus by regulating the hierarchical organization of chromatin and, thus, genome organization. Here, we discuss the repertoire of these potential actin functions and how they are likely to play a role in the context of cellular differentiation.
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Affiliation(s)
- Xin Xie
- Science Division, Biology Program, New York University Abu Dhabi (NYUAD), Abu Dhabi, United Arab Emirates
| | - S Raza Mahmood
- Science Division, Biology Program, New York University Abu Dhabi (NYUAD), Abu Dhabi, United Arab Emirates.,Department of Biology, New York University, New York, NY, USA
| | - Tamara Gjorgjieva
- Science Division, Biology Program, New York University Abu Dhabi (NYUAD), Abu Dhabi, United Arab Emirates
| | - Piergiorgio Percipalle
- Science Division, Biology Program, New York University Abu Dhabi (NYUAD), Abu Dhabi, United Arab Emirates.,Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
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28
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Gjorgjieva T, Xie X, Commins P, Pasricha R, Mahmood SR, Gunsalus KC, Naumov P, Percipalle P. Loss of β-Actin Leads to Accelerated Mineralization and Dysregulation of Osteoblast-Differentiation Genes during Osteogenic Reprogramming. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2020; 7:2002261. [PMID: 33304760 PMCID: PMC7709978 DOI: 10.1002/advs.202002261] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 08/29/2020] [Indexed: 06/12/2023]
Abstract
Actin plays fundamental roles in both the cytoplasm and the cell nucleus. In the nucleus, β-actin regulates neuronal reprogramming by consolidating a heterochromatin landscape required for transcription of neuronal gene programs, yet it remains unknown whether it has a role in other differentiation models. To explore the potential roles of β-actin in osteogenesis, β-actin wild-type (WT) and β-actin knockout (KO) mouse embryonic fibroblasts (MEFs) are reprogrammed to osteoblast-like cells using small molecules in vitro. It is discovered that loss of β-actin leads to an accelerated mineralization phenotype (hypermineralization), accompanied with enhanced formation of extracellular hydroxyapatite microcrystals, which originate in the mitochondria in the form of microgranules. This phenotype is a consequence of rapid upregulation of mitochondrial genes including those involved in oxidative phosphorylation (OXPHOS) in reprogrammed KO cells. It is further found that osteogenic gene programs are differentially regulated between WT and KO cells, with clusters of genes exhibiting different temporal expression patterns. A novel function for β-actin in osteogenic reprogramming through a mitochondria-based mechanism that controls cell-mediated mineralization is proposed.
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Affiliation(s)
- Tamara Gjorgjieva
- Program in BiologyDivision of Science and MathematicsNew York University Abu Dhabi (NYUAD)P.O. Box 129188Abu DhabiUnited Arab Emirates
| | - Xin Xie
- Program in BiologyDivision of Science and MathematicsNew York University Abu Dhabi (NYUAD)P.O. Box 129188Abu DhabiUnited Arab Emirates
- Center for Genomics and Systems BiologyNew York University Abu Dhabi (NYUAD)P.O. Box 129188Abu DhabiUnited Arab Emirates
| | - Patrick Commins
- Program in ChemistryDivision of Science and MathematicsNew York University Abu Dhabi (NYUAD)P.O. Box 129188Abu DhabiUnited Arab Emirates
| | - Renu Pasricha
- Core Technology PlatformsNew York University Abu Dhabi (NYUAD)P.O. Box 129188Abu DhabiUnited Arab Emirates
| | - Syed Raza Mahmood
- Program in BiologyDivision of Science and MathematicsNew York University Abu Dhabi (NYUAD)P.O. Box 129188Abu DhabiUnited Arab Emirates
- Department of BiologyNew York UniversityNew YorkNY10003USA
| | - Kristin C. Gunsalus
- Center for Genomics and Systems BiologyNew York University Abu Dhabi (NYUAD)P.O. Box 129188Abu DhabiUnited Arab Emirates
- Department of BiologyNew York UniversityNew YorkNY10003USA
| | - Panče Naumov
- Program in ChemistryDivision of Science and MathematicsNew York University Abu Dhabi (NYUAD)P.O. Box 129188Abu DhabiUnited Arab Emirates
| | - Piergiorgio Percipalle
- Program in BiologyDivision of Science and MathematicsNew York University Abu Dhabi (NYUAD)P.O. Box 129188Abu DhabiUnited Arab Emirates
