1
|
Lee S, Le Roux AL, Mors M, Vanni S, Roca‑Cusachs P, Bahmanyar S. Amphipathic helices sense the inner nuclear membrane environment through lipid packing defects. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.11.14.623600. [PMID: 39605395 PMCID: PMC11601446 DOI: 10.1101/2024.11.14.623600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/29/2024]
Abstract
Amphipathic helices (AHs) are ubiquitous protein motifs that modulate targeting to organellar membranes by sensing differences in bulk membrane properties. However, the adaptation between membrane-targeting AHs and the nuclear membrane environment that surrounds the genome is poorly understood. Here, we computationally screened for candidate AHs in a curated list of characterized and putative human inner nuclear membrane (INM) proteins. Cell biological and in vitro experimental assays combined with computational calculations demonstrated that AHs detect lipid packing defects over electrostatics to bind to the INM, indicating that the INM is loosely packed under basal conditions. Membrane tension resulting from hypotonic shock further promoted AH binding to the INM, whereas cell-substrate stretch did not enhance recruitment of membrane tension-sensitive AHs. Together, our work demonstrates the rules driving lipid-protein interactions at the INM, and its implications in the response of the nucleus to different stimuli.
Collapse
Affiliation(s)
- Shoken Lee
- Department of Molecular Cellular and Developmental Biology, Yale University, 260 Whitney Ave, Yale Science Building 116, New Haven, CT 06511, USA
| | - Anabel-Lise Le Roux
- Institute for Bioengineering of Catalonia, the Barcelona Institute of Technology (BIST), Barcelona, Spain
| | - Mira Mors
- Department of Biology, University of Fribourg, Switzerland
| | - Stefano Vanni
- Department of Biology, University of Fribourg, Switzerland
- Swiss National Center for Competence in Research Bio-Inspired Materials, University of Fribourg, Fribourg CH-1700, Switzerland
| | - Pere Roca‑Cusachs
- Institute for Bioengineering of Catalonia, the Barcelona Institute of Technology (BIST), Barcelona, Spain
- Departament de Biomedicina, Unitat de Biofísica i Bioenginyeria, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain
| | - Shirin Bahmanyar
- Department of Molecular Cellular and Developmental Biology, Yale University, 260 Whitney Ave, Yale Science Building 116, New Haven, CT 06511, USA
| |
Collapse
|
2
|
Pereira RT, Samarakone C, Bridger JM, de Castro IJ. Pushing the envelope - How the genome interacts with the nuclear envelope in health and disease. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2024; 143:155-190. [PMID: 39843135 DOI: 10.1016/bs.apcsb.2024.09.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2025]
Abstract
The nuclear envelope has for long been considered more than just the physical border between the nucleoplasm and the cytoplasm, emerging as a crucial player in genome organisation and regulation within the 3D nucleus. Consequently, its study has become a valuable topic in the research of cancer, ageing and several other diseases where chromatin organisation is compromised. In this chapter, we will delve into its several sub-elements, such as the nuclear lamina, nuclear pore complexes and nuclear envelope proteins, and their diverse roles in nuclear function and maintenance. We will explore their functions beyond nuclear structure and transport focusing on their interactions with chromatin and their paramount influence in its organisation, regulation and expression at the nuclear periphery. Finally, we will outline how this chromatin organisation and regulation at the nuclear envelope is affected in diseases, including laminopathies, cancer, neurodegenerative diseases and during viral infections.
Collapse
Affiliation(s)
- Rita Torres Pereira
- Genome Organisation and Dynamics Cluster, Center for Genome Engineering and Maintenance, Division of Biosciences, College of Health, Medicine and Life Sciences, Brunel University London, Uxbridge, London, United Kingdom
| | - Cresentia Samarakone
- Genome Organisation and Dynamics Cluster, Center for Genome Engineering and Maintenance, Division of Biosciences, College of Health, Medicine and Life Sciences, Brunel University London, Uxbridge, London, United Kingdom
| | - Joanna M Bridger
- Genome Organisation and Dynamics Cluster, Center for Genome Engineering and Maintenance, Division of Biosciences, College of Health, Medicine and Life Sciences, Brunel University London, Uxbridge, London, United Kingdom
| | - Ines J de Castro
- Genome Organisation and Dynamics Cluster, Center for Genome Engineering and Maintenance, Division of Biosciences, College of Health, Medicine and Life Sciences, Brunel University London, Uxbridge, London, United Kingdom.
| |
Collapse
|
3
|
Czapiewski R, Schirmer EC. Enhancers on the edge - how the nuclear envelope controls gene regulatory elements. Curr Opin Genet Dev 2024; 87:102234. [PMID: 39047586 DOI: 10.1016/j.gde.2024.102234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 06/20/2024] [Accepted: 07/05/2024] [Indexed: 07/27/2024]
Abstract
Precise temporal and sequential control of gene expression during development and in response to environmental stimuli requires tight regulation of the physical contact between gene regulatory elements and promoters. Current models describing how the genome folds in 3D space to establish these interactions often ignore the role of the most stable structural nuclear feature - the nuclear envelope. While contributions of 3D folding within/between topologically associated domains (TADs) have been extensively described, mechanical contributions from the nuclear envelope can impact enhancer-promoter interactions both directly and indirectly through influencing intra/inter-TAD interactions. Importantly, these nuclear envelope contributions clearly link this mechanism to development and, when defective, to human disease. Here, we discuss evidence for nuclear envelope regulation of tissue-specific enhancer-promoter pairings, potential mechanisms for this regulation, exciting recent findings that other regulatory elements such as microRNAs and long noncoding RNAs are under nuclear envelope regulation, the possible involvement of condensates, and how disruption of this regulation can lead to disease.
Collapse
Affiliation(s)
- Rafal Czapiewski
- Institute of Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom; MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom.
| | - Eric C Schirmer
- Institute of Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom.
| |
Collapse
|
4
|
Jühlen R, Fahrenkrog B. From the sideline: Tissue-specific nucleoporin function in health and disease, an update. FEBS Lett 2023; 597:2750-2768. [PMID: 37873737 DOI: 10.1002/1873-3468.14761] [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: 08/10/2023] [Revised: 09/26/2023] [Accepted: 10/04/2023] [Indexed: 10/25/2023]
Abstract
The subcellular compartmentalisation of eukaryotic cells requires selective exchange between the cytoplasm and the nucleus. Intact nucleocytoplasmic transport is vital for normal cell function and mutations in the executing machinery have been causally linked to human disease. Central players in nucleocytoplasmic exchange are nuclear pore complexes (NPCs), which are built from ~30 distinct proteins collectively termed nucleoporins. Aberrant nucleoporin expression was detected in human cancers and autoimmune diseases since quite some time, while it was through the increasing use of next generation sequencing that mutations in nucleoporin genes associated with mainly rare hereditary diseases were revealed. The number of newly identified mutations is steadily increasing, as is the number of diseases. Mutational hotspots have emerged: mutations in the scaffold nucleoporins seemingly affect primarily inner organs, such as heart, kidney, and ovaries, whereas genetic alterations in peripheral, cytoplasmic nucleoporins affect primarily the central nervous system and development. In this review, we summarise latest insights on altered nucleoporin function in the context of human hereditary disorders, with a focus on those where mechanistic insights are beginning to emerge.
Collapse
Affiliation(s)
- Ramona Jühlen
- Institute of Biochemistry and Molecular Cell Biology, Medical School, RWTH Aachen University, Aachen, Germany
| | | |
Collapse
|
5
|
Elzamzami FD, Samal A, Arun AS, Dharmaraj T, Prasad NR, Rendon-Jonguitud A, DeVine L, Walston JD, Cole RN, Wilson KL. Native lamin A/C proteomes and novel partners from heart and skeletal muscle in a mouse chronic inflammation model of human frailty. Front Cell Dev Biol 2023; 11:1240285. [PMID: 37936983 PMCID: PMC10626543 DOI: 10.3389/fcell.2023.1240285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 10/05/2023] [Indexed: 11/09/2023] Open
Abstract
Clinical frailty affects ∼10% of people over age 65 and is studied in a chronically inflamed (Interleukin-10 knockout; "IL10-KO") mouse model. Frailty phenotypes overlap the spectrum of diseases ("laminopathies") caused by mutations in LMNA. LMNA encodes nuclear intermediate filament proteins lamin A and lamin C ("lamin A/C"), important for tissue-specific signaling, metabolism and chromatin regulation. We hypothesized that wildtype lamin A/C associations with tissue-specific partners are perturbed by chronic inflammation, potentially contributing to dysfunction in frailty. To test this idea we immunoprecipitated native lamin A/C and associated proteins from skeletal muscle, hearts and brains of old (21-22 months) IL10-KO versus control C57Bl/6 female mice, and labeled with Tandem Mass Tags for identification and quantitation by mass spectrometry. We identified 502 candidate lamin-binding proteins from skeletal muscle, and 340 from heart, including 62 proteins identified in both tissues. Candidates included frailty phenotype-relevant proteins Perm1 and Fam210a, and nuclear membrane protein Tmem38a, required for muscle-specific genome organization. These and most other candidates were unaffected by IL10-KO, but still important as potential lamin A/C-binding proteins in native heart or muscle. A subset of candidates (21 in skeletal muscle, 30 in heart) showed significantly different lamin A/C-association in an IL10-KO tissue (p < 0.05), including AldoA and Gins3 affected in heart, and Lmcd1 and Fabp4 affected in skeletal muscle. To screen for binding, eleven candidates plus prelamin A and emerin controls were arrayed as synthetic 20-mer peptides (7-residue stagger) and incubated with recombinant purified lamin A "tail" residues 385-646 under relatively stringent conditions. We detected strong lamin A binding to peptides solvent exposed in Lmcd1, AldoA, Perm1, and Tmem38a, and plausible binding to Csrp3 (muscle LIM protein). These results validated both proteomes as sources for native lamin A/C-binding proteins in heart and muscle, identified four candidate genes for Emery-Dreifuss muscular dystrophy (CSRP3, LMCD1, ALDOA, and PERM1), support a lamin A-interactive molecular role for Tmem38A, and supported the hypothesis that lamin A/C interactions with at least two partners (AldoA in heart, transcription factor Lmcd1 in muscle) are altered in the IL10-KO model of frailty.
Collapse
Affiliation(s)
- Fatima D. Elzamzami
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Arushi Samal
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Adith S. Arun
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Tejas Dharmaraj
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Neeti R. Prasad
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Alex Rendon-Jonguitud
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Lauren DeVine
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Jeremy D. Walston
- Division of Geriatric Medicine and Gerontology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Robert N. Cole
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Katherine L. Wilson
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| |
Collapse
|
6
|
Lee S, Carrasquillo Rodríguez JW, Merta H, Bahmanyar S. A membrane-sensing mechanism links lipid metabolism to protein degradation at the nuclear envelope. J Cell Biol 2023; 222:e202304026. [PMID: 37382667 PMCID: PMC10309186 DOI: 10.1083/jcb.202304026] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/22/2023] [Accepted: 06/02/2023] [Indexed: 06/30/2023] Open
Abstract
Lipid composition determines organelle identity; however, whether the lipid composition of the inner nuclear membrane (INM) domain of the ER contributes to its identity is not known. Here, we show that the INM lipid environment of animal cells is under local control by CTDNEP1, the master regulator of the phosphatidic acid phosphatase lipin 1. Loss of CTDNEP1 reduces association of an INM-specific diacylglycerol (DAG) biosensor and results in a decreased percentage of polyunsaturated containing DAG species. Alterations in DAG metabolism impact the levels of the resident INM protein Sun2, which is under local proteasomal regulation. We identify a lipid-binding amphipathic helix (AH) in the nucleoplasmic domain of Sun2 that prefers membrane packing defects. INM dissociation of the Sun2 AH is linked to its proteasomal degradation. We suggest that direct lipid-protein interactions contribute to sculpting the INM proteome and that INM identity is adaptable to lipid metabolism, which has broad implications on disease mechanisms associated with the nuclear envelope.
Collapse
Affiliation(s)
- Shoken Lee
- Department of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | | | - Holly Merta
- Department of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Shirin Bahmanyar
- Department of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| |
Collapse
|
7
|
Cheng LC, Zhang X, Baboo S, Nguyen JA, Martinez-Bartolomé S, Loose E, Diedrich J, Yates JR, Gerace L. Comparative membrane proteomics reveals diverse cell regulators concentrated at the nuclear envelope. Life Sci Alliance 2023; 6:e202301998. [PMID: 37433644 PMCID: PMC10336727 DOI: 10.26508/lsa.202301998] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 06/23/2023] [Accepted: 06/26/2023] [Indexed: 07/13/2023] Open
Abstract
The nuclear envelope (NE) is a subdomain of the ER with prominent roles in nuclear organization, which are largely mediated by its distinctive protein composition. We developed methods to reveal low-abundance transmembrane (TM) proteins concentrated at the NE relative to the peripheral ER. Using label-free proteomics that compared isolated NEs with cytoplasmic membranes, we first identified proteins with apparent NE enrichment. In subsequent authentication, ectopically expressed candidates were analyzed by immunofluorescence microscopy to quantify their targeting to the NE in cultured cells. Ten proteins from a validation set were found to associate preferentially with the NE, including oxidoreductases, enzymes for lipid biosynthesis, and regulators of cell growth and survival. We determined that one of the validated candidates, the palmitoyltransferase Zdhhc6, modifies the NE oxidoreductase Tmx4 and thereby modulates its NE levels. This provides a functional rationale for the NE concentration of Zdhhc6. Overall, our methodology has revealed a group of previously unrecognized proteins concentrated at the NE and additional candidates. Future analysis of these can potentially unveil new mechanistic pathways associated with the NE.
