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Lipowicz JM, Malińska A, Nowicki M, Rawłuszko-Wieczorek AA. Genes Co-Expressed with ESR2 Influence Clinical Outcomes in Cancer Patients: TCGA Data Analysis. Int J Mol Sci 2024; 25:8707. [PMID: 39201394 PMCID: PMC11354723 DOI: 10.3390/ijms25168707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2024] [Revised: 08/02/2024] [Accepted: 08/07/2024] [Indexed: 09/02/2024] Open
Abstract
ERβ has been assigned a tumor suppressor role in many cancer types. However, as conflicting findings emerge, ERβ's tissue-specific expression and functional role have remained elusive. There remains a notable gap in compact and comprehensive analyses of ESR2 mRNA expression levels across diverse tumor types coupled with an exploration of its potential gene network. In this study, we aim to address these gaps by presenting a comprehensive analysis of ESR2 transcriptomic data. We distinguished cancer types with significant changes in ESR2 expression levels compared to corresponding healthy tissue and concluded that ESR2 influences patient survival. Gene Set Enrichment Analysis (GSEA) distinguished molecular pathways affected by ESR2, including oxidative phosphorylation and epithelial-mesenchymal transition. Finally, we investigated genes displaying similar expression patterns as ESR2 in tumor tissues, identifying potential co-expressed genes that may exert a synergistic effect on clinical outcomes, with significant results, including the expression of ACIN1, SYNE2, TNFRSF13C, and MDM4. Collectively, our results highlight the significant influence of ESR2 mRNA expression on the transcriptomic landscape and the overall metabolism of cancerous cells across various tumor types.
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Affiliation(s)
- Julia Maria Lipowicz
- Department of Histology and Embryology, Doctoral School, Poznan University of Medical Sciences, Święcickiego 6 Street, 60-781 Poznań, Poland;
| | - Agnieszka Malińska
- Department of Histology and Embryology, Poznan University of Medical Sciences, Święcickiego 6 Street, 60-781 Poznań, Poland
| | - Michał Nowicki
- Department of Histology and Embryology, Poznan University of Medical Sciences, Święcickiego 6 Street, 60-781 Poznań, Poland
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2
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Li C, Warren DT, Zhou C, De Silva S, Wilson DGS, Garcia-Maya M, Wheeler MA, Meinke P, Sawyer G, Ehler E, Wehnert M, Rao L, Zhang Q, Shanahan CM. Nesprin-2 is a novel scaffold protein for telethonin and FHL-2 in the cardiomyocyte sarcomere. J Biol Chem 2024; 300:107254. [PMID: 38569934 PMCID: PMC11078644 DOI: 10.1016/j.jbc.2024.107254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 03/11/2024] [Accepted: 03/19/2024] [Indexed: 04/05/2024] Open
Abstract
Nesprins comprise a family of multi-isomeric scaffolding proteins, forming the linker of nucleoskeleton-and-cytoskeleton complex with lamin A/C, emerin and SUN1/2 at the nuclear envelope. Mutations in nesprin-1/-2 are associated with Emery-Dreifuss muscular dystrophy (EDMD) with conduction defects and dilated cardiomyopathy (DCM). We have previously observed sarcomeric staining of nesprin-1/-2 in cardiac and skeletal muscle, but nesprin function in this compartment remains unknown. In this study, we show that specific nesprin-2 isoforms are highly expressed in cardiac muscle and localize to the Z-disc and I band of the sarcomere. Expression of GFP-tagged nesprin-2 giant spectrin repeats 52 to 53, localized to the sarcomere of neonatal rat cardiomyocytes. Yeast two-hybrid screening of a cardiac muscle cDNA library identified telethonin and four-and-half LIM domain (FHL)-2 as potential nesprin-2 binding partners. GST pull-down and immunoprecipitation confirmed the individual interactions between nesprin-2/telethonin and nesprin-2/FHL-2, and showed that nesprin-2 and telethonin binding was dependent on telethonin phosphorylation status. Importantly, the interactions between these binding partners were impaired by mutations in nesprin-2, telethonin, and FHL-2 identified in EDMD with DCM and hypertrophic cardiomyopathy patients. These data suggest that nesprin-2 is a novel sarcomeric scaffold protein that may potentially participate in the maintenance and/or regulation of sarcomeric organization and function.
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Affiliation(s)
- Chen Li
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London, UK; Department of Cardiology, West China Hospital of Sichuan University, Chengdu, China
| | - Derek T Warren
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London, UK; School of Pharmacy, University of East Anglia, Norwich, UK
| | - Can Zhou
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London, UK
| | - Shanelle De Silva
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London, UK
| | - Darren G S Wilson
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London, UK
| | - Mitla Garcia-Maya
- Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, King's College London, London, UK
| | - Matthew A Wheeler
- Department of Cardiac Development and Remodeling, Max-Planck-Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Peter Meinke
- Friedrich-Baur-Institute at the Department of Neurology, LMU University Hospital, Munich, Germany
| | - Greta Sawyer
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London, UK
| | - Elisabeth Ehler
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London, UK; Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, King's College London, London, UK
| | - Manfred Wehnert
- Institute of Human Genetics, University of Greifswald, Greifswald, Germany
| | - Li Rao
- Department of Cardiology, West China Hospital of Sichuan University, Chengdu, China
| | - Qiuping Zhang
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London, UK.
| | - Catherine M Shanahan
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London, UK.
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3
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Silonov SA, Mokin YI, Nedelyaev EM, Smirnov EY, Kuznetsova IM, Turoverov KK, Uversky VN, Fonin AV. On the Prevalence and Roles of Proteins Undergoing Liquid-Liquid Phase Separation in the Biogenesis of PML-Bodies. Biomolecules 2023; 13:1805. [PMID: 38136675 PMCID: PMC10741438 DOI: 10.3390/biom13121805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 12/08/2023] [Accepted: 12/12/2023] [Indexed: 12/24/2023] Open
Abstract
The formation and function of membrane-less organelles (MLOs) is one of the main driving forces in the molecular life of the cell. These processes are based on the separation of biopolymers into phases regulated by multiple specific and nonspecific inter- and intramolecular interactions. Among the realm of MLOs, a special place is taken by the promyelocytic leukemia nuclear bodies (PML-NBs or PML bodies), which are the intranuclear compartments involved in the regulation of cellular metabolism, transcription, the maintenance of genome stability, responses to viral infection, apoptosis, and tumor suppression. According to the accepted models, specific interactions, such as SUMO/SIM, the formation of disulfide bonds, etc., play a decisive role in the biogenesis of PML bodies. In this work, a number of bioinformatics approaches were used to study proteins found in the proteome of PML bodies for their tendency for spontaneous liquid-liquid phase separation (LLPS), which is usually caused by weak nonspecific interactions. A total of 205 proteins found in PML bodies have been identified. It has been suggested that UBC9, P53, HIPK2, and SUMO1 can be considered as the scaffold proteins of PML bodies. It was shown that more than half of the proteins in the analyzed proteome are capable of spontaneous LLPS, with 85% of the analyzed proteins being intrinsically disordered proteins (IDPs) and the remaining 15% being proteins with intrinsically disordered protein regions (IDPRs). About 44% of all proteins analyzed in this study contain SUMO binding sites and can potentially be SUMOylated. These data suggest that weak nonspecific interactions play a significantly larger role in the formation and biogenesis of PML bodies than previously expected.
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Affiliation(s)
- Sergey A. Silonov
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, St. Petersburg 194064, Russia; (S.A.S.); (Y.I.M.); (E.M.N.); (E.Y.S.); (I.M.K.); (K.K.T.)
| | - Yakov I. Mokin
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, St. Petersburg 194064, Russia; (S.A.S.); (Y.I.M.); (E.M.N.); (E.Y.S.); (I.M.K.); (K.K.T.)
| | - Eugene M. Nedelyaev
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, St. Petersburg 194064, Russia; (S.A.S.); (Y.I.M.); (E.M.N.); (E.Y.S.); (I.M.K.); (K.K.T.)
| | - Eugene Y. Smirnov
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, St. Petersburg 194064, Russia; (S.A.S.); (Y.I.M.); (E.M.N.); (E.Y.S.); (I.M.K.); (K.K.T.)
| | - Irina M. Kuznetsova
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, St. Petersburg 194064, Russia; (S.A.S.); (Y.I.M.); (E.M.N.); (E.Y.S.); (I.M.K.); (K.K.T.)
| | - Konstantin K. Turoverov
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, St. Petersburg 194064, Russia; (S.A.S.); (Y.I.M.); (E.M.N.); (E.Y.S.); (I.M.K.); (K.K.T.)
| | - Vladimir N. Uversky
- Department of Molecular Medicine and USF Health Byrd Alzheimer’s Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA;
| | - Alexander V. Fonin
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, St. Petersburg 194064, Russia; (S.A.S.); (Y.I.M.); (E.M.N.); (E.Y.S.); (I.M.K.); (K.K.T.)
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Song X, Li R, Liu G, Huang L, Li P, Feng W, Gao Q, Xing X. Nuclear Membrane Protein SUN5 Is Highly Expressed and Promotes Proliferation and Migration in Colorectal Cancer by Regulating the ERK Pathway. Cancers (Basel) 2022; 14:5368. [PMID: 36358787 PMCID: PMC9654567 DOI: 10.3390/cancers14215368] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 10/28/2022] [Accepted: 10/28/2022] [Indexed: 09/26/2023] Open
Abstract
SUN5 was first identified as a nuclear envelope protein involved in spermatocyte division. We found that SUN5 was highly expressed in some cancers, but its function and mechanism in cancer development remain unclear. In the present study, we demonstrated that SUN5 was highly expressed in colorectal cancer (CRC) tissues and cells, as indicated by bioinformatics analysis, and SUN5 promoted cell proliferation and migration in vitro. Moreover, the overexpression of SUN5 upregulated phosphorylated ERK1/2 (pERK1/2), whereas the knockdown of SUN5 yielded the opposite results. PD0325901 decreased the level of pERK1/2 to inhibit cell proliferation and migration, which was partially reversed by SUN5 overexpression, indicating that drug resistance existed in patients with high SUN5 expression. The xenograft transplantation experiment showed that SUN5 accelerated tumor formation in vivo. Furthermore, we found that SUN5 regulated the ERK pathway via Nesprin2 mediation and promoted the nuclear translocation of pERK1/2 by interacting with Nup93. Thus, these findings indicated that highly expressed SUN5 promoted CRC proliferation and migration by regulating the ERK pathway, which may contribute to the clinical diagnosis and new treatment strategies for CRC.
