1
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Nair A, Khanna J, Kler J, Ragesh R, Sengupta K. Nuclear envelope and chromatin choreography direct cellular differentiation. Nucleus 2025; 16:2449520. [PMID: 39943681 PMCID: PMC11834525 DOI: 10.1080/19491034.2024.2449520] [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: 10/01/2024] [Revised: 12/28/2024] [Accepted: 12/30/2024] [Indexed: 02/20/2025] Open
Abstract
The nuclear envelope plays an indispensable role in the spatiotemporal organization of chromatin and transcriptional regulation during the intricate process of cell differentiation. This review outlines the distinct regulatory networks between nuclear envelope proteins, transcription factors and epigenetic modifications in controlling the expression of cell lineage-specific genes during differentiation. Nuclear lamina with its associated nuclear envelope proteins organize heterochromatin via Lamina-Associated Domains (LADs), proximal to the nuclear periphery. Since nuclear lamina is mechanosensitive, we critically examine the impact of extracellular forces on differentiation outcomes. The nuclear envelope is spanned by nuclear pore complexes which, in addition to their central role in transport, are associated with chromatin organization. Furthermore, mutations in the nuclear envelope proteins disrupt differentiation, resulting in developmental disorders. Investigating the underlying nuclear envelope controlled regulatory mechanisms of chromatin remodelling during lineage commitment will accelerate our fundamental understanding of developmental biology and regenerative medicine.
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Affiliation(s)
- Anjitha Nair
- Chromosome Biology Lab (CBL), Indian Institute of Science Education and Research (IISER) Pune, Maharashtra, India
| | - Jayati Khanna
- Chromosome Biology Lab (CBL), Indian Institute of Science Education and Research (IISER) Pune, Maharashtra, India
| | - Jashan Kler
- Chromosome Biology Lab (CBL), Indian Institute of Science Education and Research (IISER) Pune, Maharashtra, India
| | - Rohith Ragesh
- Chromosome Biology Lab (CBL), Indian Institute of Science Education and Research (IISER) Pune, Maharashtra, India
| | - Kundan Sengupta
- Chromosome Biology Lab (CBL), Indian Institute of Science Education and Research (IISER) Pune, Maharashtra, India
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2
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Augspurger K, Martin E, Maynard J, Welle K, Ghaemmaghami S, Burlingame A, Panning B, Buchwalter A. O-GlcNAc modifications regulate lamin A tail processing. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2025:2025.03.11.642699. [PMID: 40161616 PMCID: PMC11952380 DOI: 10.1101/2025.03.11.642699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/02/2025]
Abstract
Lamin A processing is highly regulated, and necessary for proper assembly of the nuclear lamina facilitating its role in nuclear structure and chromatin organization. Pre-lamin A is first farnesylated, and then a short C-terminal peptide is cleaved to produce mature lamin A. O-GlcNAc Transferase (OGT), a glucose sensitive post-translational modification enzyme, is a potential regulator for lamin A processing. To explore the role of OGT in lamin A biogenesis, we examined the effects of OGT levels and OGT inhibition. Variation in OGT dose or inhibition of its activity did not alter endogenous lamin A abundance or distribution. To more directly test the regulatory effects of O-GlcNAcylation on lamin A, we adapted a tail cleavage assay. Mutation of an OGT binding motif and O-GlcNAc modification sites reduced tail cleavage efficiency, suggesting that O-GlcNAcylation promotes lamin A processing. Our findings add to the understanding of the regulation of lamin A cleavage and identify a potential link between glucose metabolism and lamina biogenesis.
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Affiliation(s)
- Katherine Augspurger
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, United States
- TETRAD Graduate Program, University of California San Francisco, San Francisco, United States
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, United States
| | - Elizabeth Martin
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, United States
- TETRAD Graduate Program, University of California San Francisco, San Francisco, United States
| | - Jason Maynard
- Department of Pharmaceutical Chemistry, University of University of California San Francisco, San Francisco, United States
| | - Kevin Welle
- Mass Spectrometry Resource Laboratory, University of Rochester, Rochester, New York, United States
| | - Sina Ghaemmaghami
- Mass Spectrometry Resource Laboratory, University of Rochester, Rochester, New York, United States
- Department of Biology, University of Rochester, Rochester, New York, United States
| | - Al Burlingame
- Department of Pharmaceutical Chemistry, University of University of California San Francisco, San Francisco, United States
| | - Barbara Panning
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, United States
| | - Abby Buchwalter
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, United States
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3
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Goelzer M, Howard S, Zavala AG, Conway D, Rubin J, Uzer G. Depletion of SUN1/2 induces heterochromatin accrual in mesenchymal stem cells during adipogenesis. Commun Biol 2025; 8:428. [PMID: 40082539 PMCID: PMC11906923 DOI: 10.1038/s42003-025-07832-3] [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: 04/20/2022] [Accepted: 02/24/2025] [Indexed: 03/16/2025] Open
Abstract
Critical to the mechano-regulation of mesenchymal stem cells (MSC), Linker of the Nucleoskeleton and Cytoskeleton (LINC) complex transduces cytoskeletal forces to the nuclei. The LINC complex contains outer nuclear membrane Nesprin proteins that associate with the cytoskeleton and their inner nuclear membrane couplers, SUN proteins. Here we tested the hypothesis that severing of the LINC complex-mediated cytoskeletal connections may have different effects on chromatin organization and MSC differentiation than those due to ablation of SUN proteins. In cells cultured under adipogenic conditions, interrupting LINC complex function through dominant-negative KASH domain expression (dnKASH) increased adipogesis while heterochromatin H3K27 and H3K9 methylation was unaltered. In contrast, SUN1/2 depletion inhibited adipogenic gene expression and fat droplet formation; as well the anti-adipogenic effect of SUN1/2 depletion was accompanied by increased H3K9me3, which was enriched on Adipoq, silencing this fat locus. We conclude that releasing the nucleus from cytoskeletal constraints via dnKASH accelerates adipogenesis while depletion of SUN1/2 increases heterochromatin accrual on adipogenic genes in a fashion independent of LINC complex function. Therefore, while these two approaches both disable LINC complex functions, their divergent effects on the epigenetic landscape indicate they cannot be used interchangeably to study mechanical regulation of cell differentiation.
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Affiliation(s)
- Matthew Goelzer
- Boise State University, Boise, ID, USA
- Oral Roberts University, Tulsa, OK, USA
| | | | | | - Daniel Conway
- The Ohio State University University, Columbus, OH, USA
| | - Janet Rubin
- University of North Carolina at Chapel Hill, Chapel Hill, USA
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4
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Warren J, Wang J, Dhoro F, Chao B, Reddy A, Petrie SK, David LL, Xiao X, Li BX. SMAP3-ID for Identification of Endogenous Protein-Protein Interactions Reveals Regulation of Mitochondrial Activity by Lamins. JACS AU 2025; 5:302-319. [PMID: 39886595 PMCID: PMC11775715 DOI: 10.1021/jacsau.4c00988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2024] [Revised: 01/02/2025] [Accepted: 01/03/2025] [Indexed: 02/01/2025]
Abstract
Proteins regulate biological functions through the formation of distinct protein complexes. Identification and characterization of these protein-protein interactions are critical to deciphering their mechanism of action. Different antibody-based or cross-linking-based methods have been developed to identify the protein-protein interactions. However, these methods require genetic engineering or other means to disrupt the native environments. To circumvent this limitation, we introduce here SMAP3-ID (small-molecule-assisted identification of protein-protein interactions through proximity) method to identify protein-protein interactions in native cellular environment. This method combines a selective ligand for binding to a protein of interest for photo-cross-linking, a live-cell-compatible bioorthogonal click reaction with a trifunctional chemical probe, and a final photo-cross-linking reaction to covalently capture the interacting proteins. Using the SMAP3-ID method and nuclear lamins as an example, we identified numerous lamin interactors in native cells. Significantly, we identified a number of mitochondrial enzymes as novel lamin A (LA) interactors. The interactions between mitochondrial enzymes and LA were further validated, which provides mechanistic insights underlying the metabolic alterations caused by mutations in LA. Furthermore, our previously described small-molecule ligand for LA, LBL1, also induced changes in mitochondrial activity and cellular bioenergetic organization. We conclude that SMAP3-ID is a potentially powerful and generalizable method to identify protein-protein interactions in the native cellular environment.
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Affiliation(s)
- Julia Warren
- Program
in Chemical Biology, Department of Chemical Physiology and
Biochemistry, Proteomics Shared Resources, Knight Cancer Institute, Department of Neurology, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd, Portland, Oregon 97239, United States
| | - Jian Wang
- Program
in Chemical Biology, Department of Chemical Physiology and
Biochemistry, Proteomics Shared Resources, Knight Cancer Institute, Department of Neurology, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd, Portland, Oregon 97239, United States
| | - Francis Dhoro
- Program
in Chemical Biology, Department of Chemical Physiology and
Biochemistry, Proteomics Shared Resources, Knight Cancer Institute, Department of Neurology, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd, Portland, Oregon 97239, United States
| | - Bo Chao
- Program
in Chemical Biology, Department of Chemical Physiology and
Biochemistry, Proteomics Shared Resources, Knight Cancer Institute, Department of Neurology, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd, Portland, Oregon 97239, United States
| | - Ashok Reddy
- Program
in Chemical Biology, Department of Chemical Physiology and
Biochemistry, Proteomics Shared Resources, Knight Cancer Institute, Department of Neurology, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd, Portland, Oregon 97239, United States
| | - Stefanie Kaech Petrie
- Program
in Chemical Biology, Department of Chemical Physiology and
Biochemistry, Proteomics Shared Resources, Knight Cancer Institute, Department of Neurology, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd, Portland, Oregon 97239, United States
| | - Larry L. David
- Program
in Chemical Biology, Department of Chemical Physiology and
Biochemistry, Proteomics Shared Resources, Knight Cancer Institute, Department of Neurology, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd, Portland, Oregon 97239, United States
| | - Xiangshu Xiao
- Program
in Chemical Biology, Department of Chemical Physiology and
Biochemistry, Proteomics Shared Resources, Knight Cancer Institute, Department of Neurology, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd, Portland, Oregon 97239, United States
| | - Bingbing X. Li
- Program
in Chemical Biology, Department of Chemical Physiology and
Biochemistry, Proteomics Shared Resources, Knight Cancer Institute, Department of Neurology, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd, Portland, Oregon 97239, United States
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5
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Mella J, Volk R, Zaro B, Buchwalter A. C-terminal tagging, transmembrane domain hydrophobicity, and an ER retention motif influence the secretory trafficking of the inner nuclear membrane protein emerin. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2025:2025.01.19.633811. [PMID: 39896633 PMCID: PMC11785080 DOI: 10.1101/2025.01.19.633811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2025]
Abstract
The inner nuclear membrane (INM), a subdomain of the endoplasmic reticulum (ER), sequesters hundreds of transmembrane proteins within the nucleus. We previously found that one INM protein, emerin, can evade the INM by secretory transport to the lysosome, where it is degraded. In this work, we used targeted mutagenesis to identify intrinsic sequences that promote or inhibit emerin's secretory trafficking. By manipulating these sequences across several tag and expression level combinations, we now find that emerin's localization is sensitive to C-terminal GFP tagging. While emerin's long, hydrophobic C-terminal transmembrane domain facilitates trafficking to the lysosome, extending its lumenal terminus with a GFP tag biases the protein toward this pathway. In contrast, we identify a conserved ER retention sequence that stabilizes N- and C-terminally tagged emerin by limiting its lysosomal flux. These findings underscore long-standing concerns about tagging artifacts and reveal novel determinants of tail-anchored INM protein targeting.
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Affiliation(s)
- Jessica Mella
- Cardiovascular Research Institute, University of California, San Francisco, CA, USA
| | - Regan Volk
- Cardiovascular Research Institute, University of California, San Francisco, CA, USA
| | - Balyn Zaro
- Cardiovascular Research Institute, University of California, San Francisco, CA, USA
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA, USA
| | - Abigail Buchwalter
- Cardiovascular Research Institute, University of California, San Francisco, CA, USA
- Department of Physiology, University of California, San Francisco, CA, USA
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6
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Kono Y, Shimi T. Crosstalk between mitotic reassembly and repair of the nuclear envelope. Nucleus 2024; 15:2352203. [PMID: 38780365 PMCID: PMC11123513 DOI: 10.1080/19491034.2024.2352203] [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: 09/01/2023] [Accepted: 05/01/2024] [Indexed: 05/25/2024] Open
Abstract
In eukaryotic cells, the nuclear envelope (NE) is a membrane partition between the nucleus and the cytoplasm to compartmentalize nuclear contents. It plays an important role in facilitating nuclear functions including transcription, DNA replication and repair. In mammalian cells, the NE breaks down and then reforms during cell division, and in interphase it is restored shortly after the NE rupture induced by mechanical force. In this way, the partitioning effect is regulated through dynamic processes throughout the cell cycle. A failure in rebuilding the NE structure triggers the mixing of nuclear and cytoplasmic contents, leading to catastrophic consequences for the nuclear functions. Whereas the precise details of molecular mechanisms for NE reformation during cell division and NE restoration in interphase are still being investigated, here, we mostly focus on mammalian cells to describe key aspects that have been identified and to discuss the crosstalk between them.