Collapse
Affiliation(s)
- Li-Chun Cheng
- Department of Molecular Medicine, Scripps Research, La Jolla, CA, USA
| | - Xi Zhang
- Department of Molecular Medicine, Scripps Research, La Jolla, CA, USA
| | - Sabyasachi Baboo
- Department of Molecular Medicine, Scripps Research, La Jolla, CA, USA
| | - Julie A Nguyen
- Department of Molecular Medicine, Scripps Research, La Jolla, CA, USA
| | | | - Esther Loose
- Department of Molecular Medicine, Scripps Research, La Jolla, CA, USA
| | - Jolene Diedrich
- Department of Molecular Medicine, Scripps Research, La Jolla, CA, USA
| | - John R Yates
- Department of Molecular Medicine, Scripps Research, La Jolla, CA, USA
| | - Larry Gerace
- Department of Molecular Medicine, Scripps Research, La Jolla, CA, USA
| |
Collapse
|
8
|
Cheng LC, Zhang X, Baboo S, Nguyen JA, Martinez-Bartolomé S, Loose E, Diedrich J, Yates JR, Gerace L. Comparative membrane proteomics reveals diverse cell regulators concentrated at the nuclear envelope. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.13.528342. [PMID: 36824861 PMCID: PMC9949040 DOI: 10.1101/2023.02.13.528342] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
The nuclear envelope (NE) is a subdomain of the ER with prominent roles in nuclear organization, largely mediated by its distinctive protein composition. We developed methods to reveal novel, low abundance transmembrane (TM) proteins concentrated at the NE relative to the peripheral ER. Using label-free proteomics that compared isolated NEs to cytoplasmic membranes, we first identified proteins with apparent NE enrichment. In subsequent authentication, ectopically expressed candidates were analyzed by immunofluorescence microscopy to quantify their targeting to the NE in cultured cells. Ten proteins from a validation set were found to associate preferentially with the NE, including oxidoreductases, enzymes for lipid biosynthesis and regulators of cell growth and survival. We determined that one of the validated candidates, the palmitoyltransferase Zdhhc6, modifies the NE oxidoreductase Tmx4 and thereby modulates its NE levels. This provides a functional rationale for the NE concentration of Zdhhc6. Overall, our methodology has revealed a group of previously unrecognized proteins concentrated at the NE and additional candidates. Future analysis of these can potentially unveil new mechanistic pathways associated with the NE.
Collapse
Affiliation(s)
- Li-Chun Cheng
- Department of Molecular Medicine, Scripps Research, 10550 N Torrey Pines Rd, La Jolla CA, USA
| | - Xi Zhang
- Department of Molecular Medicine, Scripps Research, 10550 N Torrey Pines Rd, La Jolla CA, USA
| | - Sabyasachi Baboo
- Department of Molecular Medicine, Scripps Research, 10550 N Torrey Pines Rd, La Jolla CA, USA
| | - Julie A Nguyen
- Department of Molecular Medicine, Scripps Research, 10550 N Torrey Pines Rd, La Jolla CA, USA
| | | | - Esther Loose
- Department of Molecular Medicine, Scripps Research, 10550 N Torrey Pines Rd, La Jolla CA, USA
| | - Jolene Diedrich
- Department of Molecular Medicine, Scripps Research, 10550 N Torrey Pines Rd, La Jolla CA, USA
| | - John R Yates
- Department of Molecular Medicine, Scripps Research, 10550 N Torrey Pines Rd, La Jolla CA, USA
| | - Larry Gerace
- Department of Molecular Medicine, Scripps Research, 10550 N Torrey Pines Rd, La Jolla CA, USA
| |
Collapse
|
9
|
Schirmer EC, Latonen L, Tollis S. Nuclear size rectification: A potential new therapeutic approach to reduce metastasis in cancer. Front Cell Dev Biol 2022; 10:1022723. [PMID: 36299481 PMCID: PMC9589484 DOI: 10.3389/fcell.2022.1022723] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 09/12/2022] [Indexed: 03/07/2024] Open
Abstract
Research on metastasis has recently regained considerable interest with the hope that single cell technologies might reveal the most critical changes that support tumor spread. However, it is possible that part of the answer has been visible through the microscope for close to 200 years. Changes in nuclear size characteristically occur in many cancer types when the cells metastasize. This was initially discarded as contributing to the metastatic spread because, depending on tumor types, both increases and decreases in nuclear size could correlate with increased metastasis. However, recent work on nuclear mechanics and the connectivity between chromatin, the nucleoskeleton, and the cytoskeleton indicate that changes in this connectivity can have profound impacts on cell mobility and invasiveness. Critically, a recent study found that reversing tumor type-dependent nuclear size changes correlated with reduced cell migration and invasion. Accordingly, it seems appropriate to now revisit possible contributory roles of nuclear size changes to metastasis.
Collapse
Affiliation(s)
- Eric C. Schirmer
- Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Leena Latonen
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
- Foundation for the Finnish Cancer Institute, Helsinki, Finland
| | - Sylvain Tollis
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
| |
Collapse
|
10
|
Borah S, Dhanasekaran K, Kumar S. The LEM-ESCRT toolkit: Repair and maintenance of the nucleus. Front Cell Dev Biol 2022; 10:989217. [PMID: 36172278 PMCID: PMC9512039 DOI: 10.3389/fcell.2022.989217] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 08/24/2022] [Indexed: 12/04/2022] Open
Abstract
The eukaryotic genome is enclosed in a nuclear envelope that protects it from potentially damaging cellular activities and physically segregates transcription and translation.Transport across the NE is highly regulated and occurs primarily via the macromolecular nuclear pore complexes.Loss of nuclear compartmentalization due to defects in NPC function and NE integrity are tied to neurological and ageing disorders like Alzheimer’s, viral pathogenesis, immune disorders, and cancer progression.Recent work implicates inner-nuclear membrane proteins of the conserved LEM domain family and the ESCRT machinery in NE reformation during cell division and NE repair upon rupture in migrating cancer cells, and generating seals over defective NPCs. In this review, we discuss the recent in-roads made into defining the molecular mechanisms and biochemical networks engaged by LEM and many other integral inner nuclear membrane proteins to preserve the nuclear barrier.
Collapse
Affiliation(s)
- Sapan Borah
- National Institute of Immunohaematology, Mumbai, Maharashtra, India
- *Correspondence: Sapan Borah, ; Karthigeyan Dhanasekaran, ; Santosh Kumar,
| | - Karthigeyan Dhanasekaran
- Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad, Haryana, India
- *Correspondence: Sapan Borah, ; Karthigeyan Dhanasekaran, ; Santosh Kumar,
| | - Santosh Kumar
- National Centre for Cell Science, Pune, Maharashtra, India
- *Correspondence: Sapan Borah, ; Karthigeyan Dhanasekaran, ; Santosh Kumar,
| |
Collapse
|
11
|
Li Y, Chen M, Chang W. Roles of the nucleus in leukocyte migration. J Leukoc Biol 2022; 112:771-783. [PMID: 35916042 DOI: 10.1002/jlb.1mr0622-473rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 06/20/2022] [Indexed: 11/09/2022] Open
Abstract
Leukocytes patrol our bodies in search of pathogens and migrate to sites of injury in response to various stimuli. Rapid and directed leukocyte motility is therefore crucial to our immunity. The nucleus is the largest and stiffest cellular organelle and a mechanical obstacle for migration through constrictions. However, the nucleus is also essential for 3D cell migration. Here, we review the roles of the nucleus in leukocyte migration, focusing on how cells deform their nuclei to aid cell motility and the contributions of the nucleus to cell migration. We discuss the regulation of the nuclear biomechanics by the nuclear lamina and how it, together with the cytoskeleton, modulates the shapes of leukocyte nuclei. We then summarize the functions of nesprins and SUN proteins in leukocytes and discuss how forces are exerted on the nucleus. Finally, we examine the mechanical roles of the nucleus in cell migration, including its roles in regulating the direction of migration and path selection.
Collapse
Affiliation(s)
- Yutao Li
- Department of Biomedical Sciences, Faculty of Health Sciences, University of Macau, Taipa, Macau, China
| | - Mengqi Chen
- Department of Biomedical Sciences, Faculty of Health Sciences, University of Macau, Taipa, Macau, China
| | - Wakam Chang
- Department of Biomedical Sciences, Faculty of Health Sciences, University of Macau, Taipa, Macau, China
| |
Collapse
|
12
|
Abstract
Lamins interact with a host of nuclear membrane proteins, transcription factors, chromatin regulators, signaling molecules, splicing factors, and even chromatin itself to form a nuclear subcompartment, the nuclear lamina, that is involved in a variety of cellular processes such as the governance of nuclear integrity, nuclear positioning, mitosis, DNA repair, DNA replication, splicing, signaling, mechanotransduction and -sensation, transcriptional regulation, and genome organization. Lamins are the primary scaffold for this nuclear subcompartment, but interactions with lamin-associated peptides in the inner nuclear membrane are self-reinforcing and mutually required. Lamins also interact, directly and indirectly, with peripheral heterochromatin domains called lamina-associated domains (LADs) and help to regulate dynamic 3D genome organization and expression of developmentally regulated genes.
Collapse
Affiliation(s)
- Xianrong Wong
- Laboratory of Developmental and Regenerative Biology, Skin Research Institute of Singapore, Agency for Science, Technology and Research (A∗STAR), Singapore 138648
| | - Ashley J Melendez-Perez
- Department of Biological Chemistry and Center for Epigenetics, Johns Hopkins University of Medicine, Baltimore, Maryland 21205, USA
| | - Karen L Reddy
- Department of Biological Chemistry and Center for Epigenetics, Johns Hopkins University of Medicine, Baltimore, Maryland 21205, USA
- Sidney Kimmel Cancer Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, USA
| |
Collapse
|
13
|
Czapiewski R, Batrakou DG, de Las Heras JI, Carter RN, Sivakumar A, Sliwinska M, Dixon CR, Webb S, Lattanzi G, Morton NM, Schirmer EC. Genomic loci mispositioning in Tmem120a knockout mice yields latent lipodystrophy. Nat Commun 2022; 13:321. [PMID: 35027552 PMCID: PMC8758788 DOI: 10.1038/s41467-021-27869-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 12/19/2021] [Indexed: 12/13/2022] Open
Abstract
Little is known about how the observed fat-specific pattern of 3D-spatial genome organisation is established. Here we report that adipocyte-specific knockout of the gene encoding nuclear envelope transmembrane protein Tmem120a disrupts fat genome organisation, thus causing a lipodystrophy syndrome. Tmem120a deficiency broadly suppresses lipid metabolism pathway gene expression and induces myogenic gene expression by repositioning genes, enhancers and miRNA-encoding loci between the nuclear periphery and interior. Tmem120a-/- mice, particularly females, exhibit a lipodystrophy syndrome similar to human familial partial lipodystrophy FPLD2, with profound insulin resistance and metabolic defects that manifest upon exposure to an obesogenic diet. Interestingly, similar genome organisation defects occurred in cells from FPLD2 patients that harbour nuclear envelope protein encoding LMNA mutations. Our data indicate TMEM120A genome organisation functions affect many adipose functions and its loss may yield adiposity spectrum disorders, including a miRNA-based mechanism that could explain muscle hypertrophy in human lipodystrophy.
