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Storey EC, Holt I, Brown S, Synowsky S, Shirran S, Fuller HR. Proteomic characterization of human LMNA-related congenital muscular dystrophy muscle cells. Neuromuscul Disord 2024; 38:26-41. [PMID: 38554696 DOI: 10.1016/j.nmd.2024.03.006] [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: 01/19/2024] [Revised: 03/08/2024] [Accepted: 03/11/2024] [Indexed: 04/02/2024]
Abstract
LMNA-related congenital muscular dystrophy (L-CMD) is caused by mutations in the LMNA gene, encoding lamin A/C. To further understand the molecular mechanisms of L-CMD, proteomic profiling using DIA mass spectrometry was conducted on immortalized myoblasts and myotubes from controls and L-CMD donors each harbouring a different LMNA mutation (R249W, del.32 K and L380S). Compared to controls, 124 and 228 differentially abundant proteins were detected in L-CMD myoblasts and myotubes, respectively, and were associated with enriched canonical pathways including synaptogenesis and necroptosis in myoblasts, and Huntington's disease and insulin secretion in myotubes. Abnormal nuclear morphology and reduced lamin A/C and emerin abundance was evident in all L-CMD cell lines compared to controls, while nucleoplasmic aggregation of lamin A/C was restricted to del.32 K cells, and mislocalization of emerin was restricted to R249W cells. Abnormal nuclear morphology indicates loss of nuclear lamina integrity as a common feature of L-CMD, likely rendering muscle cells vulnerable to mechanically induced stress, while differences between L-CMD cell lines in emerin and lamin A localization suggests that some molecular alterations in L-CMD are mutation specific. Nonetheless, identifying common proteomic alterations and molecular pathways across all three L-CMD lines has highlighted potential targets for the development of non-mutation specific therapies.
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Affiliation(s)
- Emily C Storey
- Wolfson Centre for Inherited Neuromuscular Disease, RJAH Orthopaedic Hospital, Oswestry, SY10 7AG, UK; The School of Pharmacy and Bioengineering, Keele University, ST5 5BG, UK
| | - Ian Holt
- Wolfson Centre for Inherited Neuromuscular Disease, RJAH Orthopaedic Hospital, Oswestry, SY10 7AG, UK; The School of Pharmacy and Bioengineering, Keele University, ST5 5BG, UK
| | - Sharon Brown
- Wolfson Centre for Inherited Neuromuscular Disease, RJAH Orthopaedic Hospital, Oswestry, SY10 7AG, UK; The School of Pharmacy and Bioengineering, Keele University, ST5 5BG, UK
| | - Silvia Synowsky
- BSRC Mass Spectrometry and Proteomics Facility, University of St Andrews, KY16 9ST, UK
| | - Sally Shirran
- BSRC Mass Spectrometry and Proteomics Facility, University of St Andrews, KY16 9ST, UK
| | - Heidi R Fuller
- Wolfson Centre for Inherited Neuromuscular Disease, RJAH Orthopaedic Hospital, Oswestry, SY10 7AG, UK; The School of Pharmacy and Bioengineering, Keele University, ST5 5BG, UK.
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2
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Zi-Yi Z, Qin Q, Fei Z, Cun-Yu C, Lin T. Nesprin proteins: bridging nuclear envelope dynamics to muscular dysfunction. Cell Commun Signal 2024; 22:208. [PMID: 38566066 PMCID: PMC10986154 DOI: 10.1186/s12964-024-01593-y] [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: 01/28/2024] [Accepted: 03/24/2024] [Indexed: 04/04/2024] Open
Abstract
This review presents a comprehensive exploration of the pivotal role played by the Linker of Nucleoskeleton and Cytoskeleton (LINC) complex, with a particular focus on Nesprin proteins, in cellular mechanics and the pathogenesis of muscular diseases. Distinguishing itself from prior works, the analysis delves deeply into the intricate interplay of the LINC complex, emphasizing its indispensable contribution to maintaining cellular structural integrity, especially in mechanically sensitive tissues such as cardiac and striated muscles. Additionally, the significant association between mutations in Nesprin proteins and the onset of Dilated Cardiomyopathy (DCM) and Emery-Dreifuss Muscular Dystrophy (EDMD) is highlighted, underscoring their pivotal role in disease pathogenesis. Through a comprehensive examination of DCM and EDMD cases, the review elucidates the disruptions in the LINC complex, nuclear morphology alterations, and muscular developmental disorders, thus emphasizing the essential function of an intact LINC complex in preserving muscle physiological functions. Moreover, the review provides novel insights into the implications of Nesprin mutations for cellular dynamics in the pathogenesis of muscular diseases, particularly in maintaining cardiac structural and functional integrity. Furthermore, advanced therapeutic strategies, including rectifying Nesprin gene mutations, controlling Nesprin protein expression, enhancing LINC complex functionality, and augmenting cardiac muscle cell function are proposed. By shedding light on the intricate molecular mechanisms underlying nuclear-cytoskeletal interactions, the review lays the groundwork for future research and therapeutic interventions aimed at addressing genetic muscle disorders.
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Affiliation(s)
- Zhou Zi-Yi
- Department of Cardiology, Yichang Central People's Hospital, Yichang, 443003, Hubei, People's Republic of China
- School of Basic Medicine, China Three Gorges University, Yichang, 443000, Hubei, People's Republic of China
| | - Qin Qin
- Department of Cardiology, Yichang Central People's Hospital, Yichang, 443003, Hubei, People's Republic of China
- School of Basic Medicine, China Three Gorges University, Yichang, 443000, Hubei, People's Republic of China
| | - Zhou Fei
- Department of Cardiology, Yichang Central People's Hospital, Yichang, 443003, Hubei, People's Republic of China
| | - Cao Cun-Yu
- School of Basic Medicine, China Three Gorges University, Yichang, 443000, Hubei, People's Republic of China
- College of Basic Medical Sciences, Hubei Key Laboratory of Tumor Microencironment and immunotherapy, China Three Gorges University, Yichang, 443000, Hubei, People's Republic of China
| | - Teng Lin
- Department of Cardiology, Yichang Central People's Hospital, Yichang, 443003, Hubei, People's Republic of China.
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London, SE5 9NU, UK.
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3
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Benarroch E. What Is the Role of Nuclear Envelope Proteins in Neurologic Disorders? Neurology 2024; 102:e209202. [PMID: 38330281 DOI: 10.1212/wnl.0000000000209202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 12/12/2023] [Indexed: 02/10/2024] Open
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4
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Liu C, Rex R, Lung Z, Wang JS, Wu F, Kim HJ, Zhang L, Sohn LL, Dernburg AF. A cooperative network at the nuclear envelope counteracts LINC-mediated forces during oogenesis in C. elegans. SCIENCE ADVANCES 2023; 9:eabn5709. [PMID: 37436986 PMCID: PMC10337908 DOI: 10.1126/sciadv.abn5709] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Accepted: 06/08/2023] [Indexed: 07/14/2023]
Abstract
Oogenesis involves transduction of mechanical forces from the cytoskeleton to the nuclear envelope (NE). In Caenorhabditis elegans, oocyte nuclei lacking the single lamin protein LMN-1 are vulnerable to collapse under forces mediated through LINC (linker of nucleoskeleton and cytoskeleton) complexes. Here, we use cytological analysis and in vivo imaging to investigate the balance of forces that drive this collapse and protect oocyte nuclei. We also use a mechano-node-pore sensing device to directly measure the effect of genetic mutations on oocyte nuclear stiffness. We find that nuclear collapse is not a consequence of apoptosis. It is promoted by dynein, which induces polarization of a LINC complex composed of Sad1 and UNC-84 homology 1 (SUN-1) and ZYGote defective 12 (ZYG-12). Lamins contribute to oocyte nuclear stiffness and cooperate with other inner nuclear membrane proteins to distribute LINC complexes and protect nuclei from collapse. We speculate that a similar network may protect oocyte integrity during extended oocyte arrest in mammals.
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Affiliation(s)
- Chenshu Liu
- California Institute for Quantitative Biosciences (QB3) and Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720, USA
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Rachel Rex
- Department of Mechanical Engineering, University of California Berkeley, Berkeley, CA 94720, USA
| | - Zoe Lung
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - John S. Wang
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Fan Wu
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Hyung Jun Kim
- California Institute for Quantitative Biosciences (QB3) and Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720, USA
| | - Liangyu Zhang
- California Institute for Quantitative Biosciences (QB3) and Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720, USA
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Lydia L. Sohn
- Department of Mechanical Engineering, University of California Berkeley, Berkeley, CA 94720, USA
| | - Abby F. Dernburg
- California Institute for Quantitative Biosciences (QB3) and Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720, USA
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
- Department of Biological Sciences and Engineering, Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
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5
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Fan Q, Li XM, Zhai C, Li B, Li ST, Dong MQ. Somatic nuclear blebbing in Caenorhabditis elegans is not a feature of organismal aging but a potential indicator of germline proliferation in early adulthood. G3 (BETHESDA, MD.) 2023; 13:jkad029. [PMID: 36735812 PMCID: PMC10085788 DOI: 10.1093/g3journal/jkad029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 01/26/2023] [Accepted: 01/27/2023] [Indexed: 02/05/2023]
Abstract
Abnormal nuclear morphology is suggested to be a hallmark of aging and one such abnormality is nuclear blebbing. However, little is known about whether and how nuclear blebbing participates in animal aging, and what regulates it. In this study, we show that the frequency of nuclear blebbing in the hypodermis increases during aging in wild-type C. elegans. These nuclear blebs are enveloped by the nuclear lamina, the inner and the outer nuclear membrane, and 42% of them contain chromatin. Although nuclear blebbing could lead to DNA loss if chromatin-containing blebs detach and fuse with lysosomes, we find by time-lapse imaging that nuclear blebs rarely detach, and the estimated lifetime of a nuclear bleb is 772 h or 32 days. The amount of DNA lost through nuclear blebbing is estimated to be about 0.1% of the total DNA loss by adult Day 11. Furthermore, the frequency of nuclear blebbing does not correlate with the rate of aging in C. elegans. Old age does not necessarily induce nuclear blebbing, neither does starvation, heat stress, or oxidative stress. Intriguingly, we find that proliferation of germ cells promotes nuclear blebbing.
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Affiliation(s)
- Qiang Fan
- Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China
- National Institute of Biological Sciences (NIBS), Beijing 102206, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing 102206, China
| | - Xue-Mei Li
- National Institute of Biological Sciences (NIBS), Beijing 102206, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing 102206, China
| | - Chao Zhai
- National Institute of Biological Sciences (NIBS), Beijing 102206, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing 102206, China
| | - Bin Li
- National Institute of Biological Sciences (NIBS), Beijing 102206, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing 102206, China
| | - Shang-Tong Li
- National Institute of Biological Sciences (NIBS), Beijing 102206, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing 102206, China
| | - Meng-Qiu Dong
- Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China
- National Institute of Biological Sciences (NIBS), Beijing 102206, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing 102206, China
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6
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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: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [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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7
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Hiroe T, Moriya S, Kobayashi S, Nishijima Y, Watanabe A, Shirabe K, Ikota H, Yokoo H, Saio M. Negative correlation between the nuclear size and nuclear Lamina component Lamin A in intraductal papillary mucinous neoplasms of the pancreas. Pathol Oncol Res 2022; 28:1610684. [PMID: 36561231 PMCID: PMC9764245 DOI: 10.3389/pore.2022.1610684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Accepted: 11/23/2022] [Indexed: 12/12/2022]
Abstract
Background: The nuclear laminar protein Lamin A and inner nuclear membrane protein Emerin plays important role in sustaining nuclear structure. However, They have not investigated the significance of these proteins for development of pancreatic intraductal papillary mucinous neoplasm (IPMN). Methods: We examined pancreatic IPMN specimens for nuclear morphology and nuclear protein expression pattern of Lamin A and Emerin. Forty-two IPMN specimens were included, with 30 classified as intraductal papillary mucinous adenoma (IPMA) and 12 as intraductal papillary mucinous carcinoma (IPMC). Results: Classification according to histological subtype revealed that 26 specimens were of the gastric subtype (1 IPMC case), 8 were pancreatobiliary (6 IPMC cases), 6 were intestinal (3 IPMC cases), and 2 were oncocytic (all cases were IPMC). The frequency of IPMN subtypes in this study seemed to agree with those in previous reports. We analyzed Feulgen staining sections for nuclear morphological analysis using computer-assisted image analysis. Nuclear area and perimeter were significantly larger in IPMC than in IPMA. Finally, we examined the positive ratios of Lamin A and Emerin in immunohistochemical staining sections by image analysis. We found a negative correlation between the nuclear size and Lamin A-positive ratio, which was significantly lower in IPMC than that in IPMA. However, no significant correlation was observed between nuclear size and Emerin expression was observed, and no differences were found in the Emerin-positive ratio between IPMA and IPMC. Conclusion: Our results suggest that a decreased Lamin A positive ratio induces nuclear enlargement in adenomas, which thereby induce promotion to carcinomas. Furthermore, Lamin A expression can be a reliable biomarker for distinguishing between IPMC and IPMA.
