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Perales IE, Jones SD, Piaszynski KM, Geyer PK. Developmental changes in nuclear lamina components during germ cell differentiation. Nucleus 2024; 15:2339214. [PMID: 38597409 PMCID: PMC11008544 DOI: 10.1080/19491034.2024.2339214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Accepted: 04/02/2024] [Indexed: 04/11/2024] Open
Abstract
The nuclear lamina (NL) changes composition for regulation of nuclear events. We investigated changes that occur in Drosophila oogenesis, revealing switches in NL composition during germ cell differentiation. Germline stem cells (GSCs) express only LamB and predominantly emerin, whereas differentiating nurse cells predominantly express LamC and emerin2. A change in LamC-specific localization also occurs, wherein phosphorylated LamC redistributes to the nuclear interior only in the oocyte, prior to transcriptional reactivation of the meiotic genome. These changes support existing concepts that LamC promotes differentiation, a premise that was tested. Remarkably ectopic LamC production in GSCs did not promote premature differentiation. Increased LamC levels in differentiating germ cells altered internal nuclear structure, increased RNA production, and reduced female fertility due to defects in eggshell formation. These studies suggest differences between Drosophila lamins are regulatory, not functional, and reveal an unexpected robustness to level changes of a major scaffolding component of the NL.
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Affiliation(s)
- Isabella E. Perales
- Department of Biochemistry and Molecular Biology, University of Iowa, Iowa City, IA, USA
| | - Samuel D. Jones
- Department of Biochemistry and Molecular Biology, University of Iowa, Iowa City, IA, USA
| | | | - Pamela K. Geyer
- Department of Biochemistry and Molecular Biology, University of Iowa, Iowa City, IA, USA
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2
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Duan T, Thyagarajan S, Amoiroglou A, Rogers GC, Geyer PK. Analysis of a rare progeria variant of Barrier-to-autointegration factor in Drosophila connects centromere function to tissue homeostasis. Cell Mol Life Sci 2023; 80:73. [PMID: 36842139 DOI: 10.1007/s00018-023-04721-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 02/05/2023] [Accepted: 02/07/2023] [Indexed: 02/27/2023]
Abstract
Barrier-to-autointegration factor (BAF/BANF) is a nuclear lamina protein essential for nuclear integrity, chromatin structure, and genome stability. Whereas complete loss of BAF causes lethality in multiple organisms, the A12T missense mutation of the BANF1 gene in humans causes a premature aging syndrome, called Néstor-Guillermo Progeria Syndrome (NGPS). Here, we report the first in vivo animal investigation of progeroid BAF, using CRISPR editing to introduce the NGPS mutation into the endogenous Drosophila baf gene. Progeroid BAF adults are born at expected frequencies, demonstrating that this BAF variant retains some function. However, tissue homeostasis is affected, supported by studies of the ovary, a tissue that depends upon BAF for stem cell survival and continuous oocyte production. We find that progeroid BAF causes defects in germline stem cell mitosis that delay anaphase progression and compromise chromosome segregation. We link these defects to decreased recruitment of centromeric proteins of the kinetochore, indicating dysfunction of cenBAF, a localized pool of dephosphorylated BAF produced by Protein Phosphatase PP4. We show that DNA damage increases in progenitor germ cells, which causes germ cell death due to activation of the DNA damage transducer kinase Chk2. Mitotic defects appear widespread, as aberrant chromosome segregation and increased apoptosis occur in another tissue. Together, these data highlight the importance of BAF in establishing centromeric structures critical for mitosis. Further, these studies link defects in cenBAF function to activation of a checkpoint that depletes progenitor reserves critical for tissue homeostasis, aligning with phenotypes of NGPS patients.
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3
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Kirkland NJ, Skalak SH, Whitehead AJ, Hocker JD, Beri P, Vogler G, Hum B, Wang M, Lakatta EG, Ren B, Bodmer R, Engler AJ. Age-dependent Lamin changes induce cardiac dysfunction via dysregulation of cardiac transcriptional programs. Nat Aging 2023; 3:17-33. [PMID: 36845078 PMCID: PMC9956937 DOI: 10.1038/s43587-022-00323-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 10/31/2022] [Indexed: 12/24/2022]
Abstract
As we age, structural changes contribute to progressive decline in organ function, which in the heart act through poorly characterized mechanisms. Taking advantage of the short lifespan and conserved cardiac proteome of the fruit fly, we found that cardiomyocytes exhibit progressive loss of Lamin C (mammalian Lamin A/C homologue) with age, coincident with decreasing nuclear size and increasing nuclear stiffness. Premature genetic reduction of Lamin C phenocopies aging's effects on the nucleus, and subsequently decreases heart contractility and sarcomere organization. Surprisingly, Lamin C reduction downregulates myogenic transcription factors and cytoskeletal regulators, possibly via reduced chromatin accessibility. Subsequently, we find a role for cardiac transcription factors in regulating adult heart contractility and show that maintenance of Lamin C, and cardiac transcription factor expression, prevents age-dependent cardiac decline. Our findings are conserved in aged non-human primates and mice, demonstrating that age-dependent nuclear remodeling is a major mechanism contributing to cardiac dysfunction.
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Affiliation(s)
- Natalie J. Kirkland
- Department of Bioengineering, University California San Diego; La Jolla, CA, USA 92093
- Sanford Consortium for Regenerative Medicine; La Jolla, CA, USA 92037
| | - Scott H. Skalak
- Department of Bioengineering, University California San Diego; La Jolla, CA, USA 92093
- Sanford Consortium for Regenerative Medicine; La Jolla, CA, USA 92037
| | - Alexander J. Whitehead
- Department of Bioengineering, University California San Diego; La Jolla, CA, USA 92093
- Sanford Consortium for Regenerative Medicine; La Jolla, CA, USA 92037
| | - James D. Hocker
- Cell and Molecular Medicine, University California San Diego; La Jolla, CA, USA 92093
- Biomedical Sciences Program, University California San Diego; La Jolla, CA, USA 92093
| | - Pranjali Beri
- Department of Bioengineering, University California San Diego; La Jolla, CA, USA 92093
- Sanford Consortium for Regenerative Medicine; La Jolla, CA, USA 92037
| | - Geo Vogler
- Development, Aging and Regeneration Program, Sanford-Burnham-Prebys Medical Discovery Institute; La Jolla, CA, USA 92037
| | - Bill Hum
- Development, Aging and Regeneration Program, Sanford-Burnham-Prebys Medical Discovery Institute; La Jolla, CA, USA 92037
| | - Mingyi Wang
- Laboratory of Cardiovascular Science, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA 21224
| | - Edward G. Lakatta
- Laboratory of Cardiovascular Science, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA 21224
| | - Bing Ren
- Cell and Molecular Medicine, University California San Diego; La Jolla, CA, USA 92093
- Biomedical Sciences Program, University California San Diego; La Jolla, CA, USA 92093
- Ludwig Institute for Cancer Research; La Jolla, CA, USA 92037
| | - Rolf Bodmer
- Development, Aging and Regeneration Program, Sanford-Burnham-Prebys Medical Discovery Institute; La Jolla, CA, USA 92037
| | - Adam J. Engler
- Department of Bioengineering, University California San Diego; La Jolla, CA, USA 92093
- Biomedical Sciences Program, University California San Diego; La Jolla, CA, USA 92093
- Sanford Consortium for Regenerative Medicine; La Jolla, CA, USA 92037
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4
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Cheng J, Allgeyer ES, Richens JH, Dzafic E, Palandri A, Lewków B, Sirinakis G, St Johnston D. A single-molecule localization microscopy method for tissues reveals nonrandom nuclear pore distribution in Drosophila. J Cell Sci 2021; 134:jcs259570. [PMID: 34806753 PMCID: PMC8729783 DOI: 10.1242/jcs.259570] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 11/11/2021] [Indexed: 01/19/2023] Open
Abstract
Single-molecule localization microscopy (SMLM) can provide nanoscale resolution in thin samples but has rarely been applied to tissues because of high background from out-of-focus emitters and optical aberrations. Here, we describe a line scanning microscope that provides optical sectioning for SMLM in tissues. Imaging endogenously-tagged nucleoporins and F-actin on this system using DNA- and peptide-point accumulation for imaging in nanoscale topography (PAINT) routinely gives 30 nm resolution or better at depths greater than 20 µm. This revealed that the nuclear pores are nonrandomly distributed in most Drosophila tissues, in contrast to what is seen in cultured cells. Lamin Dm0 shows a complementary localization to the nuclear pores, suggesting that it corrals the pores. Furthermore, ectopic expression of the tissue-specific Lamin C causes the nuclear pores to distribute more randomly, whereas lamin C mutants enhance nuclear pore clustering, particularly in muscle nuclei. Given that nucleoporins interact with specific chromatin domains, nuclear pore clustering could regulate local chromatin organization and contribute to the disease phenotypes caused by human lamin A/C laminopathies.