- Department of Molecular BiosciencesThe Wenner‐Gren InstituteStockholm UniversityStockholmSE‐106 91Sweden
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29
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Michel JB. Phylogenic Determinants of Cardiovascular Frailty, Focus on Hemodynamics and Arterial Smooth Muscle Cells. Physiol Rev 2020; 100:1779-1837. [DOI: 10.1152/physrev.00022.2019] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The evolution of the circulatory system from invertebrates to mammals has involved the passage from an open system to a closed in-parallel system via a closed in-series system, accompanying the increasing complexity and efficiency of life’s biological functions. The archaic heart enables pulsatile motion waves of hemolymph in invertebrates, and the in-series circulation in fish occurs with only an endothelium, whereas mural smooth muscle cells appear later. The present review focuses on evolution of the circulatory system. In particular, we address how and why this evolution took place from a closed, flowing, longitudinal conductance at low pressure to a flowing, highly pressurized and bifurcating arterial compartment. However, although arterial pressure was the latest acquired hemodynamic variable, the general teleonomy of the evolution of species is the differentiation of individual organ function, supported by specific fueling allowing and favoring partial metabolic autonomy. This was achieved via the establishment of an active contractile tone in resistance arteries, which permitted the regulation of blood supply to specific organ activities via its localized function-dependent inhibition (active vasodilation). The global resistance to viscous blood flow is the peripheral increase in frictional forces caused by the tonic change in arterial and arteriolar radius, which backscatter as systemic arterial blood pressure. Consequently, the arterial pressure gradient from circulating blood to the adventitial interstitium generates the unidirectional outward radial advective conductance of plasma solutes across the wall of conductance arteries. This hemodynamic evolution was accompanied by important changes in arterial wall structure, supported by smooth muscle cell functional plasticity, including contractility, matrix synthesis and proliferation, endocytosis and phagocytosis, etc. These adaptive phenotypic shifts are due to epigenetic regulation, mainly related to mechanotransduction. These paradigms actively participate in cardio-arterial pathologies such as atheroma, valve disease, heart failure, aneurysms, hypertension, and physiological aging.
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30
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Al-Sayegh MA, Mahmood SR, Khair SBA, Xie X, El Gindi M, Kim T, Almansoori A, Percipalle P. β-actin contributes to open chromatin for activation of the adipogenic pioneer factor CEBPA during transcriptional reprograming. Mol Biol Cell 2020; 31:2511-2521. [PMID: 32877276 PMCID: PMC7851876 DOI: 10.1091/mbc.e19-11-0628] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Adipogenesis is regulated by a cascade of signals that drive transcriptional reprogramming in adipocytes. Here, we report that nuclear actin regulates the chromatin states that establish tissue- specific expression during adipogenesis. To study the role of β-actin in adipocyte differentiation, we conducted RNA sequencing on wild-type and β-actin knockout mouse embryonic fibroblasts (MEFs) after reprograming to adipocytes. We found that β-actin depletion affects induction of several adipogenic genes during transcriptional reprograming. This impaired regulation of adipogenic genes is linked to reduced expression of the pioneer factor Cebpa and is rescued by reintroducing NLS-tagged β-actin. ATAC-Seq in knockout MEFs revealed that actin-dependent reduction of Cebpa expression correlates with decreased chromatin accessibility and loss of chromatin association of the ATPase Brg1. This, in turn, impairs CEBPB's association with its Cebpa promoter-proximal binding site during adipogenesis. We propose a role for the nuclear β-actin pool in maintaining open chromatin for transcriptional reprogramming during adipogenic differentiation.