Collapse
Affiliation(s)
- Rafal Czapiewski
- Institute of Cell Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Dzmitry G Batrakou
- Institute of Cell Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | | | - Roderick N Carter
- Molecular Metabolism Group, University/BHF Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, EH16 4TJ, UK
| | | | | | - Charles R Dixon
- Institute of Cell Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Shaun Webb
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Giovanna Lattanzi
- CNR - National Research Council of Italy, Institute of Molecular Genetics "Luigi Luca Cavalli-Sforza", Unit of Bologna, Bologna, 40136, Italy
- IRCCS, Istituto Ortopedico Rizzoli, Bologna, 40136, Italy
| | - Nicholas M Morton
- Molecular Metabolism Group, University/BHF Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, EH16 4TJ, UK
| | - Eric C Schirmer
- Institute of Cell Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK.
| |
Collapse
|
14
|
Randzavola LO, Mortimer PM, Garside E, Dufficy ER, Schejtman A, Roumelioti G, Yu L, Pardo M, Spirohn K, Tolley C, Brandt C, Harcourt K, Nichols E, Nahorski M, Woods G, Williamson JC, Suresh S, Sowerby JM, Matsumoto M, Santos CXC, Kiar CS, Mukhopadhyay S, Rae WM, Dougan GJ, Grainger J, Lehner PJ, Calderwood MA, Choudhary J, Clare S, Speak A, Santilli G, Bateman A, Smith KGC, Magnani F, Thomas DC. EROS is a selective chaperone regulating the phagocyte NADPH oxidase and purinergic signalling. eLife 2022; 11:76387. [PMID: 36421765 PMCID: PMC9767466 DOI: 10.7554/elife.76387] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 10/31/2022] [Indexed: 11/25/2022] Open
Abstract
EROS (essential for reactive oxygen species) protein is indispensable for expression of gp91phox, the catalytic core of the phagocyte NADPH oxidase. EROS deficiency in humans is a novel cause of the severe immunodeficiency, chronic granulomatous disease, but its mechanism of action was unknown until now. We elucidate the role of EROS, showing it acts at the earliest stages of gp91phox maturation. It binds the immature 58 kDa gp91phox directly, preventing gp91phox degradation and allowing glycosylation via the oligosaccharyltransferase machinery and the incorporation of the heme prosthetic groups essential for catalysis. EROS also regulates the purine receptors P2X7 and P2X1 through direct interactions, and P2X7 is almost absent in EROS-deficient mouse and human primary cells. Accordingly, lack of murine EROS results in markedly abnormal P2X7 signalling, inflammasome activation, and T cell responses. The loss of both ROS and P2X7 signalling leads to resistance to influenza infection in mice. Our work identifies EROS as a highly selective chaperone for key proteins in innate and adaptive immunity and a rheostat for immunity to infection. It has profound implications for our understanding of immune physiology, ROS dysregulation, and possibly gene therapy.
Collapse
Affiliation(s)
- Lyra O Randzavola
- Department of Immunology and Inflammation, Centre for Inflammatory Disease, Imperial College LondonLondonUnited Kingdom
| | - Paige M Mortimer
- Department of Immunology and Inflammation, Centre for Inflammatory Disease, Imperial College LondonLondonUnited Kingdom
| | - Emma Garside
- Department of Immunology and Inflammation, Centre for Inflammatory Disease, Imperial College LondonLondonUnited Kingdom
| | - Elizabeth R Dufficy
- The Department of Medicine, University of Cambridge School of Clinical MedicineCambridgeUnited Kingdom
| | - Andrea Schejtman
- Molecular Immunology Unit, UCL Great Ormond Street Institute of Child HealthLondonUnited Kingdom
| | - Georgia Roumelioti
- Functional Proteomics, Division of Cancer Biology, Institute of Cancer ResearchLondonUnited Kingdom
| | - Lu Yu
- Functional Proteomics, Division of Cancer Biology, Institute of Cancer ResearchLondonUnited Kingdom
| | - Mercedes Pardo
- Functional Proteomics, Division of Cancer Biology, Institute of Cancer ResearchLondonUnited Kingdom
| | - Kerstin Spirohn
- Center for Cancer Systems Biology (CCSB), Dana-Farber Cancer InstituteBostonUnited States,Department of Genetics, Blavatnik Institute, Harvard Medical SchoolBostonUnited States,Department of Cancer Biology, Dana-Farber Cancer InstituteBostonUnited States
| | | | | | | | - Esme Nichols
- Department of Immunology and Inflammation, Centre for Inflammatory Disease, Imperial College LondonLondonUnited Kingdom
| | - Mike Nahorski
- Cambridge Institute of Medical Research, University of CambridgeCambridgeUnited Kingdom
| | - Geoff Woods
- Cambridge Institute of Medical Research, University of CambridgeCambridgeUnited Kingdom
| | - James C Williamson
- The Department of Medicine, University of Cambridge School of Clinical MedicineCambridgeUnited Kingdom,Cambridge Institute of Therapeutic Immunology & Infectious Disease, Jeffrey Cheah Biomedical Centre Cambridge Biomedical CampusCambridgeUnited Kingdom
| | - Shreehari Suresh
- The Department of Medicine, University of Cambridge School of Clinical MedicineCambridgeUnited Kingdom
| | - John M Sowerby
- The Department of Medicine, University of Cambridge School of Clinical MedicineCambridgeUnited Kingdom,Cambridge Institute of Therapeutic Immunology & Infectious Disease, Jeffrey Cheah Biomedical Centre Cambridge Biomedical CampusCambridgeUnited Kingdom
| | - Misaki Matsumoto
- Department of Pharmacology, Kyoto Prefectural University of MedicineKyotoJapan
| | - Celio XC Santos
- School of Cardiovascular Medicine and Sciences, James Black Centre, King's College LondonLondonUnited Kingdom
| | - Cher Shen Kiar
- Peter Gorer Department of Immunobiology, School of Immunology & Microbial Sciences, King's College LondonLondonUnited Kingdom
| | - Subhankar Mukhopadhyay
- Peter Gorer Department of Immunobiology, School of Immunology & Microbial Sciences, King's College LondonLondonUnited Kingdom
| | - William M Rae
- The Department of Medicine, University of Cambridge School of Clinical MedicineCambridgeUnited Kingdom,Cambridge Institute of Therapeutic Immunology & Infectious Disease, Jeffrey Cheah Biomedical Centre Cambridge Biomedical CampusCambridgeUnited Kingdom
| | - Gordon J Dougan
- The Department of Medicine, University of Cambridge School of Clinical MedicineCambridgeUnited Kingdom
| | - John Grainger
- Functional Proteomics, Division of Cancer Biology, Institute of Cancer ResearchLondonUnited Kingdom,Lydia Becker Institute of Immunology and Inflammation, Faculty of Biology, Medicine and Health, University of ManchesterManchesterUnited Kingdom
| | - Paul J Lehner
- The Department of Medicine, University of Cambridge School of Clinical MedicineCambridgeUnited Kingdom,Cambridge Institute of Therapeutic Immunology & Infectious Disease, Jeffrey Cheah Biomedical Centre Cambridge Biomedical CampusCambridgeUnited Kingdom
| | - Michael A Calderwood
- Center for Cancer Systems Biology (CCSB), Dana-Farber Cancer InstituteBostonUnited States,Department of Genetics, Blavatnik Institute, Harvard Medical SchoolBostonUnited States,Department of Cancer Biology, Dana-Farber Cancer InstituteBostonUnited States
| | - Jyoti Choudhary
- Functional Proteomics, Division of Cancer Biology, Institute of Cancer ResearchLondonUnited Kingdom
| | - Simon Clare
- Wellcome Trust Sanger InstituteHinxtonUnited Kingdom
| | | | - Giorgia Santilli
- Molecular Immunology Unit, UCL Great Ormond Street Institute of Child HealthLondonUnited Kingdom
| | - Alex Bateman
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome CampusHinxtonUnited Kingdom
| | - Kenneth GC Smith
- The Department of Medicine, University of Cambridge School of Clinical MedicineCambridgeUnited Kingdom,Cambridge Institute of Therapeutic Immunology & Infectious Disease, Jeffrey Cheah Biomedical Centre Cambridge Biomedical CampusCambridgeUnited Kingdom
| | - Francesca Magnani
- Department of Biology and Biotechnology, University of PaviaPaviaItaly
| | - David C Thomas
- Department of Immunology and Inflammation, Centre for Inflammatory Disease, Imperial College LondonLondonUnited Kingdom
| |
Collapse
|
15
|
Kong Y, Zhang Y, Wang H, Kan W, Guo H, Liu Y, Zang Y, Li J. Inner nuclear membrane protein TMEM201 promotes breast cancer metastasis by positive regulating TGFβ signaling. Oncogene 2022; 41:647-656. [PMID: 34799661 DOI: 10.1038/s41388-021-02098-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 10/12/2021] [Accepted: 10/25/2021] [Indexed: 12/31/2022]
Abstract
Emerging evidence shows the association between nuclear envelope and tumor progression, however, the functional contributions of specific constituents of the nuclear envelope remain largely unclear. We found that the expression level of transmembrane protein 201 (TMEM201), an integral inner nuclear membrane protein of unknown function, was significantly elevated in invasive breast cancer and predicted poor breast cancer prognosis. We showed that TMEM201, as a positive modulator, was both necessary and sufficient to regulate the migration and invasion of breast cancer cells in vitro and in vivo. Mechanistically, RNA-sequencing analysis and validation showed that TMEM201 deficiency inhibited epithelial-to-mesenchymal transition and transforming growth factor-β signaling. Finally, we showed that TMEM201 physically interacted with SMAD2/3 and was required for the phosphorylation of SMAD2/3, nuclear translocation and transcriptional activation of the TGFβ. Thus, we demonstrated that specific inner nuclear membrane component mediated signal-dependent transcriptional effects to control breast cancer metastasis.
Collapse
Affiliation(s)
- Ya Kong
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yutian Zhang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Hanlin Wang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- Department of Pharmacology, Fudan University, Shanghai, 201203, China
| | - Weijuan Kan
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Haoran Guo
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yun Liu
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Drug Screening, China Pharmaceutical University, #24 Tong Jia Xiang Street, Nanjing, 210009, China
| | - Yi Zang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, UCAS, Hangzhou, China.
| | - Jia Li
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, UCAS, Hangzhou, China.
- Open Studio for Druggability Research of Marine Natural Products, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, 266237, China.
| |
Collapse
|
16
|
Abstract
The nuclear envelope and nucleoskeleton are emerging as signaling centers that regulate how physical information from the extracellular matrix is biochemically transduced into the nucleus, affecting chromatin and controlling cell function. Bone is a mechanically driven tissue that relies on physical information to maintain its physiological function and structure. Disorder that present with musculoskeletal and cardiac symptoms, such as Emery-Dreifuss muscular dystrophies and progeria, correlate with mutations in nuclear envelope proteins including Linker of Nucleoskeleton and Cytoskeleton (LINC) complex, Lamin A/C, and emerin. However, the role of nuclear envelope mechanobiology on bone function remains underexplored. The mesenchymal stem cell (MSC) model is perhaps the most studied relationship between bone regulation and nuclear envelope function. MSCs maintain the musculoskeletal system by differentiating into multiple cell types including osteocytes and adipocytes, thus supporting the bone's ability to respond to mechanical challenge. In this review, we will focus on how MSC function is regulated by mechanical challenges both in vitro and in vivo within the context of bone function specifically focusing on integrin, β-catenin and YAP/TAZ signaling. The importance of the nuclear envelope will be explored within the context of musculoskeletal diseases related to nuclear envelope protein mutations and nuclear envelope regulation of signaling pathways relevant to bone mechanobiology in vitro and in vivo.
Collapse
Affiliation(s)
- Scott Birks
- Boise State University, Micron School of Materials Science and Engineering, United States of America
| | - Gunes Uzer
- Boise State University, Mechanical and Biomedical Engineering, United States of America.
| |
Collapse
|
17
|
Dixon CR, Malik P, de las Heras JI, Saiz-Ros N, de Lima Alves F, Tingey M, Gaunt E, Richardson AC, Kelly DA, Goldberg MW, Towers GJ, Yang W, Rappsilber J, Digard P, Schirmer EC. STING nuclear partners contribute to innate immune signaling responses. iScience 2021; 24:103055. [PMID: 34541469 PMCID: PMC8436130 DOI: 10.1016/j.isci.2021.103055] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 07/19/2021] [Accepted: 08/25/2021] [Indexed: 02/08/2023] Open
Abstract
STimulator of INterferon Genes (STING) is an adaptor for cytoplasmic DNA sensing by cGAMP/cGAS that helps trigger innate immune responses (IIRs). Although STING is mostly localized in the ER, we find a separate inner nuclear membrane pool of STING that increases mobility and redistributes to the outer nuclear membrane upon IIR stimulation by transfected dsDNA or dsRNA mimic poly(I:C). Immunoprecipitation of STING from isolated nuclear envelopes coupled with mass spectrometry revealed a distinct nuclear envelope-STING proteome consisting of known nuclear membrane proteins and enriched in DNA- and RNA-binding proteins. Seventeen of these nuclear envelope STING partners are known to bind direct interactors of IRF3/7 transcription factors, and testing a subset of these revealed STING partners SYNCRIP, MEN1, DDX5, snRNP70, RPS27a, and AATF as novel modulators of dsDNA-triggered IIRs. Moreover, we find that SYNCRIP is a novel antagonist of the RNA virus, influenza A, potentially shedding light on reports of STING inhibition of RNA viruses.