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Affiliation(s)
- Tamaki Hiroe
- Laboratory of Histopathology and Cytopathology, Department of Laboratory Sciences, Graduate School of Health Sciences, Gunma University, Maebashi, Gunma, Japan
| | - Shunichi Moriya
- Laboratory of Histopathology and Cytopathology, Department of Laboratory Sciences, Graduate School of Health Sciences, Gunma University, Maebashi, Gunma, Japan
| | - Sayaka Kobayashi
- Laboratory of Histopathology and Cytopathology, Department of Laboratory Sciences, Graduate School of Health Sciences, Gunma University, Maebashi, Gunma, Japan
| | - Yoshimi Nishijima
- Laboratory of Histopathology and Cytopathology, Department of Laboratory Sciences, Graduate School of Health Sciences, Gunma University, Maebashi, Gunma, Japan
| | - Akira Watanabe
- Department of Hepatobiliary and Pancreatic Surgery, Graduate School of Medicine, Gunma University, Maebashi, Gunma, Japan
| | - Ken Shirabe
- Department of Hepatobiliary and Pancreatic Surgery, Graduate School of Medicine, Gunma University, Maebashi, Gunma, Japan
| | - Hayato Ikota
- Clinical Department of Pathology, Gunma University Hospital, Maebashi, Gunma, Japan
| | - Hideaki Yokoo
- Department of Human Pathology, Graduate School of Medicine, Gunma University, Maebashi, Gunma, Japan
| | - Masanao Saio
- Laboratory of Histopathology and Cytopathology, Department of Laboratory Sciences, Graduate School of Health Sciences, Gunma University, Maebashi, Gunma, Japan,*Correspondence: Masanao Saio,
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8
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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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9
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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: 4.0] [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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10
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Abstract
The nuclear envelope is composed of the nuclear membranes, nuclear lamina, and nuclear pore complexes. Laminopathies are diseases caused by mutations in genes encoding protein components of the lamina and these other nuclear envelope substructures. Mutations in the single gene encoding lamin A and C, which are expressed in most differentiated somatic cells, cause diseases affecting striated muscle, adipose tissue, peripheral nerve, and multiple systems with features of accelerated aging. Mutations in genes encoding other nuclear envelope proteins also cause an array of diseases that selectively affect different tissues or organs. In some instances, the molecular and cellular consequences of laminopathy-causing mutations are known. However, even when these are understood, mechanisms explaining specific tissue or organ pathology remain enigmatic. Current mechanistic hypotheses focus on how alterations in the nuclear envelope may affect gene expression, including via the regulation of signaling pathways, or cellular mechanics, including responses to mechanical stress.
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Affiliation(s)
- Ji-Yeon Shin
- Department of Medicine and Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Howard J. Worman
- Department of Medicine and Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
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11
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Pawar S, Kutay U. The Diverse Cellular Functions of Inner Nuclear Membrane Proteins. Cold Spring Harb Perspect Biol 2021; 13:a040477. [PMID: 33753404 PMCID: PMC8411953 DOI: 10.1101/cshperspect.a040477] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The nuclear compartment is delimited by a specialized expanded sheet of the endoplasmic reticulum (ER) known as the nuclear envelope (NE). Compared to the outer nuclear membrane and the contiguous peripheral ER, the inner nuclear membrane (INM) houses a unique set of transmembrane proteins that serve a staggering range of functions. Many of these functions reflect the exceptional position of INM proteins at the membrane-chromatin interface. Recent research revealed that numerous INM proteins perform crucial roles in chromatin organization, regulation of gene expression, genome stability, and mediation of signaling pathways into the nucleus. Other INM proteins establish mechanical links between chromatin and the cytoskeleton, help NE remodeling, or contribute to the surveillance of NE integrity and homeostasis. As INM proteins continue to gain prominence, we review these advancements and give an overview on the functional versatility of the INM proteome.
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Affiliation(s)
- Sumit Pawar
- Institute of Biochemistry, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland
| | - Ulrike Kutay
- Institute of Biochemistry, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland
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12
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Expression of the Ebola Virus VP24 Protein Compromises the Integrity of the Nuclear Envelope and Induces a Laminopathy-Like Cellular Phenotype. mBio 2021; 12:e0097221. [PMID: 34225493 PMCID: PMC8406168 DOI: 10.1128/mbio.00972-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Ebola virus (EBOV) VP24 protein is a nucleocapsid-associated protein that inhibits interferon (IFN) gene expression and counteracts the IFN-mediated antiviral response, preventing nuclear import of signal transducer and activator of transcription 1 (STAT1). Proteomic studies to identify additional EBOV VP24 partners have pointed to the nuclear membrane component emerin as a potential element of the VP24 cellular interactome. Here, we have further studied this interaction and its impact on cell biology. We demonstrate that VP24 interacts with emerin but also with other components of the inner nuclear membrane, such as lamin A/C and lamin B. We also show that VP24 diminishes the interaction between emerin and lamin A/C and compromises the integrity of the nuclear membrane. This disruption is associated with nuclear morphological abnormalities, activation of a DNA damage response, the phosphorylation of extracellular signal-regulated kinase (ERK), and the induction of interferon-stimulated gene 15 (ISG15). Interestingly, expression of VP24 also promoted the cytoplasmic translocation and downmodulation of barrier-to-autointegration factor (BAF), a common interactor of lamin A/C and emerin, leading to repression of the BAF-regulated CSF1 gene. Importantly, we found that EBOV infection results in the activation of pathways associated with nuclear envelope damage, consistent with our observations in cells expressing VP24. In summary, here we demonstrate that VP24 acts at the nuclear membrane, causing morphological and functional changes in cells that recapitulate several of the hallmarks of laminopathy diseases.
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Chromatin and Cytoskeletal Tethering Determine Nuclear Morphology in Progerin-Expressing Cells. Biophys J 2020; 118:2319-2332. [PMID: 32320674 DOI: 10.1016/j.bpj.2020.04.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 03/18/2020] [Accepted: 04/03/2020] [Indexed: 12/13/2022] Open
Abstract
The nuclear morphology of eukaryotic cells is determined by the interplay between the lamina forming the nuclear skeleton, the chromatin inside the nucleus, and the coupling with the cytoskeleton. Nuclear alterations are often associated with pathological conditions as in Hutchinson-Gilford progeria syndrome, in which a mutation in the lamin A gene yields an altered form of the protein, named progerin, and an aberrant nuclear shape. Here, we introduce an inducible cellular model of Hutchinson-Gilford progeria syndrome in HeLa cells in which increased progerin expression leads to alterations in the coupling of the lamin shell with cytoskeletal or chromatin tethers as well as with polycomb group proteins. Furthermore, our experiments show that progerin expression leads to enhanced nuclear shape fluctuations in response to cytoskeletal activity. To interpret the experimental results, we introduce a computational model of the cell nucleus that explicitly includes chromatin fibers, the nuclear shell, and coupling with the cytoskeleton. The model allows us to investigate how the geometrical organization of the chromatin-lamin tether affects nuclear morphology and shape fluctuations. In sum, our findings highlight the crucial role played by lamin-chromatin and lamin-cytoskeletal alterations in determining nuclear shape morphology and in affecting cellular functions and gene regulation.
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14
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Heller SA, Shih R, Kalra R, Kang PB. Emery-Dreifuss muscular dystrophy. Muscle Nerve 2019; 61:436-448. [PMID: 31840275 PMCID: PMC7154529 DOI: 10.1002/mus.26782] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 12/04/2019] [Accepted: 12/07/2019] [Indexed: 12/19/2022]
Abstract
Emery-Dreifuss muscular dystrophy (EDMD) is a rare muscular dystrophy, but is particularly important to diagnose due to frequent life-threatening cardiac complications. EDMD classically presents with muscle weakness, early contractures, cardiac conduction abnormalities and cardiomyopathy, although the presence and severity of these manifestations vary by subtype and individual. Associated genes include EMD, LMNA, SYNE1, SYNE2, FHL1, TMEM43, SUN1, SUN2, and TTN, encoding emerin, lamin A/C, nesprin-1, nesprin-2, FHL1, LUMA, SUN1, SUN2, and titin, respectively. The Online Mendelian Inheritance in Man database recognizes subtypes 1 through 7, which captures most but not all of the associated genes. Genetic diagnosis is essential whenever available, but traditional diagnostic tools can help steer the evaluation toward EDMD and assist with interpretation of equivocal genetic test results. Management is primarily supportive, but it is important to monitor patients closely, especially for potential cardiac complications. There is a high potential for progress in the treatment of EDMD in the coming years.
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Affiliation(s)
- Scott A Heller
- Department of Neurology, University of Florida College of Medicine, Gainesville, Florida
| | - Renata Shih
- Congenital Heart Center, University of Florida College of Medicine, Gainesville, Florida
| | - Raghav Kalra
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida
| | - Peter B Kang
- Department of Neurology, University of Florida College of Medicine, Gainesville, Florida.,Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida.,Genetics Institute and Myology Institute, University of Florida, Gainesville, Florida
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15
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Lambert MW. The functional importance of lamins, actin, myosin, spectrin and the LINC complex in DNA repair. Exp Biol Med (Maywood) 2019; 244:1382-1406. [PMID: 31581813 DOI: 10.1177/1535370219876651] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Three major proteins in the nucleoskeleton, lamins, actin, and spectrin, play essential roles in maintenance of nuclear architecture and the integrity of the nuclear envelope, in mechanotransduction and mechanical coupling between the nucleoskeleton and cytoskeleton, and in nuclear functions such as regulation of gene expression, transcription and DNA replication. Less well known, but critically important, are the role these proteins play in DNA repair. The A-type and B-type lamins, nuclear actin and myosin, spectrin and the LINC (linker of nucleoskeleton and cytoskeleton) complex each function in repair of DNA damage utilizing various repair pathways. The lamins play a role in repair of DNA double-strand breaks (DSBs) by nonhomologous end joining (NHEJ) or homologous recombination (HR). Actin is involved in repair of DNA DSBs and interacts with myosin in facilitating relocalization of these DSBs in heterochromatin for HR repair. Nonerythroid alpha spectrin (αSpII) plays a critical role in repair of DNA interstrand cross-links (ICLs) where it acts as a scaffold in recruitment of repair proteins to sites of damage and is important in the initial damage recognition and incision steps of the repair process. The LINC complex contributes to the repair of DNA DSBs and ICLs. This review will address the important functions of these proteins in the DNA repair process, their mechanism of action, and the profound impact a defect or deficiency in these proteins has on cellular function. The critical roles of these proteins in DNA repair will be further emphasized by discussing the human disorders and the pathophysiological changes that result from or are related to deficiencies in these proteins. The demonstrated function for each of these proteins in the DNA repair process clearly indicates that there is another level of complexity that must be considered when mechanistically examining factors crucial for DNA repair.Impact statementProteins in the nucleoskeleton, lamins, actin, myosin, and spectrin, have been shown to play critical roles in DNA repair. Deficiencies in these proteins are associated with a number of disorders. This review highlights the role these proteins and their association with the LINC complex play in DNA repair processes, their mechanism of action and the impacts deficiencies in these proteins have on DNA repair and on disorders associated with a deficiency in these proteins. It will clarify how these proteins, which interact with “classic DNA repair proteins” (e.g., RAD51, XPF), represent another level of complexity in the DNA repair process, which must be taken into consideration when carrying out mechanistic studies on proteins involved in DNA repair and in developing models for DNA repair pathways. This knowledge is essential for determining how deficiencies in these proteins relate to disorders resulting from loss of functional activity of these proteins.