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Affiliation(s)
- M A Al-Sayegh
- Biology Program, Science Division, New York University Abu Dhabi (NYUAD), Abu Dhabi, United Arab Emirates
| | - S R Mahmood
- Biology Program, Science Division, New York University Abu Dhabi (NYUAD), Abu Dhabi, United Arab Emirates.,Department of Biology, New York University, New York, NY 10003
| | - S B Abul Khair
- Biology Program, Science Division, New York University Abu Dhabi (NYUAD), Abu Dhabi, United Arab Emirates
| | - X Xie
- Biology Program, Science Division, New York University Abu Dhabi (NYUAD), Abu Dhabi, United Arab Emirates
| | - M El Gindi
- Biology Program, Science Division, New York University Abu Dhabi (NYUAD), Abu Dhabi, United Arab Emirates
| | - T Kim
- Biology Program, Science Division, New York University Abu Dhabi (NYUAD), Abu Dhabi, United Arab Emirates
| | - A Almansoori
- Biology Program, Science Division, New York University Abu Dhabi (NYUAD), Abu Dhabi, United Arab Emirates
| | - P Percipalle
- Biology Program, Science Division, New York University Abu Dhabi (NYUAD), Abu Dhabi, United Arab Emirates.,Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden
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31
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Nuclear actin dynamics in gene expression and genome organization. Semin Cell Dev Biol 2020; 102:105-112. [DOI: 10.1016/j.semcdb.2019.10.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 08/28/2019] [Accepted: 10/24/2019] [Indexed: 11/19/2022]
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32
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Nuclear myosin 1 activates p21 gene transcription in response to DNA damage through a chromatin-based mechanism. Commun Biol 2020; 3:115. [PMID: 32161327 PMCID: PMC7066169 DOI: 10.1038/s42003-020-0836-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 02/18/2020] [Indexed: 12/20/2022] Open
Abstract
Nuclear myosin 1 (NM1) has been implicated in key nuclear functions. Together with actin, it has been shown to initiate and regulate transcription, it is part of the chromatin remodeling complex B-WICH, and is responsible for rearrangements of chromosomal territories in response to external stimuli. Here we show that deletion of NM1 in mouse embryonic fibroblasts leads to chromatin and transcription dysregulation affecting the expression of DNA damage and cell cycle genes. NM1 KO cells exhibit increased DNA damage and changes in cell cycle progression, proliferation, and apoptosis, compatible with a phenotype resulting from impaired p53 signaling. We show that upon DNA damage, NM1 forms a complex with p53 and activates the expression of checkpoint regulator p21 (Cdkn1A) by PCAF and Set1 recruitment to its promoter for histone H3 acetylation and methylation. We propose a role for NM1 in the transcriptional response to DNA damage response and maintenance of genome stability. Venit et al. demonstrate a role for Nuclear myosin 1 (NM1) in the DNA Damage Response by affecting the expression of the p53 target, p21, through chromatin remodeling. They used embryonic fibroblasts from mouse model, high content phenotypic profiling and cell assays, RNA-Seq and ChIP-Seq and pull-down assays and show that NM1 is required for the recruitment of PCAF and SET1 to the p21 gene in response to etoposide.
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33
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Hyrskyluoto A, Vartiainen MK. Regulation of nuclear actin dynamics in development and disease. Curr Opin Cell Biol 2020; 64:18-24. [PMID: 32088545 DOI: 10.1016/j.ceb.2020.01.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 01/17/2020] [Accepted: 01/22/2020] [Indexed: 12/21/2022]
Abstract
Actin has essential functions both in the cytoplasm and in the nucleus, where it has been linked to key nuclear processes, from transcription to DNA damage response. The multifunctional nature of actin suggests that the cell must contain mechanisms to accurately control the cellular actin balance. Indeed, recent results have demonstrated that nuclear actin levels fluctuate to regulate the transcriptional activity of the cell and that controlled nuclear actin polymerization is required for transcription activation, cell cycle progression, and DNA repair. Intriguingly, aberrant nuclear actin regulation has been observed, for example, in cancer, signifying the importance of this process for cellular homeostasis. This review discussed the latest research on how nuclear actin is regulated, and how this influences actin-dependent nuclear processes.