Collapse
Affiliation(s)
- Charles R. Dixon
- Institute of Cell Biology, University of Edinburgh, Kings Buildings, Swann 5.22, Mayfield Road, Edinburgh EH9 3BF, UK
| | - Poonam Malik
- Institute of Cell Biology, University of Edinburgh, Kings Buildings, Swann 5.22, Mayfield Road, Edinburgh EH9 3BF, UK
| | - Jose I. de las Heras
- Institute of Cell Biology, University of Edinburgh, Kings Buildings, Swann 5.22, Mayfield Road, Edinburgh EH9 3BF, UK
| | - Natalia Saiz-Ros
- Institute of Cell Biology, University of Edinburgh, Kings Buildings, Swann 5.22, Mayfield Road, Edinburgh EH9 3BF, UK
| | - Flavia de Lima Alves
- Institute of Cell Biology, University of Edinburgh, Kings Buildings, Swann 5.22, Mayfield Road, Edinburgh EH9 3BF, UK
| | - Mark Tingey
- Department of Biology, Temple University, Philadelphia 19121, USA
| | - Eleanor Gaunt
- Division of Infection and Immunity, Roslin Institute, University of Edinburgh, Edinburgh EH25 9RG, UK
| | | | - David A. Kelly
- Institute of Cell Biology, University of Edinburgh, Kings Buildings, Swann 5.22, Mayfield Road, Edinburgh EH9 3BF, UK
| | - Martin W. Goldberg
- School of Biological and Biomedical Sciences, Durham University, Durham DH1 3LE, UK
| | - Greg J. Towers
- Department of Infection and Immunity, University College London, London WC1E 6BT, UK
| | - Weidong Yang
- Department of Biology, Temple University, Philadelphia 19121, USA
| | - Juri Rappsilber
- Institute of Cell Biology, University of Edinburgh, Kings Buildings, Swann 5.22, Mayfield Road, Edinburgh EH9 3BF, UK
- Department of Bioanalytics, Institute of Biotechnology, Technische Universitat Berlin, 13355 Berlin, Germany
| | - Paul Digard
- Division of Infection and Immunity, Roslin Institute, University of Edinburgh, Edinburgh EH25 9RG, UK
| | - Eric C. Schirmer
- Institute of Cell Biology, University of Edinburgh, Kings Buildings, Swann 5.22, Mayfield Road, Edinburgh EH9 3BF, UK
| |
Collapse
|
18
|
Pawar S, Kutay U. The Diverse Cellular Functions of Inner Nuclear Membrane Proteins. Cold Spring Harb Perspect Biol 2021; 13:a040477. [PMID: 33753404 PMCID: PMC8411953 DOI: 10.1101/cshperspect.a040477] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The nuclear compartment is delimited by a specialized expanded sheet of the endoplasmic reticulum (ER) known as the nuclear envelope (NE). Compared to the outer nuclear membrane and the contiguous peripheral ER, the inner nuclear membrane (INM) houses a unique set of transmembrane proteins that serve a staggering range of functions. Many of these functions reflect the exceptional position of INM proteins at the membrane-chromatin interface. Recent research revealed that numerous INM proteins perform crucial roles in chromatin organization, regulation of gene expression, genome stability, and mediation of signaling pathways into the nucleus. Other INM proteins establish mechanical links between chromatin and the cytoskeleton, help NE remodeling, or contribute to the surveillance of NE integrity and homeostasis. As INM proteins continue to gain prominence, we review these advancements and give an overview on the functional versatility of the INM proteome.
Collapse
Affiliation(s)
- Sumit Pawar
- Institute of Biochemistry, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland
| | - Ulrike Kutay
- Institute of Biochemistry, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland
| |
Collapse
|
19
|
High-Throughput Identification of Nuclear Envelope Protein Interactions in Schizosaccharomyces pombe Using an Arrayed Membrane Yeast-Two Hybrid Library. G3-GENES GENOMES GENETICS 2020; 10:4649-4663. [PMID: 33109728 PMCID: PMC7718735 DOI: 10.1534/g3.120.401880] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The nuclear envelope (NE) contains a specialized set of integral membrane proteins that maintain nuclear shape and integrity and influence chromatin organization and gene expression. Advances in proteomics techniques and studies in model organisms have identified hundreds of proteins that localize to the NE. However, the function of many of these proteins at the NE remains unclear, in part due to a lack of understanding of the interactions that these proteins participate in at the NE membrane. To assist in the characterization of NE transmembrane protein interactions we developed an arrayed library of integral and peripheral membrane proteins from the fission yeast Schizosaccharomyces pombe for high-throughput screening using the split-ubiquitin based membrane yeast two -hybrid system. We used this approach to characterize protein interactions for three conserved proteins that localize to the inner nuclear membrane: Cut11/Ndc1, Lem2 and Ima1/Samp1/Net5. Additionally, we determined how the interaction network for Cut11 is altered in canonical temperature-sensitive cut11-ts mutants. This library and screening approach is readily applicable to characterizing the interactomes of integral membrane proteins localizing to various subcellular compartments.
Collapse
|
20
|
Gatticchi L, de las Heras JI, Sivakumar A, Zuleger N, Roberti R, Schirmer EC. Tm7sf2 Disruption Alters Radial Gene Positioning in Mouse Liver Leading to Metabolic Defects and Diabetes Characteristics. Front Cell Dev Biol 2020; 8:592573. [PMID: 33330474 PMCID: PMC7719783 DOI: 10.3389/fcell.2020.592573] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 10/26/2020] [Indexed: 01/23/2023] Open
Abstract
Tissue-specific patterns of radial genome organization contribute to genome regulation and can be established by nuclear envelope proteins. Studies in this area often use cancer cell lines, and it is unclear how well such systems recapitulate genome organization of primary cells or animal tissues; so, we sought to investigate radial genome organization in primary liver tissue hepatocytes. Here, we have used a NET47/Tm7sf2-/- liver model to show that manipulating one of these nuclear membrane proteins is sufficient to alter tissue-specific gene positioning and expression. Dam-LaminB1 global profiling in primary liver cells shows that nearly all the genes under such positional regulation are related to/important for liver function. Interestingly, Tm7sf2 is a paralog of the HP1-binding nuclear membrane protein LBR that, like Tm7sf2, also has an enzymatic function in sterol reduction. Fmo3 gene/locus radial mislocalization could be rescued with human wild-type, but not TM7SF2 mutants lacking the sterol reductase function. One central pathway affected is the cholesterol synthesis pathway. Within this pathway, both Cyp51 and Msmo1 are under Tm7sf2 positional and expression regulation. Other consequences of the loss of Tm7sf2 included weight gain, insulin sensitivity, and reduced levels of active Akt kinase indicating additional pathways under its regulation, several of which are highlighted by mispositioning genes. This study emphasizes the importance for tissue-specific radial genome organization in tissue function and the value of studying genome organization in animal tissues and primary cells over cell lines.
Collapse
Affiliation(s)
- Leonardo Gatticchi
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
| | | | - Aishwarya Sivakumar
- Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Nikolaj Zuleger
- Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Rita Roberti
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
| | - Eric C. Schirmer
- Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| |
Collapse
|
21
|
Bellet MM, Pieroni S, Castelli M, Piobbico D, Fallarino F, Romani L, Della-Fazia MA, Servillo G. HOPS/Tmub1 involvement in the NF-kB-mediated inflammatory response through the modulation of TRAF6. Cell Death Dis 2020; 11:865. [PMID: 33060567 PMCID: PMC7567074 DOI: 10.1038/s41419-020-03086-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 09/28/2020] [Accepted: 09/30/2020] [Indexed: 12/23/2022]
Abstract
HOPS/Tmub1 is a ubiquitously expressed transmembrane ubiquitin-like protein that shuttles between nucleus and cytoplasm during cell cycle progression. HOPS causes cell cycle arrest in G0/G1 phase, an event associated to stabilization of p19Arf, an important tumor suppressor protein. Moreover, HOPS plays an important role in driving centrosomal assembly and maintenance, mitotic spindle proper organization, and ultimately a correct cell division. Recently, HOPS has been described as an important regulator of p53, which acts as modifier, stabilizing p53 half-life and playing a key role in p53 mediating apoptosis after DNA damage. NF-κB is a transcription factor with a central role in many cellular events, including inflammation and apoptosis. Our experiments demonstrate that the transcriptional activity of the p65/RelA NF-κB subunit is regulated by HOPS. Importantly, Hops-/- cells have remarkable alterations of pro-inflammatory responses. Specifically, we found that HOPS enhances NF-κB activation leading to increase transcription of inflammatory mediators, through the reduction of IκBα stability. Notably, this effect is mediated by a direct HOPS binding to the E3 ubiquitin ligase TRAF6, which lessens TRAF6 stability ultimately leading increased IKK complex activation. These findings uncover a previously unidentified function of HOPS/Tmub1 as a novel modulator of TRAF6, regulating inflammatory responses driven by activation of the NF-κB signaling pathway. The comprehension on how HOPS/Tmub1 takes part to the inflammatory processes in vivo and whether this function is important in the control of proliferation and tumorigenesis could establish the basis for the development of novel pharmacological strategies.
Collapse
Affiliation(s)
- Marina Maria Bellet
- Department of Experimental Medicine, University of Perugia, 06132, Perugia, Italy
| | - Stefania Pieroni
- Department of Experimental Medicine, University of Perugia, 06132, Perugia, Italy
| | - Marilena Castelli
- Department of Experimental Medicine, University of Perugia, 06132, Perugia, Italy
| | - Danilo Piobbico
- Department of Experimental Medicine, University of Perugia, 06132, Perugia, Italy
| | - Francesca Fallarino
- Department of Experimental Medicine, University of Perugia, 06132, Perugia, Italy
| | - Luigina Romani
- Department of Experimental Medicine, University of Perugia, 06132, Perugia, Italy
| | | | - Giuseppe Servillo
- Department of Experimental Medicine, University of Perugia, 06132, Perugia, Italy.
| |
Collapse
|
22
|
Richardson A, Zentz ZA, Chambers AE, Sandwith SN, Reisinger MA, Saunders DW, Tompkins JD, Riggs AD, Routh ED, Rubenstein EM, Smaldino MA, Vaughn JP, Haney RA, Smaldino PJ. G-Quadruplex Helicase DHX36/G4R1 Engages Nuclear Lamina Proteins in Quiescent Breast Cancer Cells. ACS OMEGA 2020; 5:24916-24926. [PMID: 33015511 PMCID: PMC7528498 DOI: 10.1021/acsomega.0c03723] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 08/21/2020] [Indexed: 06/11/2023]
Abstract
G-quadruplexes (G4s) are nucleic acid structures found enriched within gene regulatory sequences. G4s control fundamental cellular processes, including replication, transcription, and translation. Proto-oncogenes are enriched with G4 sequences, while tumor-suppressor genes are depleted, suggesting roles for G4s in cell survival and proliferation. Specialized helicases participate in G4-mediated gene regulation via enzymatic unwinding activity. One such enzyme, DHX36/G4R1, is the major G4-helicase and is a master regulator of G4-DNAs and mRNAs. G4-resolution promotes the expression of proproliferative genes; as such, DHX36/G4R1 promotes cell proliferation. Little is known about how DHX36/G4R1 itself is regulated in nondividing cells. We hypothesized that DHX36/G4R1 protein binding partners are altered when a cell transitions from a dividing to a quiescent state. We found that DHX36/G4R1 co-purifies with a distinct set of proteins under quiescent conditions, which may represent a novel complex that regulates DHX36/G4R1 during cell cycle transitions and have implications for development and cancer.
Collapse
Affiliation(s)
- Adam.
E. Richardson
- Department
of Biology, Ball State University, Muncie, Indiana 47306, United States
| | - Zachary. A. Zentz
- Department
of Biology, Ball State University, Muncie, Indiana 47306, United States
| | - Antonio E. Chambers
- Department
of Biology, Ball State University, Muncie, Indiana 47306, United States
| | - Siara N. Sandwith
- Department
of Biology, Ball State University, Muncie, Indiana 47306, United States
| | - Michael A. Reisinger
- Department
of Biology, Ball State University, Muncie, Indiana 47306, United States
| | - Destinee W. Saunders
- Department
of Biology, Ball State University, Muncie, Indiana 47306, United States
| | - Joshua D. Tompkins
- Department
of Diabetes Complications and Metabolism, City of Hope, Duarte, California 91010, United States
| | - Arthur D. Riggs
- Department
of Diabetes Complications and Metabolism, City of Hope, Duarte, California 91010, United States
| | - Eric D. Routh
- Lineberger
Comprehensive Cancer Center, University
of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Eric M. Rubenstein
- Department
of Biology, Ball State University, Muncie, Indiana 47306, United States
| | - Melissa A. Smaldino
- Department
of Biology, Ball State University, Muncie, Indiana 47306, United States
| | - James P. Vaughn
- NanoMedica
LLC, Winston-Salem, North Carolina 27101, United States
| | - Robert A. Haney
- Department
of Biology, Ball State University, Muncie, Indiana 47306, United States
| | - Philip J. Smaldino
- Department
of Biology, Ball State University, Muncie, Indiana 47306, United States
| |
Collapse
|
23
|
Cheng LC, Baboo S, Lindsay C, Brusman L, Martinez-Bartolomé S, Tapia O, Zhang X, Yates JR, Gerace L. Identification of new transmembrane proteins concentrated at the nuclear envelope using organellar proteomics of mesenchymal cells. Nucleus 2020; 10:126-143. [PMID: 31142202 PMCID: PMC6550788 DOI: 10.1080/19491034.2019.1618175] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The double membrane nuclear envelope (NE), which is contiguous with the ER, contains nuclear pore complexes (NPCs) – the channels for nucleocytoplasmic transport, and the nuclear lamina (NL) – a scaffold for NE and chromatin organization. Since numerous human diseases linked to NE proteins occur in mesenchyme-derived cells, we used proteomics to characterize NE and other subcellular fractions isolated from mesenchymal stem cells and from adipocytes and myocytes. Based on spectral abundance, we calculated enrichment scores for proteins in the NE fractions. We demonstrated by quantitative immunofluorescence microscopy that five little-characterized proteins with high enrichment scores are substantially concentrated at the NE, with Itprip exposed at the outer nuclear membrane, Smpd4 enriched at the NPC, and Mfsd10, Tmx4, and Arl6ip6 likely residing in the inner nuclear membrane. These proteins provide new focal points for studying the functions of the NE. Moreover, our datasets provide a resource for evaluating additional potential NE proteins.