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Affiliation(s)
- Jinmei Cheng
- The Gurdon Institute and Department of Genetics, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
- Institute of Reproductive Medicine, School of Medicine, Nantong University, Nantong 226001, China
| | - Edward S. Allgeyer
- The Gurdon Institute and Department of Genetics, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
| | - Jennifer H. Richens
- The Gurdon Institute and Department of Genetics, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
| | - Edo Dzafic
- The Gurdon Institute and Department of Genetics, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
| | - Amandine Palandri
- The Gurdon Institute and Department of Genetics, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
| | - Bohdan Lewków
- The Gurdon Institute and Department of Genetics, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
| | - George Sirinakis
- The Gurdon Institute and Department of Genetics, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
| | - Daniel St Johnston
- The Gurdon Institute and Department of Genetics, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
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Ryan SM, Almassey M, Burch AM, Ngo G, Martin JM, Myers D, Compton D, Archie S, Cross M, Naeger L, Salzman A, Virola‐Iarussi A, Barbee SA, Mortimer NT, Sanyal S, Vrailas‐Mortimer AD. Drosophila p38 MAPK interacts with BAG-3/starvin to regulate age-dependent protein homeostasis. Aging Cell 2021; 20:e13481. [PMID: 34674371 PMCID: PMC8590102 DOI: 10.1111/acel.13481] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 08/23/2021] [Accepted: 09/09/2021] [Indexed: 12/25/2022] Open
Abstract
As organisms age, they often accumulate protein aggregates that are thought to be toxic, potentially leading to age‐related diseases. This accumulation of protein aggregates is partially attributed to a failure to maintain protein homeostasis. A variety of genetic factors have been linked to longevity, but how these factors also contribute to protein homeostasis is not completely understood. In order to understand the relationship between aging and protein aggregation, we tested how a gene that regulates lifespan and age‐dependent locomotor behaviors, p38 MAPK (p38Kb), influences protein homeostasis as an organism ages. We find that p38Kb regulates age‐dependent protein aggregation through an interaction with starvin, a regulator of muscle protein homeostasis. Furthermore, we have identified Lamin as an age‐dependent target of p38Kb and starvin.
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Affiliation(s)
- Sarah M. Ryan
- Department of Biological Sciences University of Denver Denver CO USA
| | - Michael Almassey
- School of Biological Sciences Illinois State University Normal IL USA
| | | | - Gia Ngo
- Department of Biological Sciences University of Denver Denver CO USA
| | - Julia M. Martin
- School of Biological Sciences Illinois State University Normal IL USA
| | - David Myers
- School of Biological Sciences Illinois State University Normal IL USA
| | - Devin Compton
- School of Biological Sciences Illinois State University Normal IL USA
| | - Shira Archie
- School of Biological Sciences Illinois State University Normal IL USA
| | - Megan Cross
- School of Biological Sciences Illinois State University Normal IL USA
| | - Lauren Naeger
- School of Biological Sciences Illinois State University Normal IL USA
| | - Ashley Salzman
- School of Biological Sciences Illinois State University Normal IL USA
| | | | - Scott A. Barbee
- Department of Biological Sciences University of Denver Denver CO USA
| | | | - Subhabrata Sanyal
- Department of Cell Biology Emory University Atlanta GA USA
- Calico San Francisco CA USA
| | - Alysia D. Vrailas‐Mortimer
- Department of Biological Sciences University of Denver Denver CO USA
- School of Biological Sciences Illinois State University Normal IL USA
- Department of Cell Biology Emory University Atlanta GA USA
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6
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Hinz BE, Walker SG, Xiong A, Gogal RA, Schnieders MJ, Wallrath LL. In Silico and In Vivo Analysis of Amino Acid Substitutions That Cause Laminopathies. Int J Mol Sci 2021; 22:ijms222011226. [PMID: 34681887 PMCID: PMC8536974 DOI: 10.3390/ijms222011226] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 10/07/2021] [Accepted: 10/11/2021] [Indexed: 01/08/2023] Open
Abstract
Mutations in the LMNA gene cause diseases called laminopathies. LMNA encodes lamins A and C, intermediate filaments with multiple roles at the nuclear envelope. LMNA mutations are frequently single base changes that cause diverse disease phenotypes affecting muscles, nerves, and fat. Disease-associated amino acid substitutions were mapped in silico onto three-dimensional structures of lamin A/C, revealing no apparent genotype–phenotype connections. In silico analyses revealed that seven of nine predicted partner protein binding pockets in the Ig-like fold domain correspond to sites of disease-associated amino acid substitutions. Different amino acid substitutions at the same position within lamin A/C cause distinct diseases, raising the question of whether the nature of the amino acid replacement or genetic background differences contribute to disease phenotypes. Substitutions at R249 in the rod domain cause muscular dystrophies with varying severity. To address this variability, we modeled R249Q and R249W in Drosophila Lamin C, an orthologue of LMNA. Larval body wall muscles expressing mutant Lamin C caused abnormal nuclear morphology and premature death. When expressed in indirect flight muscles, R249W caused a greater number of adults with wing posturing defects than R249Q, consistent with observations that R249W and R249Q cause distinct muscular dystrophies, with R249W more severe. In this case, the nature of the amino acid replacement appears to dictate muscle disease severity. Together, our findings illustrate the utility of Drosophila for predicting muscle disease severity and pathogenicity of variants of unknown significance.
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Affiliation(s)
- Benjamin E. Hinz
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA; (B.E.H.); (S.G.W.); (A.X.); (M.J.S.)
| | - Sydney G. Walker
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA; (B.E.H.); (S.G.W.); (A.X.); (M.J.S.)
| | - Austin Xiong
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA; (B.E.H.); (S.G.W.); (A.X.); (M.J.S.)
| | - Rose A. Gogal
- Department of Biomedical Engineering, University of Iowa, Iowa City, IA 52242, USA;
| | - Michael J. Schnieders
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA; (B.E.H.); (S.G.W.); (A.X.); (M.J.S.)
- Department of Biomedical Engineering, University of Iowa, Iowa City, IA 52242, USA;
| | - Lori L. Wallrath
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA; (B.E.H.); (S.G.W.); (A.X.); (M.J.S.)
- Correspondence: ; Tel.: +1-319-335-7920
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7
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Abstract
Lamins interact with the nuclear membrane and chromatin but the precise players and mechanisms of these interactions are unknown. Here, we tested whether the removal of the CaaX motif from Lamin B disrupts its attachment to the nuclear membrane and affects chromatin distribution. We used Drosophila melanogaster LamA25 homozygous mutants that lack the CaaX box. We found that the mutant Lamin B was not confined to the nuclear periphery but was distributed throughout the nuclear interior, colocalizing with chromosomes in salivary gland and proventriculus. The peripheral position of Lamin C, nuclear pore complex (NPC), heterochromatin protein 1a (HP1a), H3K9me2- and H3K27me3-associated chromatin remained intact. The fluorescence intensity of the DAPI-stained peripheral chromatin significantly decreased and that of the central chromatin significantly increased in the proventriculus nuclei of the mutantflies compared to wild-type. However, the mutation had little effect on chromatin radial distribution inside highly polytenized salivary gland nuclei.
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Affiliation(s)
- Semen M Bondarenko
- Department of Entomology, Virginia Polytechnic Institute and State University , Blacksburg, Virginia, USA.,Department of Cytology and Genetics, Tomsk State University , Tomsk, Russian Federation
| | - Igor V Sharakhov
- Department of Entomology, Virginia Polytechnic Institute and State University , Blacksburg, Virginia, USA
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8
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Pathak RU, Soujanya M, Mishra RK. Deterioration of nuclear morphology and architecture: A hallmark of senescence and aging. Ageing Res Rev 2021; 67:101264. [PMID: 33540043 DOI: 10.1016/j.arr.2021.101264] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 01/04/2021] [Accepted: 01/26/2021] [Indexed: 12/15/2022]
Abstract
The metazoan nucleus is a highly structured organelle containing several well-defined sub-organelles. It is the largest organelle inside a cell taking up from one tenth to half of entire cell volume. This makes it one of the easiest organelles to identify and study under the microscope. Abnormalities in the nuclear morphology and architecture are commonly observed in an aged and senescent cell. For example, the nuclei enlarge, loose their shape, appear lobulated, harbour nuclear membrane invaginations, carry enlarged/fragmented nucleolus, loose heterochromatin, etc. In this review we discuss about the age-related changes in nuclear features and elaborate upon the molecular reasons driving the change. Many of these changes can be easily imaged under a microscope and analysed in silico. Thus, computational image analysis of nuclear features appears to be a promising tool to evaluate physiological age of a cell and offers to be a legitimate biomarker. It can be used to examine progression of age-related diseases and evaluate therapies.
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Affiliation(s)
| | - Mamilla Soujanya
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, 500007, Telangana, India
| | - Rakesh Kumar Mishra
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, 500007, Telangana, India.