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Affiliation(s)
- Alise Hyrskyluoto
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, 00014, Helsinki, Finland
| | - Maria K Vartiainen
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, 00014, Helsinki, Finland.
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34
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El-Samahy MA, Yao X, Zhang G, Zhang Y, Wang F. A proposed sample handling of ovine cotyledon for proteomic studies. Anal Biochem 2020; 593:113585. [PMID: 31954698 DOI: 10.1016/j.ab.2020.113585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 01/12/2020] [Accepted: 01/14/2020] [Indexed: 11/28/2022]
Abstract
Ovine trophoblast is a suitable material for placental studies. However, a universal protocol for handling ruminant cotyledon samples has still not been reported. Considering the villous structure of ovine cotyledon, we suggest procedures to prepare cotyledons with limited inherent contamination, using semi-dry conditions to avoid freezing damage and sample errors. The cytosolic water-soluble proteins were physically extracted from the frozen cotyledons. High homogeneity was demonstrated between the replicates of both tissue and extract samples. Importantly, the chemical lysis of placental crude extracts was necessary for protein separation and immunoreaction. The integrity of stored tissues was histologically validated using a formalin-fixed paraffin-embedded technique. Using label-free proteomics, we detected 388 Ovis protein-groups in at least two of three biological replicates of either the tissue or extract. Although the water-soluble proteins were dominated by hemoglobin subunits, ten proteins were identified exclusively in all extract replicates. The physical extraction selectively reduced the membrane, extracellular matrix, and cytoskeleton proteins. The hydrolase enzymes, in the extract, hindered the identification of some specific proteins, such as histone H2A. In summary, the proposed workflow may guide further proteomic investigations of ovine cotyledon biology. Furthermore, our proteomic data have inferred some potential mechanisms of ovine trophoblast at parturition.
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Affiliation(s)
- M A El-Samahy
- Jiangsu Livestock Embryo Engineering Laboratory, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China
| | - Xiaolei Yao
- Jiangsu Livestock Embryo Engineering Laboratory, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China
| | - Guomin Zhang
- Jiangsu Livestock Embryo Engineering Laboratory, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China; Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China
| | - Yanli Zhang
- Jiangsu Livestock Embryo Engineering Laboratory, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China
| | - Feng Wang
- Jiangsu Livestock Embryo Engineering Laboratory, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China.
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35
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Percipalle P, Vartiainen M. Cytoskeletal proteins in the cell nucleus: a special nuclear actin perspective. Mol Biol Cell 2020; 30:1781-1785. [PMID: 31306096 PMCID: PMC6727747 DOI: 10.1091/mbc.e18-10-0645] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The emerging role of cytoskeletal proteins in the cell nucleus has become a new frontier in cell biology. Actin and actin-binding proteins regulate chromatin and gene expression, but importantly they are beginning to be essential players in genome organization. These actin-based functions contribute to genome stability and integrity while affecting DNA replication and global transcription patterns. This is likely to occur through interactions of actin with nuclear components including nuclear lamina and subnuclear organelles. An exciting future challenge is to understand how these actin-based genome-wide mechanisms may regulate development and differentiation by interfering with the mechanical properties of the cell nucleus and how regulated actin polymerization plays a role in maintaining nuclear architecture. With a special focus on actin, here we summarize how cytoskeletal proteins operate in the nucleus and how they may be important to consolidate nuclear architecture for sustained gene expression or silencing.
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Affiliation(s)
- Piergiorgio Percipalle
- Biology Program, Science Division, New York University Abu Dhabi, 12988 Abu Dhabi, United Arab Emirates.,Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Maria Vartiainen
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
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36
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Venit T, Mahmood SR, Endara-Coll M, Percipalle P. Nuclear actin and myosin in chromatin regulation and maintenance of genome integrity. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2020; 355:67-108. [DOI: 10.1016/bs.ircmb.2020.05.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/06/2022]
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37
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Ho PJ, Lloyd SM, Bao X. Unwinding chromatin at the right places: how BAF is targeted to specific genomic locations during development. Development 2019; 146:146/19/dev178780. [PMID: 31570369 DOI: 10.1242/dev.178780] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The BAF (SWI/SNF) chromatin remodeling complex plays a crucial role in modulating spatiotemporal gene expression during mammalian development. Although its remodeling activity was characterized in vitro decades ago, the complex actions of BAF in vivo have only recently begun to be unraveled. In living cells, BAF only binds to and remodels a subset of genomic locations. This selectivity of BAF genomic targeting is crucial for cell-type specification and for mediating precise responses to environmental signals. Here, we provide an overview of the distinct molecular mechanisms modulating BAF chromatin binding, including its combinatory assemblies, DNA/histone modification-binding modules and post-translational modifications, as well as its interactions with proteins, RNA and lipids. This Review aims to serve as a primer for future studies to decode the actions of BAF in developmental processes.