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Affiliation(s)
- Xiaoyue Song
- Center for Experimental Medicine, Third Xiangya Hospital, Central South University, Changsha 410013, China
- Department of Laboratory Medicine, Third Xiangya Hospital, Central South University, Changsha 410013, China
| | - Ruhong Li
- Department of General Surgery, Yanan Hospital Affiliated to Kunming Medical University, Kunming 650051, China
| | - Gang Liu
- The Institute of Reproduction and Stem Cell Engineering, School of Basic Medical Sciences, Central South University, Changsha 410078, China
| | - Lihua Huang
- Center for Experimental Medicine, Third Xiangya Hospital, Central South University, Changsha 410013, China
| | - Peng Li
- Department of General Surgery, Yanan Hospital Affiliated to Kunming Medical University, Kunming 650051, China
| | - Wanjiang Feng
- Center for Experimental Medicine, Third Xiangya Hospital, Central South University, Changsha 410013, China
| | - Qiujie Gao
- Center for Experimental Medicine, Third Xiangya Hospital, Central South University, Changsha 410013, China
- Department of Laboratory Medicine, Third Xiangya Hospital, Central South University, Changsha 410013, China
| | - Xiaowei Xing
- Center for Experimental Medicine, Third Xiangya Hospital, Central South University, Changsha 410013, China
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Meqbel BRM, Gomes M, Omer A, Gallouzi IE, Horn HF. LINCing Senescence and Nuclear Envelope Changes. Cells 2022; 11:1787. [PMID: 35681483 PMCID: PMC9179861 DOI: 10.3390/cells11111787] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 05/23/2022] [Accepted: 05/24/2022] [Indexed: 01/27/2023] Open
Abstract
The nuclear envelope (NE) has emerged as a nexus for cellular organization, signaling, and survival. Beyond its role as a barrier to separate the nucleoplasm from the cytoplasm, the NE's role in supporting and maintaining a myriad of other functions has made it a target of study in many cellular processes, including senescence. The nucleus undergoes dramatic changes in senescence, many of which are driven by changes in the NE. Indeed, Lamin B1, a key NE protein that is consistently downregulated in senescence, has become a marker for senescence. Other NE proteins have also been shown to play a role in senescence, including LINC (linker of nucleoskeleton and cytoskeleton) complex proteins. LINC complexes span the NE, forming physical connections between the cytoplasm to the nucleoplasm. In this way, they integrate nuclear and cytoplasmic mechanical signals and are essential not only for a variety of cellular functions but are needed for cell survival. However, LINC complex proteins have been shown to have a myriad of functions in addition to forming a LINC complex, often existing as nucleoplasmic or cytoplasmic soluble proteins in a variety of isoforms. Some of these proteins have now been shown to play important roles in DNA repair, cell signaling, and nuclear shape regulation, all of which are important in senescence. This review will focus on some of these roles and highlight the importance of LINC complex proteins in senescence.
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Affiliation(s)
- Bakhita R. M. Meqbel
- College of Health and Life Sciences, Hamad Bin Khalifa University, Doha P.O. Box 34110, Qatar;
| | - Matilde Gomes
- KAUST Smart-Health Initiative and Biological and Environmental Science and Engineering (BESE) Division, King Abdullah University of Science and Technology (KAUST), Jeddah 21589, Saudi Arabia; (M.G.); (I.E.G.)
| | - Amr Omer
- Department of Biochemistry, McGill University, 3655 Promenade Sir William Osler, Montreal, QC H3G 1Y6, Canada;
| | - Imed E. Gallouzi
- KAUST Smart-Health Initiative and Biological and Environmental Science and Engineering (BESE) Division, King Abdullah University of Science and Technology (KAUST), Jeddah 21589, Saudi Arabia; (M.G.); (I.E.G.)
- Department of Biochemistry, McGill University, 3655 Promenade Sir William Osler, Montreal, QC H3G 1Y6, Canada;
| | - Henning F. Horn
- College of Health and Life Sciences, Hamad Bin Khalifa University, Doha P.O. Box 34110, Qatar;
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Biallelic SYNE2 Missense Mutations Leading to Nesprin-2 Giant Hypo-Expression Are Associated with Intellectual Disability and Autism. Genes (Basel) 2021; 12:genes12091294. [PMID: 34573277 PMCID: PMC8470961 DOI: 10.3390/genes12091294] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/06/2021] [Accepted: 08/20/2021] [Indexed: 12/20/2022] Open
Abstract
Autism spectrum disorder (ASD) is a group of neurological and developmental disabilities characterised by clinical and genetic heterogeneity. The current study aimed to expand ASD genotyping by investigating potential associations with SYNE2 mutations. Specifically, the disease-causing variants of SYNE2 in 410 trios manifesting neurodevelopmental disorders using whole-exome sequencing were explored. The consequences of the identified variants were studied at the transcript level using quantitative polymerase chain reaction (qPCR). For validation, immunofluorescence and immunoblotting were performed to analyse mutational effects at the protein level. The compound heterozygous variants of SYNE2 (NM_182914.3:c.2483T>G; p.(Val828Gly) and NM_182914.3:c.2362G>A; p.(Glu788Lys)) were identified in a 4.5-year-old male, clinically diagnosed with autism spectrum disorder, developmental delay and intellectual disability. Both variants reside within the nesprin-2 giant spectrin repeat (SR5) domain and are predicted to be highly damaging using in silico tools. Specifically, a significant reduction of nesprin-2 giant protein levels is revealed in patient cells. SYNE2 transcription and the nuclear envelope localisation of the mutant proteins was however unaffected as compared to parental control cells. Collectively, these data provide novel insights into the cardinal role of the nesprin-2 giant in neurodevelopment and suggest that the biallelic hypomorphic SYNE2 mutations may be a new cause of intellectual disability and ASD.
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Zhang H, Ji N, Gong X, Ni S, Wang Y. NEAT1/miR-140-3p/MAPK1 mediates the viability and survival of coronary endothelial cells and affects coronary atherosclerotic heart disease. Acta Biochim Biophys Sin (Shanghai) 2020; 52:967-974. [PMID: 32844995 DOI: 10.1093/abbs/gmaa087] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 02/28/2020] [Indexed: 12/11/2022] Open
Abstract
Studies have shown that long non-coding RNAs (lncRNA) play critical roles in coronary atherosclerotic heart disease (CAD). However, the function of lncRNA nuclear enriched abundant transcript 1 (NEAT1) in CAD is unclear. In this study, we aimed to investigate the functions of lncRNA NEAT1 in CAD. RT-PCR and western blot analysis were carried out to examine the expressions of related RNAs. Colony formation assay, cell proliferation assay, apoptosis assay, and dual-luciferase reporter assay were conducted to investigate the abilities of colony migration, cell proliferation, apoptosis, and targeting. The results showed that NEAT1 was up-regulated in CAD blood samples and in human coronary endothelial cells (HCAECs). Transfection of pcNEAT1 significantly inhibited the survival rate of HCAECs and induced apoptosis of HCAECs. MiR-140-3p was down-regulated in HCAECs. NEAT1 directly targeted miR-140-3p, and the expression of miR-140-3p was inversely correlated with the expression of NEAT1 in CAD patients. In addition, co-transfection of NEAT1 with miR-140-3p mimic reversed the effect of pcNEAT1 on cell viability and apoptosis. mitogen-activated protein kinase 1 (MAPK1) was proved to be a target gene of miR-140-3p, and the miR-140-3p mimic was shown to reduce the expression of MAPK1 in HCAECs. pcNEAT1 significantly increased the expression level of MAPK1, while shNEAT1 significantly reduced the expression level of MAPK1. Our results revealed that lncRNA NEAT1 increased cell viability and inhibited CAD cell apoptosis possibly by activating the miR-140-3p/MAPK1 pathway, and lncRNA NEAT1 might serve as a potential therapeutic target for CAD.
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Affiliation(s)
- Hui Zhang
- Department of Cardiology, Yiwu Central Hospital, Yiwu 322000, China
| | - Ningning Ji
- Department of Cardiology, Yiwu Central Hospital, Yiwu 322000, China
| | - Xinyan Gong
- Department of Cardiology, Yiwu Central Hospital, Yiwu 322000, China
| | - Shimao Ni
- Department of Cardiology, Yiwu Central Hospital, Yiwu 322000, China
| | - Yu Wang
- Department of Cardiology, Yiwu Central Hospital, Yiwu 322000, China
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Mroß C, Marko M, Munck M, Glöckner G, Motameny S, Altmüller J, Noegel AA, Eichinger L, Peche VS, Neumann S. Depletion of Nesprin-2 is associated with an embryonic lethal phenotype in mice. Nucleus 2019; 9:503-515. [PMID: 30220251 PMCID: PMC6244730 DOI: 10.1080/19491034.2018.1523664] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Nesprin-2 is a nuclear envelope component and provides a link between cytoskeletal components of the cytoplasm and the nucleoplasm. Several isoforms are generated from its gene Syne2. Loss of the largest isoform Nesprin-2 Giant in mice is associated with a skin phenotype and altered wound healing, loss of C-terminal isoforms in mice leads to cardiomyopathies and neurological defects. Here we attempted to establish mice with an inducible knockout of all Nesprin-2 isoforms by inserting shRNA encoding sequences targeting the N- and C-terminus into the ROSA26 locus of mice. This caused early embryonic death of the animals harboring the mutant allele, which was presumably due to leaky expression of the shRNAs. Mutant embryos were only observed before E13. They had an altered appearance and were smaller in size than their wild type littermates. From this we conclude that the Nesprin-2 gene function is crucial during embryonic growth, differentiation and organogenesis.
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Affiliation(s)
- Carmen Mroß
- a Institute of Biochemistry I, Medical Faculty , University Hospital Cologne; Center for Molecular Medicine Cologne (CMMC) and Cologne Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) , Koeln , Germany
| | - Marija Marko
- a Institute of Biochemistry I, Medical Faculty , University Hospital Cologne; Center for Molecular Medicine Cologne (CMMC) and Cologne Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) , Koeln , Germany
| | - Martina Munck
- a Institute of Biochemistry I, Medical Faculty , University Hospital Cologne; Center for Molecular Medicine Cologne (CMMC) and Cologne Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) , Koeln , Germany
| | - Gernot Glöckner
- a Institute of Biochemistry I, Medical Faculty , University Hospital Cologne; Center for Molecular Medicine Cologne (CMMC) and Cologne Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) , Koeln , Germany
| | - Susanne Motameny
- b Cologne Center for Genomics (CCG) , University of Cologne , Koeln , Germany
| | - Janine Altmüller
- b Cologne Center for Genomics (CCG) , University of Cologne , Koeln , Germany
| | - Angelika A Noegel
- a Institute of Biochemistry I, Medical Faculty , University Hospital Cologne; Center for Molecular Medicine Cologne (CMMC) and Cologne Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) , Koeln , Germany
| | - Ludwig Eichinger
- a Institute of Biochemistry I, Medical Faculty , University Hospital Cologne; Center for Molecular Medicine Cologne (CMMC) and Cologne Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) , Koeln , Germany
| | - Vivek S Peche
- a Institute of Biochemistry I, Medical Faculty , University Hospital Cologne; Center for Molecular Medicine Cologne (CMMC) and Cologne Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) , Koeln , Germany
| | - Sascha Neumann
- a Institute of Biochemistry I, Medical Faculty , University Hospital Cologne; Center for Molecular Medicine Cologne (CMMC) and Cologne Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) , Koeln , Germany
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MicroRNA-125a-3p affects smooth muscle cell function in vascular stenosis. J Mol Cell Cardiol 2019; 136:85-94. [PMID: 31499051 DOI: 10.1016/j.yjmcc.2019.08.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 08/04/2019] [Accepted: 08/31/2019] [Indexed: 11/21/2022]
Abstract
AIMS Many studies have indicated that microRNAs are closely related to the process of peripheral arterial disease (PAD). Previously, we found that microRNA-125a-3p (miR-125a-3p) in restenotic arteries after interventional therapy of lower extremity vessels was notably decreased compared with that of normal control arteries. However, its role in the development of vascular stenosis is not yet clearly understood. The purpose of this study was to investigate the expression, regulatory mechanism and function of miR-125a-3p in the process of vascular stenosis. METHODS AND RESULTS Quantitative reverse-transcription polymerase chain reaction assays indicated that miR-125a-3p in restenotic arteries after interventional therapy was significantly lower than that in normal control arteries. Immunofluorescence and in situ hybridization co-staining assays in arterial sections demonstrated that miR-125a-3p was mainly expressed in the medial smooth muscle layer. Transfection of miR-125a-3p mimics into cultured vascular smooth muscle cells (VSMCs) effectively inhibited cell proliferation and migration. Then, western blot and luciferase activity assays showed that recombinant human mitogen-activated protein kinase 1 (MAPK1) was a functional target of miR-125a-3p and was involved in miR-125a-3p-mediated cell effects. Finally, the lentiviral infection of miR-125a-3p in balloon-injured rat carotid vascular walls showed that miR-125a-3p overexpression significantly reduced the probability of neointimal membrane production. CONCLUSIONS miR-125a-3p can effectively inhibit the function of VSMCs and the occurrence of vascular stenosis by targeting MAPK1. This study introduces a new molecular mechanism of PAD. We show that regulation of the miR-125a-3p level has the potential to provide a new treatment for PAD and other proliferative vascular diseases.