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9
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Iyer KV, Taubenberger A, Zeidan SA, Dye NA, Eaton S, Jülicher F. Apico-basal cell compression regulates Lamin A/C levels in epithelial tissues. Nat Commun 2021; 12:1756. [PMID: 33767161 PMCID: PMC7994818 DOI: 10.1038/s41467-021-22010-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 02/22/2021] [Indexed: 01/31/2023] Open
Abstract
The levels of nuclear protein Lamin A/C are crucial for nuclear mechanotransduction. Lamin A/C levels are known to scale with tissue stiffness and extracellular matrix levels in mesenchymal tissues. But in epithelial tissues, where cells lack a strong interaction with the extracellular matrix, it is unclear how Lamin A/C is regulated. Here, we show in epithelial tissues that Lamin A/C levels scale with apico-basal cell compression, independent of tissue stiffness. Using genetic perturbations in Drosophila epithelial tissues, we show that apico-basal cell compression regulates the levels of Lamin A/C by deforming the nucleus. Further, in mammalian epithelial cells, we show that nuclear deformation regulates Lamin A/C levels by modulating the levels of phosphorylation of Lamin A/C at Serine 22, a target for Lamin A/C degradation. Taken together, our results reveal a mechanism of Lamin A/C regulation which could provide key insights for understanding nuclear mechanotransduction in epithelial tissues.
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Affiliation(s)
- K. Venkatesan Iyer
- grid.419537.d0000 0001 2113 4567Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany ,grid.419560.f0000 0001 2154 3117Max Planck Institute for the Physics of Complex Systems, Dresden, Germany ,grid.34980.360000 0001 0482 5067Present Address: Department of Mechanical Engineering, Indian Institute of Science, Bangalore, India
| | - Anna Taubenberger
- grid.4488.00000 0001 2111 7257Biotechnology Center TU Dresden, Dresden, Germany
| | - Salma Ahmed Zeidan
- grid.419537.d0000 0001 2113 4567Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Natalie A. Dye
- grid.419537.d0000 0001 2113 4567Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany ,grid.4488.00000 0001 2111 7257Cluster of Excellence Physics of Life, TU Dresden, Dresden, Germany
| | - Suzanne Eaton
- grid.419537.d0000 0001 2113 4567Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany ,grid.4488.00000 0001 2111 7257Cluster of Excellence Physics of Life, TU Dresden, Dresden, Germany
| | - Frank Jülicher
- grid.419560.f0000 0001 2154 3117Max Planck Institute for the Physics of Complex Systems, Dresden, Germany ,grid.4488.00000 0001 2111 7257Cluster of Excellence Physics of Life, TU Dresden, Dresden, Germany ,grid.495510.cCenter for Systems Biology Dresden, Dresden, Germany
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10
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Jiang P, He S, Li Y, Xu Z. Identification of Therapeutic and Prognostic Biomarkers of Lamin C (LAMC) Family Members in Head and Neck Squamous Cell Carcinoma. Med Sci Monit 2020; 26:e925735. [PMID: 32860673 PMCID: PMC7477928 DOI: 10.12659/msm.925735] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Background Head and neck squamous cell carcinoma (HNSC) is an invasive malignancy with a high worldwide mortality, despite considerable recent advancements in diagnosis and treatment. Increasing evidence indicates that the Lamin C (LAMC) gene family is associated with the progression of diverse cancers, nevertheless, this association is not well understood. Material/Methods A systematic study addressing the expression and prognostic value of LAMC, and the relationship between LAMC and tumor immune response in HNSC was done. Finally, we performed drug screening to identify specific drugs. Results Compared to normal samples, expressions of LAMC1 and LAMC2 were significantly increased in HNSC, and LAMC2 was obviously correlated with an adverse prognosis for patients. LAMC2 expression level was significantly correlated with the infiltrating levels of B cells, CD8+ T cells, CD4+ T cells, and macrophages. Moreover, LAMC2 exhibited strong correlations with diverse immune markers, immune microenvironment, and immune checkpoint molecules. Finally, candidate drugs that targeted LAMC2 were identified. Conclusions This study suggests that LAMC2 could serve as a new prognostic biomarker, and it could be used for efficacy of target for immune response and for drug sensitivity prediction in HNSC.
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Affiliation(s)
- Pan Jiang
- Department of Stomatology, The Third People Hospital of Hainan Province, Sanya, Hainan, China (mainland)
| | - Shengteng He
- Department of Stomatology, The Third People Hospital of Hainan Province, Sanya, Hainan, China (mainland)
| | - Yanli Li
- Department of Stomatology, The Third People Hospital of Hainan Province, Sanya, Hainan, China (mainland)
| | - Zheng Xu
- Department of Stomatology, The Third People Hospital of Hainan Province, Sanya, Hainan, China (mainland)
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11
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Grandon B, Rincheval-Arnold A, Jah N, Corsi JM, Araujo LM, Glatigny S, Prevost E, Roche D, Chiocchia G, Guénal I, Gaumer S, Breban M. HLA-B27 alters BMP/TGFβ signalling in Drosophila, revealing putative pathogenic mechanism for spondyloarthritis. Ann Rheum Dis 2019; 78:1653-1662. [PMID: 31563893 DOI: 10.1136/annrheumdis-2019-215832] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 09/08/2019] [Accepted: 09/09/2019] [Indexed: 01/16/2023]
Abstract
OBJECTIVES The human leucocyte antigen (HLA)-B27 confers an increased risk of spondyloarthritis (SpA) by unknown mechanism. The objective of this work was to uncover HLA-B27 non-canonical properties that could explain its pathogenicity, using a new Drosophila model. METHODS We produced transgenic Drosophila expressing the SpA-associated HLA-B*27:04 or HLA-B*27:05 subtypes, or the non-associated HLA-B*07:02 allele, alone or in combination with human β2-microglobulin (hβ2m), under tissue-specific drivers. Consequences of transgenes expression in Drosophila were examined and affected pathways were investigated by the genetic interaction experiments. Predictions of the model were further tested in immune cells from patients with SpA. RESULTS Loss of crossveins in the wings and a reduced eye phenotype were observed after expression of HLA-B*27:04 or HLA-B*27:05 in Drosophila but not in fruit flies expressing the non-associated HLA-B*07:02 allele. These HLA-B27-induced phenotypes required the presence of hβ2m that allowed expression of well-folded HLA-B conformers at the cell surface. Loss of crossveins resulted from a dominant negative effect of HLA-B27 on the type I bone morphogenetic protein (BMP) receptor saxophone (Sax) with which it interacted, resulting in elevated mothers against decapentaplegic (Mad, a Drosophila receptor-mediated Smad) phosphorylation. Likewise, in immune cells from patients with SpA, HLA-B27 specifically interacted with activin receptor-like kinase-2 (ALK2), the mammalian Sax ortholog, at the cell surface and elevated Smad phosphorylation was observed in response to activin A and transforming growth factor β (TGFβ). CONCLUSIONS Antagonistic interaction of HLA-B27 with ALK2, which exerts inhibitory functions on the TGFβ/BMP signalling pathway at the cross-road between inflammation and ossification, could adequately explain SpA development.