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Affiliation(s)
- Yohei Kono
- Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kanazawa, Japan
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Takeshi Shimi
- Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kanazawa, Japan
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7
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Wang Y, Chen Z, Yang G, Yuan G. Unveiling the roles of LEMD proteins in cellular processes. Life Sci 2024; 357:123116. [PMID: 39374771 DOI: 10.1016/j.lfs.2024.123116] [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: 07/16/2024] [Revised: 09/30/2024] [Accepted: 10/03/2024] [Indexed: 10/09/2024]
Abstract
Proteins localized in the inner nuclear membrane (INM) engage in various fundamental cellular processes via their interactions with outer nuclear membrane (ONM) proteins and nuclear lamina. LAP2-emerin-MAN1 domain (LEMD) family proteins, predominantly positioned in the INM, participate in the maintenance of INM functions, including the reconstruction of the nuclear envelope during mitosis, mechanotransduction, and gene transcriptional modulation. Malfunction of LEMD proteins leads to severe tissue-restricted diseases, which may manifest as fatal deformities and defects. In this review, we summarize the significant roles of LEMD proteins in cellular processes, explains the mechanisms of LEMD protein-related diseases, and puts forward questions in less-explored areas like details in tissue-restricted phenotypes. It intends to sort out previous works about LEMD proteins and pave way for future researchers who might discover deeper mechanisms of and better treatment strategies for LEMD protein-related diseases.
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Affiliation(s)
- Yiyun Wang
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, Hubei Key Laboratory of Stomatology, School & Hospital of Stomatology, Wuhan University, Wuhan, Hubei 430079, China; Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan 430071, China
| | - Zhi Chen
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, Hubei Key Laboratory of Stomatology, School & Hospital of Stomatology, Wuhan University, Wuhan, Hubei 430079, China; Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan 430071, China
| | - Guobin Yang
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, Hubei Key Laboratory of Stomatology, School & Hospital of Stomatology, Wuhan University, Wuhan, Hubei 430079, China; Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan 430071, China
| | - Guohua Yuan
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, Hubei Key Laboratory of Stomatology, School & Hospital of Stomatology, Wuhan University, Wuhan, Hubei 430079, China; Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan 430071, China.
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8
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Jinesh GG, Smallin MT, Mtchedlidze N, Napoli M, Lockhart JH, Flores ER, Brohl AS. C19MC drives nucleolar invasion of mitochondria and meiotic nuclear division in human cancers. iScience 2024; 27:111132. [PMID: 39563898 PMCID: PMC11575172 DOI: 10.1016/j.isci.2024.111132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 06/26/2024] [Accepted: 10/07/2024] [Indexed: 11/21/2024] Open
Abstract
The chromosome-19 miRNA cluster (C19MC) restricts viruses depending on the multinucleated state of placental trophoblasts. However, the relationship of C19MC to multinucleation is unknown. Here we show that C19MC is coexpressed in multiple cancer type subsets with meiosis-related genes. We discovered a novel meiosis-III that exhibits simultaneous progression of meiotic nuclear division (MND) and cytokinesis. C19MC promotes meiotic bridged-chromosomes to block MND and cytokinesis to generate multinucleated cells. MND starts with the invagination of nuclear membrane to form nucle(ol)ar invasive cytoplasm (NiC), mitochondria and protein cargoes. Aurora-B regulates the efflux of cargos from NiC, whereas C19MC, CDK1, and autophagy promote cargo influx to inflate NiC size for MND progression. Using CRISPR human genetic engineering we demonstrate that the C19MC expression is required for NiC-driven MND and multinucleation. This discovery has impacts on cancer-pathogen interactions, immunotherapy, vertical transmission of viruses, antiviral research and SpCas9-CRISPR therapeutics.
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Affiliation(s)
- Goodwin G Jinesh
- Department of Molecular Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA
- Molecular Medicine Program, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA
| | - Marian T Smallin
- Department of Molecular Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA
- Molecular Medicine Program, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA
| | - Nino Mtchedlidze
- Department of Molecular Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA
- Molecular Medicine Program, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA
| | - Marco Napoli
- Department of Molecular Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA
| | - John H Lockhart
- Department of Molecular Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA
| | - Elsa R Flores
- Department of Molecular Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA
- Cancer Biology and Evolution Program, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA
| | - Andrew S Brohl
- Molecular Medicine Program, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA
- Sarcoma Department, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA
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9
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Hansen E, Rolling C, Wang M, Holaska JM. Emerin deficiency drives MCF7 cells to an invasive phenotype. Sci Rep 2024; 14:19998. [PMID: 39198511 PMCID: PMC11358522 DOI: 10.1038/s41598-024-70752-5] [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: 03/05/2024] [Accepted: 08/20/2024] [Indexed: 09/01/2024] Open
Abstract
During metastasis, cancer cells traverse the vasculature by squeezing through very small gaps in the endothelium. Thus, nuclei in metastatic cancer cells must become more malleable to move through these gaps. Our lab showed invasive breast cancer cells have 50% less emerin protein resulting in smaller, misshapen nuclei, and higher metastasis rates than non-cancerous controls. Thus, emerin deficiency was predicted to cause increased nuclear compliance, cell migration, and metastasis. We tested this hypothesis by downregulating emerin in noninvasive MCF7 cells and found emerin knockdown causes smaller, dysmorphic nuclei, resulting in increased impeded cell migration. Emerin reduction in invasive breast cancer cells showed similar results. Supporting the clinical relevance of emerin reduction in cancer progression, our analysis of 192 breast cancer patient samples showed emerin expression inversely correlates with cancer invasiveness. We conclude emerin loss is an important driver of invasive transformation and has utility as a biomarker for tumor progression.
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Affiliation(s)
- Emily Hansen
- Department of Biomedical Sciences, Cooper Medical School of Rowan University, MEB 534, 401 South Broadway, Camden, NJ, 08103, USA
- Molecular and Cell Biology and Neuroscience Program, Rowan-Virtua School of Translational Biomedical Engineering and Sciences, Stratford, NJ, 08084, USA
| | - Christal Rolling
- Department of Biomedical Sciences, Cooper Medical School of Rowan University, MEB 534, 401 South Broadway, Camden, NJ, 08103, USA
- Molecular and Cell Biology and Neuroscience Program, Rowan-Virtua School of Translational Biomedical Engineering and Sciences, Stratford, NJ, 08084, USA
| | - Matthew Wang
- Department of Biomedical Sciences, Cooper Medical School of Rowan University, MEB 534, 401 South Broadway, Camden, NJ, 08103, USA
- Rowan-Virtua School of Osteopathic Medicine, Stratford, NJ, 08084, USA
| | - James M Holaska
- Department of Biomedical Sciences, Cooper Medical School of Rowan University, MEB 534, 401 South Broadway, Camden, NJ, 08103, USA.
- Molecular and Cell Biology and Neuroscience Program, Rowan-Virtua School of Translational Biomedical Engineering and Sciences, Stratford, NJ, 08084, USA.
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10
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Hansen E, Rolling C, Wang M, Holaska JM. Emerin deficiency drives MCF7 cells to an invasive phenotype. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.21.581379. [PMID: 38712242 PMCID: PMC11071294 DOI: 10.1101/2024.02.21.581379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
During metastasis, cancer cells traverse the vasculature by squeezing through very small gaps in the endothelium. Thus, nuclei in metastatic cancer cells must become more malleable to move through these gaps. Our lab showed invasive breast cancer cells have 50% less emerin protein resulting in smaller, misshapen nuclei, and higher metastasis rates than non-cancerous controls. Thus, emerin deficiency was predicted to cause increased nuclear compliance, cell migration, and metastasis. We tested this hypothesis by downregulating emerin in noninvasive MCF7 cells and found emerin knockdown causes smaller, dysmorphic nuclei, resulting in increased impeded cell migration. Emerin reduction in invasive breast cancer cells showed similar results. Supporting the clinical relevance of emerin reduction in cancer progression, our analysis of 192 breast cancer patient samples showed emerin expression inversely correlates with cancer invasiveness. We conclude emerin loss is an important driver of invasive transformation and has utility as a biomarker for tumor progression.
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Affiliation(s)
- Emily Hansen
- Department of Biomedical Sciences, Cooper Medical School of Rowan University, Camden, NJ
- Molecular and Cell Biology and Neuroscience Program, Rowan-Virtua School of Translational Biomedical Engineering and Sciences, Stratford, NJ
| | - Christal Rolling
- Department of Biomedical Sciences, Cooper Medical School of Rowan University, Camden, NJ
- Molecular and Cell Biology and Neuroscience Program, Rowan-Virtua School of Translational Biomedical Engineering and Sciences, Stratford, NJ
| | - Matthew Wang
- Department of Biomedical Sciences, Cooper Medical School of Rowan University, Camden, NJ
- Rowan-Virtua School of Osteopathic Medicine
| | - James M. Holaska
- Department of Biomedical Sciences, Cooper Medical School of Rowan University, Camden, NJ
- Molecular and Cell Biology and Neuroscience Program, Rowan-Virtua School of Translational Biomedical Engineering and Sciences, Stratford, NJ
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11
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Dhankhar M, Guo Z, Kant A, Basir R, Joshi R, Heo SC, Mauck RL, Lakadamyali M, Shenoy VB. Revealing the Biophysics of Lamina-Associated Domain Formation by Integrating Theoretical Modeling and High-Resolution Imaging. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.24.600310. [PMID: 38979207 PMCID: PMC11230226 DOI: 10.1101/2024.06.24.600310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
The interactions between chromatin and the nuclear lamina orchestrate cell type-specific gene activity by forming lamina-associated domains (LADs) which preserve cellular characteristics through gene repression. However, unlike the interactions between chromatin segments, the strength of chromatin-lamina interactions and their dependence on cellular environment are not well understood. Here, we develop a theory to predict the size and shape of peripheral heterochromatin domains by considering the energetics of chromatin-chromatin interactions, the affinity between chromatin and the nuclear lamina and the kinetics of methylation and acetylation9in human mesenchymal stem cells (hMSCs). Through the analysis of super-resolution images of peripheral heterochromatin domains using this theoretical framework, we determine the nuclear lamina-wide distribution of chromatin-lamina affinities. We find that the extracted affinity is highly spatially heterogeneous and shows a bimodal distribution, indicating regions along the lamina with strong chromatin binding and those exhibiting vanishing chromatin affinity interspersed with some regions exhibiting a relatively diminished chromatin interactions, in line with the presence of structures such as nuclear pores. Exploring the role of environmental cues on peripheral chromatin, we find that LAD thickness increases when hMSCs are cultured on a softer substrate, in correlation with contractility-dependent translocation of histone deacetylase 3 (HDAC3) from the cytosol to the nucleus. In soft microenvironments, chromatin becomes sequestered at the nuclear lamina, likely due to the interactions of HDAC3 with the chromatin anchoring protein LAP2 β ,increasing chromatin-lamina affinity, as well as elevated levels of the intranuclear histone methylation. Our findings are further corroborated by pharmacological interventions that inhibit contractility, as well as by manipulating methylation levels using epigenetic drugs. Notably, in the context of tendinosis, a chronic condition characterized by collagen degeneration, we observed a similar increase in the thickness of peripheral chromatin akin to that of cells cultured on soft substrates consistent with theoretical predictions. Our findings underscore the pivotal role of the microenvironment in shaping genome organization and highlight its relevance in pathological conditions.
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Keuper K, Bartek J, Maya-Mendoza A. The nexus of nuclear envelope dynamics, circular economy and cancer cell pathophysiology. Eur J Cell Biol 2024; 103:151394. [PMID: 38340500 DOI: 10.1016/j.ejcb.2024.151394] [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: 02/01/2024] [Accepted: 02/02/2024] [Indexed: 02/12/2024] Open
Abstract
The nuclear envelope (NE) is a critical component in maintaining the function and structure of the eukaryotic nucleus. The NE and lamina are disassembled during each cell cycle to enable an open mitosis. Nuclear architecture construction and deconstruction is a prime example of a circular economy, as it fulfills a highly efficient recycling program bound to continuous assessment of the quality and functionality of the building blocks. Alterations in the nuclear dynamics and lamina structure have emerged as important contributors to both oncogenic transformation and cancer progression. However, the knowledge of the NE breakdown and reassembly is still limited to a fraction of participating proteins and complexes. As cancer cells contain highly diverse nuclei in terms of DNA content, but also in terms of nuclear number, size, and shape, it is of great interest to understand the intricate relationship between these nuclear features in cancer cell pathophysiology. In this review, we provide insights into how those NE dynamics are regulated, and how lamina destabilization processes may alter the NE circular economy. Moreover, we expand the knowledge of the lamina-associated domain region by using strategic algorithms, including Artificial Intelligence, to infer protein associations, assess their function and location, and predict cancer-type specificity with implications for the future of cancer diagnosis, prognosis and treatment. Using this approach we identified NUP98 and MECP2 as potential proteins that exhibit upregulation in Acute Myeloid Leukemia (LAML) patients with implications for early diagnosis.