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Detection of SUN1 Splicing Variants at the mRNA and Protein Levels in Cancer. Methods Mol Biol 2018. [PMID: 30141053 DOI: 10.1007/978-1-4939-8691-0_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
The linker of nucleoskeleton and cytoskeleton (LINC) complex, containing the proteins SUN and nesprin, is the fundamental structural unit of the nuclear envelope. The neoplastic-based regulation of the LINC complex in cancer tissues has become increasingly recognized in recent years, including the altered expression, somatic mutation, and methylation of genes. However, precisely how mutations and deregulated expression of the LINC complex contribute to the pathogenic mechanisms of tumorigenesis remain to be elucidated, mainly because of several technical difficulties. First, both the SUN and SYNE (encoding nesprin) genes give rise to a vast number of splicing variants. Second, immunoprecipitation experiments of endogenous SUN and nesprin proteins are difficult owing to the lack of suitable reagents as well as the limited solubility of these proteins in mild extraction conditions. Here, we describe three protocols to investigate these aspects: (1) immunohistochemistry to determine the expression levels and localization of the LINC complex in cancer tissue, (2) detection of SUN1 splicing variants at the mRNA level, and (3) detection of SUN1 splicing variants and binding partners at the protein level.
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Zhao T, Li R, Tan X, Zhang J, Fan C, Zhao Q, Deng Y, Xu A, Lukong KE, Genth H, Xiang J. Simulated Microgravity Reduces Focal Adhesions and Alters Cytoskeleton and Nuclear Positioning Leading to Enhanced Apoptosis via Suppressing FAK/RhoA-Mediated mTORC1/NF-κB and ERK1/2 Pathways. Int J Mol Sci 2018; 19:ijms19071994. [PMID: 29986550 PMCID: PMC6073227 DOI: 10.3390/ijms19071994] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 07/04/2018] [Accepted: 07/06/2018] [Indexed: 12/16/2022] Open
Abstract
Simulated-microgravity (SMG) promotes cell-apoptosis. We demonstrated that SMG inhibited cell proliferation/metastasis via FAK/RhoA-regulated mTORC1 pathway. Since mTORC1, NF-κB, and ERK1/2 signaling are important in cell apoptosis, we examined whether SMG-enhanced apoptosis is regulated via these signals controlled by FAK/RhoA in BL6-10 melanoma cells under clinostat-modelled SMG-condition. We show that SMG promotes cell-apoptosis, alters cytoskeleton, reduces focal adhesions (FAs), and suppresses FAK/RhoA signaling. SMG down-regulates expression of mTORC1-related Raptor, pS6K, pEIF4E, pNF-κB, and pNF-κB-regulated Bcl2, and induces relocalization of pNF-κB from the nucleus to the cytoplasm. In addition, SMG also inhibits expression of nuclear envelope proteins (NEPs) lamin-A, emerin, sun1, and nesprin-3, which control nuclear positioning, and suppresses nuclear positioning-regulated pERK1/2 signaling. Moreover, rapamycin, the mTORC1 inhibitor, also enhances apoptosis in cells under 1 g condition via suppressing the mTORC1/NF-κB pathway. Furthermore, the FAK/RhoA activator, toxin cytotoxic necrotizing factor-1 (CNF1), reduces cell apoptosis, restores the cytoskeleton, FAs, NEPs, and nuclear positioning, and converts all of the above SMG-induced changes in molecular signaling in cells under SMG. Therefore, our data demonstrate that SMG reduces FAs and alters the cytoskeleton and nuclear positioning, leading to enhanced cell apoptosis via suppressing the FAK/RhoA-regulated mTORC1/NF-κB and ERK1/2 pathways. The FAK/RhoA regulatory network may, thus, become a new target for the development of novel therapeutics for humans under spaceflight conditions with stressed physiological challenges, and for other human diseases.
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Affiliation(s)
- Tuo Zhao
- School of Life Sciences, Beijing Institute of Technology, Beijing 10081, China.
| | - Rong Li
- Cancer Research, Saskatchewan Cancer Agency, Saskatoon, SK S7N 4H4, Canada.
- Department of Oncology, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada.
| | - Xin Tan
- School of Life Sciences, Beijing Institute of Technology, Beijing 10081, China.
| | - Jun Zhang
- School of Life Sciences, Beijing Institute of Technology, Beijing 10081, China.
| | - Cuihong Fan
- School of Life Sciences, Beijing Institute of Technology, Beijing 10081, China.
| | - Qin Zhao
- School of Life Sciences, Beijing Institute of Technology, Beijing 10081, China.
| | - Yulin Deng
- School of Life Sciences, Beijing Institute of Technology, Beijing 10081, China.
| | - Aizhang Xu
- Cancer Research, Saskatchewan Cancer Agency, Saskatoon, SK S7N 4H4, Canada.
- Department of Oncology, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada.
| | - Kiven Erique Lukong
- Department of Biochemistry, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada.
| | - Harald Genth
- Institute of Toxicology, Hannover Medical School, D-30625 Hannover, Germany.
| | - Jim Xiang
- Cancer Research, Saskatchewan Cancer Agency, Saskatoon, SK S7N 4H4, Canada.
- Department of Oncology, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada.
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12
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Mouse models of nesprin-related diseases. Biochem Soc Trans 2018; 46:669-681. [PMID: 29784648 DOI: 10.1042/bst20180085] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 04/05/2018] [Accepted: 04/20/2018] [Indexed: 02/05/2023]
Abstract
Nesprins (nuclear envelope spectrin repeat proteins) are a family of multi-isomeric scaffolding proteins. Nesprins form the LInker of Nucleoskeleton-and-Cytoskeleton (LINC) complex with SUN (Sad1p/UNC84) domain-containing proteins at the nuclear envelope, in association with lamin A/C and emerin, linking the nucleoskeleton to the cytoskeleton. The LINC complex serves as both a physical linker between the nuclear lamina and the cytoskeleton and a mechanosensor. The LINC complex has a broad range of functions and is involved in maintaining nuclear architecture, nuclear positioning and migration, and also modulating gene expression. Over 80 disease-related variants have been identified in SYNE-1/2 (nesprin-1/2) genes, which result in muscular or central nervous system disorders including autosomal dominant Emery-Dreifuss muscular dystrophy, dilated cardiomyopathy and autosomal recessive cerebellar ataxia type 1. To date, 17 different nesprin mouse lines have been established to mimic these nesprin-related human diseases, which have provided valuable insights into the roles of nesprin and its scaffold LINC complex in a tissue-specific manner. In this review, we summarise the existing nesprin mouse models, compare their phenotypes and discuss the potential mechanisms underlying nesprin-associated diseases.
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13
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Nesprin-2 Interacts with Condensin Component SMC2. Int J Cell Biol 2018; 2017:8607532. [PMID: 29445399 PMCID: PMC5763115 DOI: 10.1155/2017/8607532] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 11/17/2017] [Accepted: 12/07/2017] [Indexed: 01/24/2023] Open
Abstract
The nuclear envelope proteins, Nesprins, have been primarily studied during interphase where they function in maintaining nuclear shape, size, and positioning. We analyze here the function of Nesprin-2 in chromatin interactions in interphase and dividing cells. We characterize a region in the rod domain of Nesprin-2 that is predicted as SMC domain (aa 1436-1766). We show that this domain can interact with itself. It furthermore has the capacity to bind to SMC2 and SMC4, the core subunits of condensin. The interaction was observed during all phases of the cell cycle; it was particularly strong during S phase and persisted also during mitosis. Nesprin-2 knockdown did not affect condensin distribution; however we noticed significantly higher numbers of chromatin bridges in Nesprin-2 knockdown cells in anaphase. Thus, Nesprin-2 may have an impact on chromosomes which might be due to its interaction with condensins or to indirect mechanisms provided by its interactions at the nuclear envelope.
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14
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Zhou C, Li C, Zhou B, Sun H, Koullourou V, Holt I, Puckelwartz MJ, Warren DT, Hayward R, Lin Z, Zhang L, Morris GE, McNally EM, Shackleton S, Rao L, Shanahan CM, Zhang Q. Novel nesprin-1 mutations associated with dilated cardiomyopathy cause nuclear envelope disruption and defects in myogenesis. Hum Mol Genet 2017; 26:2258-2276. [PMID: 28398466 PMCID: PMC5458344 DOI: 10.1093/hmg/ddx116] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 03/22/2017] [Indexed: 02/05/2023] Open
Abstract
Nesprins-1 and -2 are highly expressed in skeletal and cardiac muscle and together with SUN (Sad1p/UNC84)-domain containing proteins and lamin A/C form the LInker of Nucleoskeleton-and-Cytoskeleton (LINC) bridging complex at the nuclear envelope (NE). Mutations in nesprin-1/2 have previously been found in patients with autosomal dominant Emery–Dreifuss muscular dystrophy (EDMD) as well as dilated cardiomyopathy (DCM). In this study, three novel rare variants (R8272Q, S8381C and N8406K) in the C-terminus of the SYNE1 gene (nesprin-1) were identified in seven DCM patients by mutation screening. Expression of these mutants caused nuclear morphology defects and reduced lamin A/C and SUN2 staining at the NE. GST pull-down indicated that nesprin-1/lamin/SUN interactions were disrupted. Nesprin-1 mutations were also associated with augmented activation of the ERK pathway in vitro and in hearts in vivo. During C2C12 muscle cell differentiation, nesprin-1 levels are increased concomitantly with kinesin light chain (KLC-1/2) and immunoprecipitation and GST pull-down showed that these proteins interacted via a recently identified LEWD domain in the C-terminus of nesprin-1. Expression of nesprin-1 mutants in C2C12 cells caused defects in myoblast differentiation and fusion associated with dysregulation of myogenic transcription factors and disruption of the nesprin-1 and KLC-1/2 interaction at the outer nuclear membrane. Expression of nesprin-1α2 WT and mutants in zebrafish embryos caused heart developmental defects that varied in severity. These findings support a role for nesprin-1 in myogenesis and muscle disease, and uncover a novel mechanism whereby disruption of the LINC complex may contribute to the pathogenesis of DCM.