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Affiliation(s)
- Benjamin Grandon
- LGBC, EA4589, UVSQ/Université Paris-Saclay, EPHE/PSL Research University, Montigny-le-Bretonneux, France.,Infection & Inflammation, UMR 1173, Inserm, UVSQ/ Université Paris Saclay, Montigny-le-Bretonneux, France
| | - Aurore Rincheval-Arnold
- LGBC, EA4589, UVSQ/Université Paris-Saclay, EPHE/PSL Research University, Montigny-le-Bretonneux, France
| | - Nadège Jah
- Infection & Inflammation, UMR 1173, Inserm, UVSQ/ Université Paris Saclay, Montigny-le-Bretonneux, France
| | - Jean-Marc Corsi
- LGBC, EA4589, UVSQ/Université Paris-Saclay, EPHE/PSL Research University, Montigny-le-Bretonneux, France
| | - Luiza M Araujo
- Infection & Inflammation, UMR 1173, Inserm, UVSQ/ Université Paris Saclay, Montigny-le-Bretonneux, France
| | - Simon Glatigny
- Infection & Inflammation, UMR 1173, Inserm, UVSQ/ Université Paris Saclay, Montigny-le-Bretonneux, France
| | - Erwann Prevost
- LGBC, EA4589, UVSQ/Université Paris-Saclay, EPHE/PSL Research University, Montigny-le-Bretonneux, France.,Infection & Inflammation, UMR 1173, Inserm, UVSQ/ Université Paris Saclay, Montigny-le-Bretonneux, France
| | - Delphine Roche
- LGBC, EA4589, UVSQ/Université Paris-Saclay, EPHE/PSL Research University, Montigny-le-Bretonneux, France
| | - Gilles Chiocchia
- Infection & Inflammation, UMR 1173, Inserm, UVSQ/ Université Paris Saclay, Montigny-le-Bretonneux, France
| | - Isabelle Guénal
- LGBC, EA4589, UVSQ/Université Paris-Saclay, EPHE/PSL Research University, Montigny-le-Bretonneux, France
| | - Sébastien Gaumer
- LGBC, EA4589, UVSQ/Université Paris-Saclay, EPHE/PSL Research University, Montigny-le-Bretonneux, France
| | - Maxime Breban
- Infection & Inflammation, UMR 1173, Inserm, UVSQ/ Université Paris Saclay, Montigny-le-Bretonneux, France .,Rheumatology, Ambroise Paré Hospital, Boulogne Billancourt, France
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12
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Nicolas HA, Akimenko MA, Tesson F. Cellular and Animal Models of Striated Muscle Laminopathies. Cells 2019; 8:E291. [PMID: 30934932 DOI: 10.3390/cells8040291] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 03/18/2019] [Accepted: 03/25/2019] [Indexed: 01/12/2023] Open
Abstract
The lamin A/C (LMNA) gene codes for nuclear intermediate filaments constitutive of the nuclear lamina. LMNA has 12 exons and alternative splicing of exon 10 results in two major isoforms—lamins A and C. Mutations found throughout the LMNA gene cause a group of diseases collectively known as laminopathies, of which the type, diversity, penetrance and severity of phenotypes can vary from one individual to the other, even between individuals carrying the same mutation. The majority of the laminopathies affect cardiac and/or skeletal muscles. The underlying molecular mechanisms contributing to such tissue-specific phenotypes caused by mutations in a ubiquitously expressed gene are not yet well elucidated. This review will explore the different phenotypes observed in established models of striated muscle laminopathies and their respective contributions to advancing our understanding of cardiac and skeletal muscle-related laminopathies. Potential future directions for developing effective treatments for patients with lamin A/C mutation-associated cardiac and/or skeletal muscle conditions will be discussed.
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13
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Chandran S, Suggs JA, Wang BJ, Han A, Bhide S, Cryderman DE, Moore SA, Bernstein SI, Wallrath LL, Melkani GC. Suppression of myopathic lamin mutations by muscle-specific activation of AMPK and modulation of downstream signaling. Hum Mol Genet 2019; 28:351-371. [PMID: 30239736 PMCID: PMC6337691 DOI: 10.1093/hmg/ddy332] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 09/11/2018] [Accepted: 09/13/2018] [Indexed: 12/14/2022] Open
Abstract
Laminopathies are diseases caused by dominant mutations in the human LMNA gene encoding A-type lamins. Lamins are intermediate filaments that line the inner nuclear membrane, provide structural support for the nucleus and regulate gene expression. Drosophila melanogaster models of skeletal muscle laminopathies were developed to investigate the pathological defects caused by mutant lamins and identify potential therapeutic targets. Human disease-causing LMNA mutations were modeled in Drosophila Lamin C (LamC) and expressed in indirect flight muscle (IFM). IFM-specific expression of mutant, but not wild-type LamC, caused held-up wings indicative of myofibrillar defects. Analyses of the muscles revealed cytoplasmic aggregates of nuclear envelope (NE) proteins, nuclear and mitochondrial dysmorphology, myofibrillar disorganization and up-regulation of the autophagy cargo receptor p62. We hypothesized that the cytoplasmic aggregates of NE proteins trigger signaling pathways that alter cellular homeostasis, causing muscle dysfunction. In support of this hypothesis, transcriptomics data from human muscle biopsy tissue revealed misregulation of the AMP-activated protein kinase (AMPK)/4E-binding protein 1 (4E-BP1)/autophagy/proteostatic pathways. Ribosomal protein S6K (S6K) messenger RNA (mRNA) levels were increased and AMPKα and mRNAs encoding downstream targets were decreased in muscles expressing mutant LMNA relative controls. The Drosophila laminopathy models were used to determine if altering the levels of these factors modulated muscle pathology. Muscle-specific over-expression of AMPKα and down-stream targets 4E-BP, Forkhead box transcription factors O (Foxo) and Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α), as well as inhibition of S6K, suppressed the held-up wing phenotype, myofibrillar defects and LamC aggregation. These findings provide novel insights on mutant LMNA-based disease mechanisms and identify potential targets for drug therapy.
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Affiliation(s)
- Sahaana Chandran
- Department of Biology, Molecular Biology and Heart Institutes, San Diego State University, San Diego, CA, USA
| | - Jennifer A Suggs
- Department of Biology, Molecular Biology and Heart Institutes, San Diego State University, San Diego, CA, USA
| | - Bingyan J Wang
- Department of Biology, Molecular Biology and Heart Institutes, San Diego State University, San Diego, CA, USA
| | - Andrew Han
- Department of Biology, Molecular Biology and Heart Institutes, San Diego State University, San Diego, CA, USA
| | - Shruti Bhide
- Department of Biology, Molecular Biology and Heart Institutes, San Diego State University, San Diego, CA, USA
| | - Diane E Cryderman
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Steven A Moore
- Department of Pathology, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Sanford I Bernstein
- Department of Biology, Molecular Biology and Heart Institutes, San Diego State University, San Diego, CA, USA
| | - Lori L Wallrath
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Girish C Melkani
- Department of Biology, Molecular Biology and Heart Institutes, San Diego State University, San Diego, CA, USA
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Pałka M, Tomczak A, Grabowska K, Machowska M, Piekarowicz K, Rzepecka D, Rzepecki R. Laminopathies: what can humans learn from fruit flies. Cell Mol Biol Lett 2018; 23:32. [PMID: 30002683 PMCID: PMC6034310 DOI: 10.1186/s11658-018-0093-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 06/05/2018] [Indexed: 01/01/2023] Open
Abstract
Lamin proteins are type V intermediate filament proteins (IFs) located inside the cell nucleus. They are evolutionarily conserved and have similar domain organization and properties to cytoplasmic IFs. Lamins provide a skeletal network for chromatin, the nuclear envelope, nuclear pore complexes and the entire nucleus. They are also responsible for proper connections between the karyoskeleton and structural elements in the cytoplasm: actin and the microtubule and cytoplasmic IF networks. Lamins affect transcription and splicing either directly or indirectly. Translocation of active genes into the close proximity of nuclear lamina is thought to result in their transcriptional silencing. Mutations in genes coding for lamins and interacting proteins in humans result in various genetic disorders, called laminopathies. Human genes coding for A-type lamin (LMNA) are the most frequently mutated. The resulting phenotypes include muscle, cardiac, neuronal, lipodystrophic and metabolic pathologies, early aging phenotypes, and combined complex phenotypes. The Drosophila melanogaster genome codes for lamin B-type (lamin Dm), lamin A-type (lamin C), and for LEM-domain proteins, BAF, LINC-complex proteins and all typical nuclear proteins. The fruit fly system is simpler than the vertebrate one since in flies there is only single lamin B-type and single lamin A-type protein, as opposed to the complex system of B- and A-type lamins in Danio, Xenopus and Mus musculus. This offers a unique opportunity to study laminopathies. Applying genetic tools based on Gal4 and in vitro nuclear assembly system to the fruit fly model may successfully advance knowledge of laminopathies. Here, we review studies of the laminopathies in the fly model system.