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Affiliation(s)
- Kristina Keuper
- DNA Replication and Cancer Group, Danish Cancer Institute, Copenhagen, Denmark; Genome Integrity Group, Danish Cancer Institute, Copenhagen, Denmark
| | - Jiri Bartek
- Genome Integrity Group, Danish Cancer Institute, Copenhagen, Denmark; Division of Genome Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SciLifeLab, Stockholm, Sweden
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13
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Bougaran P, Bautch VL. Life at the crossroads: the nuclear LINC complex and vascular mechanotransduction. Front Physiol 2024; 15:1411995. [PMID: 38831796 PMCID: PMC11144885 DOI: 10.3389/fphys.2024.1411995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Accepted: 05/02/2024] [Indexed: 06/05/2024] Open
Abstract
Vascular endothelial cells line the inner surface of all blood vessels, where they are exposed to polarized mechanical forces throughout their lifespan. Both basal substrate interactions and apical blood flow-induced shear stress regulate blood vessel development, remodeling, and maintenance of vascular homeostasis. Disruption of these interactions leads to dysfunction and vascular pathologies, although how forces are sensed and integrated to affect endothelial cell behaviors is incompletely understood. Recently the endothelial cell nucleus has emerged as a prominent force-transducing organelle that participates in vascular mechanotransduction, via communication to and from cell-cell and cell-matrix junctions. The LINC complex, composed of SUN and nesprin proteins, spans the nuclear membranes and connects the nuclear lamina, the nuclear envelope, and the cytoskeleton. Here we review LINC complex involvement in endothelial cell mechanotransduction, describe unique and overlapping functions of each LINC complex component, and consider emerging evidence that two major SUN proteins, SUN1 and SUN2, orchestrate a complex interplay that extends outward to cell-cell and cell-matrix junctions and inward to interactions within the nucleus and chromatin. We discuss these findings in relation to vascular pathologies such as Hutchinson-Gilford progeria syndrome, a premature aging disorder with cardiovascular impairment. More knowledge of LINC complex regulation and function will help to understand how the nucleus participates in endothelial cell force sensing and how dysfunction leads to cardiovascular disease.
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Affiliation(s)
- Pauline Bougaran
- Department of Biology, The University of North Carolina, Chapel Hill, NC, United States
| | - Victoria L. Bautch
- Department of Biology, The University of North Carolina, Chapel Hill, NC, United States
- McAllister Heart Institute, The University of North Carolina, Chapel Hill, NC, United States
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14
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James C, Möller U, Spillner C, König S, Dybkov O, Urlaub H, Lenz C, Kehlenbach RH. Phosphorylation of ELYS promotes its interaction with VAPB at decondensing chromosomes during mitosis. EMBO Rep 2024; 25:2391-2417. [PMID: 38605278 PMCID: PMC11094025 DOI: 10.1038/s44319-024-00125-6] [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: 09/15/2023] [Revised: 02/23/2024] [Accepted: 03/11/2024] [Indexed: 04/13/2024] Open
Abstract
ELYS is a nucleoporin that localizes to the nuclear side of the nuclear pore complex (NPC) in interphase cells. In mitosis, it serves as an assembly platform that interacts with chromatin and then with nucleoporin subcomplexes to initiate post-mitotic NPC assembly. Here we identify ELYS as a major binding partner of the membrane protein VAPB during mitosis. In mitosis, ELYS becomes phosphorylated at many sites, including a predicted FFAT (two phenylalanines in an acidic tract) motif, which mediates interaction with the MSP (major sperm protein)-domain of VAPB. Binding assays using recombinant proteins or cell lysates and co-immunoprecipitation experiments show that VAPB binds the FFAT motif of ELYS in a phosphorylation-dependent manner. In anaphase, the two proteins co-localize to the non-core region of the newly forming nuclear envelope. Depletion of VAPB results in prolonged mitosis, slow progression from meta- to anaphase and in chromosome segregation defects. Together, our results suggest a role of VAPB in mitosis upon recruitment to or release from ELYS at the non-core region of the chromatin in a phosphorylation-dependent manner.
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Affiliation(s)
- Christina James
- Department of Molecular Biology, Faculty of Medicine, GZMB, Georg-August-University Göttingen, Humboldtallee 23, 37073, Göttingen, Germany
| | - Ulrike Möller
- Department of Molecular Biology, Faculty of Medicine, GZMB, Georg-August-University Göttingen, Humboldtallee 23, 37073, Göttingen, Germany
| | - Christiane Spillner
- Department of Molecular Biology, Faculty of Medicine, GZMB, Georg-August-University Göttingen, Humboldtallee 23, 37073, Göttingen, Germany
| | - Sabine König
- Bioanalytics Group, Institute of Clinical Chemistry, University Medical Center Göttingen, Robert-Koch-Straße 40, 37075, Göttingen, Germany
- Bioanalytical Mass Spectrometry Group, Max-Planck-Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077, Göttingen, Germany
| | - Olexandr Dybkov
- Bioanalytical Mass Spectrometry Group, Max-Planck-Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077, Göttingen, Germany
| | - Henning Urlaub
- Bioanalytics Group, Institute of Clinical Chemistry, University Medical Center Göttingen, Robert-Koch-Straße 40, 37075, Göttingen, Germany
- Bioanalytical Mass Spectrometry Group, Max-Planck-Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077, Göttingen, Germany
| | - Christof Lenz
- Bioanalytics Group, Institute of Clinical Chemistry, University Medical Center Göttingen, Robert-Koch-Straße 40, 37075, Göttingen, Germany
- Bioanalytical Mass Spectrometry Group, Max-Planck-Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077, Göttingen, Germany
| | - Ralph H Kehlenbach
- Department of Molecular Biology, Faculty of Medicine, GZMB, Georg-August-University Göttingen, Humboldtallee 23, 37073, Göttingen, Germany.
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15
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Ko BS, Han MH, Kwon MJ, Cha DG, Ji Y, Park ES, Jeon MJ, Kim S, Lee K, Choi YH, Lee J, Torras-Llort M, Yoon KJ, Lee H, Kim JK, Lee SB. Baf-mediated transcriptional regulation of teashirt is essential for the development of neural progenitor cell lineages. Exp Mol Med 2024; 56:422-440. [PMID: 38374207 PMCID: PMC10907700 DOI: 10.1038/s12276-024-01169-3] [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: 03/10/2023] [Revised: 09/20/2023] [Accepted: 12/10/2023] [Indexed: 02/21/2024] Open
Abstract
Accumulating evidence hints heterochromatin anchoring to the inner nuclear membrane as an upstream regulatory process of gene expression. Given that the formation of neural progenitor cell lineages and the subsequent maintenance of postmitotic neuronal cell identity critically rely on transcriptional regulation, it seems possible that the development of neuronal cells is influenced by cell type-specific and/or context-dependent programmed regulation of heterochromatin anchoring. Here, we explored this possibility by genetically disrupting the evolutionarily conserved barrier-to-autointegration factor (Baf) in the Drosophila nervous system. Through single-cell RNA sequencing, we demonstrated that Baf knockdown induces prominent transcriptomic changes, particularly in type I neuroblasts. Among the differentially expressed genes, our genetic analyses identified teashirt (tsh), a transcription factor that interacts with beta-catenin, to be closely associated with Baf knockdown-induced phenotypes that were suppressed by the overexpression of tsh or beta-catenin. We also found that Baf and tsh colocalized in a region adjacent to heterochromatin in type I NBs. Notably, the subnuclear localization pattern remained unchanged when one of these two proteins was knocked down, indicating that both proteins contribute to the anchoring of heterochromatin to the inner nuclear membrane. Overall, this study reveals that the Baf-mediated transcriptional regulation of teashirt is a novel molecular mechanism that regulates the development of neural progenitor cell lineages.
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Affiliation(s)
- Byung Su Ko
- Department of Brain Sciences, DGIST, Daegu, 42988, Republic of Korea
| | - Myeong Hoon Han
- Department of Brain Sciences, DGIST, Daegu, 42988, Republic of Korea
| | - Min Jee Kwon
- Department of Brain Sciences, DGIST, Daegu, 42988, Republic of Korea
| | - Dong Gon Cha
- Department of New Biology, DGIST, Daegu, 42988, Republic of Korea
| | - Yuri Ji
- Department of Brain Sciences, DGIST, Daegu, 42988, Republic of Korea
| | - Eun Seo Park
- Department of New Biology, DGIST, Daegu, 42988, Republic of Korea
| | - Min Jae Jeon
- Department of Brain Sciences, DGIST, Daegu, 42988, Republic of Korea
| | - Somi Kim
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Kyeongho Lee
- Department of Brain Sciences, DGIST, Daegu, 42988, Republic of Korea
- Convergence Research Advanced Centre for Olfaction, DGIST, Daegu, 42988, Republic of Korea
| | - Yoon Ha Choi
- Department of New Biology, DGIST, Daegu, 42988, Republic of Korea
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Jusung Lee
- Department of New Biology, DGIST, Daegu, 42988, Republic of Korea
| | | | - Ki-Jun Yoon
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Hyosang Lee
- Department of Brain Sciences, DGIST, Daegu, 42988, Republic of Korea
- Convergence Research Advanced Centre for Olfaction, DGIST, Daegu, 42988, Republic of Korea
| | - Jong Kyoung Kim
- Department of New Biology, DGIST, Daegu, 42988, Republic of Korea.
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea.
| | - Sung Bae Lee
- Department of Brain Sciences, DGIST, Daegu, 42988, Republic of Korea.
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16
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Elzamzami FD, Samal A, Arun AS, Dharmaraj T, Prasad NR, Rendon-Jonguitud A, DeVine L, Walston JD, Cole RN, Wilson KL. Native lamin A/C proteomes and novel partners from heart and skeletal muscle in a mouse chronic inflammation model of human frailty. Front Cell Dev Biol 2023; 11:1240285. [PMID: 37936983 PMCID: PMC10626543 DOI: 10.3389/fcell.2023.1240285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 10/05/2023] [Indexed: 11/09/2023] Open
Abstract
Clinical frailty affects ∼10% of people over age 65 and is studied in a chronically inflamed (Interleukin-10 knockout; "IL10-KO") mouse model. Frailty phenotypes overlap the spectrum of diseases ("laminopathies") caused by mutations in LMNA. LMNA encodes nuclear intermediate filament proteins lamin A and lamin C ("lamin A/C"), important for tissue-specific signaling, metabolism and chromatin regulation. We hypothesized that wildtype lamin A/C associations with tissue-specific partners are perturbed by chronic inflammation, potentially contributing to dysfunction in frailty. To test this idea we immunoprecipitated native lamin A/C and associated proteins from skeletal muscle, hearts and brains of old (21-22 months) IL10-KO versus control C57Bl/6 female mice, and labeled with Tandem Mass Tags for identification and quantitation by mass spectrometry. We identified 502 candidate lamin-binding proteins from skeletal muscle, and 340 from heart, including 62 proteins identified in both tissues. Candidates included frailty phenotype-relevant proteins Perm1 and Fam210a, and nuclear membrane protein Tmem38a, required for muscle-specific genome organization. These and most other candidates were unaffected by IL10-KO, but still important as potential lamin A/C-binding proteins in native heart or muscle. A subset of candidates (21 in skeletal muscle, 30 in heart) showed significantly different lamin A/C-association in an IL10-KO tissue (p < 0.05), including AldoA and Gins3 affected in heart, and Lmcd1 and Fabp4 affected in skeletal muscle. To screen for binding, eleven candidates plus prelamin A and emerin controls were arrayed as synthetic 20-mer peptides (7-residue stagger) and incubated with recombinant purified lamin A "tail" residues 385-646 under relatively stringent conditions. We detected strong lamin A binding to peptides solvent exposed in Lmcd1, AldoA, Perm1, and Tmem38a, and plausible binding to Csrp3 (muscle LIM protein). These results validated both proteomes as sources for native lamin A/C-binding proteins in heart and muscle, identified four candidate genes for Emery-Dreifuss muscular dystrophy (CSRP3, LMCD1, ALDOA, and PERM1), support a lamin A-interactive molecular role for Tmem38A, and supported the hypothesis that lamin A/C interactions with at least two partners (AldoA in heart, transcription factor Lmcd1 in muscle) are altered in the IL10-KO model of frailty.
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Affiliation(s)
- Fatima D. Elzamzami
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Arushi Samal
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Adith S. Arun
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Tejas Dharmaraj
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Neeti R. Prasad
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Alex Rendon-Jonguitud
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Lauren DeVine
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Jeremy D. Walston
- Division of Geriatric Medicine and Gerontology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Robert N. Cole
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Katherine L. Wilson
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
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17
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Schenkel L, Wang X, Le N, Burger M, Kroschewski R. A dedicated cytoplasmic container collects extrachromosomal DNA away from the mammalian nucleus. Mol Biol Cell 2023; 34:ar105. [PMID: 37556227 PMCID: PMC10559310 DOI: 10.1091/mbc.e23-04-0118] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 07/27/2023] [Accepted: 07/31/2023] [Indexed: 08/11/2023] Open
Abstract
Expression from transfected plasmid DNA is generally transient, but it is unclear what process terminates it. We show that DNA entering mammalian cells is rapidly surrounded by a double membrane in the cytoplasm, in some cases after leaving the nucleus. This cytoplasmic container, termed exclusome, frequently also contains extrachromosomal telomeric DNA, and is maintained by the cell over several division cycles. The exclusome envelope contains endoplasmic reticulum proteins and the inner-nuclear membrane proteins Lap2β and Emerin, but differs from the nuclear envelope by its fenestrations and the absence of the Lamin B Receptor and nuclear pore complexes. Reduction of exclusome frequency upon overexpressing Emerin's LEM-domain suggests a role for Emerin in plasmid DNA compartmentalization. Thus, cells distinguish extrachromosomal DNA and chromosomes and wrap them into similar yet distinct envelopes keeping the former in the exclusome but the latter in the nucleus, where transcription occurs.