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Affiliation(s)
- Can Zhou
- King's College London British Heart Foundation Centre of Research Excellence, Cardiovascular Division, London SE5 9NU, UK.,Department of Cardiology, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Chen Li
- King's College London British Heart Foundation Centre of Research Excellence, Cardiovascular Division, London SE5 9NU, UK.,Department of Cardiology, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Bin Zhou
- Laboratory of Molecular Translational Medicine.,Key Laboratory of Obstetric & Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education
| | - Huaqin Sun
- Key Laboratory of Obstetric & Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education.,SCU-CUHK Joint Laboratory for Reproductive Medicine, West China Second University Hospital, Sichuan University, Chengdu, 610041, China
| | - Victoria Koullourou
- King's College London British Heart Foundation Centre of Research Excellence, Cardiovascular Division, London SE5 9NU, UK.,Department of Molecular and Cell Biology, University of Leicester, Leicester LE1 9HN, UK
| | - Ian Holt
- Wolfson Centre for Inherited Neuromuscular Disease, RJAH Orthopaedic Hospital, Oswestry SY10?7AG, UK and Institute for Science and Technology in Medicine, Keele University, ST5?5BG, UK
| | - Megan J Puckelwartz
- Center for Genetic Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Derek T Warren
- King's College London British Heart Foundation Centre of Research Excellence, Cardiovascular Division, London SE5?9NU, UK
| | - Robert Hayward
- King's College London British Heart Foundation Centre of Research Excellence, Cardiovascular Division, London SE5?9NU, UK
| | - Ziyuan Lin
- Key Laboratory of Obstetric & Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education.,SCU-CUHK Joint Laboratory for Reproductive Medicine, West China Second University Hospital, Sichuan University, Chengdu, 610041, China
| | - Lin Zhang
- Laboratory of Molecular Translational Medicine.,Key Laboratory of Obstetric & Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education
| | - Glenn E Morris
- Wolfson Centre for Inherited Neuromuscular Disease, RJAH Orthopaedic Hospital, Oswestry SY10?7AG, UK and Institute for Science and Technology in Medicine, Keele University, ST5?5BG, UK
| | - Elizabeth M McNally
- Center for Genetic Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Sue Shackleton
- Department of Molecular and Cell Biology, University of Leicester, Leicester LE1?9HN, UK
| | - Li Rao
- Department of Cardiology, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Catherine M Shanahan
- King's College London British Heart Foundation Centre of Research Excellence, Cardiovascular Division, London SE5?9NU, UK
| | - Qiuping Zhang
- King's College London British Heart Foundation Centre of Research Excellence, Cardiovascular Division, London SE5?9NU, UK
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15
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Cobb AM, Murray TV, Warren DT, Liu Y, Shanahan CM. Disruption of PCNA-lamins A/C interactions by prelamin A induces DNA replication fork stalling. Nucleus 2017; 7:498-511. [PMID: 27676213 PMCID: PMC5120601 DOI: 10.1080/19491034.2016.1239685] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
The accumulation of prelamin A is linked to disruption of cellular homeostasis, tissue degeneration and aging. Its expression is implicated in compromised genome stability and increased levels of DNA damage, but to date there is no complete explanation for how prelamin A exerts its toxic effects. As the nuclear lamina is important for DNA replication we wanted to investigate the relationship between prelamin A expression and DNA replication fork stability. In this study we report that the expression of prelamin A in U2OS cells induced both mono-ubiquitination of proliferating cell nuclear antigen (PCNA) and subsequent induction of Pol η, two hallmarks of DNA replication fork stalling. Immunofluorescence microscopy revealed that cells expressing prelamin A presented with high levels of colocalisation between PCNA and γH2AX, indicating collapse of stalled DNA replication forks into DNA double-strand breaks. Subsequent protein-protein interaction assays showed prelamin A interacted with PCNA and that its presence mitigated interactions between PCNA and the mature nuclear lamina. Thus, we propose that the cytotoxicity of prelamin A arises in part, from it actively competing against mature lamin A to bind PCNA and that this destabilises DNA replication to induce fork stalling which in turn contributes to genomic instability.
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Affiliation(s)
- Andrew M Cobb
- a King's College London , The James Black Center , London , United Kingdom
| | - Thomas V Murray
- a King's College London , The James Black Center , London , United Kingdom
| | - Derek T Warren
- a King's College London , The James Black Center , London , United Kingdom
| | - Yiwen Liu
- a King's College London , The James Black Center , London , United Kingdom
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16
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Lim JH, Song MK, Cho Y, Kim W, Han SO, Ryu JC. Expression of exosomal and cellular microRNAs: as biomarkers for toluene, ethylbenzene, xylene (TEX) exposure. Mol Cell Toxicol 2017. [DOI: 10.1007/s13273-016-0040-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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17
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Rajgor D, Hanley JG, Shanahan CM. Identification of novel nesprin-1 binding partners and cytoplasmic matrin-3 in processing bodies. Mol Biol Cell 2016; 27:3894-3902. [PMID: 27733621 PMCID: PMC5170611 DOI: 10.1091/mbc.e16-06-0346] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 09/20/2016] [Accepted: 10/05/2016] [Indexed: 11/25/2022] Open
Abstract
Several new nesprin-1 binding partners were identified, of which many are well-characterized RNA-binding proteins involved in various forms of nuclear RNA-processing events. Matrin-3 was one such protein identified, and a new cytoplasmic localization for matrin-3 is shown. Nesprins are highly conserved spectrin repeat–containing scaffold proteins predominantly known to function at the nuclear envelope (NE). However, nesprin isoforms are emerging with localizations and scaffolding functions at sites away from the NE, suggesting their functions are more diverse than originally thought. In this study, we combined nesprin-1 coimmunoprecipitations with mass spectrometry to identify novel nesprin-1 binding partners for isoforms that localize to subcellular compartments beyond the NE. We show that one of these interactors, matrin-3 (matr3), localizes to mRNA processing bodies (PBs), where we have previously shown a nesprin-1 isoform to localize. Furthermore, we show that Matr3 is part of PB mRNP complexes, is a regulator of miRNA-mediated gene silencing, and possibly shuttles to stress granules in stressed cells. More importantly, we identify a new C-terminally truncated Matr3 isoform that is likely to be involved in these functions and PB localization. This study highlights several novel nesprin-1 binding partners and a new function and localization for Matr3 in cytoplasmic RNA granules.
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Affiliation(s)
- Dipen Rajgor
- Cardiovascular Division, King's College London, London SE5 9NU, United Kingdom .,Department of Biochemistry, University of Bristol, Bristol BS8 1TD, United Kingdom
| | - Jonathan G Hanley
- Department of Biochemistry, University of Bristol, Bristol BS8 1TD, United Kingdom
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18
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Abstract
The nucleus is separated from the cytosol by the nuclear envelope, which is a double lipid bilayer composed of the outer nuclear membrane and the inner nuclear membrane. The intermediate filament proteins lamin A, lamin B, and lamin C form a network underlying the inner nuclear membrane. This proteinaceous network provides the nucleus with its strength, rigidity, and elasticity. Positioned within the inner nuclear membrane are more than 150 inner nuclear membrane proteins, many of which interact directly with lamins and require lamins for their inner nuclear membrane localization. Inner nuclear membrane proteins and the nuclear lamins define the nuclear lamina. These inner nuclear membrane proteins have tissue-specific expression and diverse functions including regulating cytoskeletal organization, nuclear architecture, cell cycle dynamics, and genomic organization. Loss or mutations in lamins and inner nuclear membrane proteins cause a wide spectrum of diseases. Here, I will review the functions of the well-studied nuclear lamina proteins and the diseases associated with loss or mutations in these proteins. © 2016 American Physiological Society. Compr Physiol 6:1655-1674, 2016.
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Affiliation(s)
- James M. Holaska
- Department of Pharmaceutical Sciences, University of the Sciences, Philadelphia, Pennsylvania, USA
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19
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Han C, Liao X, Qin W, Yu L, Liu X, Chen G, Liu Z, Lu S, Chen Z, Su H, Zhu G, Lu Z, Liu Z, Qin X, Gui Y, Mo Z, Li L, Peng T. EGFR and SYNE2 are associated with p21 expression and SYNE2 variants predict post-operative clinical outcomes in HBV-related hepatocellular carcinoma. Sci Rep 2016; 6:31237. [PMID: 27502069 PMCID: PMC4977508 DOI: 10.1038/srep31237] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 07/15/2016] [Indexed: 02/08/2023] Open
Abstract
This study was to explore the association between gene variants and p21 expression and investigate the TP53-independent p21 regulation in hepatitis B virus (HBV) related hepatocellular carcinoma (HCC) patients from Guangxi by genome-wide association study. 426 HBV-related HCC patients were enrolled. Results showed that, after quality control, a total of 21,643 SNPs were identified in 107 p21 positive and 298 p21 negative patients. The variants of epidermal growth factor receptor (EGFR; rs2227983 and rs6950826) and spectrin repeat containing, nuclear envelope 2 (SYNE2; rs8010699, rs4027405 and rs1890908) were associated with p21 expression. Moreover the haplotype block (rs2227983 and rs6950826, r2 = 0.378) in EGFR and the haplotype block in SYNE2 (rs8010699 was in strong LD with rs4027405 and rs1890908 (r2 = 0.91 and 0.70, respectively)) were identified, and the haplotype A-G of EGFR and haplotype G-A-A of SYNE2 were significantly associated with p21 expression (P < 0.01). rs4027405 and rs1890908 were significantly associated with overall survival, and patients with AG/GG genotypes of SYNE2 gene had a worse overall survival (P = 0.001, P = 0.002). Our findings indicate that variants of EGFR and SYNE2 play an important role in p21 regulation and are associated with the clinical outcome of HBV-related HCC in a TP53-indenpdent manner.