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Affiliation(s)
- Marta Pałka
- Laboratory of Nuclear Proteins, Faculty of Biotechnology, University of Wroclaw, Fryderyka Joliot-Curie 14a, 50-383 Wroclaw, Poland
| | - Aleksandra Tomczak
- Laboratory of Nuclear Proteins, Faculty of Biotechnology, University of Wroclaw, Fryderyka Joliot-Curie 14a, 50-383 Wroclaw, Poland
| | - Katarzyna Grabowska
- Laboratory of Nuclear Proteins, Faculty of Biotechnology, University of Wroclaw, Fryderyka Joliot-Curie 14a, 50-383 Wroclaw, Poland
| | - Magdalena Machowska
- Laboratory of Nuclear Proteins, Faculty of Biotechnology, University of Wroclaw, Fryderyka Joliot-Curie 14a, 50-383 Wroclaw, Poland
| | - Katarzyna Piekarowicz
- Laboratory of Nuclear Proteins, Faculty of Biotechnology, University of Wroclaw, Fryderyka Joliot-Curie 14a, 50-383 Wroclaw, Poland
| | - Dorota Rzepecka
- Laboratory of Nuclear Proteins, Faculty of Biotechnology, University of Wroclaw, Fryderyka Joliot-Curie 14a, 50-383 Wroclaw, Poland
| | - Ryszard Rzepecki
- Laboratory of Nuclear Proteins, Faculty of Biotechnology, University of Wroclaw, Fryderyka Joliot-Curie 14a, 50-383 Wroclaw, Poland
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15
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Donohoe CD, Csordás G, Correia A, Jindra M, Klein C, Habermann B, Uhlirova M. Atf3 links loss of epithelial polarity to defects in cell differentiation and cytoarchitecture. PLoS Genet 2018; 14:e1007241. [PMID: 29494583 PMCID: PMC5849342 DOI: 10.1371/journal.pgen.1007241] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 03/13/2018] [Accepted: 02/05/2018] [Indexed: 12/27/2022] Open
Abstract
Interplay between apicobasal cell polarity modules and the cytoskeleton is critical for differentiation and integrity of epithelia. However, this coordination is poorly understood at the level of gene regulation by transcription factors. Here, we establish the Drosophila activating transcription factor 3 (atf3) as a cell polarity response gene acting downstream of the membrane-associated Scribble polarity complex. Loss of the tumor suppressors Scribble or Dlg1 induces atf3 expression via aPKC but independent of Jun-N-terminal kinase (JNK) signaling. Strikingly, removal of Atf3 from Dlg1 deficient cells restores polarized cytoarchitecture, levels and distribution of endosomal trafficking machinery, and differentiation. Conversely, excess Atf3 alters microtubule network, vesicular trafficking and the partition of polarity proteins along the apicobasal axis. Genomic and genetic approaches implicate Atf3 as a regulator of cytoskeleton organization and function, and identify Lamin C as one of its bona fide target genes. By affecting structural features and cell morphology, Atf3 functions in a manner distinct from other transcription factors operating downstream of disrupted cell polarity. Epithelial cells form sheets and line both the outside and inside of our body. Their proper development and function require the asymmetric distribution of cellular components from the top to the bottom, known as apicobasal polarization. As loss of polarity hallmarks a majority of cancers in humans, understanding how epithelia respond to a collapse of the apicobasal axis is of great interest. Here, we show that in the fruit fly Drosophila melanogaster the breakdown of epithelial polarity engages Activating transcription factor 3 (Atf3), a protein that directly binds the DNA and regulates gene expression. We demonstrate that many of the pathological consequences of disturbed polarity require Atf3, as its loss in this context results in normalization of cellular architecture, vesicle trafficking and differentiation. Using unbiased genome-wide approaches we identify the genetic program controlled by Atf3 and experimentally verify select candidates. Given the evolutionary conservation of Atf3 between flies and man, we believe that our findings in the Drosophila model will contribute to a better understanding of diseases stemming from compromised epithelial polarity.
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Affiliation(s)
- Colin D. Donohoe
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Gábor Csordás
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Andreia Correia
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Marek Jindra
- Biology Center, Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice, Czech Republic
| | - Corinna Klein
- Max Planck Institute for Biology of Ageing, Cologne, Germany
| | | | - Mirka Uhlirova
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
- * E-mail:
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16
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Abstract
Drosophila melanogaster is a useful organism for determining protein function and modeling human disease. Drosophila offers a rapid generation time and an abundance of genomic resources and genetic tools. Conservation in protein structure, signaling pathways, and developmental processes make studies performed in Drosophila relevant to other species, including humans. Drosophila models have been generated for neurodegenerative diseases, muscular dystrophy, cancer, and many other disorders. Recently, intermediate filament protein diseases have been modeled in Drosophila. These models have revealed novel mechanisms of pathology, illuminated potential new routes of therapy, and make whole organism compound screens feasible. The goal of this chapter is to outline steps to study intermediate filament function and model intermediate filament-associated diseases in Drosophila. The steps are general and can be applied to study the function of almost any protein. The protocols outlined here are for both the novice and experienced Drosophila researcher, allowing the rich developmental and cell biology that Drosophila offers to be applied to studies of intermediate filaments.
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Affiliation(s)
- Jens Bohnekamp
- Institute of Biology and Translational Center for Regenerative Medicine, University of Leipzig, Leipzig, Germany
| | - Diane E Cryderman
- Department of Biochemistry, University of Iowa, Iowa City, Iowa, USA
| | - Dylan A Thiemann
- Department of Biochemistry, University of Iowa, Iowa City, Iowa, USA
| | - Thomas M Magin
- Institute of Biology and Translational Center for Regenerative Medicine, University of Leipzig, Leipzig, Germany.
| | - Lori L Wallrath
- Department of Biochemistry, University of Iowa, Iowa City, Iowa, USA.
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17
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Dialynas G, Shrestha OK, Ponce JM, Zwerger M, Thiemann DA, Young GH, Moore SA, Yu L, Lammerding J, Wallrath LL. Myopathic lamin mutations cause reductive stress and activate the nrf2/keap-1 pathway. PLoS Genet 2015; 11:e1005231. [PMID: 25996830 DOI: 10.1371/journal.pgen.1005231] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 04/20/2015] [Indexed: 12/29/2022] Open
Abstract
Mutations in the human LMNA gene cause muscular dystrophy by mechanisms that are incompletely understood. The LMNA gene encodes A-type lamins, intermediate filaments that form a network underlying the inner nuclear membrane, providing structural support for the nucleus and organizing the genome. To better understand the pathogenesis caused by mutant lamins, we performed a structural and functional analysis on LMNA missense mutations identified in muscular dystrophy patients. These mutations perturb the tertiary structure of the conserved A-type lamin Ig-fold domain. To identify the effects of these structural perturbations on lamin function, we modeled these mutations in Drosophila Lamin C and expressed the mutant lamins in muscle. We found that the structural perturbations had minimal dominant effects on nuclear stiffness, suggesting that the muscle pathology was not accompanied by major structural disruption of the peripheral nuclear lamina. However, subtle alterations in the lamina network and subnuclear reorganization of lamins remain possible. Affected muscles had cytoplasmic aggregation of lamins and additional nuclear envelope proteins. Transcription profiling revealed upregulation of many Nrf2 target genes. Nrf2 is normally sequestered in the cytoplasm by Keap-1. Under oxidative stress Nrf2 dissociates from Keap-1, translocates into the nucleus, and activates gene expression. Unexpectedly, biochemical analyses revealed high levels of reducing agents, indicative of reductive stress. The accumulation of cytoplasmic lamin aggregates correlated with elevated levels of the autophagy adaptor p62/SQSTM1, which also binds Keap-1, abrogating Nrf2 cytoplasmic sequestration, allowing Nrf2 nuclear translocation and target gene activation. Elevated p62/SQSTM1 and nuclear enrichment of Nrf2 were identified in muscle biopsies from the corresponding muscular dystrophy patients, validating the disease relevance of our Drosophila model. Thus, novel connections were made between mutant lamins and the Nrf2 signaling pathway, suggesting new avenues of therapeutic intervention that include regulation of protein folding and metabolism, as well as maintenance of redox homoeostasis.
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18
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Barton LJ, Wilmington SR, Martin MJ, Skopec HM, Lovander KE, Pinto BS, Geyer PK. Unique and shared functions of nuclear lamina LEM domain proteins in Drosophila. Genetics 2014; 197:653-65. [PMID: 24700158 DOI: 10.1534/genetics.114.162941] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The nuclear lamina is an extensive protein network that contributes to nuclear structure and function. LEM domain (LAP2, emerin, MAN1 domain, LEM-D) proteins are components of the nuclear lamina, identified by a shared ∼45-amino-acid motif that binds Barrier-to-autointegration factor (BAF), a chromatin-interacting protein. Drosophila melanogaster has three nuclear lamina LEM-D proteins, named Otefin (Ote), Bocksbeutel (Bocks), and dMAN1. Although these LEM-D proteins are globally expressed, loss of either Ote or dMAN1 causes tissue-specific defects in adult flies that differ from each other. The reason for such distinct tissue-restricted defects is unknown. Here, we generated null alleles of bocks, finding that loss of Bocks causes no overt adult phenotypes. Next, we defined phenotypes associated with lem-d double mutants. Although the absence of individual LEM-D proteins does not affect viability, loss of any two proteins causes lethality. Mutant phenotypes displayed by lem-d double mutants differ from baf mutants, suggesting that BAF function is retained in animals with a single nuclear lamina LEM-D protein. Interestingly, lem-d double mutants displayed distinct developmental and cellular mutant phenotypes, suggesting that Drosophila LEM-D proteins have developmental functions that are differentially shared with other LEM-D family members. This conclusion is supported by studies showing that ectopically produced LEM-D proteins have distinct capacities to rescue the tissue-specific phenotypes found in single lem-d mutants. Our findings predict that cell-specific mutant phenotypes caused by loss of LEM-D proteins reflect both the constellation of LEM-D proteins within the nuclear lamina and the capacity of functional compensation of the remaining LEM-D proteins.