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Affiliation(s)
- Laura Schenkel
- Institute of Biochemistry, Eidgenössische Technische Hochschule Zürich, Otto-Stern-Weg 3, 8093 Zürich, Switzerland
- Molecular Life Science PhD Program, Life Science Zurich Graduate School, 8057 Zurich, Switzerland
| | - Xuan Wang
- Institute of Biochemistry, Eidgenössische Technische Hochschule Zürich, Otto-Stern-Weg 3, 8093 Zürich, Switzerland
- Molecular Life Science PhD Program, Life Science Zurich Graduate School, 8057 Zurich, Switzerland
| | - Nhung Le
- Institute of Biochemistry, Eidgenössische Technische Hochschule Zürich, Otto-Stern-Weg 3, 8093 Zürich, Switzerland
- Molecular Life Science PhD Program, Life Science Zurich Graduate School, 8057 Zurich, Switzerland
| | - Michael Burger
- Institute of Biochemistry, Eidgenössische Technische Hochschule Zürich, Otto-Stern-Weg 3, 8093 Zürich, Switzerland
| | - Ruth Kroschewski
- Institute of Biochemistry, Eidgenössische Technische Hochschule Zürich, Otto-Stern-Weg 3, 8093 Zürich, Switzerland
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18
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Pande S, Ghosh DK. Nuclear proteostasis imbalance in laminopathy-associated premature aging diseases. FASEB J 2023; 37:e23116. [PMID: 37498235 DOI: 10.1096/fj.202300878r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 06/15/2023] [Accepted: 07/13/2023] [Indexed: 07/28/2023]
Abstract
Laminopathies are a group of rare genetic disorders with heterogeneous clinical phenotypes such as premature aging, cardiomyopathy, lipodystrophy, muscular dystrophy, microcephaly, epilepsy, and so on. The cellular phenomena associated with laminopathy invariably show disruption of nucleoskeleton of lamina due to deregulated expression, localization, function, and interaction of mutant lamin proteins. Impaired spatial and temporal tethering of lamin proteins to the lamina or nucleoplasmic aggregation of lamins are the primary molecular events that can trigger nuclear proteotoxicity by modulating differential protein-protein interactions, sequestering quality control proteins, and initiating a cascade of abnormal post-translational modifications. Clearly, laminopathic cells exhibit moderate to high nuclear proteotoxicity, raising the question of whether an imbalance in nuclear proteostasis is involved in laminopathic diseases, particularly in diseases of early aging such as HGPS and laminopathy-associated premature aging. Here, we review nuclear proteostasis and its deregulation in the context of lamin proteins and laminopathies.
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Affiliation(s)
- Shruti Pande
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Debasish Kumar Ghosh
- Enteric Disease Division, Department of Microbiology, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
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19
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De Silva S, Fan Z, Kang B, Shanahan CM, Zhang Q. Nesprin-1: novel regulator of striated muscle nuclear positioning and mechanotransduction. Biochem Soc Trans 2023; 51:1331-1345. [PMID: 37171063 PMCID: PMC10317153 DOI: 10.1042/bst20221541] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 04/20/2023] [Accepted: 04/20/2023] [Indexed: 05/13/2023]
Abstract
Nesprins (nuclear envelope spectrin repeat proteins) are multi-isomeric scaffolding proteins. Giant nesprin-1 and -2 localise to the outer nuclear membrane, interact with SUN (Sad1p/UNC-84) domain-containing proteins at the inner nuclear membrane to form the LInker of Nucleoskeleton and Cytoskeleton (LINC) complex, which, in association with lamin A/C and emerin, mechanically couples the nucleus to the cytoskeleton. Despite ubiquitous expression of nesprin giant isoforms, pathogenic mutations in nesprin-1 and -2 are associated with tissue-specific disorders, particularly related to striated muscle such as dilated cardiomyopathy and Emery-Dreifuss muscular dystrophy. Recent evidence suggests this muscle-specificity might be attributable in part, to the small muscle specific isoform, nesprin-1α2, which has a novel role in striated muscle function. Our current understanding of muscle-specific functions of nesprin-1 and its isoforms will be summarised in this review to provide insight into potential pathological mechanisms of nesprin-related muscle disease and may inform potential targets of therapeutic modulation.
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Affiliation(s)
- Shanelle De Silva
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London SE5 9NU, U.K
| | - Zhijuan Fan
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London SE5 9NU, U.K
- Clinical Laboratory, Tianjin Third Central Hospital, Tianjin 300170, China
| | - Baoqiang Kang
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London SE5 9NU, U.K
| | - Catherine M. Shanahan
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London SE5 9NU, U.K
| | - Qiuping Zhang
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London SE5 9NU, U.K
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20
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Zhang B, Powers JD, McCulloch AD, Chi NC. Nuclear mechanosignaling in striated muscle diseases. Front Physiol 2023; 14:1126111. [PMID: 36960155 PMCID: PMC10027932 DOI: 10.3389/fphys.2023.1126111] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Accepted: 02/22/2023] [Indexed: 03/09/2023] Open
Abstract
Mechanosignaling describes processes by which biomechanical stimuli are transduced into cellular responses. External biophysical forces can be transmitted via structural protein networks that span from the cellular membrane to the cytoskeleton and the nucleus, where they can regulate gene expression through a series of biomechanical and/or biochemical mechanosensitive mechanisms, including chromatin remodeling, translocation of transcriptional regulators, and epigenetic factors. Striated muscle cells, including cardiac and skeletal muscle myocytes, utilize these nuclear mechanosignaling mechanisms to respond to changes in their intracellular and extracellular mechanical environment and mediate gene expression and cell remodeling. In this brief review, we highlight and discuss recent experimental work focused on the pathway of biomechanical stimulus propagation at the nucleus-cytoskeleton interface of striated muscles, and the mechanisms by which these pathways regulate gene regulation, muscle structure, and function. Furthermore, we discuss nuclear protein mutations that affect mechanosignaling function in human and animal models of cardiomyopathy. Furthermore, current open questions and future challenges in investigating striated muscle nuclear mechanosignaling are further discussed.
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Affiliation(s)
- Bo Zhang
- Department of Bioengineering, University of California San Diego, La Jolla, CA, United States
| | - Joseph D. Powers
- Department of Bioengineering, University of California San Diego, La Jolla, CA, United States
| | - Andrew D. McCulloch
- Department of Bioengineering, University of California San Diego, La Jolla, CA, United States
- Institute for Engineering in Medicine, University of California San Diego, La Jolla, CA, United States
| | - Neil C. Chi
- Department of Bioengineering, University of California San Diego, La Jolla, CA, United States
- Institute for Engineering in Medicine, University of California San Diego, La Jolla, CA, United States
- Department of Medicine, Division of Cardiovascular Medicine, University of California San Diego, La Jolla, CA, United States
- Institute of Genomic Medicine, University of California San Diego, La Jolla, CA, United States
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21
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Wang Y, Dobreva G. Epigenetics in LMNA-Related Cardiomyopathy. Cells 2023; 12:cells12050783. [PMID: 36899919 PMCID: PMC10001118 DOI: 10.3390/cells12050783] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 02/18/2023] [Accepted: 02/26/2023] [Indexed: 03/06/2023] Open
Abstract
Mutations in the gene for lamin A/C (LMNA) cause a diverse range of diseases known as laminopathies. LMNA-related cardiomyopathy is a common inherited heart disease and is highly penetrant with a poor prognosis. In the past years, numerous investigations using mouse models, stem cell technologies, and patient samples have characterized the phenotypic diversity caused by specific LMNA variants and contributed to understanding the molecular mechanisms underlying the pathogenesis of heart disease. As a component of the nuclear envelope, LMNA regulates nuclear mechanostability and function, chromatin organization, and gene transcription. This review will focus on the different cardiomyopathies caused by LMNA mutations, address the role of LMNA in chromatin organization and gene regulation, and discuss how these processes go awry in heart disease.
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Affiliation(s)
- Yinuo Wang
- Department of Cardiovascular Genomics and Epigenomics, European Center for Angioscience (ECAS), Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany
- German Centre for Cardiovascular Research (DZHK), 68167 Mannheim, Germany
- Correspondence: (Y.W.); (G.D.)
| | - Gergana Dobreva
- Department of Cardiovascular Genomics and Epigenomics, European Center for Angioscience (ECAS), Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany
- German Centre for Cardiovascular Research (DZHK), 68167 Mannheim, Germany
- Correspondence: (Y.W.); (G.D.)
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22
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Genotype-Phenotype Correlations in Human Diseases Caused by Mutations of LINC Complex-Associated Genes: A Systematic Review and Meta-Summary. Cells 2022; 11:cells11244065. [PMID: 36552829 PMCID: PMC9777268 DOI: 10.3390/cells11244065] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 12/09/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022] Open
Abstract
Mutations in genes encoding proteins associated with the linker of nucleoskeleton and cytoskeleton (LINC) complex within the nuclear envelope cause different diseases with varying phenotypes including skeletal muscle, cardiac, metabolic, or nervous system pathologies. There is some understanding of the structure of LINC complex-associated proteins and how they interact, but it is unclear how mutations in genes encoding them can cause the same disease, and different diseases with different phenotypes. Here, published mutations in LINC complex-associated proteins were systematically reviewed and analyzed to ascertain whether patterns exist between the genetic sequence variants and clinical phenotypes. This revealed LMNA is the only LINC complex-associated gene in which mutations commonly cause distinct conditions, and there are no clear genotype-phenotype correlations. Clusters of LMNA variants causing striated muscle disease are located in exons 1 and 6, and metabolic disease-associated LMNA variants are frequently found in the tail of lamin A/C. Additionally, exon 6 of the emerin gene, EMD, may be a mutation "hot-spot", and diseases related to SYNE1, encoding nesprin-1, are most often caused by nonsense type mutations. These results provide insight into the diverse roles of LINC-complex proteins in human disease and provide direction for future gene-targeted therapy development.
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23
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Kono Y, Adam SA, Sato Y, Reddy KL, Zheng Y, Medalia O, Goldman RD, Kimura H, Shimi T. Nucleoplasmic lamin C rapidly accumulates at sites of nuclear envelope rupture with BAF and cGAS. J Cell Biol 2022; 221:e202201024. [PMID: 36301259 PMCID: PMC9617480 DOI: 10.1083/jcb.202201024] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 07/14/2022] [Accepted: 09/06/2022] [Indexed: 12/13/2022] Open
Abstract
In mammalian cell nuclei, the nuclear lamina (NL) underlies the nuclear envelope (NE) to maintain nuclear structure. The nuclear lamins, the major structural components of the NL, are involved in the protection against NE rupture induced by mechanical stress. However, the specific role of the lamins in repair of NE ruptures has not been fully determined. Our analyses using immunofluorescence and live-cell imaging revealed that the nucleoplasmic pool of lamin C rapidly accumulated at sites of NE rupture induced by laser microirradiation in mouse embryonic fibroblasts. The accumulation of lamin C at the rupture sites required both the immunoglobulin-like fold domain that binds to barrier-to-autointegration factor (BAF) and a nuclear localization signal. The accumulation of nuclear BAF and cytoplasmic cyclic GMP-AMP synthase (cGAS) at the rupture sites was in part dependent on lamin A/C. These results suggest that nucleoplasmic lamin C, BAF, and cGAS concertedly accumulate at sites of NE rupture for rapid repair.
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Affiliation(s)
- Yohei Kono
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Stephen A. Adam
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Yuko Sato
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Karen L. Reddy
- Department of Biological Chemistry, Johns Hopkins University, Baltimore, MD
| | - Yixian Zheng
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD
| | - Ohad Medalia
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Robert D. Goldman
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Hiroshi Kimura
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
- World Research Hub Initiative, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Takeshi Shimi
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
- World Research Hub Initiative, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
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24
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Snyers L, Löhnert R, Weipoltshammer K, Schöfer C. Emerin prevents BAF-mediated aggregation of lamin A on chromosomes in telophase to allow nuclear membrane expansion and nuclear lamina formation. Mol Biol Cell 2022; 33:ar137. [PMID: 36200863 PMCID: PMC9727812 DOI: 10.1091/mbc.e22-01-0007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Several studies have suggested a role for the LEM-domain protein emerin and the DNA binding factor BAF in nuclear envelope reformation after mitosis, but the exact molecular mechanisms are not understood. Using HeLa cells deficient for emerin or both emerin and lamin A, we show that emerin deficiency induces abnormal aggregation of lamin A at the nuclear periphery in telophase. As a result, nuclear membrane expansion is impaired and BAF accumulates at the core region, the middle part of telophase nuclei. Aggregates do not form when lamin A carries the mutation R435C in the immunoglobulin fold known to prevent interaction of lamin A with BAF suggesting that aggregation is caused by a stabilized association of lamin A with BAF bound to chromosomal DNA. Reintroduction of emerin in the cells prevents formation of lamin A clusters and BAF accumulation at the core region. Therefore emerin is required for the expansion of the nuclear membrane at the core region to enclose the nucleus and for the rapid reformation of the nuclear lamina based on lamin A/C in telophase. Finally, we show that LEM-domain and lumenal domain are required for the targeting of emerin to exert its function at the core region.