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Affiliation(s)
- Muriel W Lambert
- Department of Pathology, Immunology and Laboratory Medicine, Rutgers New Jersey Medical School, Newark, NJ 07103, USA
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16
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Wada E, Kato M, Yamashita K, Kokuba H, Liang WC, Bonne G, Hayashi YK. Deficiency of emerin contributes differently to the pathogenesis of skeletal and cardiac muscles in LmnaH222P/H222P mutant mice. PLoS One 2019; 14:e0221512. [PMID: 31430335 PMCID: PMC6701770 DOI: 10.1371/journal.pone.0221512] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 08/08/2019] [Indexed: 11/18/2022] Open
Abstract
Laminopathies are tissue-selective diseases that affect differently in organ systems. Mutations in nuclear envelopes, emerin (Emd) and lamin A/C (Lmna) genes, cause clinically indistinguishable myopathy called Emery-Dreifuss muscular dystrophy (EDMD) and limb-girdle muscular dystrophy. Several murine models for EDMD have been generated; however, emerin-null (Emd) mice do not show obvious skeletal and cardiac muscle phenotypes, and Lmna H222P/H222P mutant (H222P) mice show only a mild phenotype in skeletal muscle when they already have severe cardiomyopathy. Thus, the underlying molecular mechanism of muscle involvement due to nuclear abnormalities is still unclarified. We generated double mutant (Emd-/-/LmnaH222P/H222P; EH) mice to characterize dystrophic changes and to elucidate interactions between emerin and lamin A/C in skeletal and cardiac muscles. As H222P mice, EH mice grow normally and have breeding productivity. EH mice showed severer muscle involvement compared with that of H222P mice which was an independent of cardiac abnormality at 12 weeks of age. Nuclear abnormalities, reduced muscle fiber size and increased fibrosis were prominent in EH mice. Roles of emerin and lamin A/C in satellite cells function and regeneration of muscle fiber were also evaluated by cardiotoxin-induced muscle injury. Delayed increases in myog and myh3 expression were seen in both H222P and EH mice; however, the expression levels of those genes were similar with control and regenerated muscle fiber size was not different at day 7 after injury. These results indicate that EH mouse is a suitable model for studying skeletal muscle involvement, independent of cardiac function, in laminopathies and an interaction between emerin and lamin A/C in different tissues.
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Affiliation(s)
- Eiji Wada
- Department of Pathophysiology, Tokyo Medical University, Tokyo, Japan
| | - Megumi Kato
- Department of Pathophysiology, Tokyo Medical University, Tokyo, Japan
| | - Kaori Yamashita
- Department of Pathophysiology, Tokyo Medical University, Tokyo, Japan
| | - Hiroko Kokuba
- Institute of Medical Science, Tokyo Medical University, Tokyo, Japan
| | - Wen-Chen Liang
- Department of Pediatrics, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
- Department of Pediatrics, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Gisèle Bonne
- Sorbonne Université, Inserm UMRS 974, Center of Research in Myology, Paris, France
| | - Yukiko K. Hayashi
- Department of Pathophysiology, Tokyo Medical University, Tokyo, Japan
- * E-mail:
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17
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Wang Y, Shin JY, Nakanishi K, Homma S, Kim GJ, Tanji K, Joseph LC, Morrow JP, Stewart CL, Dauer WT, Worman HJ. Postnatal development of mice with combined genetic depletions of lamin A/C, emerin and lamina-associated polypeptide 1. Hum Mol Genet 2019; 28:2486-2500. [PMID: 31009944 DOI: 10.1093/hmg/ddz082] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 03/28/2019] [Accepted: 04/15/2019] [Indexed: 01/18/2023] Open
Abstract
Mutations in LMNA encoding lamin A/C and EMD encoding emerin cause cardiomyopathy and muscular dystrophy. Lmna null mice develop these disorders and have a lifespan of 7-8 weeks. Emd null mice show no overt pathology and have normal skeletal muscle but with regeneration defects. We generated mice with germline deletions of both Lmna and Emd to determine the effects of combined loss of the encoded proteins. Mice without lamin A/C and emerin are born at the expected Mendelian ratio, are grossly normal at birth but have shorter lifespans than those lacking only lamin A/C. However, there are no major differences between these mice with regards to left ventricular function, heart ultrastructure or electrocardiographic parameters except for slower heart rates in the mice lacking both lamin A/C and emerin. Skeletal muscle is similarly affected in both of these mice. Lmna+/- mice also lacking emerin live to at least 1 year and have no significant differences in growth, heart or skeletal muscle compared to Lmna+/- mice. Deletion of the mouse gene encoding lamina-associated protein 1 leads to prenatal death; however, mice with heterozygous deletion of this gene lacking both lamin A/C and emerin are born at the expected Mendelian ratio but had a shorter lifespan than those only lacking lamin A/C and emerin. These results show that mice with combined deficiencies of three interacting nuclear envelope proteins have normal embryonic development and that early postnatal defects are primarily driven by loss of lamin A/C or lamina-associated polypeptide 1 rather than emerin.
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Affiliation(s)
- Yuexia Wang
- Department of Medicine and.,Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Ji-Yeon Shin
- Department of Medicine and.,Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | | | | | | | - Kurenai Tanji
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | | | | | - Colin L Stewart
- Development and Regenerative Biology Group, Institute of Medical Biology, Immunos, Singapore
| | - Willian T Dauer
- Department of Neurology.,Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Howard J Worman
- Department of Medicine and.,Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
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18
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Cellular and Animal Models of Striated Muscle Laminopathies. Cells 2019; 8:cells8040291. [PMID: 30934932 PMCID: PMC6523539 DOI: 10.3390/cells8040291] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 03/18/2019] [Accepted: 03/25/2019] [Indexed: 01/12/2023] Open
Abstract
The lamin A/C (LMNA) gene codes for nuclear intermediate filaments constitutive of the nuclear lamina. LMNA has 12 exons and alternative splicing of exon 10 results in two major isoforms—lamins A and C. Mutations found throughout the LMNA gene cause a group of diseases collectively known as laminopathies, of which the type, diversity, penetrance and severity of phenotypes can vary from one individual to the other, even between individuals carrying the same mutation. The majority of the laminopathies affect cardiac and/or skeletal muscles. The underlying molecular mechanisms contributing to such tissue-specific phenotypes caused by mutations in a ubiquitously expressed gene are not yet well elucidated. This review will explore the different phenotypes observed in established models of striated muscle laminopathies and their respective contributions to advancing our understanding of cardiac and skeletal muscle-related laminopathies. Potential future directions for developing effective treatments for patients with lamin A/C mutation-associated cardiac and/or skeletal muscle conditions will be discussed.
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19
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Perepelina K, Klauzen P, Kostareva A, Malashicheva A. Tissue-Specific Influence of Lamin A Mutations on Notch Signaling and Osteogenic Phenotype of Primary Human Mesenchymal Cells. Cells 2019; 8:cells8030266. [PMID: 30901896 PMCID: PMC6468400 DOI: 10.3390/cells8030266] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 03/16/2019] [Accepted: 03/19/2019] [Indexed: 12/19/2022] Open
Abstract
Lamin A is involved in many cellular functions due to its ability to bind chromatin and transcription factors and affect their properties. Mutations of LMNA gene encoding lamin A affect the differentiation capacity of stem cells, but the mechanisms of this influence remain largely unclear. We and others have reported recently an interaction of lamin A with Notch pathway, which is among the main developmental regulators of cellular identity. The aim of this study was to explore the influence of LMNA mutations on the proosteogenic response of human cells of mesenchymal origin and to further explore the interaction of LMNA with Notch pathway. Mutations R527C and R471C in LMNA are associated with mandibuloacral dysplasia type A, a highly penetrant disease with a variety of abnormalities involving bone development. We used lentiviral constructs bearing mutations R527C and R471C and explored its influence on proosteogenic phenotype expression and Notch pathway activity in four types of human cells: umbilical vein endothelial cells (HUVEC), cardiac mesenchymal cells (HCMC), aortic smooth muscle cells (HASMC), and aortic valve interstitial cells (HAVIC). The proosteogenic response of the cells was induced by the addition of either LPS or specific effectors of osteogenic differentiation to the culture medium; phenotype was estimated by the expression of osteogenic markers by qPCR; activation of Notch was assessed by expression of Notch-related and Notch-responsive genes by qPCR and by activation of a luciferase CSL-reporter construct. Overall, we observed different reactivity of all four cell lineages to the stimulation with either LPS or osteogenic factors. R527C had a stronger influence on the proosteogenic phenotype. We observed the inhibiting action of LMNA R527C on osteogenic differentiation in HCMC in the presence of activated Notch signaling, while LMNA R527C caused the activation of osteogenic differentiation in HAVIC in the presence of activated Notch signaling. Our results suggest that the effect of a LMNA mutation is strongly dependent not only on a specific mutation itself, but also might be influenced by the intrinsic molecular context of a cell lineage.
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Affiliation(s)
- Kseniya Perepelina
- Almazov National Medical Research Centre, 2 Akkuratova Str., St-Petersburg 197341, Russia.
- St-Petersburg State University, 7-9, Universitetskaya nab., St-Petersburg 199034, Russia.
| | - Polina Klauzen
- Almazov National Medical Research Centre, 2 Akkuratova Str., St-Petersburg 197341, Russia.
- St-Petersburg State University, 7-9, Universitetskaya nab., St-Petersburg 199034, Russia.
- Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Ave., St-Petersburg 194064, Russia.
| | - Anna Kostareva
- Almazov National Medical Research Centre, 2 Akkuratova Str., St-Petersburg 197341, Russia.
- St-Petersburg State University, 7-9, Universitetskaya nab., St-Petersburg 199034, Russia.
| | - Anna Malashicheva
- Almazov National Medical Research Centre, 2 Akkuratova Str., St-Petersburg 197341, Russia.
- St-Petersburg State University, 7-9, Universitetskaya nab., St-Petersburg 199034, Russia.
- Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Ave., St-Petersburg 194064, Russia.
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20
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Dubińska-Magiera M, Kozioł K, Machowska M, Piekarowicz K, Filipczak D, Rzepecki R. Emerin Is Required for Proper Nucleus Reassembly after Mitosis: Implications for New Pathogenetic Mechanisms for Laminopathies Detected in EDMD1 Patients. Cells 2019; 8:cells8030240. [PMID: 30871242 PMCID: PMC6468536 DOI: 10.3390/cells8030240] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 02/26/2019] [Accepted: 03/05/2019] [Indexed: 12/29/2022] Open
Abstract
Emerin is an essential LEM (LAP2, Emerin, MAN1) domain protein in metazoans and an integral membrane protein associated with inner and outer nuclear membranes. Mutations in the human EMD gene coding for emerin result in the rare genetic disorder: Emery–Dreifuss muscular dystrophy type 1 (EDMD1). This disease belongs to a broader group called laminopathies—a heterogeneous group of rare genetic disorders affecting tissues of mesodermal origin. EDMD1 phenotype is characterized by progressive muscle wasting, contractures of the elbow and Achilles tendons, and cardiac conduction defects. Emerin is involved in many cellular and intranuclear processes through interactions with several partners: lamins; barrier-to-autointegration factor (BAF), β-catenin, actin, and tubulin. Our study demonstrates the presence of the emerin fraction which associates with mitotic spindle microtubules and centrosomes during mitosis and colocalizes during early mitosis with lamin A/C, BAF, and membranes at the mitotic spindle. Transfection studies with cells expressing EGFP-emerin protein demonstrate that the emerin fusion protein fraction also localizes to centrosomes and mitotic spindle microtubules during mitosis. Transient expression of emerin deletion mutants revealed that the resulting phenotypes vary and are mutant dependent. The most frequent phenotypes include aberrant nuclear shape, tubulin network mislocalization, aberrant mitosis, and mislocalization of centrosomes. Emerin deletion mutants demonstrated different chromatin binding capacities in an in vitro nuclear assembly assay and chromatin-binding properties correlated with the strength of phenotypic alteration in transfected cells. Aberrant tubulin staining and microtubule network phenotype appearance depended on the presence of the tubulin binding region in the expressed deletion mutants. We believe that the association with tubulin might help to “deliver” emerin and associated membranes to decondensing chromatin. Preliminary analyses of cells from Polish patients with EDMD1 revealed that for several mutations thought to be null for emerin protein, a truncated emerin protein was present. We infer that the EDMD1 phenotype may be strengthened by the toxicity of truncated emerin expressed in patients with certain nonsense mutations in EMD.
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Affiliation(s)
- Magda Dubińska-Magiera
- Laboratory of Nuclear Proteins, Faculty of Biotechnology, University of Wroclaw, Fryderyka Joliot-Curie 14a, 50-383 Wroclaw, Poland.