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19
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Zwerger M, Jaalouk DE, Lombardi ML, Isermann P, Mauermann M, Dialynas G, Herrmann H, Wallrath LL, Lammerding J. Myopathic lamin mutations impair nuclear stability in cells and tissue and disrupt nucleo-cytoskeletal coupling. Hum Mol Genet 2013; 22:2335-49. [PMID: 23427149 DOI: 10.1093/hmg/ddt079] [Citation(s) in RCA: 128] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Lamins are intermediate filament proteins that assemble into a meshwork underneath the inner nuclear membrane, the nuclear lamina. Mutations in the LMNA gene, encoding lamins A and C, cause a variety of diseases collectively called laminopathies. The disease mechanism for these diverse conditions is not well understood. Since lamins A and C are fundamental determinants of nuclear structure and stability, we tested whether defects in nuclear mechanics could contribute to the disease development, especially in laminopathies affecting mechanically stressed tissue such as muscle. Using skin fibroblasts from laminopathy patients and lamin A/C-deficient mouse embryonic fibroblasts stably expressing a broad panel of laminopathic lamin A mutations, we found that several mutations associated with muscular dystrophy and dilated cardiomyopathy resulted in more deformable nuclei; in contrast, lamin mutants responsible for diseases without muscular phenotypes did not alter nuclear deformability. We confirmed our results in intact muscle tissue, demonstrating that nuclei of transgenic Drosophila melanogaster muscle expressing myopathic lamin mutations deformed more under applied strain than controls. In vivo and in vitro studies indicated that the loss of nuclear stiffness resulted from impaired assembly of mutant lamins into the nuclear lamina. Although only a subset of lamin mutations associated with muscular diseases caused increased nuclear deformability, almost all mutations tested had defects in force transmission between the nucleus and cytoskeleton. In conclusion, our results indicate that although defective nuclear stability may play a role in the development of muscle diseases, other factors, such as impaired nucleo-cytoskeletal coupling, likely contribute to the muscle phenotype.
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Affiliation(s)
- Monika Zwerger
- Department of Medicine, Brigham and Women's Hospital/Harvard Medical School, Boston, MA 02115, USA
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20
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Rohrbaugh M, Clore A, Davis J, Johnson S, Jones B, Jones K, Kim J, Kithuka B, Lunsford K, Mitchell J, Mott B, Ramos E, Tchedou MR, Acosta G, Araujo M, Cushing S, Duffy G, Graves F, Griffin K, Gurudatta BV, Jackson D, Jaimes D, Jamison K, Jones K, Kelley D, Kilgore M, Laramore D, Le T, Mazhar B, Mazhar MM, McCrary B, Miller T, Moreland C, Mullins A, Munye E, Okoorie S, Pittman E, Roberts N, Rose D, Rowland A, Shagarabi A, Smith J, Stallworth T, Stroud N, Sung E, Sung K, Takenaka N, Torre E, Veira J, Vu K, Wagstaff W, Wood AM, Wu K, Yang J, Corces VG. Identification and characterization of proteins involved in nuclear organization using Drosophila GFP protein trap lines. PLoS One 2013; 8:e53091. [PMID: 23341925 DOI: 10.1371/journal.pone.0053091] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Accepted: 11/23/2012] [Indexed: 12/22/2022] Open
Abstract
Background Strains from a collection of Drosophila GFP protein trap lines express GFP in the normal tissues where the endogenous protein is present. This collection can be used to screen for proteins distributed in the nucleus in a non-uniform pattern. Methodology/Principal Findings We analyzed four lines that show peripheral or punctate nuclear staining. One of these lines affects an uncharacterized gene named CG11138. The CG11138 protein shows a punctate distribution in the nuclear periphery similar to that of Drosophila insulator proteins but does not co-localize with known insulators. Interestingly, mutations in Lamin proteins result in alterations in CG11138 localization, suggesting that this protein may be a novel component of the nuclear lamina. A second line affects the Decondensation factor 31 (Df31) gene, which encodes a protein with a unique nuclear distribution that appears to segment the nucleus into four different compartments. The X-chromosome of males is confined to one of these compartments. We also find that Drosophila Nucleoplasmin (dNlp) is present in regions of active transcription. Heat shock leads to loss of dNlp from previously transcribed regions of polytene chromosome without redistribution to the heat shock genes. Analysis of Stonewall (Stwl), a protein previously found to be necessary for the maintenance of germline stem cells, shows that Stwl is present in a punctate pattern in the nucleus that partially overlaps with that of known insulator proteins. Finally we show that Stwl, dNlp, and Df31 form part of a highly interactive network. The properties of other components of this network may help understand the role of these proteins in nuclear biology. Conclusions/Significance These results establish screening of GFP protein trap alleles as a strategy to identify factors with novel cellular functions. Information gained from the analysis of CG11138 Stwl, dNlp, and Df31 sets the stage for future studies of these proteins.
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21
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Uchino R, Nonaka YK, Horigome T, Sugiyama S, Furukawa K. Loss of Drosophila A-type lamin C initially causes tendon abnormality including disintegration of cytoskeleton and nuclear lamina in muscular defects. Dev Biol 2012; 373:216-27. [PMID: 22982669 DOI: 10.1016/j.ydbio.2012.08.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Revised: 07/19/2012] [Accepted: 08/01/2012] [Indexed: 11/25/2022]
Abstract
Lamins are the major components of nuclear envelope architecture, being required for both the structural and informational roles of the nuclei. Mutations of lamins cause a spectrum of diseases in humans, including muscular dystrophy. We report here that the loss of the A-type lamin gene, lamin C in Drosophila resulted in pupal metamorphic lethality caused by tendon defects, matching the characteristics of human A-type lamin revealed by Emery-Dreifuss muscular dystrophy (EDMD). In tendon cells lacking lamin C activity, overall cell morphology was affected and organization of the spectraplakin family cytoskeletal protein Shortstop which is prominently expressed in tendon cells gradually disintegrated, notably around the nucleus and in a manner correlating well with the degradation of musculature. Furthermore, lamin C null mutants were efficiently rescued by restoring lamin C expression to shortstop-expressing cells, which include tendon cells but exclude skeletal muscle cells. Thus the critical function of A-type lamin C proteins in Drosophila musculature is to maintain proper function and morphology of tendon cells.
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Affiliation(s)
- Ryo Uchino
- Department of Chemistry, Faculty of Science, Niigata University, Niigata 950-2181, Japan
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22
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Speese SD, Ashley J, Jokhi V, Nunnari J, Barria R, Li Y, Ataman B, Koon A, Chang YT, Li Q, Moore MJ, Budnik V. Nuclear envelope budding enables large ribonucleoprotein particle export during synaptic Wnt signaling. Cell 2012; 149:832-46. [PMID: 22579286 DOI: 10.1016/j.cell.2012.03.032] [Citation(s) in RCA: 249] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Revised: 12/08/2011] [Accepted: 03/14/2012] [Indexed: 01/25/2023]
Abstract
Localized protein synthesis requires assembly and transport of translationally silenced ribonucleoprotein particles (RNPs), some of which are exceptionally large. Where in the cell such large RNP granules first assemble was heretofore unknown. We previously reported that during synapse development, a fragment of the Wnt-1 receptor, DFrizzled2, enters postsynaptic nuclei where it forms prominent foci. Here we show that these foci constitute large RNP granules harboring synaptic protein transcripts. These granules exit the nucleus by budding through the inner and the outer nuclear membranes in a nuclear egress mechanism akin to that of herpes viruses. This budding involves phosphorylation of A-type lamin, a protein linked to muscular dystrophies. Thus nuclear envelope budding is an endogenous nuclear export pathway for large RNP granules.
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Affiliation(s)
- Sean D Speese
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, 01605, USA
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23
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Adolphsen K, Amell A, Havko N, Kevorkian S, Mears K, Neher H, Schwarz D, Schulze SR. Type-I prenyl protease function is required in the male germline of Drosophila melanogaster. G3 (Bethesda) 2012; 2:629-42. [PMID: 22690372 PMCID: PMC3362292 DOI: 10.1534/g3.112.002188] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2012] [Accepted: 03/20/2012] [Indexed: 12/23/2022]
Abstract
Many proteins require the addition of a hydrophobic prenyl anchor (prenylation) for proper trafficking and localization in the cell. Prenyl proteases play critical roles in modifying proteins for membrane anchorage. The type I prenyl protease has a defined function in yeast (Ste24p/Afc1p) where it modifies a mating pheromone, and in humans (Zmpste24) where it has been implicated in a disease of premature aging. Despite these apparently very different biological processes, the type I prenyl protease gene is highly conserved, encoded by a single gene in a wide range of animal and plant groups. A notable exception is Drosophila melanogaster, where the gene encoding the type I prenyl protease has undergone an unprecedented series of duplications in the genome, resulting in five distinct paralogs, three of which are organized in a tandem array, and demonstrate high conservation, particularly in the vicinity of the active site of the enzyme. We have undertaken targeted deletion to remove the three tandem paralogs from the genome. The result is a male fertility defect, manifesting late in spermatogenesis. Our results also show that the ancestral type I prenyl protease gene in Drosophila is under strong purifying selection, while the more recent replicates are evolving rapidly. Our rescue data support a role for the rapidly evolving tandem paralogs in the male germline. We propose that potential targets for the male-specific type I prenyl proteases include proteins involved in the very dramatic cytoskeletal remodeling events required for spermatid maturation.