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Affiliation(s)
- L. Snyers
- Medical University of Vienna, Center for Anatomy and Cell Biology, Division of Cell and Developmental Biology, Schwarzspanierstrasse 17, 1090 Vienna, Austria,*Address correspondence to: L. Snyers ()
| | - R. Löhnert
- Medical University of Vienna, Center for Anatomy and Cell Biology, Division of Cell and Developmental Biology, Schwarzspanierstrasse 17, 1090 Vienna, Austria
| | - K. Weipoltshammer
- Medical University of Vienna, Center for Anatomy and Cell Biology, Division of Cell and Developmental Biology, Schwarzspanierstrasse 17, 1090 Vienna, Austria
| | - C. Schöfer
- Medical University of Vienna, Center for Anatomy and Cell Biology, Division of Cell and Developmental Biology, Schwarzspanierstrasse 17, 1090 Vienna, Austria
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25
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Loss of the Nuclear Envelope Protein LAP1B Disrupts the Myogenic Differentiation of Patient-Derived Fibroblasts. Int J Mol Sci 2022; 23:ijms232113615. [PMID: 36362402 PMCID: PMC9656778 DOI: 10.3390/ijms232113615] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 10/27/2022] [Accepted: 10/31/2022] [Indexed: 11/10/2022] Open
Abstract
Lamina-associated polypeptide 1 (LAP1) is a ubiquitously expressed inner nuclear membrane protein encoded by TOR1AIP1, and presents as two isoforms in humans, LAP1B and LAP1C. While loss of both isoforms results in a multisystemic progeroid-like syndrome, specific loss of LAP1B causes muscular dystrophy and cardiomyopathy, suggesting that LAP1B has a critical role in striated muscle. To gain more insight into the molecular pathophysiology underlying muscular dystrophy caused by LAP1B, we established a patient-derived fibroblast line that was transdifferentiated into myogenic cells using inducible MyoD expression. Compared to the controls, we observed strongly reduced myogenic differentiation and fusion potentials. Similar defects were observed in the C2C12 murine myoblasts carrying loss-of-function LAP1A/B mutations. Using RNA sequencing, we found that, despite MyoD overexpression and efficient cell cycle exit, transcriptional reprogramming of the LAP1B-deficient cells into the myogenic lineage is impaired with delayed activation of MYOG and muscle-specific genes. Gene set enrichment analyses suggested dysregulations of protein metabolism, extracellular matrix, and chromosome organization. Finally, we found that the LAP1B-deficient cells exhibit nuclear deformations, such as an increased number of micronuclei and altered morphometric parameters. This study uncovers the phenotypic and transcriptomic changes occurring during myoconversion of patient-derived LAP1B-deficient fibroblasts and provides a useful resource to gain insights into the mechanisms implicated in LAP1B-associated nuclear envelopathies.
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26
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Şener Uslupehlivan E, Deveci R, Şahar U, İzzetoğlu S. Glycan analysis of Lamin A/C protein at G2/M and S phases of the cell cycle. Cell Biochem Biophys 2022; 80:689-698. [PMID: 36180658 DOI: 10.1007/s12013-022-01102-3] [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: 08/03/2022] [Accepted: 09/20/2022] [Indexed: 11/28/2022]
Abstract
During mitosis, phosphorylation and dephosphorylation of lamins triggers the nuclear envelope disassembly/assembly. However, it hasn't been known whether lamin proteins undergo any modification other than phosphorylation during the cell cycle. Glycosylation of lamin proteins is one of the less studied post-translational modification. Glycosylation and phosphorylation compete for the same positions and interplay between two modifications generate a post-translational code in the cell. Based on this, we hypothesized that glycosylation of lamin A/C protein may be important in the regulation of the structural organization of the nuclear lamina during interphase and mitosis. We analysed the glycan units of lamin A/C protein in lung carcinoma cells synchronized at G2/M and S phases via CapLC-ESI-MS/MS. Besides, the outermost glycan units were determined using lectin blotting and gold-conjugated antibody and lectin staining. TEM studies also allowed us to observe the localization of glycosylated lamin A/C protein. With this study, we determined that lamin A/C protein shows O-glycosylation at G2/M and S phases of the cell cycle. In addition to O-GlcNAcylation and O-GalNAcylation, lamin A/C is found to be contain Gal, Fuc, Man, and Sia sugars at G2/M and S phases for the first time. Having found the glycan units of the lamin A/C protein suggests that glycosylation might have a role in the nuclear organization during the cell cycle.
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Affiliation(s)
- Ecem Şener Uslupehlivan
- Faculty of Science, Department of Biology, Molecular Biology Section, Ege University, Izmir, Turkey
| | - Remziye Deveci
- Faculty of Science, Department of Biology, Molecular Biology Section, Ege University, Izmir, Turkey
| | - Umut Şahar
- Faculty of Science, Department of Biology, Molecular Biology Section, Ege University, Izmir, Turkey
| | - Savaş İzzetoğlu
- Faculty of Science, Department of Biology, Molecular Biology Section, Ege University, Izmir, Turkey.
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27
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Han L, Shi J, Zhao L, Deng J, Li Y, Zhao H, Wang H, Yan Y, Zou F. BCAP31 is involved in modulating colorectal cancer cell proliferation via the Emerin/β-catenin axis. Exp Cell Res 2022; 418:113265. [PMID: 35716785 DOI: 10.1016/j.yexcr.2022.113265] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 05/12/2022] [Accepted: 06/13/2022] [Indexed: 11/15/2022]
Abstract
Understanding the mechanisms of colorectal cancer (CRC) progression is critical for developing innovative treatment strategies. As an endoplasmic reticulum-located protein, B cell receptor-associated protein 31 (BCAP31) has been identified to be highly expressed in multiple cancers. However, its function and molecular mechanism in CRC remain not fully understood. In the present study, BCAP31 expression and its correlation with the clinical stage were analyzed based on TCGA database. We demonstrated that loss of BCAP31 suppressed CRC cell proliferation in vitro and tumor growth in vivo. Mechanistically, we demonstrated that Emerin was an interaction partner and downstream molecule of BCAP31. Knockdown of BCAP31 promoted the nuclear envelope localization of Emerin, leading to a reduction of β-catenin accumulation in the nucleus, which resulted in downregulation of Wnt/β-catenin downstream target genes, including c-Myc, cyclin D1, Survivin, and Mcl-1. Moreover, downregulation of Emerin partially restored the BCAP31 depletion-mediated β-catenin protein level and tumor suppressive effects in CRC cells.Our data highlights the pivotal role of BCAP31 depletion in inhibiting cell proliferation in CRC cells, and mechanistically via Emerin/β-catenin signaling, which may serve as a promising target for CRC treatment.
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Affiliation(s)
- Liping Han
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Junyang Shi
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Lili Zhao
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Jiaqiang Deng
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Yan Li
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Hong Zhao
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Huani Wang
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Yan Yan
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Fangdong Zou
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China.
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Rubio-Ramos A, Bernabé-Rubio M, Labat-de-Hoz L, Casares-Arias J, Kremer L, Correas I, Alonso MA. MALL, a membrane-tetra-spanning proteolipid overexpressed in cancer, is present in membraneless nuclear biomolecular condensates. Cell Mol Life Sci 2022; 79:236. [PMID: 35399121 PMCID: PMC8995265 DOI: 10.1007/s00018-022-04270-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 03/08/2022] [Accepted: 03/22/2022] [Indexed: 12/04/2022]
Abstract
Proteolipids are proteins with unusual lipid-like properties. It has long been established that PLP and plasmolipin, which are two unrelated membrane-tetra-spanning myelin proteolipids, can be converted in vitro into a water-soluble form with a distinct conformation, raising the question of whether these, or other similar proteolipids, can adopt two different conformations in the cell to adapt their structure to distinct environments. Here, we show that MALL, another proteolipid with a membrane-tetra-spanning structure, distributes in membranes outside the nucleus and, within the nucleus, in membrane-less, liquid-like PML body biomolecular condensates. Detection of MALL in one or other environment was strictly dependent on the method of cell fixation used, suggesting that MALL adopts different conformations depending on its physical environment —lipidic or aqueous— in the cell. The acquisition of the condensate-compatible conformation requires PML expression. Excess MALL perturbed the distribution of the inner nuclear membrane proteins emerin and LAP2β, and that of the DNA-binding protein BAF, leading to the formation of aberrant nuclei. This effect, which is consistent with studies identifying overexpressed MALL as an unfavorable prognostic factor in cancer, could contribute to cell malignancy. Our study establishes a link between proteolipids, membranes and biomolecular condensates, with potential biomedical implications.
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Affiliation(s)
- Armando Rubio-Ramos
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - Miguel Bernabé-Rubio
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - Leticia Labat-de-Hoz
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - Javier Casares-Arias
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - Leonor Kremer
- Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, 28049, Madrid, Spain
| | - Isabel Correas
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, 28049, Madrid, Spain
- Department of Molecular Biology, Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - Miguel A Alonso
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, 28049, Madrid, Spain.
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29
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Fernandez A, Bautista M, Wu L, Pinaud F. Emerin self-assembly and nucleoskeletal coupling regulate nuclear envelope mechanics against stress. J Cell Sci 2022; 135:274432. [PMID: 35178558 PMCID: PMC8995096 DOI: 10.1242/jcs.258969] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 02/14/2022] [Indexed: 11/20/2022] Open
Abstract
Emerin is an integral nuclear envelope protein participating in the maintenance of nuclear shape. When mutated or absent, emerin causes X-linked Emery-Dreifuss muscular dystrophy (EDMD). To define how emerin takes parts in molecular scaffolding at the nuclear envelope and helps protect the nucleus against mechanical stress, we established its nanoscale organization using single molecule tracking and super-resolution microscopy. We show that emerin monomers form localized oligomeric nanoclusters stabilized by both lamin A/C and SUN1 LINC complex. Interactions of emerin with nuclear actin and BAF additionally modulate its membrane mobility and its ability to oligomerize. In nuclei subjected to mechanical challenges, the mechanotransducing functions of emerin are coupled to changes in its oligomeric state, and the incremental self-assembly of emerin determines nuclear shape adaptation against forces. We also show that the abnormal nuclear envelope deformations induced by EDMD emerin mutants stem from an improper formation of lamin A/C and LINC complex-stabilized emerin oligomers. These findings place emerin at the center of the molecular processes that regulate nuclear shape remodeling in response to mechanical challenges.
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Affiliation(s)
- Anthony Fernandez
- Department of Biological Sciences, University of Southern California, 1050 Childs Way, Los Angeles, CA 90089, USA
| | - Markville Bautista
- Department of Chemistry, University of Southern California, 1050 Childs Way, Los Angeles, CA 90089, USA
| | - Liying Wu
- Department of Biological Sciences, University of Southern California, 1050 Childs Way, Los Angeles, CA 90089, USA
| | - Fabien Pinaud
- Department of Biological Sciences, University of Southern California, 1050 Childs Way, Los Angeles, CA 90089, USA.,Department of Chemistry, University of Southern California, 1050 Childs Way, Los Angeles, CA 90089, USA.,Department of Physics and Astronomy, University of Southern California, 1050 Childs Way, Los Angeles, CA 90089, USA
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30
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Kamikawa Y, Imaizumi K. Advances in understanding the mechanisms of repairing damaged nuclear envelop. J Biochem 2022; 171:609-617. [PMID: 35134968 DOI: 10.1093/jb/mvac012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Accepted: 01/26/2022] [Indexed: 11/12/2022] Open
Abstract
The nuclear envelope (NE) separates genomic DNA from the cytoplasm in eukaryotes. The structure of the NE is dynamically altered not only in mitotic disassembly and reassembly but also during interphase. Recent studies have shown that the NE is frequently damaged by various cellular stresses that degenerate NE components and/or disrupt their functional interactions. These stresses are referred to as "NE stress." Accumulating evidence has demonstrated that NE stress potentially causes severe cellular dysfunctions, such as cell death and genome instability. In this review, the concept of NE stress, the processes repairing damage of the NE caused by NE stress, and the molecular mechanisms by which NE stress contributes to disease pathogenesis are introduced.
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Affiliation(s)
- Yasunao Kamikawa
- Department of Biochemistry, Institute of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan
| | - Kazunori Imaizumi
- Department of Biochemistry, Institute of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan
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31
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Abstract
Lamins interact with a host of nuclear membrane proteins, transcription factors, chromatin regulators, signaling molecules, splicing factors, and even chromatin itself to form a nuclear subcompartment, the nuclear lamina, that is involved in a variety of cellular processes such as the governance of nuclear integrity, nuclear positioning, mitosis, DNA repair, DNA replication, splicing, signaling, mechanotransduction and -sensation, transcriptional regulation, and genome organization. Lamins are the primary scaffold for this nuclear subcompartment, but interactions with lamin-associated peptides in the inner nuclear membrane are self-reinforcing and mutually required. Lamins also interact, directly and indirectly, with peripheral heterochromatin domains called lamina-associated domains (LADs) and help to regulate dynamic 3D genome organization and expression of developmentally regulated genes.