- Department of Animal Developmental Biology, Institute of Experimental Biology, University of Wroclaw, Sienkiewicza 21, 50-335 Wroclaw, Poland.
| | - Katarzyna Kozioł
- Laboratory of Nuclear Proteins, Faculty of Biotechnology, University of Wroclaw, Fryderyka Joliot-Curie 14a, 50-383 Wroclaw, Poland.
| | - Magdalena Machowska
- Laboratory of Nuclear Proteins, Faculty of Biotechnology, University of Wroclaw, Fryderyka Joliot-Curie 14a, 50-383 Wroclaw, Poland.
| | - Katarzyna Piekarowicz
- Laboratory of Nuclear Proteins, Faculty of Biotechnology, University of Wroclaw, Fryderyka Joliot-Curie 14a, 50-383 Wroclaw, Poland.
| | - Daria Filipczak
- Laboratory of Nuclear Proteins, Faculty of Biotechnology, University of Wroclaw, Fryderyka Joliot-Curie 14a, 50-383 Wroclaw, Poland.
| | - Ryszard Rzepecki
- Laboratory of Nuclear Proteins, Faculty of Biotechnology, University of Wroclaw, Fryderyka Joliot-Curie 14a, 50-383 Wroclaw, Poland.
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21
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Kang SM, Yoon MH, Park BJ. Laminopathies; Mutations on single gene and various human genetic diseases. BMB Rep 2018; 51:327-337. [PMID: 29764566 PMCID: PMC6089866 DOI: 10.5483/bmbrep.2018.51.7.113] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Indexed: 01/13/2023] Open
Abstract
Lamin A and its alternative splicing product Lamin C are the key intermediate filaments (IFs) of the inner nuclear membrane intermediate filament. Lamin A/C forms the inner nuclear mesh with Lamin B and works as a frame with a nuclear shape. In addition to supporting the function of nucleus, nuclear lamins perform important roles such as holding the nuclear pore complex and chromatin. However, mutations on the Lamin A or Lamin B related proteins induce various types of human genetic disorders and diseases including premature aging syndromes, muscular dystrophy, lipodystrophy and neuropathy. In this review, we briefly overview the relevance of genetic mutations of Lamin A, human disorders and laminopathies. We also discuss a mouse model for genetic diseases. Finally, we describe the current treatment for laminopathies. [BMB Reports 2018; 51(7): 327-337].
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Affiliation(s)
- So-Mi Kang
- Department of Molecular Biology, College of Natural Science, Pusan National University, Busan 46241, Korea
| | - Min-Ho Yoon
- Department of Molecular Biology, College of Natural Science, Pusan National University, Busan 46241, Korea
| | - Bum-Joon Park
- Department of Molecular Biology, College of Natural Science, Pusan National University, Busan 46241, Korea
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22
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Pradhan R, Ranade D, Sengupta K. Emerin modulates spatial organization of chromosome territories in cells on softer matrices. Nucleic Acids Res 2018; 46:5561-5586. [PMID: 29684168 PMCID: PMC6009696 DOI: 10.1093/nar/gky288] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 04/04/2018] [Accepted: 04/06/2018] [Indexed: 02/06/2023] Open
Abstract
Cells perceive and relay external mechanical forces into the nucleus through the nuclear envelope. Here we examined the effect of lowering substrate stiffness as a paradigm to address the impact of altered mechanical forces on nuclear structure-function relationships. RNA sequencing of cells on softer matrices revealed significant transcriptional imbalances, predominantly in chromatin associated processes and transcriptional deregulation of human Chromosome 1. Furthermore, 3-Dimensional fluorescence in situ hybridization (3D-FISH) analyses showed a significant mislocalization of Chromosome 1 and 19 Territories (CT) into the nuclear interior, consistent with their transcriptional deregulation. However, CT18 with relatively lower transcriptional dysregulation, also mislocalized into the nuclear interior. Furthermore, nuclear Lamins that regulate chromosome positioning, were mislocalized into the nuclear interior in response to lowered matrix stiffness. Notably, Lamin B2 overexpression retained CT18 near the nuclear periphery in cells on softer matrices. While, cells on softer matrices also activated emerin phosphorylation at a novel Tyr99 residue, the inhibition of which in a phospho-deficient mutant (emerinY99F), selectively retained chromosome 18 and 19 but not chromosome 1 territories at their conserved nuclear locations. Taken together, emerin functions as a key mechanosensor, that modulates the spatial organization of chromosome territories in the interphase nucleus.
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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, Dr Homi Bhabha Road, Pashan, Pune 411008, Maharashtra, India
| | - Devika Ranade
- Biology, Main Building, First Floor, Room#B-216, Indian Institute of Science Education and Research (IISER), Pune, Dr Homi Bhabha Road, Pashan, Pune 411008, Maharashtra, India
| | - Kundan Sengupta
- Biology, Main Building, First Floor, Room#B-216, Indian Institute of Science Education and Research (IISER), Pune, Dr Homi Bhabha Road, Pashan, Pune 411008, Maharashtra, India
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23
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Abstract
PURPOSE OF REVIEW Nuclear envelope links to a wide range of disorders, including several myopathies and neuropathies over the past 2 decades, has spurred research leading to a completely changed view of this important cellular structure and its functions. However, the many functions now assigned to the nuclear envelope make it increasingly hard to determine which functions underlie these disorders. RECENT FINDINGS New nuclear envelope functions in genome organization, regulation and repair, signaling, and nuclear and cellular mechanics have been added to its classical barrier function. Arguments can be made for any of these functions mediating abnormality in nuclear envelope disorders and data exist supporting many. Moreover, transient and/or distal nuclear envelope connections to other cellular proteins and structures may increase the complexity of these disorders. SUMMARY Although the increased understanding of nuclear envelope functions has made it harder to distinguish specific causes of nuclear envelope disorders, this is because it has greatly expanded the spectrum of possible mechanisms underlying them. This change in perspective applies well beyond the known nuclear envelope disorders, potentially implicating the nuclear envelope in a much wider range of myopathies and neuropathies.
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Zhu R, Liu C, Gundersen GG. Nuclear positioning in migrating fibroblasts. Semin Cell Dev Biol 2017; 82:41-50. [PMID: 29241691 DOI: 10.1016/j.semcdb.2017.11.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 11/03/2017] [Accepted: 11/06/2017] [Indexed: 01/09/2023]
Abstract
The positioning and movement of the nucleus has recently emerged as an important aspect of cell migration. Understanding of nuclear positioning and movement has reached an apogee in studies of fibroblast migration. Specific nuclear positioning and movements have been described in the polarization of fibroblast for cell migration and in active migration in 2D and 3D environments. Here, we review recent studies that have uncovered novel molecular mechanisms that contribute to these events in fibroblasts. Many of these involve a connection between the nucleus and the cytoskeleton through the LINC complex composed of outer nuclear membrane nesprins and inner nuclear membrane SUN proteins. We consider evidence that appropriate nuclear positioning contributes to efficient fibroblast polarization and migration and the possible mechanism through which the nucleus affects cell migration.
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Affiliation(s)
- Ruijun Zhu
- Department of Pathology and Cell Biology, Columbia University, New York, NY, 10032, USA
| | - Chenshu Liu
- Department of Pathology and Cell Biology, Columbia University, New York, NY, 10032, USA
| | - Gregg G Gundersen
- Department of Pathology and Cell Biology, Columbia University, New York, NY, 10032, USA.
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25
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Perepelina K, Dmitrieva R, Ignatieva E, Borodkina A, Kostareva A, Malashicheva A. Lamin A/C mutation associated with lipodystrophy influences adipogenic differentiation of stem cells through interaction with Notch signaling. Biochem Cell Biol 2017; 96:342-348. [PMID: 29040816 DOI: 10.1139/bcb-2017-0210] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Lamins A and C are involved in many cellular functions, owing to its ability to bind chromatin and transcription factors and affect their properties. Mutations of the LMNA gene encoding lamin A/C affect differentiation capacity of stem cells. However, the signaling pathways involved in interactions with lamins during cellular differentiation remain unclear. Lipodystrophy associated with LMNA mutation R482L causes loss of fat tissue. In this study we investigated the role of LMNA mutation R482L in modulating Notch signaling activity in the adipogenic differentiation of mesenchymal stem cells. Notch was activated using lentiviral Notch intracellular domain. Activation of Notch was estimated through the expression of Notch-responsive genes by qPCR and by activation of a luciferase CSL-reporter construct. The effect of LMNA mutation on Notch activation and adipogenic differentiation was analyzed in cells bearing lentiviral LMNA WT or LMNA R482L. We show that, when Notch is activated, LMNA R482L contributes to down-regulation of Notch activation in undifferentiated and differentiated cells, and decreases adipogenic differentiation. Thus, lamin A/C interacts with Notch signaling, thereby influencing cellular differentiation, and point mutation in LMNA could halt this interaction.
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Affiliation(s)
- K Perepelina
- e Almazov National Medical Research Centre, 2 Akkuratova street, Saint-Petersburg 197341, Russia.,f Saint-Petersburg State University, 7/9, Universitetskaya nab., Saint-Petersburg, 199034, Russia
| | - R Dmitrieva
- a Almazov National Medical Research Centre, Saint-Petersburg, Russia
| | - E Ignatieva
- a Almazov National Medical Research Centre, Saint-Petersburg, Russia
| | - A Borodkina
- c Institute of Cytology, Russian Academy of Sciences, 4, Tikhoretsky ave., Saint-Petersburg, 194064, Russia
| | - A Kostareva
- a Almazov National Medical Research Centre, Saint-Petersburg, Russia.,g ITMO University, Institute of Translational Medicine, 49 Kronverkskiy ave., Saint-Petersburg, 197101, Russia
| | - A Malashicheva
- a Almazov National Medical Research Centre, Saint-Petersburg, Russia.,b Saint-Petersburg State University, Saint-Petersburg, Russia.,d ITMO University, Institute of Translational Medicine, Saint-Petersburg, Russia
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Ranade D, Koul S, Thompson J, Prasad KB, Sengupta K. Chromosomal aneuploidies induced upon Lamin B2 depletion are mislocalized in the interphase nucleus. Chromosoma 2017; 126:223-244. [PMID: 26921073 PMCID: PMC5371638 DOI: 10.1007/s00412-016-0580-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Revised: 01/28/2016] [Accepted: 02/09/2016] [Indexed: 12/31/2022]
Abstract
Chromosome territories assume non-random positions in the interphase nucleus with gene-rich chromosomes localized toward the nuclear interior and gene-poor chromosome territories toward the nuclear periphery. Lamins are intermediate filament proteins of the inner nuclear membrane required for the maintenance of nuclear structure and function. Here, we show using whole-genome expression profiling that Lamin A/C or Lamin B2 depletion in an otherwise diploid colorectal cancer cell line (DLD1) deregulates transcript levels from specific chromosomes. Further, three-dimensional fluorescence in situ hybridization (3D-FISH) analyses of a subset of these transcriptionally deregulated chromosome territories revealed that the diploid chromosome territories in Lamin-depleted cells largely maintain conserved positions in the interphase nucleus in a gene-density-dependent manner. In addition, chromosomal aneuploidies were induced in ~25 % of Lamin A/C or Lamin B2-depleted cells. Sub-populations of these aneuploid cells consistently showed a mislocalization of the gene-rich aneuploid chromosome 19 territory toward the nuclear periphery, while gene-poor aneuploid chromosome 18 territory was mislocalized toward the nuclear interior predominantly upon Lamin B2 than Lamin A/C depletion. In addition, a candidate gene locus ZNF570 (Chr.19q13.12) significantly overexpressed upon Lamin B2 depletion was remarkably repositioned away from the nuclear lamina. Taken together, our studies strongly implicate an overarching role for Lamin B2 in the maintenance of nuclear architecture since loss of Lamin B2 relieves the spatial positional constraints required for maintaining conserved localization of aneuploid chromosome territories in the interphase nucleus.
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Affiliation(s)
- Devika Ranade
- Biology, Indian Institute of Science Education and Research, Pune, Main Building, Homi Bhabha Road, Pashan, Pune, Maharashtra, 411008, India
| | - Shivsmriti Koul
- Biology, Indian Institute of Science Education and Research, Pune, Main Building, Homi Bhabha Road, Pashan, Pune, Maharashtra, 411008, India
| | - Joyce Thompson
- Biology, Indian Institute of Science Education and Research, Pune, Main Building, Homi Bhabha Road, Pashan, Pune, Maharashtra, 411008, India
| | - Kumar Brajesh Prasad
- Biology, Indian Institute of Science Education and Research, Pune, Main Building, Homi Bhabha Road, Pashan, Pune, Maharashtra, 411008, India
| | - Kundan Sengupta
- Biology, Indian Institute of Science Education and Research, Pune, Main Building, Homi Bhabha Road, Pashan, Pune, Maharashtra, 411008, India.