Collapse
Affiliation(s)
- Li-Chun Cheng
- a Department of Molecular Medicine , The Scripps Research Institute , La Jolla , CA , USA
| | - Sabyasachi Baboo
- a Department of Molecular Medicine , The Scripps Research Institute , La Jolla , CA , USA
| | - Cory Lindsay
- a Department of Molecular Medicine , The Scripps Research Institute , La Jolla , CA , USA
| | - Liza Brusman
- a Department of Molecular Medicine , The Scripps Research Institute , La Jolla , CA , USA
| | | | - Olga Tapia
- a Department of Molecular Medicine , The Scripps Research Institute , La Jolla , CA , USA
| | - Xi Zhang
- a Department of Molecular Medicine , The Scripps Research Institute , La Jolla , CA , USA
| | - John R Yates
- a Department of Molecular Medicine , The Scripps Research Institute , La Jolla , CA , USA
| | - Larry Gerace
- a Department of Molecular Medicine , The Scripps Research Institute , La Jolla , CA , USA
| |
Collapse
|
24
|
Bossone KA, Ellis JA, Holaska JM. Histone acetyltransferase inhibition rescues differentiation of emerin-deficient myogenic progenitors. Muscle Nerve 2020; 62:128-136. [PMID: 32304242 DOI: 10.1002/mus.26892] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 03/05/2020] [Accepted: 04/07/2020] [Indexed: 12/20/2022]
Abstract
INTRODUCTION Emery-Dreifuss muscular dystrophy (EDMD) is a disease characterized by skeletal muscle wasting, major tendon contractures, and cardiac conduction defects. Mutations in the gene encoding emerin cause EDMD1. Our previous studies suggested that emerin activation of histone deacetylase 3 (HDAC3) to reduce histone 4-lysine 5 (H4K5) acetylation (ac) is important for myogenic differentiation. METHODS Pharmacological inhibitors (Nu9056, L002) of histone acetyltransferases targeting acetylated H4K5 were used to test whether increased acetylated H4K5 was responsible for the impaired differentiation seen in emerin-deficient myogenic progenitors. RESULTS Nu9056 and L002 rescued impaired differentiation in emerin deficiency. SRT1720, which inhibits the nicotinamide adenine dinucleotide (NAD)+ -dependent deacetylase sirtuin 1 (SIRT1), failed to rescue myotube formation. DISCUSSION We conclude that emerin regulation of HDAC3 activity to affect H4K5 acetylation dynamics is important for myogenic differentiation. Targeting H4K5ac dynamics represents a potential new strategy for ameliorating the skeletal muscle wasting seen in EDMD1.
Collapse
Affiliation(s)
- Katherine A Bossone
- Department of Biomedical Sciences, Cooper Medical School of Rowan University, Camden, New Jersey, United States.,Department of Pharmaceutical Sciences, University of the Sciences, Philadelphia, Pennsylvania, United States
| | - Joseph A Ellis
- Department of Pharmaceutical Sciences, University of the Sciences, Philadelphia, Pennsylvania, United States
| | - James M Holaska
- Department of Biomedical Sciences, Cooper Medical School of Rowan University, Camden, New Jersey, United States.,Department of Pharmaceutical Sciences, University of the Sciences, Philadelphia, Pennsylvania, United States
| |
Collapse
|
25
|
Casting a Wider Net: Differentiating between Inner Nuclear Envelope and Outer Nuclear Envelope Transmembrane Proteins. Int J Mol Sci 2019; 20:ijms20215248. [PMID: 31652739 PMCID: PMC6862087 DOI: 10.3390/ijms20215248] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 10/17/2019] [Accepted: 10/18/2019] [Indexed: 12/11/2022] Open
Abstract
The nuclear envelope (NE) surrounds the nucleus with a double membrane in eukaryotic cells. The double membranes are embedded with proteins that are synthesized on the endoplasmic reticulum and often destined specifically for either the outer nuclear membrane (ONM) or the inner nuclear membrane (INM). These nuclear envelope transmembrane proteins (NETs) play important roles in cellular function and participate in transcription, epigenetics, splicing, DNA replication, genome architecture, nuclear structure, nuclear stability, nuclear organization, and nuclear positioning. These vital functions are dependent upon both the correct localization and relative concentrations of NETs on the appropriate membrane of the NE. It is, therefore, important to understand the distribution and abundance of NETs on the NE. This review will evaluate the current tools and methodologies available to address this important topic.
Collapse
|
26
|
Capitanchik C, Dixon CR, Swanson SK, Florens L, Kerr ARW, Schirmer EC. Analysis of RNA-Seq datasets reveals enrichment of tissue-specific splice variants for nuclear envelope proteins. Nucleus 2019; 9:410-430. [PMID: 29912636 PMCID: PMC7000147 DOI: 10.1080/19491034.2018.1469351] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Laminopathies yield tissue-specific pathologies, yet arise from mutation of ubiquitously-expressed genes. A little investigated hypothesis to explain this is that the mutated proteins or their partners have tissue-specific splice variants. To test this, we analyzed RNA-Seq datasets, finding novel isoforms or isoform tissue-specificity for: Lap2, linked to cardiomyopathy; Nesprin 2, linked to Emery-Dreifuss muscular dystrophy and Lmo7, that regulates the Emery-Dreifuss muscular dystrophy linked emerin gene. Interestingly, the muscle-specific Lmo7 exon is rich in serine phosphorylation motifs, suggesting regulatory function. Muscle-specific splice variants in non-nuclear envelope proteins linked to other muscular dystrophies were also found. Nucleoporins tissue-specific variants were found for Nup54, Nup133, Nup153 and Nup358/RanBP2. RT-PCR confirmed novel Lmo7 and RanBP2 variants and specific knockdown of the Lmo7 variantreduced myogenic index. Nuclear envelope proteins were enriched for tissue-specific splice variants compared to the rest of the genome, suggesting that splice variants contribute to its tissue-specific functions.
Collapse
Affiliation(s)
- Charlotte Capitanchik
- a The Wellcome Centre for Cell Biology and Institute of Cell Biology , University of Edinburgh , Edinburgh , UK
| | - Charles R Dixon
- a The Wellcome Centre for Cell Biology and Institute of Cell Biology , University of Edinburgh , Edinburgh , UK
| | - Selene K Swanson
- b Stowers Institute for Medical Research , Kansas City , MO , USA
| | - Laurence Florens
- b Stowers Institute for Medical Research , Kansas City , MO , USA
| | - Alastair R W Kerr
- a The Wellcome Centre for Cell Biology and Institute of Cell Biology , University of Edinburgh , Edinburgh , UK
| | - Eric C Schirmer
- a The Wellcome Centre for Cell Biology and Institute of Cell Biology , University of Edinburgh , Edinburgh , UK
| |
Collapse
|
27
|
Wada E, Kato M, Yamashita K, Kokuba H, Liang WC, Bonne G, Hayashi YK. Deficiency of emerin contributes differently to the pathogenesis of skeletal and cardiac muscles in LmnaH222P/H222P mutant mice. PLoS One 2019; 14:e0221512. [PMID: 31430335 PMCID: PMC6701770 DOI: 10.1371/journal.pone.0221512] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 08/08/2019] [Indexed: 11/18/2022] Open
Abstract
Laminopathies are tissue-selective diseases that affect differently in organ systems. Mutations in nuclear envelopes, emerin (Emd) and lamin A/C (Lmna) genes, cause clinically indistinguishable myopathy called Emery-Dreifuss muscular dystrophy (EDMD) and limb-girdle muscular dystrophy. Several murine models for EDMD have been generated; however, emerin-null (Emd) mice do not show obvious skeletal and cardiac muscle phenotypes, and Lmna H222P/H222P mutant (H222P) mice show only a mild phenotype in skeletal muscle when they already have severe cardiomyopathy. Thus, the underlying molecular mechanism of muscle involvement due to nuclear abnormalities is still unclarified. We generated double mutant (Emd-/-/LmnaH222P/H222P; EH) mice to characterize dystrophic changes and to elucidate interactions between emerin and lamin A/C in skeletal and cardiac muscles. As H222P mice, EH mice grow normally and have breeding productivity. EH mice showed severer muscle involvement compared with that of H222P mice which was an independent of cardiac abnormality at 12 weeks of age. Nuclear abnormalities, reduced muscle fiber size and increased fibrosis were prominent in EH mice. Roles of emerin and lamin A/C in satellite cells function and regeneration of muscle fiber were also evaluated by cardiotoxin-induced muscle injury. Delayed increases in myog and myh3 expression were seen in both H222P and EH mice; however, the expression levels of those genes were similar with control and regenerated muscle fiber size was not different at day 7 after injury. These results indicate that EH mouse is a suitable model for studying skeletal muscle involvement, independent of cardiac function, in laminopathies and an interaction between emerin and lamin A/C in different tissues.
Collapse
Affiliation(s)
- Eiji Wada
- Department of Pathophysiology, Tokyo Medical University, Tokyo, Japan
| | - Megumi Kato
- Department of Pathophysiology, Tokyo Medical University, Tokyo, Japan
| | - Kaori Yamashita
- Department of Pathophysiology, Tokyo Medical University, Tokyo, Japan
| | - Hiroko Kokuba
- Institute of Medical Science, Tokyo Medical University, Tokyo, Japan
| | - Wen-Chen Liang
- Department of Pediatrics, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
- Department of Pediatrics, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Gisèle Bonne
- Sorbonne Université, Inserm UMRS 974, Center of Research in Myology, Paris, France
| | - Yukiko K. Hayashi
- Department of Pathophysiology, Tokyo Medical University, Tokyo, Japan
- * E-mail:
| |
Collapse
|
28
|
Sivakumar A, de Las Heras JI, Schirmer EC. Spatial Genome Organization: From Development to Disease. Front Cell Dev Biol 2019; 7:18. [PMID: 30949476 PMCID: PMC6437099 DOI: 10.3389/fcell.2019.00018] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 02/01/2019] [Indexed: 12/29/2022] Open
Abstract
Every living organism, from bacteria to humans, contains DNA encoding anything from a few hundred genes in intracellular parasites such as Mycoplasma, up to several tens of thousands in many higher organisms. The first observations indicating that the nucleus had some kind of organization were made over a hundred years ago. Understanding of its significance is both limited and aided by the development of techniques, in particular electron microscopy, fluorescence in situ hybridization, DamID and most recently HiC. As our knowledge about genome organization grows, it becomes apparent that the mechanisms are conserved in evolution, even if the individual players may vary. These mechanisms involve DNA binding proteins such as histones, and a number of architectural proteins, some of which are very much conserved, with some others having diversified and multiplied, acquiring specific regulatory functions. In this review we will look at the principles of genome organization in a hierarchical manner, from DNA packaging to higher order genome associations such as TADs, and the significance of radial positioning of genomic loci. We will then elaborate on the dynamics of genome organization during development, and how genome architecture plays an important role in cell fate determination. Finally, we will discuss how misregulation can be a factor in human disease.