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Affiliation(s)
- Patric J Ho
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Sarah M Lloyd
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Xiaomin Bao
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA .,Department of Dermatology, Northwestern University, Evanston, IL 60208, USA.,Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Evanston, IL 60208, USA
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38
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Caridi CP, Plessner M, Grosse R, Chiolo I. Nuclear actin filaments in DNA repair dynamics. Nat Cell Biol 2019; 21:1068-1077. [PMID: 31481797 PMCID: PMC6736642 DOI: 10.1038/s41556-019-0379-1] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Accepted: 07/24/2019] [Indexed: 02/06/2023]
Abstract
Recent development of innovative tools for live imaging of actin filaments (F-actin) enabled the detection of surprising nuclear structures responding to various stimuli, challenging previous models that actin is substantially monomeric in the nucleus. We review these discoveries, focusing on double-strand break (DSB) repair responses. These studies revealed a remarkable network of nuclear filaments and regulatory mechanisms coordinating chromatin dynamics with repair progression and led to a paradigm shift by uncovering the directed movement of repair sites.
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Affiliation(s)
| | - Matthias Plessner
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Freiburg, Freiburg im Breisgau, Germany
- CIBSS - Centre for Integrative Biological Signaling Studies, University of Freiburg, Freiburg im Breisgau, Germany
| | - Robert Grosse
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Freiburg, Freiburg im Breisgau, Germany
- CIBSS - Centre for Integrative Biological Signaling Studies, University of Freiburg, Freiburg im Breisgau, Germany
| | - Irene Chiolo
- Molecular and Computational Biology Department, University of Southern California, Los Angeles, CA, USA.
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39
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Carter TY, Gadwala S, Chougule AB, Bui APN, Sanders AC, Chaerkady R, Cormier N, Cole RN, Thomas JH. Actomyosin contraction during cellularization is regulated in part by Src64 control of Actin 5C protein levels. Genesis 2019; 57:e23297. [PMID: 30974046 DOI: 10.1002/dvg.23297] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 03/27/2019] [Indexed: 11/09/2022]
Abstract
Src64 is required for actomyosin contraction during cellularization of the Drosophila embryonic blastoderm. The mechanism of actomyosin ring constriction is poorly understood even though a number of cytoskeletal regulators have been implicated in the assembly, organization, and contraction of these microfilament rings. How these cytoskeletal processes are regulated during development is even less well understood. To investigate the role of Src64 as an upstream regulator of actomyosin contraction, we conducted a proteomics screen to identify proteins whose expression levels are controlled by src64. Global levels of actin are reduced in src64 mutant embryos. Furthermore, we show that reduction of the actin isoform Actin 5C causes defects in actomyosin contraction during cellularization similar to those caused by src64 mutation, indicating that a relatively high level of Actin 5C is required for normal actomyosin contraction and furrow canal structure. However, reduction of Actin 5C levels only slows down actomyosin ring constriction rather than preventing it, suggesting that src64 acts not only to modulate actin levels, but also to regulate the actomyosin cytoskeleton by other means.