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Arai R, En A, Ukekawa R, Miki K, Fujii M, Ayusawa D. Aberrant localization of lamin B receptor (LBR) in cellular senescence in human cells. Biochem Biophys Res Commun 2016; 473:1078-1083. [PMID: 27059139 DOI: 10.1016/j.bbrc.2016.04.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 04/05/2016] [Indexed: 01/08/2023]
Abstract
5-Bromodeoxyuridine (BrdU), a thymidine analogue, induces cellular senescence in mammalian cells. BrdU induces cellular senescence probably through the regulation of chromatin because BrdU destabilizes or disrupts nucleosome positioning and decondenses heterochromatin. Since heterochromatin is tethered to the nuclear periphery through the interaction with the nuclear envelope proteins, we examined the localization of the several nuclear envelope proteins such as lamins, lamin-interacting proteins, nuclear pore complex proteins, and nuclear transport proteins in senescent cells. We have shown here that lamin B receptor (LBR) showed a change in localization in both BrdU-induced and replicative senescent cells.
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Affiliation(s)
- Rumi Arai
- Graduate School of Nanobioscience, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama 236-0027, Japan
| | - Atsuki En
- Graduate School of Nanobioscience, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama 236-0027, Japan
| | - Ryo Ukekawa
- Graduate School of Nanobioscience, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama 236-0027, Japan
| | - Kensuke Miki
- Graduate School of Nanobioscience, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama 236-0027, Japan; Ichiban Life Corporation, 1-1-7 Horai-cho, Naka-ku, Yokohama 231-0048, Japan
| | - Michihiko Fujii
- Graduate School of Nanobioscience, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama 236-0027, Japan.
| | - Dai Ayusawa
- Graduate School of Nanobioscience, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama 236-0027, Japan; Ichiban Life Corporation, 1-1-7 Horai-cho, Naka-ku, Yokohama 231-0048, Japan
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Samson C, Herrada I, Celli F, Theillet FX, Zinn-Justin S. 1H, 13C and 15N backbone resonance assignment of the intrinsically disordered region of the nuclear envelope protein emerin. BIOMOLECULAR NMR ASSIGNMENTS 2016; 10:179-182. [PMID: 26725056 DOI: 10.1007/s12104-015-9662-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2015] [Accepted: 12/28/2015] [Indexed: 06/05/2023]
Abstract
Human emerin is an inner nuclear membrane protein involved in the response of the nucleus to mechanical stress. It contributes to the physical connection between the cytoskeleton and the nucleoskeleton. It is also involved in chromatin organization. Its N-terminal region is nucleoplasmic and comprises a globular LEM domain from residue 1 to residue 43. The three-dimensional structure of this LEM domain in complex with the chromatin BAF protein was solved from NMR data. Apart from the LEM domain, the nucleoplasmic region of emerin, from residue 44 to residue 221, is predicted to be intrinsically disordered. Mutations in this region impair binding to several emerin partners as lamin A, actin or HDAC3. However the molecular details of these recognition defects are unknown. Here we report (1)H, (15)N, (13)CO, (13)Cα and (13)Cβ NMR chemical shift assignments of the emerin fragment from residue 67 to residue 170, which is sufficient for nuclear localization and involved in lamin A binding. Chemical shift analysis confirms that this fragment is intrinsically disordered in 0 and 8 M urea.
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Affiliation(s)
- Camille Samson
- Laboratoire de Biologie Structurale et Radiobiologie, Institute for Integrative Biology of the Cell (I2BC), CNRS, Univ. Paris South and IBITECS CEA, CEA Saclay Bât. 144, 91191, Gif-sur-Yvette Cedex, France
| | - Isaline Herrada
- Laboratoire de Biologie Structurale et Radiobiologie, Institute for Integrative Biology of the Cell (I2BC), CNRS, Univ. Paris South and IBITECS CEA, CEA Saclay Bât. 144, 91191, Gif-sur-Yvette Cedex, France
| | - Florian Celli
- Laboratoire de Biologie Structurale et Radiobiologie, Institute for Integrative Biology of the Cell (I2BC), CNRS, Univ. Paris South and IBITECS CEA, CEA Saclay Bât. 144, 91191, Gif-sur-Yvette Cedex, France
| | - Francois-Xavier Theillet
- Laboratoire de Biologie Structurale et Radiobiologie, Institute for Integrative Biology of the Cell (I2BC), CNRS, Univ. Paris South and IBITECS CEA, CEA Saclay Bât. 144, 91191, Gif-sur-Yvette Cedex, France
- Department of NMR-assisted Structural Biology, Leibniz-Institut für Molekular Pharmakologie (FMP), 13125, Berlin, Germany
| | - Sophie Zinn-Justin
- Laboratoire de Biologie Structurale et Radiobiologie, Institute for Integrative Biology of the Cell (I2BC), CNRS, Univ. Paris South and IBITECS CEA, CEA Saclay Bât. 144, 91191, Gif-sur-Yvette Cedex, France.
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Navarro AP, Collins MA, Folker ES. The nucleus is a conserved mechanosensation and mechanoresponse organelle. Cytoskeleton (Hoboken) 2016; 73:59-67. [PMID: 26849407 DOI: 10.1002/cm.21277] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 01/22/2016] [Accepted: 01/22/2016] [Indexed: 11/05/2022]
Abstract
Cells in vivo exist in a dynamic environment where they experience variable mechanical influences. The precise mechanical environment influences cell-cell interactions, cell-extracellular matrix interactions, and in-turn, cell morphology and cell function. Therefore, the ability of each cell to constantly and rapidly alter their behavior in response to variations in their mechanical environment is essential for cell viability, development, and function. Mechanotransduction, the process by which mechanical force is translated into a biochemical signal to activate downstream cellular responses, is thus crucial to cell function during development and homeostasis. Although much research has focused on how protein complexes at the cell cortex respond to mechanical stress to initiate mechanotransduction, the nucleus has emerged as crucial to the ability of the cell to perceive and respond to changes in its mechanical environment. This additional method for mechanosensing allows for direct transmission of force through the cytoskeleton to the nucleus, which can increase the speed at which a cell changes its transcriptional profile. This review discusses recent work demonstrating the importance of the nucleus in mediating the cellular response to internal and external force, establishing the nucleus as an important mechanosensing organelle.
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Affiliation(s)
- Alexandra P Navarro
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02142
| | - Mary Ann Collins
- Department of Biology, Boston College, Chestnut Hill, Massachusetts, 02467
| | - Eric S Folker
- Department of Biology, Boston College, Chestnut Hill, Massachusetts, 02467
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Actin, actin-binding proteins, and actin-related proteins in the nucleus. Histochem Cell Biol 2016; 145:373-88. [PMID: 26847179 DOI: 10.1007/s00418-015-1400-9] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/21/2015] [Indexed: 10/25/2022]
Abstract
Extensive research in the past decade has significantly broadened our view about the role actin plays in the life of the cell and added novel aspects to actin research. One of these new aspects is the discovery of the existence of nuclear actin which became evident only recently. Nuclear activities including transcriptional activation in the case of all three RNA polymerases, editing and nuclear export of mRNAs, and chromatin remodeling all depend on actin. It also became clear that there is a fine-tuned equilibrium between cytoplasmic and nuclear actin pools and that this balance is ensured by an export-import system dedicated to actin. After over half a century of research on conventional actin and its organizing partners in the cytoplasm, it was also an unexpected finding that the nucleus contains more than 30 actin-binding proteins and new classes of actin-related proteins which are not able to form filaments but had evolved nuclear-specific functions. The actin-binding and actin-related proteins in the nucleus have been linked to RNA transcription and processing, nuclear transport, and chromatin remodeling. In this paper, we attempt to provide an overview of the wide range of information that is now available about actin, actin-binding, and actin-related proteins in the nucleus.
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Herrada I, Samson C, Velours C, Renault L, Östlund C, Chervy P, Puchkov D, Worman HJ, Buendia B, Zinn-Justin S. Muscular Dystrophy Mutations Impair the Nuclear Envelope Emerin Self-assembly Properties. ACS Chem Biol 2015; 10:2733-42. [PMID: 26415001 DOI: 10.1021/acschembio.5b00648] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
More than 100 genetic mutations causing X-linked Emery-Dreifuss muscular dystrophy have been identified in the gene encoding the integral inner nuclear membrane protein emerin. Most mutations are nonsense or frameshift mutations that lead to the absence of emerin in cells. Only very few cases are due to missense or short in-frame deletions. Molecular mechanisms explaining the corresponding emerin variants' loss of function are particularly difficult to identify because of the mostly intrinsically disordered state of the emerin nucleoplasmic region. We now demonstrate that this EmN region can be produced as a disordered monomer, as revealed by nuclear magnetic resonance, but rapidly self-assembles in vitro. Increases in concentration and temperature favor the formation of long curvilinear filaments with diameters of approximately 10 nm, as observed by electron microscopy. Assembly of these filaments can be followed by fluorescence through Thioflavin-T binding and by Fourier-transform Infrared spectrometry through formation of β-structures. Analysis of the assembly properties of five EmN variants reveals that del95-99 and Q133H impact filament assembly capacities. In cells, these variants are located at the nuclear envelope, but the corresponding quantities of emerin-emerin and emerin-lamin proximities are decreased compared to wild-type protein. Furthermore, variant P183H favors EmN aggregation in vitro, and variant P183T provokes emerin accumulation in cytoplasmic foci in cells. Substitution of residue Pro183 might systematically favor oligomerization, leading to emerin aggregation and mislocalization in cells. Our results suggest that emerin self-assembly is necessary for its proper function and that a loss of either the protein itself or its ability to self-assemble causes muscular dystrophy.
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Affiliation(s)
- Isaline Herrada
- Laboratoire
de Biologie Structurale et Radiobiologie, Institute for Integrative Biology of the Cell (I2BC), CEA Saclay Bât. 144, 91191 Gif-sur-Yvette Cedex, France
| | - Camille Samson
- Laboratoire
de Biologie Structurale et Radiobiologie, Institute for Integrative Biology of the Cell (I2BC), CEA Saclay Bât. 144, 91191 Gif-sur-Yvette Cedex, France
| | - Christophe Velours
- Laboratoire
d’Enzymologie et Biochimie Structurales, Institute for Integrative Biology of the Cell (I2BC), CNRS Bât.34, 1 avenue de
la terrasse, 91190 Gif-sur-Yvette, France
| | - Louis Renault
- Laboratoire
d’Enzymologie et Biochimie Structurales, Institute for Integrative Biology of the Cell (I2BC), CNRS Bât.34, 1 avenue de
la terrasse, 91190 Gif-sur-Yvette, France
| | - Cecilia Östlund
- Department
of Medicine and Department of Pathology and Cell Biology, College
of Physicians and Surgeons, Columbia University, 630 West 168th Street, New York, New York 10032, United States
| | - Pierre Chervy
- Laboratoire
de Biologie Structurale et Radiobiologie, Institute for Integrative Biology of the Cell (I2BC), CEA Saclay Bât. 144, 91191 Gif-sur-Yvette Cedex, France
| | - Dmytro Puchkov
- Department
of Molecular Pharmacology and Cell Biology, Leibniz-Institut für Molecular Pharmakologie (FMP), 13125 Berlin, Germany
| | - Howard J Worman
- Department
of Medicine and Department of Pathology and Cell Biology, College
of Physicians and Surgeons, Columbia University, 630 West 168th Street, New York, New York 10032, United States
| | - Brigitte Buendia
- Laboratoire
de Physiologie du Muscle Strié, Université Paris Diderot-Paris 7, CNRS, UMR 8251, Institut de Biologie
Fonctionnelle et Adaptative, 4 rue
M.A. Lagroua Weill Halle, 75205 Paris Cedex 13, France
| | - Sophie Zinn-Justin
- Laboratoire
de Biologie Structurale et Radiobiologie, Institute for Integrative Biology of the Cell (I2BC), CEA Saclay Bât. 144, 91191 Gif-sur-Yvette Cedex, France
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32
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Boone PM, Yuan B, Gu S, Ma Z, Gambin T, Gonzaga-Jauregui C, Jain M, Murdock TJ, White JJ, Jhangiani SN, Walker K, Wang Q, Muzny DM, Gibbs RA, Hejtmancik JF, Lupski JR, Posey JE, Lewis RA. Hutterite-type cataract maps to chromosome 6p21.32-p21.31, cosegregates with a homozygous mutation in LEMD2, and is associated with sudden cardiac death. Mol Genet Genomic Med 2015; 4:77-94. [PMID: 26788539 PMCID: PMC4707028 DOI: 10.1002/mgg3.181] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2015] [Revised: 09/22/2015] [Accepted: 09/28/2015] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Juvenile-onset cataracts are known among the Hutterites of North America. Despite being identified over 30 years ago, this autosomal recessive condition has not been mapped, and the disease gene is unknown. METHODS We performed whole exome sequencing of three Hutterite-type cataract trios and follow-up genotyping and mapping in four extended kindreds. RESULTS Trio exomes enabled genome-wide autozygosity mapping, which localized the disease gene to a 9.5-Mb region on chromosome 6p. This region contained two candidate variants, LEMD2 c.T38G and MUC21 c.665delC. Extended pedigrees recruited for variant genotyping revealed multiple additional relatives with juvenile-onset cataract, as well as six deceased relatives with both cataracts and sudden cardiac death. The candidate variants were genotyped in 84 family members, including 17 with cataracts; only the variant in LEMD2 cosegregated with cataracts (LOD = 9.62). SNP-based fine mapping within the 9.5 Mb linked region supported this finding by refining the cataract locus to a 0.5- to 2.9-Mb subregion (6p21.32-p21.31) containing LEMD2 but not MUC21. LEMD2 is expressed in mouse and human lenses and encodes a LEM domain-containing protein; the c.T38G missense mutation is predicted to mutate a highly conserved residue within this domain (p.Leu13Arg). CONCLUSION We performed a genetic and genomic study of Hutterite-type cataract and found evidence for an association of this phenotype with sudden cardiac death. Using combined genetic and genomic approaches, we mapped cataracts to a small portion of chromosome 6 and propose that they result from a homozygous missense mutation in LEMD2.