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Affiliation(s)
- Chuangye Han
- Department of Hepatobiliary Surgery, the First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi Province, China
| | - Xiwen Liao
- Department of Hepatobiliary Surgery, the First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi Province, China
| | - Wei Qin
- Department of Hepatobiliary Surgery, the First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi Province, China
| | - Long Yu
- Department of Hepatobiliary Surgery, the First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi Province, China
| | - Xiaoguang Liu
- Department of Hepatobiliary Surgery, the First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi Province, China
| | - Gang Chen
- Department of Pathology, the First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi Province, China
| | - Zhengtao Liu
- Department of Hepatobiliary Surgery, the First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi Province, China
| | - Sicong Lu
- Department of Hepatobiliary Surgery, the First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi Province, China
| | - Zhiwei Chen
- Department of Hepatobiliary Surgery, the First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi Province, China
| | - Hao Su
- Department of Hepatobiliary Surgery, the First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi Province, China
| | - Guangzhi Zhu
- Department of Hepatobiliary Surgery, the First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi Province, China
| | - Zili Lu
- Department of Pathology, the First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi Province, China
| | - Zhiming Liu
- Department of General Surgery, the First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi Province, China
| | - Xue Qin
- Department of Clinical Laboratory, the First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi Province, China
| | - Ying Gui
- Department of Clinical laboratory center, the First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi Province, China
| | - Zengnan Mo
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, 530021, Guangxi Province, China
| | - Lequn Li
- Department of Hepatobiliary Surgery, Affiliated Tumor Hospital of Guangxi Medical University, Nanning, 530021, Guangxi Province, China
| | - Tao Peng
- Department of Hepatobiliary Surgery, the First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi Province, China
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20
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Zhang Q, Minaisah RM, Ferraro E, Li C, Porter LJ, Zhou C, Gao F, Zhang J, Rajgor D, Autore F, Shanahan CM, Warren DT. N-terminal nesprin-2 variants regulate β-catenin signalling. Exp Cell Res 2016; 345:168-79. [PMID: 27321956 PMCID: PMC4948682 DOI: 10.1016/j.yexcr.2016.06.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 06/13/2016] [Accepted: 06/14/2016] [Indexed: 01/14/2023]
Abstract
The spatial compartmentalisation of biochemical signalling pathways is essential for cell function. Nesprins are a multi-isomeric family of proteins that have emerged as signalling scaffolds, herein, we investigate the localisation and function of novel nesprin-2 N-terminal variants. We show that these nesprin-2 variants display cell specific distribution and reside in both the cytoplasm and nucleus. Immunofluorescence microscopy revealed that nesprin-2 N-terminal variants colocalised with β-catenin at cell-cell junctions in U2OS cells. Calcium switch assays demonstrated that nesprin-2 and β-catenin are lost from cell-cell junctions in low calcium conditions whereas emerin localisation at the NE remained unaltered, furthermore, an N-terminal fragment of nesprin-2 was sufficient for cell-cell junction localisation and interacted with β-catenin. Disruption of these N-terminal nesprin-2 variants, using siRNA depletion resulted in loss of β-catenin from cell-cell junctions, nuclear accumulation of active β-catenin and augmented β-catenin transcriptional activity. Importantly, we show that U2OS cells lack nesprin-2 giant, suggesting that the N-terminal nesprin-2 variants regulate β-catenin signalling independently of the NE. Together, these data identify N-terminal nesprin-2 variants as novel regulators of β-catenin signalling that tether β-catenin to cell-cell contacts to inhibit β-catenin transcriptional activity.
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Affiliation(s)
- Qiuping Zhang
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King's College, SE5 9NU London, UK
| | - Rose-Marie Minaisah
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King's College, SE5 9NU London, UK
| | - Elisa Ferraro
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King's College, SE5 9NU London, UK
| | - Chen Li
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King's College, SE5 9NU London, UK
| | - Lauren J Porter
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King's College, SE5 9NU London, UK
| | - Can Zhou
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King's College, SE5 9NU London, UK
| | - Fang Gao
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King's College, SE5 9NU London, UK
| | - Junyi Zhang
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King's College, SE5 9NU London, UK
| | - Dipen Rajgor
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King's College, SE5 9NU London, UK
| | - Flavia Autore
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King's College, SE5 9NU London, UK
| | - Catherine M Shanahan
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King's College, SE5 9NU London, UK
| | - Derek T Warren
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King's College, SE5 9NU London, UK.
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21
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Kim DI, Birendra KC, Roux KJ. Making the LINC: SUN and KASH protein interactions. Biol Chem 2015; 396:295-310. [PMID: 25720065 DOI: 10.1515/hsz-2014-0267] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 01/20/2015] [Indexed: 01/15/2023]
Abstract
Cell nuclei are physically integrated with the cytoskeleton through the linker of nucleoskeleton and cytoskeleton (LINC) complex, a structure that spans the nuclear envelope to link the nucleoskeleton and cytoskeleton. Outer nuclear membrane KASH domain proteins and inner nuclear membrane SUN domain proteins interact to form the core of the LINC complex. In this review, we provide a comprehensive analysis of the reported protein-protein interactions for KASH and SUN domain proteins. This critical structure, directly connecting the genome with the rest of the cell, contributes to a myriad of cellular functions and, when perturbed, is associated with human disease.
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22
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Matsumoto A, Hieda M, Yokoyama Y, Nishioka Y, Yoshidome K, Tsujimoto M, Matsuura N. Global loss of a nuclear lamina component, lamin A/C, and LINC complex components SUN1, SUN2, and nesprin-2 in breast cancer. Cancer Med 2015; 4:1547-57. [PMID: 26175118 PMCID: PMC4618625 DOI: 10.1002/cam4.495] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 05/18/2015] [Accepted: 06/09/2015] [Indexed: 12/14/2022] Open
Abstract
Cancer cells exhibit a variety of features indicative of atypical nuclei. However, the molecular mechanisms underlying these phenomena remain to be elucidated. The linker of nucleoskeleton and cytoskeleton (LINC) complex, a nuclear envelope protein complex consisting mainly of the SUN and nesprin proteins, connects nuclear lamina and cytoskeletal filaments and helps to regulate the size and shape of the nucleus. Using immunohistology, we found that a nuclear lamina component, lamin A/C and all of the investigated LINC complex components, SUN1, SUN2, and nesprin-2, were downregulated in human breast cancer tissues. In the majority of cases, we observed lower expression levels of these analytes in samples' cancerous regions as compared to their cancer-associated noncancerous regions (in cancerous regions, percentage of tissue samples exhibiting low protein expression: lamin A/C, 85% [n = 73]; SUN1, 88% [n = 43]; SUN2, 74% [n = 43]; and nesprin-2, 79% [n = 53]). Statistical analysis showed that the frequencies of recurrence and HER2 expression were negatively correlated with lamin A/C expression (P < 0.05), and intrinsic subtype and ki-67 level were associated with nesprin-2 expression (P < 0.05). In addition, combinatorial analysis using the above four parameters showed that all patients exhibited reduced expression of at least one of four components despite the tumor's pathological classification. Furthermore, several cultured breast cancer cell lines expressed less SUN1, SUN2, nesprin-2 mRNA, and lamin A/C compared to noncancerous mammary gland cells. Together, these results suggest that the strongly reduced expression of LINC complex and nuclear lamina components may play fundamental pathological functions in breast cancer progression.
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Affiliation(s)
- Ayaka Matsumoto
- Graduate School of Medicine and Health Science, Osaka University, Suita, Japan
| | - Miki Hieda
- Graduate School of Medicine and Health Science, Osaka University, Suita, Japan
| | - Yuhki Yokoyama
- Graduate School of Medicine and Health Science, Osaka University, Suita, Japan
| | - Yu Nishioka
- Graduate School of Medicine and Health Science, Osaka University, Suita, Japan.,Present Institution, Carna Bioscience, Inc., Kobe, Japan
| | | | | | - Nariaki Matsuura
- Graduate School of Medicine and Health Science, Osaka University, Suita, Japan
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23
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Chang W, Worman HJ, Gundersen GG. Accessorizing and anchoring the LINC complex for multifunctionality. ACTA ACUST UNITED AC 2015; 208:11-22. [PMID: 25559183 PMCID: PMC4284225 DOI: 10.1083/jcb.201409047] [Citation(s) in RCA: 210] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The linker of nucleoskeleton and cytoskeleton (LINC) complex, composed of outer and inner nuclear membrane Klarsicht, ANC-1, and Syne homology (KASH) and Sad1 and UNC-84 (SUN) proteins, respectively, connects the nucleus to cytoskeletal filaments and performs diverse functions including nuclear positioning, mechanotransduction, and meiotic chromosome movements. Recent studies have shed light on the source of this diversity by identifying factors associated with the complex that endow specific functions as well as those that differentially anchor the complex within the nucleus. Additional diversity may be provided by accessory factors that reorganize the complex into higher-ordered arrays. As core components of the LINC complex are associated with several diseases, understanding the role of accessory and anchoring proteins could provide insights into pathogenic mechanisms.
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Affiliation(s)
- Wakam Chang
- Department of Pathology and Cell Biology and Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY 10032
| | - Howard J Worman
- Department of Pathology and Cell Biology and Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY 10032 Department of Pathology and Cell Biology and Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY 10032
| | - Gregg G Gundersen
- Department of Pathology and Cell Biology and Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY 10032
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24
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Warren DT, Tajsic T, Porter LJ, Minaisah RM, Cobb A, Jacob A, Rajgor D, Zhang QP, Shanahan CM. Nesprin-2-dependent ERK1/2 compartmentalisation regulates the DNA damage response in vascular smooth muscle cell ageing. Cell Death Differ 2015; 22:1540-50. [PMID: 25744025 PMCID: PMC4532777 DOI: 10.1038/cdd.2015.12] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 12/19/2014] [Accepted: 01/21/2015] [Indexed: 11/30/2022] Open
Abstract
Prelamin A accumulation and persistent DNA damage response (DDR) are hallmarks of vascular smooth muscle cell (VSMC) ageing and dysfunction. Although prelamin A is proposed to interfere with DNA repair, our understanding of the crosstalk between prelamin A and the repair process remains limited. The extracellular signal-regulated kinases 1 and 2 (ERK1/2) have emerged as key players in the DDR and are known to enhance ataxia telangiectasia-mutated protein (ATM) activity at DNA lesions, and in this study, we identified a novel relationship between prelamin A accumulation and ERK1/2 nuclear compartmentalisation during VSMC ageing. We show both prelamin A accumulation and increased DNA damage occur concomitantly, before VSMC replicative senescence, and induce the localisation of ERK1/2 to promyelocytic leukaemia protein nuclear bodies (PML NBs) at the sites of DNA damage via nesprin-2 and lamin A interactions. Importantly, VSMCs treated with DNA damaging agents also displayed prelamin A accumulation and ERK compartmentalisation at PML NBs, suggesting that prelamin A and nesprin-2 are novel components of the DDR. In support of this, disruption of ERK compartmentalisation at PML NBs, by either depletion of nesprin-2 or lamins A/C, resulted in the loss of ATM from DNA lesions. However, ATM signalling and DNA repair remained intact after lamins A/C depletion, whereas nesprin-2 disruption ablated downstream Chk2 activation and induced genomic instability. We conclude that lamins A/C and PML act as scaffolds to organise DNA-repair foci and compartmentalise nesprin-2/ERK signalling. However, nesprin-2/ERK signalling fidelity, but not their compartmentalisation at PML NBs, is essential for efficient DDR in VSMCs.