Collapse
Affiliation(s)
- Aishwarya Sivakumar
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Jose I de Las Heras
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Eric C Schirmer
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| |
Collapse
|
29
|
Serebryannyy LA, Ball DA, Karpova TS, Misteli T. Single molecule analysis of lamin dynamics. Methods 2019; 157:56-65. [PMID: 30145357 PMCID: PMC6387858 DOI: 10.1016/j.ymeth.2018.08.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 08/20/2018] [Accepted: 08/21/2018] [Indexed: 12/28/2022] Open
Abstract
The nuclear envelope (NE) is an essential cellular structure that contributes to nuclear stability, organization, and function. Mutations in NE-associated proteins result in a myriad of pathologies with widely diverse clinical manifestations, ages of onsets, and affected tissues. Notably, several hundred disease-causing mutations have been mapped to the LMNA gene, which encodes the intermediate filament proteins lamin A and C, two of the major architectural components of the nuclear envelope. However, how NE dysfunction leads to the highly variable pathologies observed in patient cells and tissues remains poorly understood. One model suggests alterations in the dynamic properties of the nuclear lamina and its associated proteins contribute to disease phenotype. Here, we describe the application of single molecule tracking (SMT) methodology to characterize the behavior of nuclear envelope transmembrane proteins and nuclear lamins in their native cellular environment at the single molecule level. As proof-of-concept, we demonstrate by SMT that Halo-tagged lamin B1, Samp1, lamin A, and lamin AΔ50 have distinct binding and kinetic properties, and we identify several disease-relevant mutants which exhibit altered binding dynamics. SMT is also able to separately probe the dynamics of the peripheral and the nucleoplasmic populations of lamin A mutants. We suggest that SMT is a robust and sensitive method to investigate the relationship between pathogenic mutations or cellular processes and protein dynamics at the NE.
Collapse
Affiliation(s)
- Leonid A Serebryannyy
- Cell Biology of Genomes Group, National Cancer Institute, National Institutes of Health, 41 Library Drive, Bethesda, MD 20892, USA
| | - David A Ball
- Center for Cancer Research, Laboratory of Receptor Biology and Gene Expression, Optical Microscopy Core, National Cancer Institute, National Institutes of Health, Building 41, 41 Library Drive, Bethesda, MD 20892, USA
| | - Tatiana S Karpova
- Center for Cancer Research, Laboratory of Receptor Biology and Gene Expression, Optical Microscopy Core, National Cancer Institute, National Institutes of Health, Building 41, 41 Library Drive, Bethesda, MD 20892, USA
| | - Tom Misteli
- Cell Biology of Genomes Group, National Cancer Institute, National Institutes of Health, 41 Library Drive, Bethesda, MD 20892, USA.
| |
Collapse
|
30
|
Michieletto D, Lusic M, Marenduzzo D, Orlandini E. Physical principles of retroviral integration in the human genome. Nat Commun 2019; 10:575. [PMID: 30718508 PMCID: PMC6362086 DOI: 10.1038/s41467-019-08333-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 12/13/2018] [Indexed: 12/26/2022] Open
Abstract
Certain retroviruses, including HIV, insert their DNA in a non-random fraction of the host genome via poorly understood selection mechanisms. Here, we develop a biophysical model for retroviral integration as stochastic and quasi-equilibrium topological reconnections between polymers. We discover that physical effects, such as DNA accessibility and elasticity, play important and universal roles in this process. Our simulations predict that integration is favoured within nucleosomal and flexible DNA, in line with experiments, and that these biases arise due to competing energy barriers associated with DNA deformations. By considering a long chromosomal region in human T-cells during interphase, we discover that at these larger scales integration sites are predominantly determined by chromatin accessibility. Finally, we propose and solve a reaction-diffusion problem that recapitulates the distribution of HIV hot-spots within T-cells. With few generic assumptions, our model can rationalise experimental observations and identifies previously unappreciated physical contributions to retroviral integration site selection.
Collapse
Affiliation(s)
- D. Michieletto
- SUPA, School of Physics and Astronomy, University of Edinburgh, Peter Guthrie Tait Road, Edinburgh, EH9 3FD UK
| | - M. Lusic
- Department of Infectious Diseases, Integrative Virology, Heidelberg University Hospital and German Center for Infection Research, Im Neuenheimer Feld 344, 69120 Heidelberg, Germany
| | - D. Marenduzzo
- SUPA, School of Physics and Astronomy, University of Edinburgh, Peter Guthrie Tait Road, Edinburgh, EH9 3FD UK
| | - E. Orlandini
- Dipartimento di Fisica e Astronomia and Sezione INFN, Universitá di Padova, Via Marzolo 8, 35131 Padova, Italy
| |
Collapse
|
31
|
Host Vesicle Fusion Protein VAPB Contributes to the Nuclear Egress Stage of Herpes Simplex Virus Type-1 (HSV-1) Replication. Cells 2019; 8:cells8020120. [PMID: 30717447 PMCID: PMC6406291 DOI: 10.3390/cells8020120] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 01/28/2019] [Accepted: 01/31/2019] [Indexed: 12/18/2022] Open
Abstract
The primary envelopment/de-envelopment of Herpes viruses during nuclear exit is poorly understood. In Herpes simplex virus type-1 (HSV-1), proteins pUL31 and pUL34 are critical, while pUS3 and some others contribute; however, efficient membrane fusion may require additional host proteins. We postulated that vesicle fusion proteins present in the nuclear envelope might facilitate primary envelopment and/or de-envelopment fusion with the outer nuclear membrane. Indeed, a subpopulation of vesicle-associated membrane protein-associated protein B (VAPB), a known vesicle trafficking protein, was present in the nuclear membrane co-locating with pUL34. VAPB knockdown significantly reduced both cell-associated and supernatant virus titers. Moreover, VAPB depletion reduced cytoplasmic accumulation of virus particles and increased levels of nuclear encapsidated viral DNA. These results suggest that VAPB is an important player in the exit of primary enveloped HSV-1 virions from the nucleus. Importantly, VAPB knockdown did not alter pUL34, calnexin or GM-130 localization during infection, arguing against an indirect effect of VAPB on cellular vesicles and trafficking. Immunogold-labelling electron microscopy confirmed VAPB presence in nuclear membranes and moreover associated with primary enveloped HSV-1 particles. These data suggest that VAPB could be a cellular component of a complex that facilitates UL31/UL34/US3-mediated HSV-1 nuclear egress.
Collapse
|
32
|
Moonlighting nuclear pore proteins: tissue-specific nucleoporin function in health and disease. Histochem Cell Biol 2018; 150:593-605. [PMID: 30361777 DOI: 10.1007/s00418-018-1748-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/19/2018] [Indexed: 12/14/2022]
Abstract
The nuclear pore complex is the main transportation hub for exchange between the cytoplasm and the nucleus. It is built from nucleoporins that form distinct subcomplexes to establish this huge protein complex in the nuclear envelope. Malfunctioning of nucleoporins is well known in human malignancies, such as gene fusions of NUP214 and NUP98 in hematological neoplasms and overexpression of NUP88 in a variety of human cancers. In the past decade, the incremental utilization of next-generation sequencing has unraveled mutations in nucleoporin genes in the context of an increasing number of hereditary diseases, often in a tissue-specific manner. It emerges that, on one hand, the central nervous system and the heart are particularly sensitive to mutations in nucleoporin genes. On the other hand, nucleoporins forming the scaffold structure of the nuclear pore complex are eminently mutation-prone. These novel and exciting associations between nucleoporins and human diseases emphasize the need to shed light on these unanticipated tissue-specific roles of nucleoporins that may go well beyond their role in nucleocytoplasmic transport. In this review, the current insights into altered nucleoporin function associated with human hereditary disorders will be discussed.
Collapse
|
33
|
Abstract
PURPOSE OF REVIEW Nuclear envelope links to a wide range of disorders, including several myopathies and neuropathies over the past 2 decades, has spurred research leading to a completely changed view of this important cellular structure and its functions. However, the many functions now assigned to the nuclear envelope make it increasingly hard to determine which functions underlie these disorders. RECENT FINDINGS New nuclear envelope functions in genome organization, regulation and repair, signaling, and nuclear and cellular mechanics have been added to its classical barrier function. Arguments can be made for any of these functions mediating abnormality in nuclear envelope disorders and data exist supporting many. Moreover, transient and/or distal nuclear envelope connections to other cellular proteins and structures may increase the complexity of these disorders. SUMMARY Although the increased understanding of nuclear envelope functions has made it harder to distinguish specific causes of nuclear envelope disorders, this is because it has greatly expanded the spectrum of possible mechanisms underlying them. This change in perspective applies well beyond the known nuclear envelope disorders, potentially implicating the nuclear envelope in a much wider range of myopathies and neuropathies.
Collapse
|
34
|
Gerace L, Tapia O. Messages from the voices within: regulation of signaling by proteins of the nuclear lamina. Curr Opin Cell Biol 2018; 52:14-21. [PMID: 29306725 DOI: 10.1016/j.ceb.2017.12.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Accepted: 12/14/2017] [Indexed: 12/30/2022]
Abstract
The nuclear lamina (NL) is a protein scaffold lining the nuclear envelope that consists of nuclear lamins and associated transmembrane proteins. It helps to organize the nuclear envelope, chromosomes, and the cytoplasmic cytoskeleton. The NL also has an important role in regulation of signaling, as highlighted by the wide range of human diseases caused by mutations in the genes for NL proteins with associated signaling defects. This review will consider diverse mechanisms for signaling regulation by the NL that have been uncovered recently, including interaction with signaling effectors, modulation of actin assembly and compositional alteration of the NL. Cells with discrete NL mutations often show disruption of multiple signaling pathways, however, and for the most part the mechanistic basis for these complex phenotypes remains to be elucidated.
Collapse
Affiliation(s)
- Larry Gerace
- Department of Molecular Medicine, The Scripps Research Institute, 10550 N Torrey Pines Rd, La Jolla, CA 92037, United States.
| | - Olga Tapia
- Department of Molecular Medicine, The Scripps Research Institute, 10550 N Torrey Pines Rd, La Jolla, CA 92037, United States; Department of Anatomy and Cell Biology and CIBERNED, University of Cantabria-IDIVAL, Cardenal H Oria s/n, 39011 Santander, Spain
| |
Collapse
|
35
|
Jafferali MH, Figueroa RA, Hasan M, Hallberg E. Spindle associated membrane protein 1 (Samp1) is required for the differentiation of muscle cells. Sci Rep 2017; 7:16655. [PMID: 29192166 PMCID: PMC5709512 DOI: 10.1038/s41598-017-16746-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 10/20/2017] [Indexed: 01/15/2023] Open
Abstract
Muscles are developed and regenerated in a differentiation process called myogenesis, which involves components of the nuclear envelope. We have investigated Samp1 (Spindle Associated Membrane Protein 1), a transmembrane nuclear envelope protein, which interacts with emerin and lamin A, both of which are linked to Emery-Dreifuss muscular dystrophy (EDMD). We found that the levels of Samp1 increased seven-fold during differentiation of mouse C2C12 muscle progenitor cells. To test if Samp1 could have a role in myogenesis we developed stable C2C12 knockdown cell lines expressing short hairpin RNA targeting Samp1 expression. The Samp1 depleted C2C12 cells displayed normal mobility and normal distribution of emerin and lamin A. However, Samp1 depletion increased ERK signaling and completely blocked differentiation of C2C12 cells, which failed to express myogenic marker proteins and failed to form myotubes. The block in myogenesis in Samp1 depleted cells was completely rescued by ectopic expression of RNAi resistant human Samp1, showing that Samp1 is required for muscle differentiation.
Collapse
Affiliation(s)
- Mohammed Hakim Jafferali
- Department of Neurochemistry, Stockholm University, Svante Arrhenius väg 16B, SE-106 91, Stockholm, Sweden
| | - Ricardo A Figueroa
- Department of Neurochemistry, Stockholm University, Svante Arrhenius väg 16B, SE-106 91, Stockholm, Sweden
| | - Mehedi Hasan
- Department of Neurochemistry, Stockholm University, Svante Arrhenius väg 16B, SE-106 91, Stockholm, Sweden
| | - Einar Hallberg
- Department of Neurochemistry, Stockholm University, Svante Arrhenius väg 16B, SE-106 91, Stockholm, Sweden.
| |
Collapse
|
36
|
Breaking the scale: how disrupting the karyoplasmic ratio gives cancer cells an advantage for metastatic invasion. Biochem Soc Trans 2017; 45:1333-1344. [PMID: 29150524 DOI: 10.1042/bst20170153] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 09/28/2017] [Accepted: 10/16/2017] [Indexed: 01/03/2023]
Abstract
Nuclear size normally scales with the size of the cell, but in cancer this 'karyoplasmic ratio' is disrupted. This is particularly so in more metastatic tumors where changes in the karyoplasmic ratio are used in both diagnosis and prognosis for several tumor types. However, the direction of nuclear size changes differs for particular tumor types: for example in breast cancer, larger nuclear size correlates with increased metastasis, while for lung cancer smaller nuclear size correlates with increased metastasis. Thus, there must be tissue-specific drivers of the nuclear size changes, but proteins thus far linked to nuclear size regulation are widely expressed. Notably, for these tumor types, ploidy changes have been excluded as the basis for nuclear size changes, and so, the increased metastasis is more likely to have a basis in the nuclear morphology change itself. We review what is known about nuclear size regulation and postulate how such nuclear size changes can increase metastasis and why the directionality can differ for particular tumor types.