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Affiliation(s)
- Philip M Boone
- Department of Molecular and Human Genetics Baylor College of Medicine Houston Texas
| | - Bo Yuan
- Department of Molecular and Human Genetics Baylor College of Medicine Houston Texas
| | - Shen Gu
- Department of Molecular and Human Genetics Baylor College of Medicine Houston Texas
| | - Zhiwei Ma
- Ophthalmic Genetics and Visual Function Branch National Eye Institute Rockville Maryland
| | - Tomasz Gambin
- Department of Molecular and Human Genetics Baylor College of Medicine Houston Texas
| | | | - Mahim Jain
- Department of Molecular and Human Genetics Baylor College of Medicine Houston Texas
| | | | - Janson J White
- Department of Molecular and Human Genetics Baylor College of Medicine Houston Texas
| | | | - Kimberly Walker
- Human Genome Sequencing Center Baylor College of Medicine Houston Texas
| | - Qiaoyan Wang
- Human Genome Sequencing Center Baylor College of Medicine Houston Texas
| | - Donna M Muzny
- Human Genome Sequencing Center Baylor College of Medicine Houston Texas
| | - Richard A Gibbs
- Department of Molecular and Human GeneticsBaylor College of MedicineHoustonTexas; Human Genome Sequencing CenterBaylor College of MedicineHoustonTexas
| | - J Fielding Hejtmancik
- Ophthalmic Genetics and Visual Function Branch National Eye Institute Rockville Maryland
| | - James R Lupski
- Department of Molecular and Human GeneticsBaylor College of MedicineHoustonTexas; Human Genome Sequencing CenterBaylor College of MedicineHoustonTexas; Department of PediatricsBaylor College of MedicineHoustonTexas; Texas Children's HospitalHoustonTexas
| | - Jennifer E Posey
- Department of Molecular and Human Genetics Baylor College of Medicine Houston Texas
| | - Richard A Lewis
- Department of Molecular and Human GeneticsBaylor College of MedicineHoustonTexas; Department of PediatricsBaylor College of MedicineHoustonTexas; Texas Children's HospitalHoustonTexas; Department of OphthalmologyBaylor College of MedicineHoustonTexas; Department of MedicineBaylor College of MedicineHoustonTexas
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33
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Computational investigation of molecular mechanism and neuropathological implications in Huntington disease. Mol Cell Biochem 2015; 409:1-11. [DOI: 10.1007/s11010-015-2462-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 05/23/2015] [Indexed: 12/31/2022]
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Yuan J, Xue B. Role of structural flexibility in the evolution of emerin. J Theor Biol 2015; 385:102-11. [PMID: 26319992 DOI: 10.1016/j.jtbi.2015.08.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Revised: 08/07/2015] [Accepted: 08/17/2015] [Indexed: 02/07/2023]
Abstract
Emerin is a short inner nuclear membrane protein with an LEM-domain at the N-terminal end and a transmembrane domain at the C-terminal end. The middle region of human emerin contains multiple binding motifs. Since emerin is often found in evolutionarily newer species, the functional conservation of emerin becomes an interesting topic. In this study, we have demonstrated that most of the functional motifs of emerin are intrinsically disordered or highly flexible. Many post-translational modification sites and mutation sites are associated with these disordered regions. The averaged substitution rates of most functional motifs between species correlate positively with the averaged disorder scores of those functional motifs. Human emerin sequence may have acquired new functions on protein-protein interaction through the formation of hydrophobic motifs in the middle region, which is resulted from accumulated mutations during the evolution process.
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Affiliation(s)
- Jia Yuan
- Department of Cell Biology, Microbiology and Molecular Biology, School of Natural Sciences and Mathematics, College of Arts and Sciences, University of South Florida, 4202 E. Fowler Ave, ISA 2015, Tampa, FL 33620, USA
| | - Bin Xue
- Department of Cell Biology, Microbiology and Molecular Biology, School of Natural Sciences and Mathematics, College of Arts and Sciences, University of South Florida, 4202 E. Fowler Ave, ISA 2015, Tampa, FL 33620, USA.
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Jeong K, Kwon H, Lee J, Jang D, Pak Y. Insulin-response epigenetic activation of Egr-1 and JunB genes at the nuclear periphery by A-type lamin-associated pY19-Caveolin-2 in the inner nuclear membrane. Nucleic Acids Res 2015; 43:3114-27. [PMID: 25753664 PMCID: PMC4381080 DOI: 10.1093/nar/gkv181] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 02/20/2015] [Indexed: 11/15/2022] Open
Abstract
Insulin controls transcription to sustain its physiologic effects for the organism to adapt to environmental changes added to genetic predisposition. Nevertheless, insulin-induced transcriptional regulation by epigenetic factors and in defined nuclear territory remains elusive. Here we show that inner nuclear membrane (INM)-integrated caveolin-2 (Cav-2) regulates insulin-response epigenetic activation of Egr-1 and JunB genes at the nuclear periphery. INM-targeted pY19-Cav-2 in response to insulin associates specifically with the A-type lamin, disengages the repressed Egr-1 and JunB promoters from lamin A/C through disassembly of H3K9me3, and facilitates assembly of H3K9ac, H3K18ac and H3K27ac by recruitment of GCN5 and p300 and the subsequent enrichment of RNA polymerase II (Pol II) on the promoters at the nuclear periphery. Our findings show that Cav-2 is an epigenetic regulator of histone H3 modifications, and provide novel mechanisms of insulin-response epigenetic activation at the nuclear periphery.
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Affiliation(s)
- Kyuho Jeong
- Department of Biochemistry, Division of Applied Life Science (BK21 Plus Program), PMBBRC, Gyeongsang National University, Jinju 660-701, Korea
| | - Hayeong Kwon
- Department of Biochemistry, Division of Applied Life Science (BK21 Plus Program), PMBBRC, Gyeongsang National University, Jinju 660-701, Korea
| | - Jaewoong Lee
- Department of Biochemistry, Division of Applied Life Science (BK21 Plus Program), PMBBRC, Gyeongsang National University, Jinju 660-701, Korea
| | - Donghwan Jang
- Department of Biochemistry, Division of Applied Life Science (BK21 Plus Program), PMBBRC, Gyeongsang National University, Jinju 660-701, Korea
| | - Yunbae Pak
- Department of Biochemistry, Division of Applied Life Science (BK21 Plus Program), PMBBRC, Gyeongsang National University, Jinju 660-701, Korea
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36
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Kim DH, Wirtz D. Cytoskeletal tension induces the polarized architecture of the nucleus. Biomaterials 2015; 48:161-72. [PMID: 25701041 DOI: 10.1016/j.biomaterials.2015.01.023] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 01/05/2015] [Accepted: 01/20/2015] [Indexed: 01/07/2023]
Abstract
The nuclear lamina is a thin filamentous meshwork that provides mechanical support to the nucleus and regulates essential cellular processes such as DNA replication, chromatin organization, cell division, and differentiation. Isolated horizontal imaging using fluorescence and electron microscopy has long suggested that the nuclear lamina is composed of structurally different A-type and B-type lamin proteins and nuclear lamin-associated membrane proteins that together form a thin layer that is spatially isotropic with no apparent difference in molecular content or density between the top and bottom of the nucleus. Chromosomes are condensed differently along the radial direction from the periphery of the nucleus to the nuclear center; therefore, chromatin accessibility for gene expression is different along the nuclear radius. However, 3D confocal reconstruction reveals instead that major lamin protein lamin A/C forms an apically polarized Frisbee-like dome structure in the nucleus of adherent cells. Here we show that both A-type lamins and transcriptionally active chromatins are vertically polarized by the tension exercised by the perinuclear actin cap (or actin cap) that is composed of highly contractile actomyosin fibers organized at the apical surface of the nucleus. Mechanical coupling between actin cap and lamina through LINC (linkers of nucleoskeleton and cytoskeleton) protein complexes induces an apical distribution of transcription-active subnucleolar compartments and epigenetic markers of transcription-active genes. This study reveals that intranuclear structures, such as nuclear lamina and chromosomal architecture, are apically polarized through the extranuclear perinuclear actin cap in a wide range of somatic adherent cells.
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Affiliation(s)
- Dong-Hwee Kim
- Johns Hopkins Physical Sciences - Oncology Center, The Johns Hopkins University, Baltimore, MD 21218, USA; Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, MD 21218, USA.
| | - Denis Wirtz
- Johns Hopkins Physical Sciences - Oncology Center, The Johns Hopkins University, Baltimore, MD 21218, USA; Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, MD 21218, USA; Department of Pathology and Oncology and Sydney Kimmel Comprehensive Cancer Center, The Johns Hopkins School of Medicine, Baltimore, MD 21205, USA.
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37
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Malik P, Zuleger N, de las Heras JI, Saiz-Ros N, Makarov AA, Lazou V, Meinke P, Waterfall M, Kelly DA, Schirmer EC. NET23/STING promotes chromatin compaction from the nuclear envelope. PLoS One 2014; 9:e111851. [PMID: 25386906 PMCID: PMC4227661 DOI: 10.1371/journal.pone.0111851] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 10/07/2014] [Indexed: 12/19/2022] Open
Abstract
Changes in the peripheral distribution and amount of condensed chromatin are observed in a number of diseases linked to mutations in the lamin A protein of the nuclear envelope. We postulated that lamin A interactions with nuclear envelope transmembrane proteins (NETs) that affect chromatin structure might be altered in these diseases and so screened thirty-one NETs for those that promote chromatin compaction as determined by an increase in the number of chromatin clusters of high pixel intensity. One of these, NET23 (also called STING, MITA, MPYS, ERIS, Tmem173), strongly promoted chromatin compaction. A correlation between chromatin compaction and endogenous levels of NET23/STING was observed for a number of human cell lines, suggesting that NET23/STING may contribute generally to chromatin condensation. NET23/STING has separately been found to be involved in innate immune response signaling. Upon infection cells make a choice to either apoptose or to alter chromatin architecture to support focused expression of interferon genes and other response factors. We postulate that the chromatin compaction induced by NET23/STING may contribute to this choice because the cells expressing NET23/STING eventually apoptose, but the chromatin compaction effect is separate from this as the condensation was still observed when cells were treated with Z-VAD to block apoptosis. NET23/STING-induced compacted chromatin revealed changes in epigenetic marks including changes in histone methylation and acetylation. This indicates a previously uncharacterized nuclear role for NET23/STING potentially in both innate immune signaling and general chromatin architecture.