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Affiliation(s)
- D T Warren
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King's College London, London SE5 9NU, UK
| | - T Tajsic
- Department of Medicine, Addenbrooke's Hospital, Cambridge CB2 2QQ, UK
| | - L J Porter
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King's College London, London SE5 9NU, UK
| | - R M Minaisah
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King's College London, London SE5 9NU, UK
| | - A Cobb
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King's College London, London SE5 9NU, UK
| | - A Jacob
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King's College London, London SE5 9NU, UK
| | - D Rajgor
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King's College London, London SE5 9NU, UK
| | - Q P Zhang
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King's College London, London SE5 9NU, UK
| | - C M Shanahan
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King's College London, London SE5 9NU, UK
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25
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Rajgor D, Mellad JA, Soong D, Rattner JB, Fritzler MJ, Shanahan CM. Mammalian microtubule P-body dynamics are mediated by nesprin-1. ACTA ACUST UNITED AC 2014; 205:457-75. [PMID: 24862572 PMCID: PMC4033771 DOI: 10.1083/jcb.201306076] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Nesprins are a multi-isomeric family of spectrin-repeat (SR) proteins, predominantly known as nuclear envelope scaffolds. However, isoforms that function beyond the nuclear envelope remain poorly examined. Here, we characterize p50(Nesp1), a 50-kD isoform that localizes to processing bodies (PBs), where it acts as a microtubule-associated protein capable of linking mRNP complexes to microtubules. Overexpression of dominant-negative p50(Nesp1) caused Rck/p54, but not GW182, displacement from microtubules, resulting in reduced PB movement and cross talk with stress granules (SGs). These cells disassembled canonical SGs induced by sodium arsenite, but not those induced by hydrogen peroxide, leading to cell death and revealing PB-microtubule attachment is required for hydrogen peroxide-induced SG anti-apoptotic functions. Furthermore, p50(Nesp1) was required for miRNA-mediated silencing and interacted with core miRISC silencers Ago2 and Rck/p54 in an RNA-dependent manner and with GW182 in a microtubule-dependent manner. These data identify p50(Nesp1) as a multi-functional PB component and microtubule scaffold necessary for RNA granule dynamics and provides evidence for PB and SG micro-heterogeneity.
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Affiliation(s)
- Dipen Rajgor
- Cardiovascular Division, BHF Centre of Excellence, James Black Centre, King's College London, London SE5 9NU, England, UK
| | - Jason A Mellad
- Cardiovascular Division, BHF Centre of Excellence, James Black Centre, King's College London, London SE5 9NU, England, UK
| | - Daniel Soong
- Cardiovascular Division, BHF Centre of Excellence, James Black Centre, King's College London, London SE5 9NU, England, UK
| | - Jerome B Rattner
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary T2N 4N1, Alberta, Canada
| | - Marvin J Fritzler
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary T2N 4N1, Alberta, Canada
| | - Catherine M Shanahan
- Cardiovascular Division, BHF Centre of Excellence, James Black Centre, King's College London, London SE5 9NU, England, UK
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26
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The Nesprin family member ANC-1 regulates synapse formation and axon termination by functioning in a pathway with RPM-1 and β-Catenin. PLoS Genet 2014; 10:e1004481. [PMID: 25010424 PMCID: PMC4091705 DOI: 10.1371/journal.pgen.1004481] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Accepted: 05/16/2014] [Indexed: 01/08/2023] Open
Abstract
Mutations in Nesprin-1 and 2 (also called Syne-1 and 2) are associated with numerous diseases including autism, cerebellar ataxia, cancer, and Emery-Dreifuss muscular dystrophy. Nesprin-1 and 2 have conserved orthologs in flies and worms called MSP-300 and abnormal nuclear Anchorage 1 (ANC-1), respectively. The Nesprin protein family mediates nuclear and organelle anchorage and positioning. In the nervous system, the only known function of Nesprin-1 and 2 is in regulation of neurogenesis and neural migration. It remains unclear if Nesprin-1 and 2 regulate other functions in neurons. Using a proteomic approach in C. elegans, we have found that ANC-1 binds to the Regulator of Presynaptic Morphology 1 (RPM-1). RPM-1 is part of a conserved family of signaling molecules called Pam/Highwire/RPM-1 (PHR) proteins that are important regulators of neuronal development. We have found that ANC-1, like RPM-1, regulates axon termination and synapse formation. Our genetic analysis indicates that ANC-1 functions via the β-catenin BAR-1, and the ANC-1/BAR-1 pathway functions cell autonomously, downstream of RPM-1 to regulate neuronal development. Further, ANC-1 binding to the nucleus is required for its function in axon termination and synapse formation. We identify variable roles for four different Wnts (LIN-44, EGL-20, CWN-1 and CWN-2) that function through BAR-1 to regulate axon termination. Our study highlights an emerging, broad role for ANC-1 in neuronal development, and unveils a new and unexpected mechanism by which RPM-1 functions. The molecular mechanisms that underpin synapse formation and axon termination are central to forming a functional, fully connected nervous system. The PHR proteins are important regulators of neuronal development that function in axon outgrowth and termination, as well as synapse formation. Here we describe the discovery of a novel, conserved pathway that is positively regulated by the C. elegans PHR protein, RPM-1. This pathway is composed of RPM-1, ANC-1 (a Nesprin family protein), and BAR-1 (a canonical β-catenin). Nesprins, such as ANC-1, regulate nuclear anchorage and positioning in multinuclear cells. We now show that in neurons, ANC-1 regulates neuronal development by positively regulating BAR-1. Thus, Nesprins are multi-functional proteins that act through β-catenin to regulate neuronal development, and link the nucleus to the actin cytoskeleton in order to mediate nuclear anchorage and positioning in multi-nuclear cells.
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27
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Duong NT, Morris GE, Lam LT, Zhang Q, Sewry CA, Shanahan CM, Holt I. Nesprins: tissue-specific expression of epsilon and other short isoforms. PLoS One 2014; 9:e94380. [PMID: 24718612 PMCID: PMC3981789 DOI: 10.1371/journal.pone.0094380] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 03/15/2014] [Indexed: 11/22/2022] Open
Abstract
Nesprin-1-giant and nesprin-2-giant regulate nuclear positioning by the interaction of their C-terminal KASH domains with nuclear membrane SUN proteins and their N-terminal calponin-homology domains with cytoskeletal actin. A number of short isoforms lacking the actin-binding domains are produced by internal promotion. We have evaluated the significance of these shorter isoforms using quantitative RT-PCR and western blotting with site-specific monoclonal antibodies. Within a complete map of nesprin isoforms, we describe two novel nesprin-2 epsilon isoforms for the first time. Epsilon isoforms are similar in size and structure to nesprin-1-alpha. Expression of nesprin isoforms was highly tissue-dependent. Nesprin-2-epsilon-1 was found in early embryonic cells, while nesprin-2-epsilon-2 was present in heart and other adult tissues, but not skeletal muscle. Some cell lines lack shorter isoforms and express only one of the two nesprin genes, suggesting that either of the giant nesprins is sufficient for basic cell functions. For the first time, localisation of endogenous nesprin away from the nuclear membrane was shown in cells where removal of the KASH domain by alternative splicing occurs. By distinguishing between degradation products and true isoforms on western blots, it was found that previously-described beta and gamma isoforms are expressed either at only low levels or with a limited tissue distribution. Two of the shortest alpha isoforms, nesprin-1-alpha-2 and nesprin-2-alpha-1, were found almost exclusively in cardiac and skeletal muscle and a highly conserved and alternatively-spliced exon, available in both nesprin genes, was always included in these tissues. These "muscle-specific" isoforms are thought to form a complex with emerin and lamin A/C at the inner nuclear membrane and mutations in all three proteins cause Emery-Dreifuss muscular dystrophy and/or inherited dilated cardiomyopathy, disorders in which only skeletal muscle and/or heart are affected.
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Affiliation(s)
- Nguyen Thuy Duong
- Wolfson Centre for Inherited Neuromuscular Disease, RJAH Orthopaedic Hospital, Oswestry, United Kingdom
- Institute of Genome Research (IGR), Vietnam Academy of Science and Technology (VAST), Hanoi, Vietnam
| | - Glenn E. Morris
- Wolfson Centre for Inherited Neuromuscular Disease, RJAH Orthopaedic Hospital, Oswestry, United Kingdom
- Institute for Science and Technology in Medicine, Keele University, Staffordshire, United Kingdom
| | - Le Thanh Lam
- Wolfson Centre for Inherited Neuromuscular Disease, RJAH Orthopaedic Hospital, Oswestry, United Kingdom
| | - Qiuping Zhang
- Cardiovascular Division, James Black Centre, King’s College, London, United Kingdom
| | - Caroline A. Sewry
- Wolfson Centre for Inherited Neuromuscular Disease, RJAH Orthopaedic Hospital, Oswestry, United Kingdom
- Dubowitz Neuromuscular Centre, Institute for Child Health and Great Ormond Street Hospital, London, United Kingdom
| | | | - Ian Holt
- Wolfson Centre for Inherited Neuromuscular Disease, RJAH Orthopaedic Hospital, Oswestry, United Kingdom
- Institute for Science and Technology in Medicine, Keele University, Staffordshire, United Kingdom
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28
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Neumann S, Noegel AA. Nesprins in Cell Stability and Migration. CANCER BIOLOGY AND THE NUCLEAR ENVELOPE 2014; 773:491-504. [DOI: 10.1007/978-1-4899-8032-8_22] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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29
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Alam S, Lovett DB, Dickinson RB, Roux KJ, Lele TP. Nuclear forces and cell mechanosensing. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2014; 126:205-15. [PMID: 25081619 DOI: 10.1016/b978-0-12-394624-9.00008-7] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Cells respond to mechanical signals, but the subcellular mechanisms are not well understood. The nucleus has recently emerged as an important mechanosensory organelle in the cell, as it is intimately connected to the cytoskeleton. Mechanical forces applied to cells that act on membrane-embedded receptors are transmitted through the cytoskeleton to the nuclear surface. Interfering with linkers of the nucleus to the cytoskeleton causes defects in cell mechanosensing and cell function. In this chapter, we discuss recent work in this area, highlighting the role that the nuclear linkages with the cytoskeleton play in cellular mechanotransduction.
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Affiliation(s)
- Samer Alam
- Department of Chemical Engineering, University of Florida, Gainesville, Florida, USA
| | - David B Lovett
- Department of Chemical Engineering, University of Florida, Gainesville, Florida, USA
| | - Richard B Dickinson
- Department of Chemical Engineering, University of Florida, Gainesville, Florida, USA
| | - Kyle J Roux
- Sanford Children's Health Research Center, University of South Dakota, Sioux Falls, South Dakota, USA
| | - Tanmay P Lele
- Department of Chemical Engineering, University of Florida, Gainesville, Florida, USA
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30
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Cartwright S, Karakesisoglou I. Nesprins in health and disease. Semin Cell Dev Biol 2013; 29:169-79. [PMID: 24374011 DOI: 10.1016/j.semcdb.2013.12.010] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Revised: 11/29/2013] [Accepted: 12/15/2013] [Indexed: 01/20/2023]
Abstract
LINC (Linker of Nucleoskeleton and Cytoskeleton) complex is an evolutionary conserved structure that spans the entire nuclear envelope (NE), and integrates the nuclear interior with the cytoskeleton, in order to support a diverse array of fundamental biological processes. Key components of the LINC complex are the nesprins (Nuclear Envelope SPectrin Repeat proteINS) that were initially described as large integral NE proteins. However, nesprin genes are complex and generate many variants, which occupy various sub-cellular compartments suggesting additional functions. Hence, the potential involvement of nesprins in disease has expanded immensely on what we already know. That is, nesprins are implicated in diseases such as cancer, myopathies, arthrogryposis, neurological disorders and hearing loss. Here we review nesprins by providing an in depth account of their structure, molecular interactions and cellular functions with relevance to their potential roles in disease. Specifically, we speculate about possible pathomechanisms underlying nesprin-associated diseases.