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Affiliation(s)
- Xianrong Wong
- Laboratory of Developmental and Regenerative Biology, Skin Research Institute of Singapore, Agency for Science, Technology and Research (A∗STAR), Singapore 138648
| | - Ashley J Melendez-Perez
- Department of Biological Chemistry and Center for Epigenetics, Johns Hopkins University of Medicine, Baltimore, Maryland 21205, USA
| | - Karen L Reddy
- Department of Biological Chemistry and Center for Epigenetics, Johns Hopkins University of Medicine, Baltimore, Maryland 21205, USA
- Sidney Kimmel Cancer Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, USA
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32
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Transfected plasmid DNA is incorporated into the nucleus via nuclear envelope reformation at telophase. Commun Biol 2022; 5:78. [PMID: 35058555 PMCID: PMC8776997 DOI: 10.1038/s42003-022-03021-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Accepted: 12/27/2021] [Indexed: 12/15/2022] Open
Abstract
AbstractDNA transfection is an important technology in life sciences, wherein nuclear entry of DNA is necessary to express exogenous DNA. Non-viral vectors and their transfection reagents are useful as safe transfection tools. However, they have no effect on the transfection of non-proliferating cells, the reason for which is not well understood. This study elucidates the mechanism through which transfected DNA enters the nucleus for gene expression. To monitor the behavior of transfected DNA, we introduce plasmid bearing lacO repeats and RFP-coding sequences into cells expressing GFP-LacI and observe plasmid behavior and RFP expression in living cells. RFP expression appears only after mitosis. Electron microscopy reveals that plasmids are wrapped with nuclear envelope (NE)‒like membranes or associated with chromosomes at telophase. The depletion of BAF, which is involved in NE reformation, delays plasmid RFP expression. These results suggest that transfected DNA is incorporated into the nucleus during NE reformation at telophase.
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33
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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: 0.7] [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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34
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Viegas D, Pereira CD, Martins F, Mateus T, da Cruz e Silva OAB, Herdeiro MT, Rebelo S. Nuclear Envelope Alterations in Myotonic Dystrophy Type 1 Patient-Derived Fibroblasts. Int J Mol Sci 2022; 23:522. [PMID: 35008948 PMCID: PMC8745202 DOI: 10.3390/ijms23010522] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 12/29/2021] [Accepted: 12/30/2021] [Indexed: 02/01/2023] Open
Abstract
Myotonic dystrophy type 1 (DM1) is a hereditary and multisystemic disease characterized by myotonia, progressive distal muscle weakness and atrophy. The molecular mechanisms underlying this disease are still poorly characterized, although there are some hypotheses that envisage to explain the multisystemic features observed in DM1. An emergent hypothesis is that nuclear envelope (NE) dysfunction may contribute to muscular dystrophies, particularly to DM1. Therefore, the main objective of the present study was to evaluate the nuclear profile of DM1 patient-derived and control fibroblasts and to determine the protein levels and subcellular distribution of relevant NE proteins in these cell lines. Our results demonstrated that DM1 patient-derived fibroblasts exhibited altered intracellular protein levels of lamin A/C, LAP1, SUN1, nesprin-1 and nesprin-2 when compared with the control fibroblasts. In addition, the results showed an altered location of these NE proteins accompanied by the presence of nuclear deformations (blebs, lobes and/or invaginations) and an increased number of nuclear inclusions. Regarding the nuclear profile, DM1 patient-derived fibroblasts had a larger nuclear area and a higher number of deformed nuclei and micronuclei than control-derived fibroblasts. These results reinforce the evidence that NE dysfunction is a highly relevant pathological characteristic observed in DM1.
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Affiliation(s)
| | | | | | | | | | | | - Sandra Rebelo
- Department of Medical Sciences, Institute of Biomedicine (iBiMED), University of Aveiro, 3810-193 Aveiro, Portugal; (D.V.); (C.D.P.); (F.M.); (T.M.); (O.A.B.d.C.e.S.); (M.T.H.)
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35
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Rose M, Bai B, Tang M, Cheong CM, Beard S, Burgess JT, Adams MN, O'Byrne KJ, Richard DJ, Gandhi NS, Bolderson E. The Impact of Rare Human Variants on Barrier-To-Auto-Integration Factor 1 (Banf1) Structure and Function. Front Cell Dev Biol 2021; 9:775441. [PMID: 34820387 PMCID: PMC8606531 DOI: 10.3389/fcell.2021.775441] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 10/18/2021] [Indexed: 11/23/2022] Open
Abstract
Barrier-to-Autointegration Factor 1 (Banf1/BAF) is a critical component of the nuclear envelope and is involved in the maintenance of chromatin structure and genome stability. Banf1 is a small DNA binding protein that is conserved amongst multicellular eukaryotes. Banf1 functions as a dimer, and binds non-specifically to the phosphate backbone of DNA, compacting the DNA in a looping process. The loss of Banf1 results in loss of nuclear envelope integrity and aberrant chromatin organisation. Significantly, mutations in Banf1 are associated with the severe premature ageing syndrome, Néstor–Guillermo Progeria Syndrome. Previously, rare human variants of Banf1 have been identified, however the impact of these variants on Banf1 function has not been explored. Here, using in silico modelling, biophysical and cell-based approaches, we investigate the effect of rare human variants on Banf1 structure and function. We show that these variants do not significantly alter the secondary structure of Banf1, but several single amino acid variants in the N- and C-terminus of Banf1 impact upon the DNA binding ability of Banf1, without altering Banf1 localisation or nuclear integrity. The functional characterisation of these variants provides further insight into Banf1 structure and function and may aid future studies examining the potential impact of Banf1 function on nuclear structure and human health.
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Affiliation(s)
- Maddison Rose
- Queensland University of Technology (QUT), Cancer and Ageing Research Program, Centre for Genomics and Personalised Health, Translational Research Institute (TRI), Brisbane, QLD, Australia
| | - Bond Bai
- Queensland University of Technology (QUT), Cancer and Ageing Research Program, Centre for Genomics and Personalised Health, Translational Research Institute (TRI), Brisbane, QLD, Australia
| | - Ming Tang
- Queensland University of Technology (QUT), Cancer and Ageing Research Program, Centre for Genomics and Personalised Health, Translational Research Institute (TRI), Brisbane, QLD, Australia
| | - Chee Man Cheong
- Queensland University of Technology (QUT), Cancer and Ageing Research Program, Centre for Genomics and Personalised Health, Translational Research Institute (TRI), Brisbane, QLD, Australia
| | - Sam Beard
- Queensland University of Technology (QUT), Cancer and Ageing Research Program, Centre for Genomics and Personalised Health, Translational Research Institute (TRI), Brisbane, QLD, Australia
| | - Joshua T Burgess
- Queensland University of Technology (QUT), Cancer and Ageing Research Program, Centre for Genomics and Personalised Health, Translational Research Institute (TRI), Brisbane, QLD, Australia
| | - Mark N Adams
- Queensland University of Technology (QUT), Cancer and Ageing Research Program, Centre for Genomics and Personalised Health, Translational Research Institute (TRI), Brisbane, QLD, Australia
| | - Kenneth J O'Byrne
- Queensland University of Technology (QUT), Cancer and Ageing Research Program, Centre for Genomics and Personalised Health, Translational Research Institute (TRI), Brisbane, QLD, Australia.,Princess Alexandra Hospital, Woolloongabba, QLD, Australia
| | - Derek J Richard
- Queensland University of Technology (QUT), Cancer and Ageing Research Program, Centre for Genomics and Personalised Health, Translational Research Institute (TRI), Brisbane, QLD, Australia
| | - Neha S Gandhi
- Queensland University of Technology (QUT), Cancer and Ageing Research Program, Centre for Genomics and Personalised Health, Translational Research Institute (TRI), Brisbane, QLD, Australia.,School of Chemistry and Physics, Queensland University of Technology, Brisbane, QLD, Australia
| | - Emma Bolderson
- Queensland University of Technology (QUT), Cancer and Ageing Research Program, Centre for Genomics and Personalised Health, Translational Research Institute (TRI), Brisbane, QLD, Australia
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36
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The Role of Emerin in Cancer Progression and Metastasis. Int J Mol Sci 2021; 22:ijms222011289. [PMID: 34681951 PMCID: PMC8537873 DOI: 10.3390/ijms222011289] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 10/14/2021] [Accepted: 10/15/2021] [Indexed: 12/27/2022] Open
Abstract
It is commonly recognized in the field that cancer cells exhibit changes in the size and shape of their nuclei. These features often serve as important biomarkers in the diagnosis and prognosis of cancer patients. Nuclear size can significantly impact cell migration due to its incredibly large size. Nuclear structural changes are predicted to regulate cancer cell migration. Nuclear abnormalities are common across a vast spectrum of cancer types, regardless of tissue source, mutational spectrum, and signaling dependencies. The pervasiveness of nuclear alterations suggests that changes in nuclear structure may be crucially linked to the transformation process. The factors driving these nuclear abnormalities, and the functional consequences, are not completely understood. Nuclear envelope proteins play an important role in regulating nuclear size and structure in cancer. Altered expression of nuclear lamina proteins, including emerin, is found in many cancers and this expression is correlated with better clinical outcomes. A model is emerging whereby emerin, as well as other nuclear lamina proteins, binding to the nucleoskeleton regulates the nuclear structure to impact metastasis. In this model, emerin and lamins play a central role in metastatic transformation, since decreased emerin expression during transformation causes the nuclear structural defects required for increased cell migration, intravasation, and extravasation. Herein, we discuss the cellular functions of nuclear lamina proteins, with a particular focus on emerin, and how these functions impact cancer progression and metastasis.
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37
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Lee B, Lee S, Lee Y, Park Y, Shim J. Emerin Represses STAT3 Signaling through Nuclear Membrane-Based Spatial Control. Int J Mol Sci 2021; 22:ijms22136669. [PMID: 34206382 PMCID: PMC8269395 DOI: 10.3390/ijms22136669] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 06/15/2021] [Accepted: 06/16/2021] [Indexed: 12/14/2022] Open
Abstract
Emerin is the inner nuclear membrane protein involved in maintaining the mechanical integrity of the nuclear membrane. Mutations in EMD encoding emerin cause Emery–Dreifuss muscular dystrophy (EDMD). Evidence is accumulating that emerin regulation of specific gene expression is associated with this disease, but the exact function of emerin has not been fully elucidated. Here, we show that emerin downregulates Signal transducer and activators of transcription 3 (STAT3) signaling, activated exclusively by Janus kinase (JAK). Deletion mutation experiments show that the lamin-binding domain of emerin is essential for the inhibition of STAT3 signaling. Emerin interacts directly and co-localizes with STAT3 in the nuclear membrane. Emerin knockdown induces STAT3 target genes Bcl2 and Survivin to increase cell survival signals and suppress hydrogen peroxide-induced cell death in HeLa cells. Specifically, downregulation of BAF or lamin A/C increases STAT3 signaling, suggesting that correct-localized emerin, by assembling with BAF and lamin A/C, acts as an intrinsic inhibitor against STAT3 signaling. In C2C12 cells, emerin knockdown induces STAT3 target gene, Pax7, and activated abnormal myoblast proliferation associated with muscle wasting in skeletal muscle homeostasis. Our results indicate that emerin downregulates STAT3 signaling by inducing retention of STAT3 and delaying STAT3 signaling in the nuclear membrane. This mechanism provides clues to the etiology of emerin-related muscular dystrophy and may be a new therapeutic target for treatment.
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Burgess JT, Cheong CM, Suraweera A, Sobanski T, Beard S, Dave K, Rose M, Boucher D, Croft LV, Adams MN, O'Byrne K, Richard DJ, Bolderson E. Barrier-to-autointegration-factor (Banf1) modulates DNA double-strand break repair pathway choice via regulation of DNA-dependent kinase (DNA-PK) activity. Nucleic Acids Res 2021; 49:3294-3307. [PMID: 33660778 PMCID: PMC8034644 DOI: 10.1093/nar/gkab110] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 02/04/2021] [Accepted: 02/23/2021] [Indexed: 01/07/2023] Open
Abstract
DNA repair pathways are essential to maintain the integrity of the genome and prevent cell death and tumourigenesis. Here, we show that the Barrier-to-Autointegration Factor (Banf1) protein has a role in the repair of DNA double-strand breaks. Banf1 is characterized as a nuclear envelope protein and mutations in Banf1 are associated with the severe premature aging syndrome, Néstor–Guillermo Progeria Syndrome. We have previously shown that Banf1 directly regulates the activity of PARP1 in the repair of oxidative DNA lesions. Here, we show that Banf1 also has a role in modulating DNA double-strand break repair through regulation of the DNA-dependent Protein Kinase catalytic subunit, DNA-PKcs. Specifically, we demonstrate that Banf1 relocalizes from the nuclear envelope to sites of DNA double-strand breaks. We also show that Banf1 can bind to and directly inhibit the activity of DNA-PKcs. Supporting this, cellular depletion of Banf1 leads to an increase in non-homologous end-joining and a decrease in homologous recombination, which our data suggest is likely due to unrestrained DNA-PKcs activity. Overall, this study identifies how Banf1 regulates double-strand break repair pathway choice by modulating DNA-PKcs activity to control genome stability within the cell.