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Affiliation(s)
- Katie Adolphsen
- Biology Department, Western Washington University, Bellingham, Washington 98225
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24
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Abstract
Lamins are the major structural components of the nuclear lamina found in metazoan organisms. Extensive studies using tissue culture cells have shown that lamins are involved in a wide range of basic cell functions. This has led to the prevailing idea that a given animal cell needs at least one lamin protein for its basic proliferation and survival. However, recent studies have shown that lamins are dispensable for the proliferation and survival of mouse embryonic stem cells (ESC). In contrast to a lack of essential functions in ESCs, certain differentiated cells lacking B-type lamins exhibit increased cell cycle exit rates and enhanced senescence. In this Extra View, we discuss how studies using animal models and cell cultures have begun to reveal cell-type specific functions of lamins in tissue building and homeostasis.
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Affiliation(s)
- Youngjo Kim
- Department of Embryology, Carnegie Institution for Science and Howard Hughes Medical Institute, Baltimore, MD, USA
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Dialynas G, Flannery KM, Zirbel LN, Nagy PL, Mathews KD, Moore SA, Wallrath LL. LMNA variants cause cytoplasmic distribution of nuclear pore proteins in Drosophila and human muscle. Hum Mol Genet 2011; 21:1544-56. [PMID: 22186027 PMCID: PMC3298278 DOI: 10.1093/hmg/ddr592] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Mutations in the human LMNA gene, encoding A-type lamins, give rise to laminopathies, which include several types of muscular dystrophy. Here, heterozygous sequence variants in LMNA, which result in single amino-acid substitutions, were identified in patients exhibiting muscle weakness. To assess whether the substitutions altered lamin function, we performed in vivo analyses using a Drosophila model. Stocks were generated that expressed mutant forms of the Drosophila A-type lamin modeled after each variant. Larvae were used for motility assays and histochemical staining of the body-wall muscle. In parallel, immunohistochemical analyses were performed on human muscle biopsy samples from the patients. In control flies, muscle-specific expression of the wild-type A-type lamin had no apparent affect. In contrast, expression of the mutant A-type lamins caused dominant larval muscle defects and semi-lethality at the pupal stage. Histochemical staining of larval body wall muscle revealed that the mutant A-type lamin, B-type lamins, the Sad1p, UNC-84 domain protein Klaroid and nuclear pore complex proteins were mislocalized to the cytoplasm. In addition, cytoplasmic actin filaments were disorganized, suggesting links between the nuclear lamina and the cytoskeleton were disrupted. Muscle biopsies from the patients showed dystrophic histopathology and architectural abnormalities similar to the Drosophila larvae, including cytoplasmic distribution of nuclear envelope proteins. These data provide evidence that the Drosophila model can be used to assess the function of novel LMNA mutations and support the idea that loss of cellular compartmentalization of nuclear proteins contributes to muscle disease pathogenesis.
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Affiliation(s)
- George Dialynas
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA
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Mattout A, Pike BL, Towbin BD, Bank EM, Gonzalez-Sandoval A, Stadler MB, Meister P, Gruenbaum Y, Gasser SM. An EDMD mutation in C. elegans lamin blocks muscle-specific gene relocation and compromises muscle integrity. Curr Biol 2011; 21:1603-14. [PMID: 21962710 DOI: 10.1016/j.cub.2011.08.030] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Revised: 06/30/2011] [Accepted: 08/12/2011] [Indexed: 11/15/2022]
Abstract
BACKGROUND In worms, as in other organisms, many tissue-specific promoters are sequestered at the nuclear periphery when repressed and shift inward when activated. It has remained unresolved, however, whether the association of facultative heterochromatin with the nuclear periphery, or its release, has functional relevance for cell or tissue integrity. RESULTS Using ablation of the unique lamin gene in C. elegans, we show that lamin is necessary for the perinuclear positioning of heterochromatin. We then express at low levels in otherwise wild-type worms a lamin carrying a point mutation, Y59C, which in humans is linked to an autosomal-dominant form of Emery-Dreifuss muscular dystrophy. Using embryos and differentiated tissues, we track the subnuclear position of integrated heterochromatic arrays and their expression. In LMN-1 Y59C-expressing worms, we see abnormal retention at the nuclear envelope of a gene array bearing a muscle-specific promoter. This correlates with impaired activation of the array-borne myo-3 promoter and altered expression of a number of muscle-specific genes. However, an equivalent array carrying the intestine-specific pha-4 promoter is expressed normally and shifts inward when activated in gut cells of LMN-1 Y59C worms. Remarkably, adult LMN-1 Y59C animals have selectively perturbed body muscle ultrastructure and reduced muscle function. CONCLUSION Lamin helps sequester heterochromatin at the nuclear envelope, and wild-type lamin permits promoter release following tissue-specific activation. A disease-linked point mutation in lamin impairs muscle-specific reorganization of a heterochromatic array during tissue-specific promoter activation in a dominant manner. This dominance and the correlated muscle dysfunction in LMN-1 Y59C worms phenocopies Emery-Dreifuss muscular dystrophy.
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Affiliation(s)
- Anna Mattout
- Department of Genetics, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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27
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Abstract
Correctly evaluating functional similarities among homologous proteins is necessary for accurate transfer of experimental knowledge from one organism to another, and is of particular importance for the development of animal models of human disease. While the fact that sequence similarity implies functional similarity is a fundamental paradigm of molecular biology, sequence comparison does not directly assess the extent to which two proteins participate in the same biological processes, and has limited utility for analyzing families with several parologous members. Nevertheless, we show that it is possible to provide a cross-organism functional similarity measure in an unbiased way through the exclusive use of high-throughput gene-expression data. Our methodology is based on probabilistic cross-species mapping of functionally analogous proteins based on Bayesian integrative analysis of gene expression compendia. We demonstrate that even among closely related genes, our method is able to predict functionally analogous homolog pairs better than relying on sequence comparison alone. We also demonstrate that the landscape of functional similarity is often complex and that definitive “functional orthologs” do not always exist. Even in these cases, our method and the online interface we provide are designed to allow detailed exploration of sources of inferred functional similarity that can be evaluated by the user. Common ancestry is a central tenet of modern biology, as genes from different species often show a high degree of sequence similarity, making it possible to study analogous processes across model organisms. However, many genes belong to large families with several duplicates and the relationship between genes from different species is often not one-to-one, complicating the transfer of experimental knowledge. We present a method that uses a large compendia of high-throughput expression data, that covers many genes that have not been analyzed in any other way, to systematically predict which genes are most likely to participate in the same biological process and thus have analogous function in different organisms. We show that our method agrees well with current experimental knowledge and we use it to investigate several families of genes that demonstrate the complexity of functional analogy.
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Affiliation(s)
- Maria D. Chikina
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Olga G. Troyanskaya
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
- Department of Computer Science, Princeton University, Princeton, New Jersey, United States of America
- * E-mail:
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Abstract
The inner side of the nuclear envelope (NE) is lined with lamins, a meshwork of intermediate filaments that provides structural support for the nucleus and plays roles in many nuclear processes. Lamins, classified as A- or B-types on the basis of biochemical properties, have a conserved globular head, central rod and C-terminal domain that includes an Ig-fold structural motif. In humans, mutations in A-type lamins give rise to diseases that exhibit tissue-specific defects, such as Emery-Dreifuss muscular dystrophy. Drosophila is being used as a model to determine tissue-specific functions of A-type lamins in development, with implications for understanding human disease mechanisms. The GAL4-UAS system was used to express wild-type and mutant forms of Lamin C (the presumed Drosophila A-type lamin), in an otherwise wild-type background. Larval muscle-specific expression of wild type Drosophila Lamin C caused no overt phenotype. By contrast, larval muscle-specific expression of a truncated form of Lamin C lacking the N-terminal head (Lamin C DeltaN) caused muscle defects and semi-lethality, with adult 'escapers' possessing malformed legs. The leg defects were due to a lack of larval muscle function and alterations in hormone-regulated gene expression. The consequences of Lamin C association at a gene were tested directly by targeting a Lamin C DNA-binding domain fusion protein upstream of a reporter gene. Association of Lamin C correlated with localization of the reporter gene at the nuclear periphery and gene repression. These data demonstrate connections among the Drosophila A-type lamin, hormone-induced gene expression and muscle function.