Collapse
|
37
|
Wasik AA, Schiller HB. Functional proteomics of cellular mechanosensing mechanisms. Semin Cell Dev Biol 2017; 71:118-128. [DOI: 10.1016/j.semcdb.2017.06.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 06/23/2017] [Accepted: 06/25/2017] [Indexed: 10/19/2022]
|
38
|
Serebryannyy L, Misteli T. Protein sequestration at the nuclear periphery as a potential regulatory mechanism in premature aging. J Cell Biol 2017; 217:21-37. [PMID: 29051264 PMCID: PMC5748986 DOI: 10.1083/jcb.201706061] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 08/10/2017] [Accepted: 08/17/2017] [Indexed: 12/19/2022] Open
Abstract
Serebryannyy and Misteli provide a perspective on how protein sequestration at the inner nuclear membrane and nuclear lamina might influence aging. Despite the extensive description of numerous molecular changes associated with aging, insights into the driver mechanisms of this fundamental biological process are limited. Based on observations in the premature aging syndrome Hutchinson–Gilford progeria, we explore the possibility that protein regulation at the inner nuclear membrane and the nuclear lamina contributes to the aging process. In support, sequestration of nucleoplasmic proteins to the periphery impacts cell stemness, the response to cytotoxicity, proliferation, changes in chromatin state, and telomere stability. These observations point to the nuclear periphery as a central regulator of the aging phenotype.
Collapse
Affiliation(s)
| | - Tom Misteli
- National Cancer Institute, National Institutes of Health, Bethesda, MD
| |
Collapse
|
39
|
Robson MI, de Las Heras JI, Czapiewski R, Sivakumar A, Kerr ARW, Schirmer EC. Constrained release of lamina-associated enhancers and genes from the nuclear envelope during T-cell activation facilitates their association in chromosome compartments. Genome Res 2017; 27:1126-1138. [PMID: 28424353 PMCID: PMC5495065 DOI: 10.1101/gr.212308.116] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 04/12/2017] [Indexed: 01/15/2023]
Abstract
The 3D organization of the genome changes concomitantly with expression changes during hematopoiesis and immune activation. Studies have focused either on lamina-associated domains (LADs) or on topologically associated domains (TADs), defined by preferential local chromatin interactions, and chromosome compartments, defined as higher-order interactions between TADs sharing functionally similar states. However, few studies have investigated how these affect one another. To address this, we mapped LADs using Lamin B1-DamID during Jurkat T-cell activation, finding significant genome reorganization at the nuclear periphery dominated by release of loci frequently important for T-cell function. To assess how these changes at the nuclear periphery influence wider genome organization, our DamID data sets were contrasted with TADs and compartments. Features of specific repositioning events were then tested by fluorescence in situ hybridization during T-cell activation. First, considerable overlap between TADs and LADs was observed with the TAD repositioning as a unit. Second, A1 and A2 subcompartments are segregated in 3D space through differences in proximity to LADs along chromosomes. Third, genes and a putative enhancer in LADs that were released from the periphery during T-cell activation became preferentially associated with A2 subcompartments and were constrained to the relative proximity of the lamina. Thus, lamina associations influence internal nuclear organization, and changes in LADs during T-cell activation may provide an important additional mode of gene regulation.
Collapse
Affiliation(s)
- Michael I Robson
- The Wellcome Trust Centre for Cell Biology and Institute of Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
| | - Jose I de Las Heras
- The Wellcome Trust Centre for Cell Biology and Institute of Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
| | - Rafal Czapiewski
- The Wellcome Trust Centre for Cell Biology and Institute of Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
| | - Aishwarya Sivakumar
- The Wellcome Trust Centre for Cell Biology and Institute of Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
| | - Alastair R W Kerr
- The Wellcome Trust Centre for Cell Biology and Institute of Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
| | - Eric C Schirmer
- The Wellcome Trust Centre for Cell Biology and Institute of Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
| |
Collapse
|
40
|
Thanisch K, Song C, Engelkamp D, Koch J, Wang A, Hallberg E, Foisner R, Leonhardt H, Stewart CL, Joffe B, Solovei I. Nuclear envelope localization of LEMD2 is developmentally dynamic and lamin A/C dependent yet insufficient for heterochromatin tethering. Differentiation 2017; 94:58-70. [PMID: 28056360 DOI: 10.1016/j.diff.2016.12.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 12/05/2016] [Accepted: 12/06/2016] [Indexed: 11/28/2022]
Abstract
Peripheral heterochromatin in mammalian nuclei is tethered to the nuclear envelope by at least two mechanisms here referred to as the A- and B-tethers. The A-tether includes lamins A/C and additional unknown components presumably INM protein(s) interacting with both lamins A/C and chromatin. The B-tether includes the inner nuclear membrane (INM) protein Lamin B-receptor, which binds B-type lamins and chromatin. Generally, at least one of the tethers is always present in the nuclear envelope of mammalian cells. Deletion of both causes the loss of peripheral heterochromatin and consequently inversion of the entire nuclear architecture, with this occurring naturally in rod photoreceptors of nocturnal mammals. The tethers are differentially utilized during development, regulate gene expression in opposite manners, and play an important role during cell differentiation. Here we aimed to identify the unknown chromatin binding component(s) of the A-tether. We analyzed 10 mouse tissues by immunostaining with antibodies against 7 INM proteins and found that every cell type has specific, although differentially and developmentally regulated, sets of these proteins. In particular, we found that INM protein LEMD2 is concomitantly expressed with A-type lamins in various cell types but is lacking in inverted nuclei of rod cells. Truncation or deletion of Lmna resulted in the downregulation and mislocalization of LEMD2, suggesting that the two proteins interact and pointing at LEMD2 as a potential chromatin binding mediator of the A-tether. Using nuclei of mouse rods as an experimental model lacking peripheral heterochromatin, we expressed a LEMD2 transgene alone or in combination with lamin C in these cells and observed no restoration of peripheral heterochromatin in either case. We conclude that in contrary to the B-tether, the A-tether has a more intricate composition and consists of multiple components that presumably vary, at differing degrees of redundancy, between cell types and differentiation stages.
Collapse
Affiliation(s)
- Katharina Thanisch
- Department of Biology II, Ludwig-Maximilians-University Munich, Grosshadernerstrasse 2, 82152 Planegg-Martinsried, Germany
| | - Congdi Song
- Department of Biology II, Ludwig-Maximilians-University Munich, Grosshadernerstrasse 2, 82152 Planegg-Martinsried, Germany
| | - Dieter Engelkamp
- Transgenic Service Facility, BTE, Franz-Penzoldt-Centre, Friedrich-Alexander-University of Erlangen-Nürnberg, Erwin-Rommel-Str.3, D-91058 Erlangen, Germany
| | - Jeannette Koch
- Department of Biology II, Ludwig-Maximilians-University Munich, Grosshadernerstrasse 2, 82152 Planegg-Martinsried, Germany
| | - Audrey Wang
- Institute of Medical Biology, 8A Biomedical Grove and Dept of Biological Sciences, NUS, 138648, Singapore
| | - Einar Hallberg
- Department of Neurochemistry, Stockholm University, Se-106 91 Stockholm, Sweden
| | - Roland Foisner
- Max F. Perutz Laboratories, Medical University of Vienna, Vienna Biocenter (VBC), Dr. Bohr-Gasse 9, A-1030 Vienna, Austria
| | - Heinrich Leonhardt
- Department of Biology II, Ludwig-Maximilians-University Munich, Grosshadernerstrasse 2, 82152 Planegg-Martinsried, Germany
| | - Colin L Stewart
- Institute of Medical Biology, 8A Biomedical Grove and Dept of Biological Sciences, NUS, 138648, Singapore.
| | - Boris Joffe
- Department of Biology II, Ludwig-Maximilians-University Munich, Grosshadernerstrasse 2, 82152 Planegg-Martinsried, Germany
| | - Irina Solovei
- Department of Biology II, Ludwig-Maximilians-University Munich, Grosshadernerstrasse 2, 82152 Planegg-Martinsried, Germany.
| |
Collapse
|
41
|
Collins CM, Ellis JA, Holaska JM. MAPK signaling pathways and HDAC3 activity are disrupted during differentiation of emerin-null myogenic progenitor cells. Dis Model Mech 2017; 10:385-397. [PMID: 28188262 PMCID: PMC5399572 DOI: 10.1242/dmm.028787] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 02/01/2017] [Indexed: 01/28/2023] Open
Abstract
Mutations in the gene encoding emerin cause Emery–Dreifuss muscular dystrophy (EDMD). Emerin is an integral inner nuclear membrane protein and a component of the nuclear lamina. EDMD is characterized by skeletal muscle wasting, cardiac conduction defects and tendon contractures. The failure to regenerate skeletal muscle is predicted to contribute to the skeletal muscle pathology of EDMD. We hypothesize that muscle regeneration defects are caused by impaired muscle stem cell differentiation. Myogenic progenitors derived from emerin-null mice were used to confirm their impaired differentiation and analyze selected myogenic molecular pathways. Emerin-null progenitors were delayed in their cell cycle exit, had decreased myosin heavy chain (MyHC) expression and formed fewer myotubes. Emerin binds to and activates histone deacetylase 3 (HDAC3). Here, we show that theophylline, an HDAC3-specific activator, improved myotube formation in emerin-null cells. Addition of the HDAC3-specific inhibitor RGFP966 blocked myotube formation and MyHC expression in wild-type and emerin-null myogenic progenitors, but did not affect cell cycle exit. Downregulation of emerin was previously shown to affect the p38 MAPK and ERK/MAPK pathways in C2C12 myoblast differentiation. Using a pure population of myogenic progenitors completely lacking emerin expression, we show that these pathways are also disrupted. ERK inhibition improved MyHC expression in emerin-null cells, but failed to rescue myotube formation or cell cycle exit. Inhibition of p38 MAPK prevented differentiation in both wild-type and emerin-null progenitors. These results show that each of these molecular pathways specifically regulates a particular stage of myogenic differentiation in an emerin-dependent manner. Thus, pharmacological targeting of multiple pathways acting at specific differentiation stages may be a better therapeutic approach in the future to rescue muscle regeneration in vivo. Editors' choice: HDAC3, p38 MAPK and ERK signaling are altered during differentiation of myogenic progenitors lacking emerin; pharmacological activation or inhibition of these signaling proteins rescues specific stages of myogenic differentiation.
Collapse
Affiliation(s)
- Carol M Collins
- University of the Sciences, Department of Pharmaceutical Sciences, 600 S. 43rd St, Philadelphia, PA 19104, USA
| | - Joseph A Ellis
- University of the Sciences, Department of Pharmaceutical Sciences, 600 S. 43rd St, Philadelphia, PA 19104, USA
| | - James M Holaska
- University of the Sciences, Department of Pharmaceutical Sciences, 600 S. 43rd St, Philadelphia, PA 19104, USA
| |
Collapse
|
42
|
Thomas C, Tampé R. Proofreading of Peptide-MHC Complexes through Dynamic Multivalent Interactions. Front Immunol 2017; 8:65. [PMID: 28228754 PMCID: PMC5296336 DOI: 10.3389/fimmu.2017.00065] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 01/16/2017] [Indexed: 11/18/2022] Open
Abstract
The adaptive immune system is able to detect and destroy cells that are malignantly transformed or infected by intracellular pathogens. Specific immune responses against these cells are elicited by antigenic peptides that are presented on major histocompatibility complex class I (MHC I) molecules and recognized by cytotoxic T lymphocytes at the cell surface. Since these MHC I-presented peptides are generated in the cytosol by proteasomal protein degradation, they can be metaphorically described as a window providing immune cells with insights into the state of the cellular proteome. A crucial element of MHC I antigen presentation is the peptide-loading complex (PLC), a multisubunit machinery, which contains as key constituents the transporter associated with antigen processing (TAP) and the MHC I-specific chaperone tapasin (Tsn). While TAP recognizes and shuttles the cytosolic antigenic peptides into the endoplasmic reticulum (ER), Tsn samples peptides in the ER for their ability to form stable complexes with MHC I, a process called peptide proofreading or peptide editing. Through its selection of peptides that improve MHC I stability, Tsn contributes to the hierarchy of immunodominant peptide epitopes. Despite the fact that it concerns a key event in adaptive immunity, insights into the catalytic mechanism of peptide proofreading carried out by Tsn have only lately been gained via biochemical, biophysical, and structural studies. Furthermore, a Tsn homolog called TAP-binding protein-related (TAPBPR) has only recently been demonstrated to function as a second MHC I-specific chaperone and peptide proofreader. Although TAPBPR is PLC-independent and has a distinct allomorph specificity, it is likely to share a common catalytic mechanism with Tsn. This review focuses on the current knowledge of the multivalent protein–protein interactions and the concomitant dynamic molecular processes underlying peptide-proofreading catalysis. We do not only derive a model that highlights the common mechanistic principles shared by the MHC I editors Tsn and TAPBPR, and the MHC II editor HLA-DM, but also illustrate the distinct quality control strategies employed by these chaperones to sample epitopes. Unraveling the mechanistic underpinnings of catalyzed peptide proofreading will be crucial for a thorough understanding of many aspects of immune recognition, from infection control and tumor immunity to autoimmune diseases and transplant rejection.