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Affiliation(s)
- Tammy Y Carter
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, Texas
| | - Swetha Gadwala
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, Texas
| | - Ashish B Chougule
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, Texas
| | - Anh P N Bui
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, Texas
| | - Alex C Sanders
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, Texas
| | - Raghothama Chaerkady
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Nathaly Cormier
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, Texas
| | - Robert N Cole
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Jeffrey H Thomas
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, Texas
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40
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Tsai E, Casaccia P. Mechano-modulation of nuclear events regulating oligodendrocyte progenitor gene expression. Glia 2019; 67:1229-1239. [PMID: 30734358 DOI: 10.1002/glia.23595] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 01/03/2019] [Accepted: 01/14/2019] [Indexed: 12/20/2022]
Abstract
Oligodendrocytes differentiate from oligodendrocyte progenitor cells (OPCs) in response to distinct extracellular signals. This process requires changes in gene expression resulting from the interplay between transcription factors and epigenetic modulators. Extracellular signals include chemical and physical stimuli. This review focuses on the signaling mechanisms activated in oligodendrocyte progenitors in response to mechanical forces. Of particular interest is a better understanding on how these forces are transduced into the OPC nuclei and subsequently reshape their epigenetic landscape. Here we will introduce the concept of epigenetic regulation of gene expression, first in general and then focusing on the oligodendrocyte lineage. We will then review the current literature on mechano-transduction in distinct cell types, followed by pathways identified in myelinating oligodendrocytes and their progenitors. Overall, the reader will be provided with a comprehensive review of the signaling pathways which allow oligodendrocyte progenitors to "sense" physical forces and transduce them into patterns of gene expression.
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Affiliation(s)
- Eric Tsai
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York.,Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Patrizia Casaccia
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York.,Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, New York.,Department of Biology and Biochemistry, Neuroscience Initiative at the Advanced Science Research Center of the Graduate Center of The City University of New York, New York
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41
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β-actin regulates a heterochromatin landscape essential for optimal induction of neuronal programs during direct reprograming. PLoS Genet 2018; 14:e1007846. [PMID: 30557298 PMCID: PMC6312353 DOI: 10.1371/journal.pgen.1007846] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 12/31/2018] [Accepted: 11/21/2018] [Indexed: 02/02/2023] Open
Abstract
During neuronal development, β-actin serves an important role in growth cone mediated axon guidance. Consistent with this notion, in vivo ablation of the β-actin gene leads to abnormalities in the nervous system. However, whether β-actin is involved in the regulation of neuronal gene programs is not known. In this study, we directly reprogramed β-actin+/+ WT, β-actin+/- HET and β-actin-/- KO mouse embryonic fibroblast (MEFs) into chemically induced neurons (CiNeurons). Using RNA-seq analysis, we profiled the transcriptome changes among the CiNeurons. We discovered that induction of neuronal gene programs was impaired in KO CiNeurons in comparison to WT ones, whereas HET CiNeurons showed an intermediate levels of induction. ChIP-seq analysis of heterochromatin markers demonstrated that the impaired expression of neuronal gene programs correlated with the elevated H3K9 and H3K27 methylation levels at gene loci in β-actin deficient MEFs, which is linked to the loss of chromatin association of the BAF complex ATPase subunit Brg1. Together, our study shows that heterochromatin alteration in β-actin null MEFs impedes the induction of neuronal gene programs during direct reprograming. These findings are in line with the notion that H3K9Me3-based heterochromatin forms a major epigenetic barrier during cell fate change. Although β-actin plays an important role in growth cone mediated axon guidance in neurons, the potential role of β-actin in controlling neuron differentiation remains unknown. Here, we converted β-actin+/+ WT, β-actin+/- HET and β-actin-/- KO mouse embryonic fibroblast (MEFs) into chemically induced neurons (CiNeurons) by direct reprograming. We found that the up-regulation of neuronal programs was impaired in β-actin-/- CiNeurons in comparison to WT ones. β-actin+/- HET CiNeurons showed an intermediate level of neuronal program expression, suggesting that β-actin dosage plays an important role during direct neuronal reprograming. Importantly, the impaired up-regulation of neuron-related genes was associated with the elevated H3K9 and H3K27 methylation levels at gene loci in KO MEFs. These epigenetic changes were accompanied by the impaired chromatin association of Brg1-containing chromatin remodeling BAF complex in β-actin null cells. Together our study demonstrates that β-actin is required for the optimal induction of neuronal gene programs during direct reprograming by presetting a favorable chromatin status.