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Affiliation(s)
- Sarah Cartwright
- School of Biological and Biomedical Sciences, University of Durham, Durham DH1 3LE, UK
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31
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Holle AW, Tang X, Vijayraghavan D, Vincent LG, Fuhrmann A, Choi YS, del Álamo JC, Engler AJ. In situ mechanotransduction via vinculin regulates stem cell differentiation. Stem Cells 2013; 31:2467-77. [PMID: 23897765 PMCID: PMC3833960 DOI: 10.1002/stem.1490] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 07/24/2013] [Accepted: 07/10/2013] [Indexed: 12/15/2022]
Abstract
Human mesenchymal stem cell (hMSC) proliferation, migration, and differentiation have all been linked to extracellular matrix stiffness, yet the signaling pathway(s) that are necessary for mechanotransduction remain unproven. Vinculin has been implicated as a mechanosensor in vitro, but here we demonstrate its ability to also regulate stem cell behavior, including hMSC differentiation. RNA interference-mediated vinculin knockdown significantly decreased stiffness-induced MyoD, a muscle transcription factor, but not Runx2, an osteoblast transcription factor, and impaired stiffness-mediated migration. A kinase binding accessibility screen predicted a cryptic MAPK1 signaling site in vinculin which could regulate these behaviors. Indeed, reintroduction of vinculin domains into knocked down cells indicated that MAPK1 binding site-containing vinculin constructs were necessary for hMSC expression of MyoD. Vinculin knockdown does not appear to interfere with focal adhesion assembly, significantly alter adhesive properties, or diminish cell traction force generation, indicating that its knockdown only adversely affected MAPK1 signaling. These data provide some of the first evidence that a force-sensitive adhesion protein can regulate stem cell fate.
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Affiliation(s)
- Andrew W. Holle
- Department of Bioengineering, University of California, San Diego; La Jolla, CA 92093, USA
| | - Xinyi Tang
- Department of Bioengineering, University of California, San Diego; La Jolla, CA 92093, USA
| | - Deepthi Vijayraghavan
- Department of Bioengineering, University of California, San Diego; La Jolla, CA 92093, USA
| | - Ludovic G. Vincent
- Department of Bioengineering, University of California, San Diego; La Jolla, CA 92093, USA
| | - Alexander Fuhrmann
- Department of Bioengineering, University of California, San Diego; La Jolla, CA 92093, USA
| | - Yu Suk Choi
- Department of Bioengineering, University of California, San Diego; La Jolla, CA 92093, USA
| | - Juan C. del Álamo
- Department of Mechanical and Aerospace Engineering, University of California, San Diego; La Jolla, CA 92093, USA
| | - Adam J. Engler
- Department of Bioengineering, University of California, San Diego; La Jolla, CA 92093, USA
- Department of Biomedical Sciences Program, University of California, San Diego; La Jolla, CA 92093, USA
- Sanford Consortium for Regenerative Medicine; La Jolla, CA 92037, USA
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32
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Schoppmann SF, Vinatzer U, Popitsch N, Mittlböck M, Liebmann-Reindl S, Jomrich G, Streubel B, Birner P. Novel Clinically Relevant Genes in Gastrointestinal Stromal Tumors Identified by Exome Sequencing. Clin Cancer Res 2013; 19:5329-39. [DOI: 10.1158/1078-0432.ccr-12-3863] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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33
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Osorio DS, Gomes ER. The contemporary nucleus: A trip down memory lane. Biol Cell 2013; 105:430-41. [DOI: 10.1111/boc.201300009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 06/21/2013] [Indexed: 01/12/2023]
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34
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Abstract
Nuclear envelope
spectrin-repeat
proteins (Nesprins), are a novel family of
nuclear and cytoskeletal proteins with rapidly expanding roles as intracellular scaffolds
and linkers. Originally described as proteins that localise to the nuclear envelope (NE)
and establish nuclear-cytoskeletal connections, nesprins have now been found to comprise a
diverse spectrum of tissue specific isoforms that localise to multiple sub-cellular
compartments. Here, we describe how nesprins are necessary in maintaining cellular
architecture by acting as essential scaffolds and linkers at both the NE and other
sub-cellular domains. More importantly, we speculate how nesprin mutations may disrupt
tissue specific nesprin scaffolds and explain the tissue specific nature of many
nesprin-associated diseases, including laminopathies.
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35
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Hwang Y, Kumar P, Barakat AI. Intracellular regulation of cell signaling cascades: how location makes a difference. J Math Biol 2013; 69:213-42. [PMID: 23774809 DOI: 10.1007/s00285-013-0701-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Revised: 06/01/2013] [Indexed: 11/26/2022]
Abstract
Organelles such as endosomes and the Golgi apparatus play a critical role in regulating signal transmission to the nucleus. Recent experiments have shown that appropriate positioning of these organelles within the intracellular space is critical for effective signal regulation. To understand the mechanism behind this observation, we consider a reaction-diffusion model of an intracellular signaling cascade and investigate the effect on the signaling of intracellular regulation in the form of a small release of phosphorylated signaling protein, kinase, and/or phosphatase. Variational analysis is applied to characterize the most effective regions for the localization of this intracellular regulation. The results demonstrate that signals reaching the nucleus are most effectively regulated by localizing the release of phosphorylated substrate protein and kinase near the nucleus. Phosphatase release, on the other hand, is nearly equally effective throughout the intracellular space. The effectiveness of the intracellular regulation is affected strongly by the characteristics of signal propagation through the cascade. For signals that are amplified as they propagate through the cascade, reactions in the upstream levels of the cascade exhibit much larger sensitivities to regulation by release of phosphorylated substrate protein and kinase than downstream reactions. On the other hand, for signals that decay through the cascade, downstream reactions exhibit larger sensitivity than upstream reactions. For regulation by phosphatase release, all reactions within the cascade show large sensitivity for amplified signals but lose this sensitivity for decaying signals. We use the analysis to develop a simple model of endosome-mediated regulation of cell signaling. The results demonstrate that signal regulation by the modeled endosome is most effective when the endosome is positioned in the vicinity of the nucleus. The present findings may explain at least in part why endosomes in many cell types localize near the nucleus.
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Affiliation(s)
- Yongyun Hwang
- Department of Applied Mathematics and Theoretical Physics (DAMTP), University of Cambridge, Cambridge, UK,
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36
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Rothballer A, Kutay U. The diverse functional LINCs of the nuclear envelope to the cytoskeleton and chromatin. Chromosoma 2013; 122:415-29. [PMID: 23736899 PMCID: PMC3777164 DOI: 10.1007/s00412-013-0417-x] [Citation(s) in RCA: 101] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Revised: 05/14/2013] [Accepted: 05/15/2013] [Indexed: 11/30/2022]
Abstract
The nuclear envelope (NE) is connected to the different types of cytoskeletal elements by linker of nucleoskeleton and cytoskeleton (LINC) complexes. LINC complexes exist from yeast to humans, and have preserved their general architecture throughout evolution. They are composed of SUN and KASH domain proteins of the inner and the outer nuclear membrane, respectively. These SUN–KASH bridges are used for the transmission of forces across the NE and support diverse biological processes. Here, we review the function of SUN and KASH domain proteins in various unicellular and multicellular species. Specifically, we discuss their influence on nuclear morphology and cytoskeletal organization. Further, emphasis is given on the role of LINC complexes in nuclear anchorage and migration as well as in genome organization.
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Affiliation(s)
- Andrea Rothballer
- Department of Biology, Institute of Biochemistry, ETH Zurich, Schafmattstrasse 18, 8093 Zurich, Switzerland
| | - Ulrike Kutay
- Department of Biology, Institute of Biochemistry, ETH Zurich, Schafmattstrasse 18, 8093 Zurich, Switzerland
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37
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Autore F, Pfuhl M, Quan X, Williams A, Roberts RG, Shanahan CM, Fraternali F. Large-scale modelling of the divergent spectrin repeats in nesprins: giant modular proteins. PLoS One 2013; 8:e63633. [PMID: 23671687 PMCID: PMC3646009 DOI: 10.1371/journal.pone.0063633] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Accepted: 04/09/2013] [Indexed: 11/29/2022] Open
Abstract
Nesprin-1 and nesprin-2 are nuclear envelope (NE) proteins characterized by a common structure of an SR (spectrin repeat) rod domain and a C-terminal transmembrane KASH [Klarsicht-ANC-Syne-homology] domain and display N-terminal actin-binding CH (calponin homology) domains. Mutations in these proteins have been described in Emery-Dreifuss muscular dystrophy and attributed to disruptions of interactions at the NE with nesprins binding partners, lamin A/C and emerin. Evolutionary analysis of the rod domains of the nesprins has shown that they are almost entirely composed of unbroken SR-like structures. We present a bioinformatical approach to accurate definition of the boundaries of each SR by comparison with canonical SR structures, allowing for a large-scale homology modelling of the 74 nesprin-1 and 56 nesprin-2 SRs. The exposed and evolutionary conserved residues identify important pbs for protein-protein interactions that can guide tailored binding experiments. Most importantly, the bioinformatics analyses and the 3D models have been central to the design of selected constructs for protein expression. 1D NMR and CD spectra have been performed of the expressed SRs, showing a folded, stable, high content α-helical structure, typical of SRs. Molecular Dynamics simulations have been performed to study the structural and elastic properties of consecutive SRs, revealing insights in the mechanical properties adopted by these modules in the cell.
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Affiliation(s)
- Flavia Autore
- Randall Division of Cell and Molecular Biophysics, School of Physical Sciences and Engineering, King's College London, London, United Kingdom
- Division of Cardiovascular Medicine, BHF Centre of Research Excellence, King's College London, London, United Kingdom
| | - Mark Pfuhl
- Randall Division of Cell and Molecular Biophysics, School of Physical Sciences and Engineering, King's College London, London, United Kingdom
| | - Xueping Quan
- Randall Division of Cell and Molecular Biophysics, School of Physical Sciences and Engineering, King's College London, London, United Kingdom
| | - Aisling Williams
- Randall Division of Cell and Molecular Biophysics, School of Physical Sciences and Engineering, King's College London, London, United Kingdom
- Division of Cardiovascular Medicine, BHF Centre of Research Excellence, King's College London, London, United Kingdom
| | - Roland G. Roberts
- Division of Medical and Molecular Genetics, Kings College London, Guy's Hospital, London, United Kingdom
| | - Catherine M. Shanahan
- Division of Cardiovascular Medicine, BHF Centre of Research Excellence, King's College London, London, United Kingdom
| | - Franca Fraternali
- Randall Division of Cell and Molecular Biophysics, School of Physical Sciences and Engineering, King's College London, London, United Kingdom
- The Thomas Young Centre for Theory and Simulation of Materials, London, United Kingdom
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38
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Abstract
The nucleus is the largest organelle and is commonly depicted in the center of the cell. Yet during cell division, migration, and differentiation, it frequently moves to an asymmetric position aligned with cell function. We consider the toolbox of proteins that move and anchor the nucleus within the cell and how forces generated by the cytoskeleton are coupled to the nucleus to move it. The significance of proper nuclear positioning is underscored by numerous diseases resulting from genetic alterations in the toolbox proteins. Finally, we discuss how nuclear position may influence cellular organization and signaling pathways.