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Affiliation(s)
- Poonam Malik
- The Wellcome Trust Centre for Cell Biology and Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Nikolaj Zuleger
- The Wellcome Trust Centre for Cell Biology and Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Jose I. de las Heras
- The Wellcome Trust Centre for Cell Biology and Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Natalia Saiz-Ros
- The Wellcome Trust Centre for Cell Biology and Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Alexandr A. Makarov
- The Wellcome Trust Centre for Cell Biology and Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Vassiliki Lazou
- The Wellcome Trust Centre for Cell Biology and Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Peter Meinke
- The Wellcome Trust Centre for Cell Biology and Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Martin Waterfall
- Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, United Kingdom
| | - David A. Kelly
- The Wellcome Trust Centre for Cell Biology and Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Eric C. Schirmer
- The Wellcome Trust Centre for Cell Biology and Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
- * E-mail:
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Bera M, Kotamarthi HC, Dutta S, Ray A, Ghosh S, Bhattacharyya D, Ainavarapu SRK, Sengupta K. Characterization of unfolding mechanism of human lamin A Ig fold by single-molecule force spectroscopy-implications in EDMD. Biochemistry 2014; 53:7247-58. [PMID: 25343322 DOI: 10.1021/bi500726f] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A- and B-type lamins are intermediate filament proteins constituting the nuclear lamina underneath the nuclear envelope thereby conferring proper shape and mechanical rigidity to the nucleus. Lamin proteins are also shown to be related diversely to basic nuclear processes. More than 400 mutations in human lamin A protein alone have been reported to produce at least 11 different disease conditions jointly termed as laminopathies. These mutations in lamin A are scattered throughout its helical rod domain, as well as the C-terminal domain containing the conserved Ig-fold region. The commonality of phenotypes in all these diseases is characterized by misshapen nuclei of the affected tissues which might stem from altered rigidity of the supporting lamina hence lamins. Here we have focused on autosomal dominant Emery-Dreifuss Muscular Dystrophy, one such laminopathy where R453W is the causative mutation located in the Ig domain of lamin A. We have investigated by single-molecule force spectroscopy how a stretching mechanical perturbation senses the destabilizing effect of the mutation in the lamin A Ig domain and compared the mechanoelastic properties of the mutant R453W with that of the wild-type in conjunction with steered molecular dynamics. Furthermore, we have shown the interaction of Ig domain with emerin, another key player and interacting partner in the pathogenesis of EDMD, is disrupted in the R453W mutant. This altered mechanoresistance of Ig domain itself and consequent uncoupling of lamin A-emerin interaction might underlie the altered mechanotransduction properties of EDMD affected nuclei.
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Affiliation(s)
- Manindra Bera
- Biophysics & Structural Genomics Division, Saha Institute of Nuclear Physics , 1/AF, Bidhannagar, Kolkata, West Bengal 700064, India
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Simon DN, Zastrow MS, Wilson KL. Direct actin binding to A- and B-type lamin tails and actin filament bundling by the lamin A tail. Nucleus 2014. [DOI: 10.4161/nucl.11799] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
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Meinke P, Mattioli E, Haque F, Antoku S, Columbaro M, Straatman KR, Worman HJ, Gundersen GG, Lattanzi G, Wehnert M, Shackleton S. Muscular dystrophy-associated SUN1 and SUN2 variants disrupt nuclear-cytoskeletal connections and myonuclear organization. PLoS Genet 2014; 10:e1004605. [PMID: 25210889 PMCID: PMC4161305 DOI: 10.1371/journal.pgen.1004605] [Citation(s) in RCA: 125] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Accepted: 07/16/2014] [Indexed: 11/19/2022] Open
Abstract
Proteins of the nuclear envelope (NE) are associated with a range of inherited disorders, most commonly involving muscular dystrophy and cardiomyopathy, as exemplified by Emery-Dreifuss muscular dystrophy (EDMD). EDMD is both genetically and phenotypically variable, and some evidence of modifier genes has been reported. Six genes have so far been linked to EDMD, four encoding proteins associated with the LINC complex that connects the nucleus to the cytoskeleton. However, 50% of patients have no identifiable mutations in these genes. Using a candidate approach, we have identified putative disease-causing variants in the SUN1 and SUN2 genes, also encoding LINC complex components, in patients with EDMD and related myopathies. Our data also suggest that SUN1 and SUN2 can act as disease modifier genes in individuals with co-segregating mutations in other EDMD genes. Five SUN1/SUN2 variants examined impaired rearward nuclear repositioning in fibroblasts, confirming defective LINC complex function in nuclear-cytoskeletal coupling. Furthermore, myotubes from a patient carrying compound heterozygous SUN1 mutations displayed gross defects in myonuclear organization. This was accompanied by loss of recruitment of centrosomal marker, pericentrin, to the NE and impaired microtubule nucleation at the NE, events that are required for correct myonuclear arrangement. These defects were recapitulated in C2C12 myotubes expressing exogenous SUN1 variants, demonstrating a direct link between SUN1 mutation and impairment of nuclear-microtubule coupling and myonuclear positioning. Our findings strongly support an important role for SUN1 and SUN2 in muscle disease pathogenesis and support the hypothesis that defects in the LINC complex contribute to disease pathology through disruption of nuclear-microtubule association, resulting in defective myonuclear positioning. Emery-Dreifuss muscular dystrophy (EDMD) is an inherited disorder involving muscle wasting and weakness, accompanied by cardiac defects. The disease is variable in its severity and also in its genetic cause. So far, 6 genes have been linked to EDMD, most encoding proteins that form a structural network that supports the nucleus of the cell and connects it to structural elements of the cytoplasm. This network is particularly important in muscle cells, providing resistance to mechanical strain. Weakening of this network is thought to contribute to development of muscle disease in these patients. Despite rigorous screening, at least 50% of patients with EDMD have no detectable mutation in the 6 known genes. We therefore undertook screening and identified mutations in two additional genes that encode other components of the nuclear structural network, SUN1 and SUN2. Our findings add to the genetic complexity of this disease since some individuals carry mutations in more than one gene. We also show that the mutations disrupt connections between the nucleus and the structural elements of cytoplasm, leading to mis-positioning and clustering of nuclei in muscle cells. This nuclear mis-positioning is likely to be another factor contributing to pathogenesis of EDMD.
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Affiliation(s)
- Peter Meinke
- Institute of Human Genetics and Interfaculty Institute of Genetics and Functional Genomics, University of Greifswald, Greifswald, Germany
| | - Elisabetta Mattioli
- National Research Council of Italy - CNR - Institute for Molecular Genetics, Unit of Bologna IOR, Bologna, Italy
- Rizzoli Orthopaedic Institute, Laboratory of Musculoskeletal Cell Biology, Bologna, Italy
| | - Farhana Haque
- Department of Biochemistry, University of Leicester, Leicester, United Kingdom
| | - Susumu Antoku
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, New York, United States of America
| | - Marta Columbaro
- Rizzoli Orthopaedic Institute, Laboratory of Musculoskeletal Cell Biology, Bologna, Italy
| | - Kees R. Straatman
- Centre for Core Biotechnology Services, University of Leicester, Leicester, United Kingdom
| | - Howard J. Worman
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, New York, United States of America
- Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, New York, United States of America
| | - Gregg G. Gundersen
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, New York, United States of America
| | - Giovanna Lattanzi
- National Research Council of Italy - CNR - Institute for Molecular Genetics, Unit of Bologna IOR, Bologna, Italy
- Rizzoli Orthopaedic Institute, Laboratory of Musculoskeletal Cell Biology, Bologna, Italy
| | - Manfred Wehnert
- Institute of Human Genetics and Interfaculty Institute of Genetics and Functional Genomics, University of Greifswald, Greifswald, Germany
| | - Sue Shackleton
- Department of Biochemistry, University of Leicester, Leicester, United Kingdom
- * E-mail:
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Deroyer C, Rénert AF, Merville MP, Fillet M. New role for EMD (emerin), a key inner nuclear membrane protein, as an enhancer of autophagosome formation in the C16-ceramide autophagy pathway. Autophagy 2014; 10:1229-40. [PMID: 24819607 DOI: 10.4161/auto.28777] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
To date, precise roles of EMD (emerin) remain poorly described. In this paper, we investigated the role of EMD in the C16-ceramide autophagy pathway. Ceramides are bioactive signaling molecules acting notably in the regulation of cell growth, differentiation, or cell death. However, the mechanisms by which they mediate these pathways are not fully understood. We found that C16-ceramide induces EMD phosphorylation on its LEM domain through PRKACA. Upon ceramide treatment, phosphorylated EMD binds MAP1LC3B leading to an increase of autophagosome formation. These data suggest a new role of EMD as an enhancer of autophagosome formation in the C16-ceramide autophagy pathway in colon cancer cells.
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Affiliation(s)
- Céline Deroyer
- GIGA-R Proteomic Unit; University of Liège; Liège, Belgium
| | | | - Marie-Paule Merville
- Department of Clinical Chemistry; Centre Hospitalier Universitaire de Liège; Liège, Belgium
| | - Marianne Fillet
- GIGA-R Proteomic Unit; University of Liège; Liège, Belgium; Department of Analytical Pharmaceutical Chemistry; Department of Pharmacy; Centre Interfacultaire de Recherche du Médicament; University of Liège; Liège, Belgium
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Wu D, Flannery AR, Cai H, Ko E, Cao K. Nuclear localization signal deletion mutants of lamin A and progerin reveal insights into lamin A processing and emerin targeting. Nucleus 2014; 5:66-74. [PMID: 24637396 PMCID: PMC4028357 DOI: 10.4161/nucl.28068] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Lamin A is a major component of the lamina, which creates a dynamic network underneath the nuclear envelope. Mutations in the lamin A gene (LMNA) cause severe genetic disorders, one of which is Hutchinson-Gilford progeria syndrome (HGPS), a disease triggered by a dominant mutant named progerin. Unlike the wild-type lamin A, whose farnesylated C-terminus is excised during post-translational processing, progerin retains its farnesyl tail and accumulates on the nuclear membrane, resulting in abnormal nuclear morphology during interphase. In addition, membrane-associated progerin forms visible cytoplasmic aggregates in mitosis. To examine the potential effects of cytoplasmic progerin, nuclear localization signal (NLS) deleted progerin and lamin A (PGΔNLS and LAΔNLS, respectively) have been constructed. We find that both ΔNLS mutants are farnesylated in the cytosol and associate with a sub-domain of the ER via their farnesyl tails. While the farnesylation on LAΔNLS can be gradually removed, which leads to its subsequent release from the ER into the cytoplasm, PGΔNLS remains permanently farnesylated and membrane-bounded. Moreover, both ΔNLS mutants dominantly affect emerin’s nuclear localization. These results reveal new insights into lamin A biogenesis and lamin A-emerin interaction.
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Affiliation(s)
- Di Wu
- Department of Cell Biology and Molecular Genetics; University of Maryland; College Park, MD USA
| | - Andrew R Flannery
- Department of Cell Biology and Molecular Genetics; University of Maryland; College Park, MD USA
| | - Helen Cai
- Department of Cell Biology and Molecular Genetics; University of Maryland; College Park, MD USA
| | - Eunae Ko
- Department of Cell Biology and Molecular Genetics; University of Maryland; College Park, MD USA
| | - Kan Cao
- Department of Cell Biology and Molecular Genetics; University of Maryland; College Park, MD USA
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Nuclear Envelope Regulation of Signaling Cascades. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 773:187-206. [DOI: 10.1007/978-1-4899-8032-8_9] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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de Las Heras JI, Schirmer EC. The nuclear envelope and cancer: a diagnostic perspective and historical overview. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 773:5-26. [PMID: 24563341 DOI: 10.1007/978-1-4899-8032-8_1] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Cancer has been diagnosed for millennia, but its cellular nature only began to be understood in the mid-nineteenth century when advances in microscopy allowed detailed specimen observations. It was soon noted that cancer cells often possessed nuclei that were altered in size and/or shape. This became an important criterion for cancer diagnosis that continues to be used today. The mechanisms linking nuclear abnormalities and cancer only started to be understood in the second half of the twentieth century, with the discovery of nuclear lamina composition differences in cancer cells compared to normal cells. The nuclear envelope, rather than providing a mere physical barrier between the genetic material in the nucleus and the cytoplasm, is a very important functional hub for many cellular processes. In this review we give an overview of the links between cancer biology and nuclear envelope, from the early days of microscopy until the present day's understanding of some of the molecular mechanisms behind those links.