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Wineland DM, Kelpsch DJ, Tootle TL. Multiple Pools of Nuclear Actin. Anat Rec (Hoboken) 2018; 301:2014-2036. [PMID: 30312534 PMCID: PMC6293971 DOI: 10.1002/ar.23964] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 04/14/2018] [Accepted: 04/17/2018] [Indexed: 02/06/2023]
Abstract
While nuclear actin was reported ~50 years ago, it's in vivo prevalence and structure remain largely unknown. Here, we use Drosophila oogenesis, that is, follicle development, to characterize nuclear actin. We find that three different reagents-DNase I, anti-actin C4, and anti-actin AC15-recognize distinct pools of nuclear actin. DNase I labels monomeric or G-actin, and, during follicle development, G-actin is present in the nucleus of every cell. Some G-actin is recognized by the C4 antibody. In particular, C4 nuclear actin colocalizes with DNase I to the nucleolus in anterior escort cells, follicle stem cells, some mitotic follicle cells, and a subset of nurse cells during early oogenesis. C4 also labels polymeric nuclear actin in the nucleoplasm of the germline stem cells, early cystoblasts, and oocytes. The AC15 antibody labels a completely distinct pool of nuclear actin from that of DNase I and C4. Specifically, AC15 nuclear actin localizes to the chromatin in the nurse and follicle cells during mid-to-late oogenesis. Within the oocyte, AC15 nuclear actin progresses from localizing to puncta surrounding the DNA, to forming a filamentous cage around the chromosomes. Together these findings reveal that nuclear actin is highly prevalent in vivo, and multiple pools of nuclear actin exist and can be recognized using different reagents. Additionally, our localization studies suggest that nuclear actin may regulate stemness, nucleolar structure and function, transcription, and nuclear structure. Such findings call for further studies to explore the prevalence, diversity, and functions of nuclear actin across tissues and organisms. Anat Rec, 301:2014-2036, 2018. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- Dylane M. Wineland
- Anatomy and Cell Biology, University of Iowa Carver College of
Medicine, 51 Newton Rd, 1-500 BSB, Iowa City, IA 52242
| | - Daniel J. Kelpsch
- Anatomy and Cell Biology, University of Iowa Carver College of
Medicine, 51 Newton Rd, 1-500 BSB, Iowa City, IA 52242
| | - Tina L. Tootle
- Anatomy and Cell Biology, University of Iowa Carver College of
Medicine, 51 Newton Rd, 1-500 BSB, Iowa City, IA 52242
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Kelpsch DJ, Tootle TL. Nuclear Actin: From Discovery to Function. Anat Rec (Hoboken) 2018; 301:1999-2013. [PMID: 30312531 PMCID: PMC6289869 DOI: 10.1002/ar.23959] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 04/20/2018] [Accepted: 05/14/2018] [Indexed: 01/02/2023]
Abstract
While actin was discovered in the nucleus over 50 years ago, research lagged for decades due to strong skepticism. The revitalization of research into nuclear actin occurred after it was found that cellular stresses induce the nuclear localization and alter the structure of actin. These studies provided the first hints that actin has a nuclear function. Subsequently, it was established that the nuclear import and export of actin is highly regulated. While the structures of nuclear actin remain unclear, it can function as monomers, polymers, and even rods. Furthermore, even within a given structure, distinct pools of nuclear actin that can be differentially labeled have been identified. Numerous mechanistic studies have uncovered an array of functions for nuclear actin. It regulates the activity of RNA polymerases, as well as specific transcription factors. Actin also modulates the activity of several chromatin remodeling complexes and histone deacetylases, to ultimately impinge on transcriptional programing and DNA damage repair. Further, nuclear actin mediates chromatin movement and organization. It has roles in meiosis and mitosis, and these functions may be functionally conserved from ancient bacterial actin homologs. The structure and integrity of the nuclear envelope and sub-nuclear compartments are also regulated by nuclear actin. Furthermore, nuclear actin contributes to human diseases like cancer, neurodegeneration, and myopathies. Here, we explore the early discovery of actin in the nucleus and discuss the forms and functions of nuclear actin in both normal and disease contexts. Anat Rec, 301:1999-2013, 2018. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- Daniel J. Kelpsch