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Affiliation(s)
- Gregg G Gundersen
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
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39
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Dreier B, Raghunathan VK, Russell P, Murphy CJ. Focal adhesion kinase knockdown modulates the response of human corneal epithelial cells to topographic cues. Acta Biomater 2012; 8:4285-94. [PMID: 22813850 DOI: 10.1016/j.actbio.2012.07.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Revised: 06/15/2012] [Accepted: 07/10/2012] [Indexed: 11/17/2022]
Abstract
A rapidly expanding literature broadly documents the impact of biophysical cues on cellular behaviors. In spite of increasing research efforts in this field, the underlying signaling processes are poorly understood. One of the candidate molecules for being involved in mechanotransduction is focal adhesion kinase (FAK). To examine the role of FAK in the response of immortalized human corneal epithelial (hTCEpi) cells to topographic cues, FAK was depleted by siRNA transfection. Contrary to expectations, FAK knockdown resulted in an enhanced response with a greater number of hTCEpi cells aligned to the long axis of anisotropically ordered surface ridges and grooves. Both underlying topographic features and FAK depletion modulated the migration of corneal epithelial cells. The impact of FAK knockdown on both migration and alignment varied depending on the topographic cues to which the cells were exposed, with the most significant change observed on the biologically relevant size scale (400nm). Additionally, a change in expression of genes encoding perinuclear Nesprins 1 and 2 (SYNE1, 2) was observed in response to topographic cues. SYNE1/2 expression was also altered by FAK depletion, suggesting that these proteins might represent a link between cytosolic and nuclear signaling processes. The data presented here have relevance to our understanding of the fundamental processes involved in corneal cell behavior to topographic cues. These results highlight the importance of incorporating biophysical cues in the conduction of in vitro studies and into the design and fabrication of implantable prosthetics.
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Affiliation(s)
- Britta Dreier
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, One Shields Avenue, University of California Davis, Davis, CA 95616, USA
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40
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Rajgor D, Mellad JA, Autore F, Zhang Q, Shanahan CM. Multiple novel nesprin-1 and nesprin-2 variants act as versatile tissue-specific intracellular scaffolds. PLoS One 2012; 7:e40098. [PMID: 22768332 PMCID: PMC3388047 DOI: 10.1371/journal.pone.0040098] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Accepted: 05/31/2012] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Nesprins (Nuclear envelope spectrin-repeat proteins) are a novel family of giant spectrin-repeat containing proteins. The nesprin-1 and nesprin-2 genes consist of 146 and 116 exons which encode proteins of ∼1mDa and ∼800 kDa is size respectively when all the exons are utilised in translation. However emerging data suggests that the nesprins have multiple alternative start and termination sites throughout their genes allowing the generation of smaller isoforms. RESULTS In this study we set out to identify novel alternatively transcribed nesprin variants by screening the EST database and by using RACE analysis to identify cDNA ends. These two methods provided potential hits for alternative start and termination sites that were validated by PCR and DNA sequencing. We show that these alternative sites are not only expressed in a tissue specific manner but by combining different sites together it is possible to create a wide array of nesprin variants. By cloning and expressing small novel nesprin variants into human fibroblasts and U2OS cells we show localization to actin stress-fibres, focal adhesions, microtubules, the nucleolus, nuclear matrix and the nuclear envelope (NE). Furthermore we show that the sub-cellular localization of individual nesprin variants can vary depending on the cell type, suggesting any single nesprin variant may have different functions in different cell types. CONCLUSIONS These studies suggest nesprins act as highly versatile tissue specific intracellular protein scaffolds and identify potential novel functions for nesprins beyond cytoplasmic-nuclear coupling. These alternate functions may also account for the diverse range of disease phenotypes observed when these genes are mutated.
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Affiliation(s)
- Dipen Rajgor
- Cardiovascular Division, James Black Centre, King’s College London, London, United Kingdom
| | - Jason A. Mellad
- Cardiovascular Division, James Black Centre, King’s College London, London, United Kingdom
| | - Flavia Autore
- The Randall Division of Cell and Molecular Biophysics, New Hunt’s House, King’s College London, London, United Kingdom
| | - Qiuping Zhang
- Cardiovascular Division, James Black Centre, King’s College London, London, United Kingdom
| | - Catherine M. Shanahan
- Cardiovascular Division, James Black Centre, King’s College London, London, United Kingdom
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41
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Rashmi RN, Eckes B, Glöckner G, Groth M, Neumann S, Gloy J, Sellin L, Walz G, Schneider M, Karakesisoglou I, Eichinger L, Noegel AA. The nuclear envelope protein Nesprin-2 has roles in cell proliferation and differentiation during wound healing. Nucleus 2012; 3:172-86. [PMID: 22198684 PMCID: PMC3383573 DOI: 10.4161/nucl.19090] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Nesprin-2, a type II transmembrane protein of the nuclear envelope, is a component of the LINC complex that connects the nuclear lamina with the actin cytoskeleton. To elucidate its physiological role we studied wound healing in Nesprin-2 Giant deficient mice and found that a loss of the protein affected wound healing particularly at later stages during fibroblast differentiation and keratinocyte proliferation leading to delayed wound closure. We identified altered expression and localization of transcription factors as one of the underlying mechanisms. Furthermore, the actin cytoskeleton which surrounds the nucleus was altered and keratinocyte migration was slowed down and focal adhesion formation enhanced. We also uncovered a new activity of Nesprin-2. When we probed for an interaction of Nesprin-2 Giant with chromatin we observed in ChIP Seq experiments an association of the protein with heterochromatic and centromeric DNA. Through this activity Nesprin-2 can affect the nuclear landscape and gene regulation. Our findings suggest functions for Nesprin-2 at the nuclear envelope (NE) in gene regulation and in regulation of the actin cytoskeleton which impact on wound healing.
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Affiliation(s)
- R N Rashmi
- Institute of Biochemistry I, Medical Faculty, University of Cologne, Cologne, Germany
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42
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Nucleocytoplasmic shuttling of cytoskeletal proteins: molecular mechanism and biological significance. Int J Cell Biol 2011; 2012:494902. [PMID: 22229032 PMCID: PMC3249633 DOI: 10.1155/2012/494902] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Revised: 10/03/2011] [Accepted: 10/06/2011] [Indexed: 01/04/2023] Open
Abstract
Various nuclear functional complexes contain cytoskeletal proteins as regulatory subunits; for example, nuclear actin participates in transcriptional complexes, and actin-related proteins are integral to chromatin remodeling complexes. Nuclear complexes such as these are involved in both basal and adaptive nuclear functions. In addition to nuclear import via classical nuclear transport pathways or passive diffusion, some large cytoskeletal proteins spontaneously migrate into the nucleus in a karyopherin-independent manner. The balance of nucleocytoplasmic distribution of such proteins can be altered by several factors, such as import versus export, or capture and release by complexes. The resulting accumulation or depletion of the nuclear populations thereby enhances or attenuates their nuclear functions. We propose that such molecular dynamics constitute a form of cytoskeleton-modulated regulation of nuclear functions which is mediated by the translocation of cytoskeletal components in and out of the nucleus.
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43
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Osman AM, van Loveren H. Phosphoproteomic analysis of mouse thymoma cells treated with tributyltin oxide: TBTO affects proliferation and energy sensing pathways. Toxicol Sci 2011; 126:84-100. [PMID: 22174045 DOI: 10.1093/toxsci/kfr333] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We report the results of phosphoproteomic analysis of mouse thymoma cells treated with tributyltin oxide (TBTO), an immunotoxic compound. After cell lysis, phosphoproteins were isolated using Phosphoprotein Purification Kit, separated by SDS-PAGE and subsequently digested with trypsin. Phosphopeptides were enriched employing titanium dioxide, and the obtained fractions were analyzed by nano-LC-MS/MS. A total of 160 phosphoproteins and 328 phosphorylation sites were identified in thymoma cells. Among the differentially phosphorylated proteins identified in TBTO-treated cells were key enzymes, which catalyze rate-limiting steps in pathways that are sensitive to cellular energy status. These proteins included acetyl-CoA carboxylase isoform 1, which catalyzes the rate-limiting step of fatty acid synthesis. Another enzyme was glutamine: fructose-6-phosphate amidotransferase, GFAT1, the first and rate-limiting enzyme for the hexoamine synthesis pathway. Pyruvate dehydrogenase (PDH), a multicomplex enzyme that catalyzes the rate-limiting step of aerobic oxidation of fuel carbohydrates, was identified in both TBTO-treated and control cells; however, phosphorylation at residue S293, known to inhibit PDH activity, was identified only in control cells. A lower expression level of ribosomal protein S6 kinase 1, a downstream kinase of the mammalian target of rapamycin signaling pathway implicated in protein synthesis through phosphorylation of 40 ribosomal S6, was observed in the treated cells. Giant kinases like AMP-activated protein kinase (AMPK) and cAMP-dependent protein kinase (PKAR1A), which are known to mediate the phosphorylation of these enzymes, were identified in TBTO-treated cells. Downregulation of proteins, such as MAPK, matrin-3 and ribonucleotide reductase, subunit RRM2, which are implicated in cell proliferation, was also observed in TBTO-treated cells. Together, the results show that TBTO affects proliferation and energy sensor pathways.
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Affiliation(s)
- Ahmed M Osman
- National Institute for Public Health and the Environment (RIVM), NL-3720 BA Bilthoven, The Netherlands.
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44
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Warren DT, Shanahan CM. Defective DNA-damage repair induced by nuclear lamina dysfunction is a key mediator of smooth muscle cell aging. Biochem Soc Trans 2011; 39:1780-5. [PMID: 22103525 DOI: 10.1042/bst20110703] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Accumulation of DNA damage is a major driving force of normal cellular aging and has recently been demonstrated to hasten the development of vascular diseases such as atherosclerosis. VSMCs (vascular smooth muscle cells) are essential for vessel wall integrity and repair, and maintenance of their proliferative capacity is essential for vascular health. The signalling pathways that determine VSMC aging remain poorly defined; however, recent evidence implicates persistent DNA damage and the A-type nuclear lamins as key regulators of this process. In the present review, we discuss the importance of the nuclear lamina in the spatial organization of nuclear signalling events, including the DNA-damage response. In particular, we focus on the evidence suggesting that prelamin A accumulation interferes with nuclear spatial compartmentalization by disrupting chromatin organization and DNA-damage repair pathways to promote VSMC aging and senescence.
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Affiliation(s)
- Derek T Warren
- BHF Centre of Research Excellence, Cardiovascular Division, King's College London, James Black Centre, 125 Coldharbour Lane, London SE5 9NU, UK.
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