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Affiliation(s)
- Joshua T Burgess
- Queensland University of Technology (QUT), Cancer & Ageing Research Program, Centre for Genomics and Personalised Health at the Translational Research Institute (TRI), Brisbane, Australia
| | - Chee Man Cheong
- Queensland University of Technology (QUT), Cancer & Ageing Research Program, Centre for Genomics and Personalised Health at the Translational Research Institute (TRI), Brisbane, Australia
| | - Amila Suraweera
- Queensland University of Technology (QUT), Cancer & Ageing Research Program, Centre for Genomics and Personalised Health at the Translational Research Institute (TRI), Brisbane, Australia
| | - Thais Sobanski
- Queensland University of Technology (QUT), Cancer & Ageing Research Program, Centre for Genomics and Personalised Health at the Translational Research Institute (TRI), Brisbane, Australia
| | - Sam Beard
- Queensland University of Technology (QUT), Cancer & Ageing Research Program, Centre for Genomics and Personalised Health at the Translational Research Institute (TRI), Brisbane, Australia
| | - Keyur Dave
- Queensland University of Technology (QUT), Cancer & Ageing Research Program, Centre for Genomics and Personalised Health at the Translational Research Institute (TRI), Brisbane, Australia
| | - Maddison Rose
- Queensland University of Technology (QUT), Cancer & Ageing Research Program, Centre for Genomics and Personalised Health at the Translational Research Institute (TRI), Brisbane, Australia
| | - Didier Boucher
- Queensland University of Technology (QUT), Cancer & Ageing Research Program, Centre for Genomics and Personalised Health at the Translational Research Institute (TRI), Brisbane, Australia
| | - Laura V Croft
- Queensland University of Technology (QUT), Cancer & Ageing Research Program, Centre for Genomics and Personalised Health at the Translational Research Institute (TRI), Brisbane, Australia
| | - Mark N Adams
- Queensland University of Technology (QUT), Cancer & Ageing Research Program, Centre for Genomics and Personalised Health at the Translational Research Institute (TRI), Brisbane, Australia
| | - Kenneth O'Byrne
- Queensland University of Technology (QUT), Cancer & Ageing Research Program, Centre for Genomics and Personalised Health at the Translational Research Institute (TRI), Brisbane, Australia.,Princess Alexandra Hospital, Ipswich Road, Woolloongabba, Brisbane, Queensland 4102, Australia
| | - Derek J Richard
- Queensland University of Technology (QUT), Cancer & Ageing Research Program, Centre for Genomics and Personalised Health at the Translational Research Institute (TRI), Brisbane, Australia
| | - Emma Bolderson
- Queensland University of Technology (QUT), Cancer & Ageing Research Program, Centre for Genomics and Personalised Health at the Translational Research Institute (TRI), Brisbane, Australia
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Halfmann CT, Roux KJ. Barrier-to-autointegration factor: a first responder for repair of nuclear ruptures. Cell Cycle 2021; 20:647-660. [PMID: 33678126 DOI: 10.1080/15384101.2021.1892320] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
The nuclear envelope (NE) is a critical barrier between the cytosol and nucleus that is key for compartmentalization within the cell and serves an essential role in organizing and protecting genomic DNA. Rupturing of the NE through loss of constitutive NE proteins and/or mechanical force applied to the nucleus results in the unregulated mixing of cytosolic and nuclear compartments, leading to DNA damage and genomic instability. Nuclear rupture has recently gained interest as a mechanism that may participate in various NE-associated diseases as well as cancer. Remarkably, these rupturing events are often transient, with cells being capable of rapidly repairing nuclear ruptures. Recently, we identified Barrier-to-Autointegration Factor (BAF), a DNA-binding protein involved in post-mitotic NE reformation and cytosolic viral regulation, as an essential protein for nuclear rupture repair. During interphase, the highly mobile cytosolic BAF is primed to monitor for a compromised NE by rapidly binding to newly exposed nuclear DNA and subsequently recruiting the factors necessary for NE repair. This review highlights the recent findings of BAF's roles in rupture repair, and offers perspectives on how regulatory factors that control BAF activity may potentially alter the cellular response to nuclear ruptures and how BAF may participate in human disease.
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Affiliation(s)
| | - Kyle J Roux
- Enabling Technologies Group, Sanford Research, Sioux Falls, SD, USA.,Department of Pediatrics, Sanford School of Medicine, University of South Dakota, Sioux Falls, SD, USA
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Unnikannan CP, Reuveny A, Grunberg D, Volk T. Recruitment of BAF to the nuclear envelope couples the LINC complex to endoreplication. Development 2020; 147:dev.191304. [PMID: 33168584 PMCID: PMC7758627 DOI: 10.1242/dev.191304] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 10/29/2020] [Indexed: 12/21/2022]
Abstract
DNA endoreplication has been implicated as a cell strategy for cell growth and in tissue injury. Here, we demonstrate that barrier-to-autointegration factor (BAF) represses endoreplication in Drosophila myofibers. We show that BAF localization at the nuclear envelope is eliminated in flies with mutations of the linker of nucleoskeleton and cytoskeleton (LINC) complex in which the LEM-domain protein Otefin is excluded, or after disruption of the nucleus-sarcomere connections. Furthermore, BAF localization at the nuclear envelope requires the activity of the BAF kinase VRK1/Ball, and, consistently, non-phosphorylatable BAF-GFP is excluded from the nuclear envelope. Importantly, removal of BAF from the nuclear envelope correlates with increased DNA content in the myonuclei. E2F1, a key regulator of endoreplication, overlaps BAF localization at the myonuclear envelope, and BAF removal from the nuclear envelope results in increased E2F1 levels in the nucleoplasm and subsequent elevated DNA content. We suggest that LINC-dependent and phosphosensitive attachment of BAF to the nuclear envelope, through its binding to Otefin, tethers E2F1 to the nuclear envelope thus inhibiting its accumulation in the nucleoplasm. Summary: Localization of BAF at the nuclear envelope of myonuclei depends on a functional LINC complex and on nucleus-sarcomere connections, and is shown to restrict E2F1 levels in the nucleoplasm.
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Affiliation(s)
- C P Unnikannan
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Adriana Reuveny
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Dvorah Grunberg
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Talila Volk
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
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Burla R, La Torre M, Maccaroni K, Verni F, Giunta S, Saggio I. Interplay of the nuclear envelope with chromatin in physiology and pathology. Nucleus 2020; 11:205-218. [PMID: 32835589 PMCID: PMC7529417 DOI: 10.1080/19491034.2020.1806661] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 07/30/2020] [Accepted: 08/03/2020] [Indexed: 12/21/2022] Open
Abstract
The nuclear envelope compartmentalizes chromatin in eukaryotic cells. The main nuclear envelope components are lamins that associate with a panoply of factors, including the LEM domain proteins. The nuclear envelope of mammalian cells opens up during cell division. It is reassembled and associated with chromatin at the end of mitosis when telomeres tether to the nuclear periphery. Lamins, LEM domain proteins, and DNA binding factors, as BAF, contribute to the reorganization of chromatin. In this context, an emerging role is that of the ESCRT complex, a machinery operating in multiple membrane assembly pathways, including nuclear envelope reformation. Research in this area is unraveling how, mechanistically, ESCRTs link to nuclear envelope associated factors as LEM domain proteins. Importantly, ESCRTs work also during interphase for repairing nuclear envelope ruptures. Altogether the advances in this field are giving new clues for the interpretation of diseases implicating nuclear envelope fragility, as laminopathies and cancer. ABBREVIATIONS na, not analyzed; ko, knockout; kd, knockdown; NE, nuclear envelope; LEM, LAP2-emerin-MAN1 (LEM)-domain containing proteins; LINC, linker of nucleoskeleton and cytoskeleton complexes; Cyt, cytoplasm; Chr, chromatin; MB, midbody; End, endosomes; Tel, telomeres; INM, inner nuclear membrane; NP, nucleoplasm; NPC, Nuclear Pore Complex; ER, Endoplasmic Reticulum; SPB, spindle pole body.
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Affiliation(s)
- Romina Burla
- Department of Biology and Biotechnology, Sapienza University of Rome, Rome, Italy
- CNR Institute of Molecular Biology and Pathology, Italy
| | - Mattia La Torre
- Department of Biology and Biotechnology, Sapienza University of Rome, Rome, Italy
| | - Klizia Maccaroni
- Department of Biology and Biotechnology, Sapienza University of Rome, Rome, Italy
| | - Fiammetta Verni
- Department of Biology and Biotechnology, Sapienza University of Rome, Rome, Italy
| | - Simona Giunta
- Department of Biology and Biotechnology, Sapienza University of Rome, Rome, Italy
- Rockefeller University, New York, NY, USA
| | - Isabella Saggio
- Department of Biology and Biotechnology, Sapienza University of Rome, Rome, Italy
- CNR Institute of Molecular Biology and Pathology, Italy
- Institute of Structural Biology, School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
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42
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Steering cell behavior through mechanobiology in 3D: A regenerative medicine perspective. Biomaterials 2020; 268:120572. [PMID: 33285439 DOI: 10.1016/j.biomaterials.2020.120572] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 09/04/2020] [Accepted: 11/21/2020] [Indexed: 12/14/2022]
Abstract
Mechanobiology, translating mechanical signals into biological ones, greatly affects cellular behavior. Steering cellular behavior for cell-based regenerative medicine approaches requires a thorough understanding of the orchestrating molecular mechanisms, among which mechanotransducive ones are being more and more elucidated. Because of their wide use and highly mechanotransduction dependent differentiation, this review focuses on mesenchymal stromal cells (MSCs), while also briefly relating the discussed results to other cell types. While the mechanotransduction pathways are relatively well-studied in 2D, much remains unknown of the role and regulation of these pathways in 3D. Ultimately, cells need to be cultured in a 3D environment to create functional de novo tissue. In this review, we explore the literature on the roles of different material properties on cellular behavior and mechanobiology in 2D and 3D. For example, while stiffness plays a dominant role in 2D MSCs differentiation, it seems to be of subordinate importance in 3D MSCs differentiation, where matrix remodeling seems to be key. Also, the role and regulation of some of the main mechanotransduction players are discussed, focusing on MSCs. We have only just begun to fundamentally understand MSCs and other stem cells behavior in 3D and more fundamental research is required to advance biomaterials able to replicate the stem cell niche and control cell activity. This better understanding will contribute to smarter tissue engineering scaffold design and the advancement of regenerative medicine.
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43
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Torras-Llort M, Medina-Giró S, Escudero-Ferruz P, Lipinszki Z, Moreno-Moreno O, Karman Z, Przewloka MR, Azorín F. A fraction of barrier-to-autointegration factor (BAF) associates with centromeres and controls mitosis progression. Commun Biol 2020; 3:454. [PMID: 32814801 PMCID: PMC7438335 DOI: 10.1038/s42003-020-01182-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 07/30/2020] [Indexed: 01/01/2023] Open
Abstract
Barrier-to-Autointegration Factor (BAF) is a conserved nuclear envelope (NE) component that binds chromatin and helps its anchoring to the NE. Cycles of phosphorylation and dephosphorylation control BAF function. Entering mitosis, phosphorylation releases BAF from chromatin and facilitates NE-disassembly. At mitotic exit, PP2A-mediated dephosphorylation restores chromatin binding and nucleates NE-reassembly. Here, we show that in Drosophila a small fraction of BAF (cenBAF) associates with centromeres. We also find that PP4 phosphatase, which is recruited to centromeres by CENP-C, prevents phosphorylation and release of cenBAF during mitosis. cenBAF is necessary for proper centromere assembly and accurate chromosome segregation, being critical for mitosis progression. Disrupting cenBAF localization prevents PP2A inactivation in mitosis compromising global BAF phosphorylation, which in turn leads to its persistent association with chromatin, delays anaphase onset and causes NE defects. These results suggest that, together with PP4 and CENP-C, cenBAF forms a centromere-based mechanism that controls chromosome segregation and mitosis progression.
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Affiliation(s)
- Mònica Torras-Llort
- Institute of Molecular Biology of Barcelona, CSIC, Barcelona, Spain.
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona, Spain.
| | - Sònia Medina-Giró
- Institute of Molecular Biology of Barcelona, CSIC, Barcelona, Spain
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Paula Escudero-Ferruz
- Institute of Molecular Biology of Barcelona, CSIC, Barcelona, Spain
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Zoltan Lipinszki
- MTA SZBK Lendület Laboratory of Cell Cycle Regulation and Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
- Doctoral School of Biology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Olga Moreno-Moreno
- Institute of Molecular Biology of Barcelona, CSIC, Barcelona, Spain
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Zoltan Karman
- MTA SZBK Lendület Laboratory of Cell Cycle Regulation and Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
- Doctoral School of Biology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Marcin R Przewloka
- School of Biological Sciences, Institute for Life Sciences, University of Southampton, Southampton, SO17 1BJ, UK
| | - Fernando Azorín
- Institute of Molecular Biology of Barcelona, CSIC, Barcelona, Spain.
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona, Spain.