- Anatomy and Cell Biology, University of Iowa Carver College of Medicine, 51 Newton Rd, 1-500 BSB, Iowa City, IA 52242
| | - Tina L. Tootle
- Anatomy and Cell Biology, University of Iowa Carver College of Medicine, 51 Newton Rd, 1-500 BSB, Iowa City, IA 52242
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Nuclear actin: ancient clue to evolution in eukaryotes? Histochem Cell Biol 2018; 150:235-244. [DOI: 10.1007/s00418-018-1693-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/29/2018] [Indexed: 12/31/2022]
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Xie X, Percipalle P. Elevated transforming growth factor β signaling activation in β-actin-knockout mouse embryonic fibroblasts enhances myofibroblast features. J Cell Physiol 2018; 233:8884-8895. [PMID: 29851084 PMCID: PMC6220129 DOI: 10.1002/jcp.26808] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Accepted: 05/30/2018] [Indexed: 01/08/2023]
Abstract
Signaling by the transforming growth factor‐β (TGF‐β) is an essential pathway regulating a variety of cellular events. TGF‐β is produced as a latent protein complex and is required to be activated before activating the receptor. The mechanical force at the cell surface is believed to be a mechanism for latent TGF‐β activation. Using β‐actin null mouse embryonic fibroblasts as a model, in which actin cytoskeleton and cell‐surface biophysical features are dramatically altered, we reveal increased TGF‐β1 activation and the upregulation of TGF‐β target genes. In β‐actin null cells, we show evidence that the enhanced TGF‐β signaling relies on the active utilization of latent TGF‐β1 in the cell culture medium. TGF‐β signaling activation contributes to the elevated reactive oxygen species production, which is likely mediated by the upregulation of Nox4. The previously observed myofibroblast phenotype of β‐actin null cells is inhibited by TGF‐β signaling inhibition, while the expression of actin cytoskeleton genes and angiogenic phenotype are not affected. Together, our study shows a scenario that the alteration of the actin cytoskeleton and the consequent changes in cellular biophysical features lead to changes in cell signaling process such as TGF‐β activation, which in turn contributes to the enhanced myofibroblast phenotype.
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Affiliation(s)
- Xin Xie
- Biology Program, Science Division, New York University Abu Dhabi (NYUAD), Abu Dhabi, United Arab Emirates
| | - Piergiorgio Percipalle
- Biology Program, Science Division, New York University Abu Dhabi (NYUAD), Abu Dhabi, United Arab Emirates.,Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
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In Mitochondria ?-Actin Regulates mtDNA Transcription and Is Required for Mitochondrial Quality Control. iScience 2018; 3:226-237. [PMID: 30428323 PMCID: PMC6137402 DOI: 10.1016/j.isci.2018.04.021] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 03/27/2018] [Accepted: 04/26/2018] [Indexed: 12/11/2022] Open
Abstract
In eukaryotic cells, actin regulates both cytoplasmic and nuclear functions. However, whether actin-based structures are present in the mitochondria and are involved in mitochondrial functions has not been investigated. Here, using wild-type ?-actin +/+ and knockout (KO) ?-actin ?/? mouse embryonic fibroblasts we show evidence for the defect in maintaining mitochondrial membrane potential (MMP) in ?-actin-null cells. MMP defects were associated with impaired mitochondrial DNA (mtDNA) transcription and nuclear oxidative phosphorylation (OXPHOS) gene expression. Using super-resolution microscopy we provided direct evidence on the presence of ?-actin-containing structures inside mitochondria. Large aggregates of TFAM-stained nucleoids were observed in bulb-shaped mitochondria in KO cells, suggesting defects in mitochondrial nucleoid segregation without ?-actin. The observation that mitochondria-targeted ?-actin rescued mtDNA transcription and MMP suggests an indispensable functional role of a mitochondrial ?-actin pool necessary for mitochondrial quality control.
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