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Affiliation(s)
- Jose I de Las Heras
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Kings Buildings, Michael Swann Building, Room 5.21, Edinburgh, EH9 3JR, UK,
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Chang W, Folker ES, Worman HJ, Gundersen GG. Emerin organizes actin flow for nuclear movement and centrosome orientation in migrating fibroblasts. Mol Biol Cell 2013; 24:3869-80. [PMID: 24152738 PMCID: PMC3861083 DOI: 10.1091/mbc.e13-06-0307] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Emerin, a nuclear membrane protein, and myosin IIB contribute to nuclear movement by regulating the directionality of nuclear movement and dorsal actin cable flow. Emerin interacts with myosin IIB and is required for its perinuclear localization. The results show that the nuclear envelope actively organizes cytoplasmic polarity. In migrating fibroblasts, rearward movement of the nucleus orients the centrosome toward the leading edge. Nuclear movement results from coupling rearward-moving, dorsal actin cables to the nucleus by linear arrays of nesprin-2G and SUN2, termed transmembrane actin-associated nuclear (TAN) lines. A-type lamins anchor TAN lines, prompting us to test whether emerin, a nuclear membrane protein that interacts with lamins and TAN line proteins, contributes to nuclear movement. In fibroblasts depleted of emerin, nuclei moved nondirectionally or completely failed to move. Consistent with these nuclear movement defects, dorsal actin cable flow was nondirectional in cells lacking emerin. TAN lines formed normally in cells lacking emerin and were coordinated with the erratic nuclear movements, although in 20% of the cases, TAN lines slipped over immobile nuclei. Myosin II drives actin flow, and depletion of myosin IIB, but not myosin IIA, showed similar nondirectional nuclear movement and actin flow as in emerin-depleted cells. Myosin IIB specifically coimmunoprecipitated with emerin, and emerin depletion prevented myosin IIB localization near nuclei. These results show that emerin functions with myosin IIB to polarize actin flow and nuclear movement in fibroblasts, suggesting a novel function for the nuclear envelope in organizing directional actin flow and cytoplasmic polarity.
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Affiliation(s)
- Wakam Chang
- Department of Pathology and Cell Biology, Columbia University, New York, NY 10032 Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY 10032
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Shin JY, Méndez-López I, Wang Y, Hays AP, Tanji K, Lefkowitch JH, Schulze PC, Worman HJ, Dauer WT. Lamina-associated polypeptide-1 interacts with the muscular dystrophy protein emerin and is essential for skeletal muscle maintenance. Dev Cell 2013; 26:591-603. [PMID: 24055652 DOI: 10.1016/j.devcel.2013.08.012] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2012] [Revised: 06/13/2013] [Accepted: 08/15/2013] [Indexed: 12/30/2022]
Abstract
X-linked Emery-Dreifuss muscular dystrophy is caused by loss of function of emerin, an integral protein of the inner nuclear membrane. Yet emerin null mice are essentially normal, suggesting the existence of a critical compensating factor. We show that the lamina-associated polypeptide1 (LAP1) interacts with emerin. Conditional deletion of LAP1 from striated muscle causes muscular dystrophy; this pathology is worsened in the absence of emerin. LAP1 levels are significantly higher in mouse than human skeletal muscle, and reducing LAP1 by approximately half in mice also induces muscle abnormalities in emerin null mice. Conditional deletion of LAP1 from hepatocytes yields mice that exhibit normal liver function and are indistinguishable from littermate controls. These results establish that LAP1 interacts physically and functionally with emerin and plays an essential and selective role in skeletal muscle maintenance. They also highlight how dissecting differences between mouse and human phenotypes can provide fundamental insights into disease mechanisms.
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Affiliation(s)
- Ji-Yeon Shin
- Department of Medicine, College of Physicians and Surgeons, Columbia University, 630 West 168(th) Street, New York, NY 10032, USA; Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, 630 West 168(th) Street, New York, NY 10032, USA
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Berk JM, Maitra S, Dawdy AW, Shabanowitz J, Hunt DF, Wilson KL. O-Linked β-N-acetylglucosamine (O-GlcNAc) regulates emerin binding to barrier to autointegration factor (BAF) in a chromatin- and lamin B-enriched "niche". J Biol Chem 2013; 288:30192-30209. [PMID: 24014020 DOI: 10.1074/jbc.m113.503060] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Emerin, a membrane component of nuclear "lamina" networks with lamins and barrier to autointegration factor (BAF), is highly O-GlcNAc-modified ("O-GlcNAcylated") in mammalian cells. Mass spectrometry analysis revealed eight sites of O-GlcNAcylation, including Ser-53, Ser-54, Ser-87, Ser-171, and Ser-173. Emerin O-GlcNAcylation was reduced ~50% by S53A or S54A mutation in vitro and in vivo. O-GlcNAcylation was reduced ~66% by the triple S52A/S53A/S54A mutant, and S173A reduced O-GlcNAcylation of the S52A/S53A/S54A mutant by ~30%, in vivo. We separated two populations of emerin, A-type lamins and BAF; one population solubilized easily, and the other required sonication and included histones and B-type lamins. Emerin and BAF associated only in histone- and lamin-B-containing fractions. The S173D mutation specifically and selectively reduced GFP-emerin association with BAF by 58% and also increased GFP-emerin hyper-phosphorylation. We conclude that β-N-acetylglucosaminyltransferase, an essential enzyme, controls two regions in emerin. The first region, defined by residues Ser-53 and Ser-54, flanks the LEM domain. O-GlcNAc modification at Ser-173, in the second region, is proposed to promote emerin association with BAF in the chromatin/lamin B "niche." These results reveal direct control of a conserved LEM domain nuclear lamina component by β-N-acetylglucosaminyltransferase, a nutrient sensor that regulates cell stress responses, mitosis, and epigenetics.
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Affiliation(s)
- Jason M Berk
- From the Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205 and
| | - Sushmit Maitra
- the Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904
| | - Andrew W Dawdy
- the Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904
| | - Jeffrey Shabanowitz
- the Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904
| | - Donald F Hunt
- the Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904
| | - Katherine L Wilson
- From the Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205 and.
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Yang L, Munck M, Swaminathan K, Kapinos LE, Noegel AA, Neumann S. Mutations in LMNA modulate the lamin A--Nesprin-2 interaction and cause LINC complex alterations. PLoS One 2013; 8:e71850. [PMID: 23977161 PMCID: PMC3748058 DOI: 10.1371/journal.pone.0071850] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Accepted: 07/03/2013] [Indexed: 11/29/2022] Open
Abstract
Background In eukaryotes the genetic material is enclosed by a continuous membrane system, the nuclear envelope (NE). Along the NE specific proteins assemble to form meshworks and mutations in these proteins have been described in a group of human diseases called laminopathies. Laminopathies include lipodystrophies, muscle and cardiac diseases as well as metabolic or progeroid syndromes. Most laminopathies are caused by mutations in the LMNAgene encoding lamins A/C. Together with Nesprins (Nuclear Envelope Spectrin Repeat Proteins) they are core components of the LINC complex (Linker of Nucleoskeleton and Cytoskeleton). The LINC complex connects the nucleoskeleton and the cytoskeleton and plays a role in the transfer of mechanically induced signals along the NE into the nucleus, and its components have been attributed functions in maintaining nuclear and cellular organization as well as signal transduction. Results Here we narrowed down the interaction sites between lamin A and Nesprin-2 to aa 403–425 in lamin A and aa 6146–6347 in Nesprin-2. Laminopathic mutations in and around the involved region of lamin A (R401C, G411D, G413C, V415I, R419C, L421P, R427G, Q432X) modulate the interaction with Nesprin-2 and this may contribute to the disease phenotype. The most notable mutation is the lamin A mutation Q432X that alters LINC complex protein assemblies and causes chromosomal and transcription factor rearrangements. Conclusion Mutations in Nesprin-2 and lamin A are characterised by complex genotype phenotype relations. Our data show that each mutation in LMNAanalysed here has a distinct impact on the interaction among both proteins that substantially explains how distinct mutations in widely expressed genes lead to the formation of phenotypically different diseases.
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Affiliation(s)
- Liu Yang
- Institute for Biochemistry I, Medical Faculty, University of Cologne, and Center for Molecular Medicine Cologne (CMMC) and Cologne Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Medical Faculty, University of Cologne, Cologne, Germany
| | - Martina Munck
- Institute for Biochemistry I, Medical Faculty, University of Cologne, and Center for Molecular Medicine Cologne (CMMC) and Cologne Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Medical Faculty, University of Cologne, Cologne, Germany
| | - Karthic Swaminathan
- Institute for Biochemistry I, Medical Faculty, University of Cologne, and Center for Molecular Medicine Cologne (CMMC) and Cologne Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Medical Faculty, University of Cologne, Cologne, Germany
| | - Larisa E. Kapinos
- Biozentrum and the Nanoscience Institute, University of Basel, Basel, Switzerland
| | - Angelika A. Noegel
- Institute for Biochemistry I, Medical Faculty, University of Cologne, and Center for Molecular Medicine Cologne (CMMC) and Cologne Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Medical Faculty, University of Cologne, Cologne, Germany
- * E-mail: (AAN); (SN)
| | - Sascha Neumann
- Institute for Biochemistry I, Medical Faculty, University of Cologne, and Center for Molecular Medicine Cologne (CMMC) and Cologne Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Medical Faculty, University of Cologne, Cologne, Germany
- * E-mail: (AAN); (SN)
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Simon DN, Domaradzki T, Hofmann WA, Wilson KL. Lamin A tail modification by SUMO1 is disrupted by familial partial lipodystrophy-causing mutations. Mol Biol Cell 2012; 24:342-50. [PMID: 23243001 PMCID: PMC3564541 DOI: 10.1091/mbc.e12-07-0527] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Lamin A tail domains are SUMO1 modified at K420 (nuclear localization signal) and K486 (Ig-fold). K486 modification requires Ig-fold surface residues E460 and D461 and is reduced by familial partial lipodystrophy–causing mutations G465D and K486N. These results suggest novel mechanisms of functional control over lamin A in cells. Lamin filaments are major components of the nucleoskeleton that bind LINC complexes and many nuclear membrane proteins. The tail domain of lamin A directly binds 21 known partners, including actin, emerin, and SREBP1, but how these interactions are regulated is unknown. We report small ubiquitin-like modifier 1 (SUMO1) as a major new posttranslational modification of the lamin A tail. Two SUMO1 modification sites were identified based on in vitro SUMOylation assays and studies of Cos-7 cells. One site (K420) matches the SUMO1 target consensus; the other (K486) does not. On the basis of the position of K486 on the lamin A Ig-fold, we hypothesize the SUMO1 E2 enzyme recognizes a folded structure–dependent motif that includes residues genetically linked to familial partial lipodystrophy (FPLD). Supporting this model, SUMO1-modification of the lamin A tail is reduced by two FPLD-causing mutations, G465D and K486N, and by single mutations in acidic residues E460 and D461. These results suggest a novel mode of functional control over lamin A in cells.
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Affiliation(s)
- Dan N Simon
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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Méjat A, Misteli T. LINC complexes in health and disease. Nucleus 2012; 1:40-52. [PMID: 21327104 DOI: 10.4161/nucl.1.1.10530] [Citation(s) in RCA: 136] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2009] [Revised: 11/04/2009] [Accepted: 11/05/2009] [Indexed: 11/19/2022] Open
Abstract
The cell nucleus communicates with the rest of the cell via nucleo/cytoplasmic transport of proteins and RNA through the nuclear pores. Direct mechanical links between the nucleus and the cytoplasm have recently emerged in the form of LINC (Linkers of the nucleoskeleton to the cytoskeleton) protein complexes. A LINC complex consists of four components. At its core are an inner nuclear membrane (INM) transmembrane protein and an outer nuclear membrane (ONM) transmembrane protein which physically interact with each other in the lumen of the NE. The INM LINC component interacts on the nucleoplasmic side with either the lamina or with an INM-associated protein. The ONM LINC component on the other hand contacts on the cytoplasmatic side a component of the cytoskeleton. This review highlights the components of LINC complexes and their emerging roles in mechanotransduction, nuclear migration, chromosome positioning, signaling, meiosis, cytoskeletal organization and human disease.
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Affiliation(s)
- Alexandre Méjat
- National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.
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