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44
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Sears RM, Roux KJ. Diverse cellular functions of barrier-to-autointegration factor and its roles in disease. J Cell Sci 2020; 133:133/16/jcs246546. [PMID: 32817163 DOI: 10.1242/jcs.246546] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Barrier-to-autointegration factor (BAF; encoded by BANF1) is a small highly conserved, ubiquitous and self-associating protein that coordinates with numerous binding partners to accomplish several key cellular processes. By interacting with double-stranded DNA, histones and various other nuclear proteins, including those enriched at the nuclear envelope, BAF appears to be essential for replicating cells to protect the genome and enable cell division. Cellular processes, such as innate immunity, post-mitotic nuclear reformation, repair of interphase nuclear envelope rupture, genomic regulation, and the DNA damage and repair response have all been shown to depend on BAF. This Review focuses on the regulation of the numerous interactions of BAF, which underlie the mechanisms by which BAF accomplishes its essential cellular functions. We will also discuss how perturbation of BAF function may contribute to human disease.
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Affiliation(s)
- Rhiannon M Sears
- Enabling Technologies Group, Sanford Research, Sioux Falls, SD 57104, USA.,Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD 57069, USA
| | - Kyle J Roux
- Enabling Technologies Group, Sanford Research, Sioux Falls, SD 57104, USA .,Department of Pediatrics, Sanford School of Medicine, University of South Dakota, Sioux Falls, SD 57069, USA
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45
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von Appen A, LaJoie D, Johnson IE, Trnka MJ, Pick SM, Burlingame AL, Ullman KS, Frost A. LEM2 phase separation promotes ESCRT-mediated nuclear envelope reformation. Nature 2020; 582:115-118. [PMID: 32494070 PMCID: PMC7321842 DOI: 10.1038/s41586-020-2232-x] [Citation(s) in RCA: 108] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 02/26/2020] [Indexed: 01/01/2023]
Abstract
During cell division, remodelling of the nuclear envelope enables chromosome segregation by the mitotic spindle1. The reformation of sealed nuclei requires ESCRTs (endosomal sorting complexes required for transport) and LEM2, a transmembrane ESCRT adaptor2-4. Here we show how the ability of LEM2 to condense on microtubules governs the activation of ESCRTs and coordinated spindle disassembly. The LEM motif of LEM2 binds BAF, conferring on LEM2 an affinity for chromatin5,6, while an adjacent low-complexity domain (LCD) promotes LEM2 phase separation. A proline-arginine-rich sequence within the LCD binds to microtubules and targets condensation of LEM2 to spindle microtubules that traverse the nascent nuclear envelope. Furthermore, the winged-helix domain of LEM2 activates the ESCRT-II/ESCRT-III hybrid protein CHMP7 to form co-oligomeric rings. Disruption of these events in human cells prevented the recruitment of downstream ESCRTs, compromised spindle disassembly, and led to defects in nuclear integrity and DNA damage. We propose that during nuclear reassembly LEM2 condenses into a liquid-like phase and coassembles with CHMP7 to form a macromolecular O-ring seal at the confluence between membranes, chromatin and the spindle. The properties of LEM2 described here, and the homologous architectures of related inner nuclear membrane proteins7,8, suggest that phase separation may contribute to other critical envelope functions, including interphase repair8-13 and chromatin organization14-17.
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Affiliation(s)
- Alexander von Appen
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA, USA
| | - Dollie LaJoie
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, USA
| | - Isabel E Johnson
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA, USA
| | - Michael J Trnka
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA, USA
| | - Sarah M Pick
- Faculty of Chemistry and Pharmacy, University of Freiburg, Freiburg, Germany
| | - Alma L Burlingame
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA, USA
| | - Katharine S Ullman
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, USA.
| | - Adam Frost
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA, USA.
- Chan Zuckerberg Biohub, San Francisco, CA, USA.
- Quantitative Biosciences Institute, University of California, San Francisco, San Francisco, CA, USA.
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46
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Duan T, Kitzman SC, Geyer PK. Survival of Drosophila germline stem cells requires the chromatin-binding protein Barrier-to-autointegration factor. Development 2020; 147:dev.186171. [PMID: 32345742 DOI: 10.1242/dev.186171] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 03/31/2020] [Indexed: 11/20/2022]
Abstract
The nuclear lamina (NL) is an extensive protein network that underlies the inner nuclear envelope. This network includes LAP2-emerin-MAN1 domain (LEM-D) proteins that associate with the chromatin and DNA-binding protein Barrier-to-autointegration factor (BAF). Here, we investigate the partnership between three NL Drosophila LEM-D proteins and BAF. In most tissues, only Emerin/Otefin is required for NL enrichment of BAF, revealing an unexpected dependence on a single LEM-D protein. Prompted by these observations, we studied BAF contributions in the ovary, a tissue where Emerin/Otefin function is essential. We show that germ cell-specific BAF knockdown causes phenotypes that mirror emerin/otefin mutants. Loss of BAF disrupts NL structure, blocks differentiation and promotes germ cell loss, phenotypes that are partially rescued by inactivation of the ATR and Chk2 kinases. These data suggest that, similar to emerin/otefin mutants, BAF depletion activates the NL checkpoint that causes germ cell loss. Taken together, our findings provide evidence for a prominent NL partnership between the LEM-D protein Emerin/Otefin and BAF, revealing that BAF functions with this partner in the maintenance of an adult stem cell population.
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Affiliation(s)
- Tingting Duan
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA
| | - S Cole Kitzman
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA
| | - Pamela K Geyer
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA
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47
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Yamamoto-Hino M, Kawaguchi K, Ono M, Furukawa K, Goto S. Lamin is essential for nuclear localization of the GPI synthesis enzyme PIG-B and GPI-anchored protein production in Drosophila. J Cell Sci 2020; 133:jcs.238527. [PMID: 32051283 PMCID: PMC7104860 DOI: 10.1242/jcs.238527] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Accepted: 01/28/2020] [Indexed: 01/13/2023] Open
Abstract
Membrane lipid biosynthesis is a complex process that occurs in various intracellular compartments. In Drosophila, phosphatidylinositol glycan-B (PIG-B), which catalyzes addition of the third mannose in glycosylphosphatidylinositol (GPI), localizes to the nuclear envelope (NE). Although this NE localization is essential for Drosophila development, the underlying molecular mechanism remains unknown. To elucidate this mechanism, we identified PIG-B-interacting proteins by performing immunoprecipitation followed by proteomic analysis. We then examined which of these proteins are required for the NE localization of PIG-B. Knockdown of Lamin Dm0, a B-type lamin, led to mislocalization of PIG-B from the NE to the endoplasmic reticulum. Lamin Dm0 associated with PIG-B at the inner nuclear membrane, a process that required the tail domain of Lamin Dm0. Furthermore, GPI moieties were distributed abnormally in the Lamin Dm0 mutant. These data indicate that Lamin Dm0 is involved in the NE localization of PIG-B and is required for proper GPI-anchor modification of proteins. Highlighted Article: Lamin plays a role in post-translational modification of plasma membrane proteins by tethering the GPI modification enzyme PIG-B to the inner nuclear membrane.
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Affiliation(s)
- Miki Yamamoto-Hino
- Department of Life Science, College of Science, Rikkyo University, Toshima-ku, Tokyo 171-8501, Japan
| | - Kohei Kawaguchi
- Department of Life Science, College of Science, Rikkyo University, Toshima-ku, Tokyo 171-8501, Japan
| | - Masaya Ono
- Department of Clinical Proteomics, National Cancer Center Hospital, Chu-o-ku, Tokyo 104-0045, Japan
| | - Kazuhiro Furukawa
- Department of Chemistry, Faculty of Science, Niigata University, Niigata 950-2181, Japan
| | - Satoshi Goto
- Department of Life Science, College of Science, Rikkyo University, Toshima-ku, Tokyo 171-8501, Japan
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48
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Pradhan R, Nallappa MJ, Sengupta K. Lamin A/C modulates spatial organization and function of the Hsp70 gene locus via nuclear myosin I. J Cell Sci 2020; 133:jcs236265. [PMID: 31988151 DOI: 10.1242/jcs.236265] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 01/13/2020] [Indexed: 02/06/2023] Open
Abstract
The structure-function relationship of the nucleus is tightly regulated, especially during heat shock. Typically, heat shock activates molecular chaperones that prevent protein misfolding and preserve genome integrity. However, the molecular mechanisms that regulate nuclear structure-function relationships during heat shock remain unclear. Here, we show that lamin A and C (hereafter lamin A/C; both lamin A and C are encoded by LMNA) are required for heat-shock-mediated transcriptional induction of the Hsp70 gene locus (HSPA genes). Interestingly, lamin A/C regulates redistribution of nuclear myosin I (NM1) into the nucleus upon heat shock, and depletion of either lamin A/C or NM1 abrogates heat-shock-induced repositioning of Hsp70 gene locus away from the nuclear envelope. Lamins and NM1 also regulate spatial positioning of the SC35 (also known as SRSF2) speckles - important nuclear landmarks that modulates Hsp70 gene locus expression upon heat shock. This suggests an intricate crosstalk between nuclear lamins, NM1 and SC35 organization in modulating transcriptional responses of the Hsp70 gene locus during heat shock. Taken together, this study unravels a novel role for lamin A/C in the regulation of the spatial dynamics and function of the Hsp70 gene locus upon heat shock, via the nuclear motor protein NM1.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Roopali Pradhan
- Biology, Main Building, First Floor, Room B-216, Indian Institute of Science Education and Research (IISER), Pune 411008, India
| | - Muhunden Jayakrishnan Nallappa
- Biology, Main Building, First Floor, Room B-216, Indian Institute of Science Education and Research (IISER), Pune 411008, India
| | - Kundan Sengupta
- Biology, Main Building, First Floor, Room B-216, Indian Institute of Science Education and Research (IISER), Pune 411008, India
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Mandigo TR, Turcich BD, Anderson AJ, Hussey MR, Folker ES. Drosophila emerins control LINC complex localization and transcription to regulate myonuclear position. J Cell Sci 2019; 132:jcs.235580. [PMID: 31548202 DOI: 10.1242/jcs.235580] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 09/16/2019] [Indexed: 01/06/2023] Open
Abstract
Mispositioned nuclei are a hallmark of skeletal muscle disease. Many of the genes that are linked to Emery-Dreifuss muscular dystrophy (EDMD) encode proteins that are critical for nuclear movement in various cells, suggesting that disruptions in nuclear movement and position may contribute to disease progression. However, how these genes are coordinated to move nuclei is not known. Here, we focussed on two different emerin proteins in Drosophila, Bocksbeutel and Otefin, and their effects on nuclear movement. Although nuclear position was dependent on both, elimination of either Bocksbeutel or Otefin produced distinct phenotypes that were based in differential effects on the KASH-domain protein Klarsicht. Specifically, loss of Bocksbeutel reduced Klarsicht localization to the nucleus and resulted in a disruption in nuclear separation. Loss of Otefin increased the transcription of Klarsicht and led to premature separation of nuclei and their positioning closer to the edge of the muscle. Consistent with opposing functions, nuclear position is normal in otefin; bocksbeutel double mutants. These data indicate emerin-dependent regulation of Klarsicht levels in the nuclear envelope is a critical determinant of nuclear position.
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Affiliation(s)
- Torrey R Mandigo
- Department of Biology, Boston College, Chestnut Hill, MA 02467, USA
| | - Blake D Turcich
- Department of Biology, Boston College, Chestnut Hill, MA 02467, USA
| | | | - Michael R Hussey
- Department of Biology, Boston College, Chestnut Hill, MA 02467, USA
| | - Eric S Folker
- Department of Biology, Boston College, Chestnut Hill, MA 02467, USA
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Buchwalter A, Schulte R, Tsai H, Capitanio J, Hetzer M. Selective clearance of the inner nuclear membrane protein emerin by vesicular transport during ER stress. eLife 2019; 8:e49796. [PMID: 31599721 PMCID: PMC6802967 DOI: 10.7554/elife.49796] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Accepted: 10/09/2019] [Indexed: 12/17/2022] Open
Abstract
The inner nuclear membrane (INM) is a subdomain of the endoplasmic reticulum (ER) that is gated by the nuclear pore complex. It is unknown whether proteins of the INM and ER are degraded through shared or distinct pathways in mammalian cells. We applied dynamic proteomics to profile protein half-lives and report that INM and ER residents turn over at similar rates, indicating that the INM's unique topology is not a barrier to turnover. Using a microscopy approach, we observed that the proteasome can degrade INM proteins in situ. However, we also uncovered evidence for selective, vesicular transport-mediated turnover of a single INM protein, emerin, that is potentiated by ER stress. Emerin is rapidly cleared from the INM by a mechanism that requires emerin's LEM domain to mediate vesicular trafficking to lysosomes. This work demonstrates that the INM can be dynamically remodeled in response to environmental inputs.
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Affiliation(s)
- Abigail Buchwalter
- Cardiovascular Research InstituteUniversity of California, San FranciscoSan FranciscoUnited States
- Department of PhysiologyUniversity of California, San FranciscoSan FranciscoUnited States
- Chan Zuckerberg BiohubSan FranciscoUnited States
| | - Roberta Schulte
- The Salk Institute for Biological StudiesLa JollaUnited States
| | - Hsiao Tsai
- The Salk Institute for Biological StudiesLa JollaUnited States
| | | | - Martin Hetzer
- The Salk Institute for Biological StudiesLa JollaUnited States
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