Collapse
Affiliation(s)
- Christoph Thomas
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt , Frankfurt am Main , Germany
| | - Robert Tampé
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt , Frankfurt am Main , Germany
| |
Collapse
|
43
|
Hieda M. Implications for Diverse Functions of the LINC Complexes Based on the Structure. Cells 2017; 6:cells6010003. [PMID: 28134781 PMCID: PMC5371868 DOI: 10.3390/cells6010003] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 01/15/2017] [Accepted: 01/17/2017] [Indexed: 12/18/2022] Open
Abstract
The linker of nucleoskeleton and cytoskeleton (LINC) complex is composed of the outer and inner nuclear membrane protein families Klarsicht, Anc-1, and Syne homology (KASH), and Sad1 and UNC-84 (SUN) homology domain proteins. Increasing evidence has pointed to diverse functions of the LINC complex, such as in nuclear migration, nuclear integrity, chromosome movement and pairing during meiosis, and mechanotransduction to the genome. In metazoan cells, the nuclear envelope possesses the nuclear lamina, which is a thin meshwork of intermediate filaments known as A-type and B-type lamins and lamin binding proteins. Both of lamins physically interact with the inner nuclear membrane spanning SUN proteins. The nuclear lamina has also been implicated in various functions, including maintenance of nuclear integrity, mechanotransduction, cellular signalling, and heterochromatin dynamics. Thus, it is clear that the LINC complex and nuclear lamins perform diverse but related functions. However, it is unknown whether the LINC complex-lamins interactions are involved in these diverse functions, and their regulation mechanism has thus far been elusive. Recent structural analysis suggested a dynamic nature of the LINC complex component, thus providing an explanation for LINC complex organization. This review, elaborating on the integration of crystallographic and biochemical data, helps to integrate this research to gain a better understanding of the diverse functions of the LINC complex.
Collapse
Affiliation(s)
- Miki Hieda
- Department of Medical Technology, Ehime Prefectural University of Health Sciences, Ehime 791-2101, Japan.
| |
Collapse
|
44
|
de Las Heras JI, Zuleger N, Batrakou DG, Czapiewski R, Kerr ARW, Schirmer EC. Tissue-specific NETs alter genome organization and regulation even in a heterologous system. Nucleus 2017; 8:81-97. [PMID: 28045568 PMCID: PMC5287206 DOI: 10.1080/19491034.2016.1261230] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Different cell types exhibit distinct patterns of 3D genome organization that correlate with changes in gene expression in tissue and differentiation systems. Several tissue-specific nuclear envelope transmembrane proteins (NETs) have been found to influence the spatial positioning of genes and chromosomes that normally occurs during tissue differentiation. Here we study 3 such NETs: NET29, NET39, and NET47, which are expressed preferentially in fat, muscle and liver, respectively. We found that even when exogenously expressed in a heterologous system they can specify particular genome organization patterns and alter gene expression. Each NET affected largely different subsets of genes. Notably, the liver-specific NET47 upregulated many genes in HT1080 fibroblast cells that are normally upregulated in hepatogenesis, showing that tissue-specific NETs can favor expression patterns associated with the tissue where the NET is normally expressed. Similarly, global profiling of peripheral chromatin after exogenous expression of these NETs using lamin B1 DamID revealed that each NET affected the nuclear positioning of distinct sets of genomic regions with a significant tissue-specific component. Thus NET influences on genome organization can contribute to gene expression changes associated with differentiation even in the absence of other factors and overt cellular differentiation changes.
Collapse
Affiliation(s)
- Jose I de Las Heras
- a The Wellcome Trust Centre for Cell Biology , University of Edinburgh , Edinburgh , UK
| | - Nikolaj Zuleger
- a The Wellcome Trust Centre for Cell Biology , University of Edinburgh , Edinburgh , UK
| | - Dzmitry G Batrakou
- a The Wellcome Trust Centre for Cell Biology , University of Edinburgh , Edinburgh , UK
| | - Rafal Czapiewski
- a The Wellcome Trust Centre for Cell Biology , University of Edinburgh , Edinburgh , UK
| | - Alastair R W Kerr
- a The Wellcome Trust Centre for Cell Biology , University of Edinburgh , Edinburgh , UK
| | - Eric C Schirmer
- a The Wellcome Trust Centre for Cell Biology , University of Edinburgh , Edinburgh , UK
| |
Collapse
|
45
|
Smoyer CJ, Katta SS, Gardner JM, Stoltz L, McCroskey S, Bradford WD, McClain M, Smith SE, Slaughter BD, Unruh JR, Jaspersen SL. Analysis of membrane proteins localizing to the inner nuclear envelope in living cells. J Cell Biol 2016; 215:575-590. [PMID: 27831485 PMCID: PMC5119940 DOI: 10.1083/jcb.201607043] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 10/03/2016] [Accepted: 10/18/2016] [Indexed: 12/31/2022] Open
Abstract
Understanding the protein composition of the inner nuclear membrane (INM) is fundamental to elucidating its role in normal nuclear function and in disease; however, few tools exist to examine the INM in living cells, and the INM-specific proteome remains poorly characterized. Here, we adapted split green fluorescent protein (split-GFP) to systematically localize known and predicted integral membrane proteins in Saccharomyces cerevisiae to the INM as opposed to the outer nuclear membrane. Our data suggest that components of the endoplasmic reticulum (ER) as well as other organelles are able to access the INM, particularly if they contain a small extraluminal domain. By pairing split-GFP with fluorescence correlation spectroscopy, we compared the composition of complexes at the INM and ER, finding that at least one is unique: Sbh2, but not Sbh1, has access to the INM. Collectively, our work provides a comprehensive analysis of transmembrane protein localization to the INM and paves the way for further research into INM composition and function.
Collapse
Affiliation(s)
| | | | | | - Lynn Stoltz
- Stowers Institute for Medical Research, Kansas City, MO 64110
| | - Scott McCroskey
- Stowers Institute for Medical Research, Kansas City, MO 64110
| | | | | | - Sarah E Smith
- Stowers Institute for Medical Research, Kansas City, MO 64110
| | | | - Jay R Unruh
- Stowers Institute for Medical Research, Kansas City, MO 64110
| | - Sue L Jaspersen
- Stowers Institute for Medical Research, Kansas City, MO 64110 .,Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160
| |
Collapse
|
46
|
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.
Collapse
Affiliation(s)
- James M. Holaska
- Department of Pharmaceutical Sciences, University of the Sciences, Philadelphia, Pennsylvania, USA
| |
Collapse
|
47
|
Zhdanov R, Schirmer E, Venkatasubramani AV, Kerr A, Mandrou E, Rodriguez Blanco G, Kagansky A. Lipids contribute to epigenetic control via chromatin structure and functions. SCIENCEOPEN RESEARCH 2016. [DOI: 10.14293/s2199-1006.1.sor-life.auxytr.v2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Abstract
Isolated cases of experimental evidence over the last few decades have shown that, where specifically tested, both prokaryotes and eukaryotes have specific lipid species bound to nucleoproteins of the genome. In vitro, some of these lipid species exhibit stoichiometric association with DNA polynucleotides with differential affinities toward certain secondary and tertiary structures. Hydrophobic interactions with inner nuclear membrane could provide attractive anchor points for lipid-modified nucleoproteins in organizing the dynamic genome and accordingly there are precedents for covalent bonds between lipids and core histones and, under certain conditions, even DNA. Advances in biophysics, functional genomics, and proteomics in recent years brought about the first sparks of light that promises to uncover some coherent new level of the epigenetic code governed by certain types of lipid–lipid, DNA–lipid, and DNA-protein–lipid interactions among other biochemical lipid transactions in the nucleus. Here, we review some of the older and more recent findings and speculate on how critical nuclear lipid transactions are for individual cells, tissues, and organisms.
Collapse
|
48
|
Lucic B, Lusic M. Connecting HIV-1 integration and transcription: a step toward new treatments. FEBS Lett 2016; 590:1927-39. [PMID: 27224516 DOI: 10.1002/1873-3468.12226] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2016] [Revised: 05/17/2016] [Accepted: 05/24/2016] [Indexed: 12/12/2022]
Abstract
Thanks to the current combined antiretroviral therapy (cART), HIV-1 infection has become a manageable although chronic disease. The reason for this lies in the fact that long-lived cellular reservoirs persist in patients on cART. Despite numerous efforts to understand molecular mechanisms that contribute to viral latency, the important question of how and when latency is established remains unanswered. Related to this is the connection between HIV-1 integration and the capacity of the provirus to enter the latent state. In this review, we will give an overview of these nuclear events in the viral life cycle in the light of current therapeutic approaches, which aim to either reactivate the provirus or even excise the proviral DNA from the cellular genome.
Collapse
Affiliation(s)
- Bojana Lucic
- Department of Infectious Diseases, Integrative Virology, University Hospital Heidelberg and German Center for Infection Research (DZIF), Germany
| | - Marina Lusic
- Department of Infectious Diseases, Integrative Virology, University Hospital Heidelberg and German Center for Infection Research (DZIF), Germany
| |
Collapse
|
49
|
Czapiewski R, Robson MI, Schirmer EC. Anchoring a Leviathan: How the Nuclear Membrane Tethers the Genome. Front Genet 2016; 7:82. [PMID: 27200088 PMCID: PMC4859327 DOI: 10.3389/fgene.2016.00082] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 04/20/2016] [Indexed: 12/21/2022] Open
Abstract
It is well established that the nuclear envelope has many distinct direct connections to chromatin that contribute to genome organization. The functional consequences of genome organization on gene regulation are less clear. Even less understood is how interactions of lamins and nuclear envelope transmembrane proteins (NETs) with chromatin can produce anchoring tethers that can withstand the physical forces of and on the genome. Chromosomes are the largest molecules in the cell, making megadalton protein structures like the nuclear pore complexes and ribosomes seem small by comparison. Thus to withstand strong forces from chromosome dynamics an anchoring tether is likely to be much more complex than a single protein-protein or protein-DNA interaction. Here we will briefly review known NE-genome interactions that likely contribute to spatial genome organization, postulate in the context of experimental data how these anchoring tethers contribute to gene regulation, and posit several hypotheses for the physical nature of these tethers that need to be investigated experimentally. Significantly, disruption of these anchoring tethers and the subsequent consequences for gene regulation could explain how mutations in nuclear envelope proteins cause diseases ranging from muscular dystrophy to lipodystrophy to premature aging progeroid syndromes. The two favored hypotheses for nuclear envelope protein involvement in disease are (1) weakening nuclear and cellular mechanical stability, and (2) disrupting genome organization and gene regulation. Considerable experimental support has been obtained for both. The integration of both mechanical and gene expression defects in the disruption of anchoring tethers could provide a unifying hypothesis consistent with both.
Collapse
Affiliation(s)
| | | | - Eric C. Schirmer
- The Wellcome Trust Centre for Cell Biology and Institute of Cell Biology, University of EdinburghEdinburgh, UK
| |
Collapse
|
50
|
Korfali N, Florens L, Schirmer EC. Isolation, Proteomic Analysis, and Microscopy Confirmation of the Liver Nuclear Envelope Proteome. Methods Mol Biol 2016; 1411:3-44. [PMID: 27147032 DOI: 10.1007/978-1-4939-3530-7_1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Nuclei can be relatively easily extracted from homogenized liver due to the softness of the tissue and crudely separated from other cellular organelles by low-speed centrifugation due to the comparatively large size of nuclei. However, further purification is complicated by nuclear envelope continuity with the endoplasmic reticulum, invaginations containing mitochondria, and connections to the cytoskeleton. Subsequent purification to nuclear envelopes is additionally confounded by connections of inner nuclear membrane proteins to chromatin. For these reasons, it is necessary to confirm proteomic identification of nuclear envelope proteins by testing targeting of individual proteins. The proteomic identification of nuclear envelope fractions is affected by the tendencies of transmembrane proteins to have extreme isoelectric points, strongly hydrophobic peptides, posttranslational modifications, and a propensity to aggregate, thus making proteolysis inefficient. To circumvent these problems, we have developed a MudPIT approach that uses multiple extractions and sequential proteolysis to increase identifications. Here we describe methods for isolating nuclear envelopes, determining their proteome by MudPIT, and confirming their targeting to the nuclear periphery by microscopy.
Collapse
Affiliation(s)
- Nadia Korfali
- The Wellcome Trust Centre for Cell Biology and Institute of Cell Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Laurence Florens
- The Stowers Institute for Medical Research, 1000 E. 50th Street, Kansas City, MO, 64110, USA.
| | - Eric C Schirmer
- The Wellcome Trust Centre for Cell Biology and Institute of Cell Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK.
| |
Collapse
|