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Affiliation(s)
- George Dialynas
- Department of Biochemistry, University of Iowa, Iowa City, IA 52241, USA
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Abstract
The development of a membrane-bound structure separating DNA from other cellular components was the epochal evolutionary event that gave rise to eukaryotes, possibly occurring up to 2 billion years ago. Yet, this view of the nuclear envelope as a physical barrier greatly underestimates its fundamental impact on cellular organization and complexity, much of which is only beginning to be understood. Indeed, alterations of nuclear envelope structure and protein composition are essential to many aspects of metazoan development and cellular differentiation. Mutations in genes encoding nuclear envelope proteins cause a fascinating array of diseases referred to as "nuclear envelopathies" or "laminopathies" that affect different tissues and organ systems. We review recent work on the nuclear envelope, including insights derived from the study of nuclear envelopathies. These studies are uncovering new functions for nuclear envelope proteins and underlie an emerging view of the nuclear envelope as a critical signaling node in development and disease.
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Affiliation(s)
- William T Dauer
- Department of Neurology, University of Michigan Medical School, Ann Arbor, MI 48109 USA.
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Schulze SR, Curio-Penny B, Speese S, Dialynas G, Cryderman DE, McDonough CW, Nalbant D, Petersen M, Budnik V, Geyer PK, Wallrath LL. A comparative study of Drosophila and human A-type lamins. PLoS One 2009; 4:e7564. [PMID: 19855837 PMCID: PMC2762312 DOI: 10.1371/journal.pone.0007564] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2009] [Accepted: 10/04/2009] [Indexed: 11/24/2022] Open
Abstract
Nuclear intermediate filament proteins, called lamins, form a meshwork that lines the inner surface of the nuclear envelope. Lamins contain three domains: an N-terminal head, a central rod and a C-terminal tail domain possessing an Ig-fold structural motif. Lamins are classified as either A- or B-type based on structure and expression pattern. The Drosophila genome possesses two genes encoding lamins, Lamin C and lamin Dm0, which have been designated A- and B-type, respectively, based on their expression profile and structural features. In humans, mutations in the gene encoding A-type lamins are associated with a spectrum of predominantly tissue-specific diseases known as laminopathies. Linking the disease phenotypes to cellular functions of lamins has been a major challenge. Drosophila is being used as a model system to identify the roles of lamins in development. Towards this end, we performed a comparative study of Drosophila and human A-type lamins. Analysis of transgenic flies showed that human lamins localize predictably within the Drosophila nucleus. Consistent with this finding, yeast two-hybrid data demonstrated conservation of partner-protein interactions. Drosophila lacking A-type lamin show nuclear envelope defects similar to those observed with human laminopathies. Expression of mutant forms of the A-type Drosophila lamin modeled after human disease-causing amino acid substitutions revealed an essential role for the N-terminal head and the Ig-fold in larval muscle tissue. This tissue-restricted sensitivity suggests a conserved role for lamins in muscle biology. In conclusion, we show that (1) localization of A-type lamins and protein-partner interactions are conserved between Drosophila and humans, (2) loss of the Drosophila A-type lamin causes nuclear defects and (3) muscle tissue is sensitive to the expression of mutant forms of A-type lamin modeled after those causing disease in humans. These studies provide new insights on the role of lamins in nuclear biology and support Drosophila as a model for studies of human laminopathies involving muscle dysfunction.
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Affiliation(s)
- Sandra R. Schulze
- Department of Biology, Western Washington University, Bellingham, Washington, United States of America
| | - Beatrice Curio-Penny
- Department of Biochemistry, University of Iowa, Iowa City, Iowa, United States of America
| | - Sean Speese
- Department of Neurobiology, University of Massachusetts, Wochester, Massachusetts, United States of America
| | - George Dialynas
- Department of Biochemistry, University of Iowa, Iowa City, Iowa, United States of America
| | - Diane E. Cryderman
- Department of Biochemistry, University of Iowa, Iowa City, Iowa, United States of America
| | - Caitrin W. McDonough
- Department of Biochemistry, University of Iowa, Iowa City, Iowa, United States of America
| | - Demet Nalbant
- Department of Biochemistry, University of Iowa, Iowa City, Iowa, United States of America
| | - Melissa Petersen
- Department of Biology, Western Washington University, Bellingham, Washington, United States of America
| | - Vivian Budnik
- Department of Neurobiology, University of Massachusetts, Wochester, Massachusetts, United States of America
| | - Pamela K. Geyer
- Department of Biochemistry, University of Iowa, Iowa City, Iowa, United States of America
| | - Lori L. Wallrath
- Department of Biochemistry, University of Iowa, Iowa City, Iowa, United States of America
- * E-mail:
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32
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Prokocimer M, Davidovich M, Nissim-Rafinia M, Wiesel-Motiuk N, Bar DZ, Barkan R, Meshorer E, Gruenbaum Y. Nuclear lamins: key regulators of nuclear structure and activities. J Cell Mol Med 2009; 13:1059-85. [PMID: 19210577 PMCID: PMC4496104 DOI: 10.1111/j.1582-4934.2008.00676.x] [Citation(s) in RCA: 200] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2008] [Accepted: 01/19/2009] [Indexed: 11/27/2022] Open
Abstract
The nuclear lamina is a proteinaceous structure located underneath the inner nuclear membrane (INM), where it associates with the peripheral chromatin. It contains lamins and lamin-associated proteins, including many integral proteins of the INM, chromatin modifying proteins, transcriptional repressors and structural proteins. A fraction of lamins is also present in the nucleoplasm, where it forms stable complexes and is associated with specific nucleoplasmic proteins. The lamins and their associated proteins are required for most nuclear activities, mitosis and for linking the nucleoplasm to all major cytoskeletal networks in the cytoplasm. Mutations in nuclear lamins and their associated proteins cause about 20 different diseases that are collectively called laminopathies'. This review concentrates mainly on lamins, their structure and their roles in DNA replication, chromatin organization, adult stem cell differentiation, aging, tumorogenesis and the lamin mutations leading to laminopathic diseases.
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Affiliation(s)
- Miron Prokocimer
- Department of Genetics, The Institute of Life Sciences, The Hebrew University of JerusalemJerusalem, Israel
| | - Maya Davidovich
- Department of Genetics, The Institute of Life Sciences, The Hebrew University of JerusalemJerusalem, Israel
| | - Malka Nissim-Rafinia
- Department of Genetics, The Institute of Life Sciences, The Hebrew University of JerusalemJerusalem, Israel
| | - Naama Wiesel-Motiuk
- Department of Genetics, The Institute of Life Sciences, The Hebrew University of JerusalemJerusalem, Israel
| | - Daniel Z Bar
- Department of Genetics, The Institute of Life Sciences, The Hebrew University of JerusalemJerusalem, Israel
| | - Rachel Barkan
- Department of Genetics, The Institute of Life Sciences, The Hebrew University of JerusalemJerusalem, Israel
| | - Eran Meshorer
- Department of Genetics, The Institute of Life Sciences, The Hebrew University of JerusalemJerusalem, Israel
| | - Yosef Gruenbaum
- Department of Genetics, The Institute of Life Sciences, The Hebrew University of JerusalemJerusalem, Israel
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Abstract
The laminopathy Hutchinson-Gilford progeria syndrome (HGPS) is caused by the mutant lamin A protein progerin and leads to premature aging of affected children. Despite numerous cell biological and biochemical insights into the basis for the cellular abnormalities seen in HGPS, the mechanism linking progerin to the organismal phenotype is not fully understood. To begin to address the mechanism behind HGPS using Drosophila melanogaster, we have ectopically expressed progerin and lamin A. We found that ectopic progerin and lamin A phenocopy several effects of laminopathies in developing and adult Drosophila, but that progerin causes a stronger phenotype than wild-type lamin A.
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Abstract
Drosophila melanogaster is an ideal model organism for various types of aging studies. They are easy to maintain, relatively inexpensive, have short life cycles, provide large sample sizes, and can be genetically manipulated via various methods for testing. The 49(th) Annual Drosophila Research Conference, held in San Diego, CA (April 2-6, 2008), had over 30 poster presentations and eight platform talks devoted to physiology and aging, and seven presentations in a longevity and functional senescence workshop. The data presented via these avenues included life span manipulation, physiological related genes, candidate aging genes, gene expression, signaling, and using D. melanogaster as a model for age related disease, to name a few. This report provides highlights of some of the information presented in the poster, platform and workshop presentations.
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Affiliation(s)
- Darby J Carlson
- Biology Department, University of Nebraska at Kearney, Kearney, Nebraska, USA
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35
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Pinto BS, Wilmington SR, Hornick EE, Wallrath LL, Geyer PK. Tissue-specific defects are caused by loss of the Drosophila MAN1 LEM domain protein. Genetics 2008; 180:133-45. [PMID: 18723885 DOI: 10.1534/genetics.108.091371] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The nuclear lamina represents a protein network required for nuclear structure and function. One family of lamina proteins is defined by an approximately 40-aa LAP2, Emerin, and MAN1 (LEM) domain (LEM-D) that binds the nonspecific DNA-binding protein, barrier-to-autointegration factor (BAF). Through interactions with BAF, LEM-D proteins serve as a bridge between chromosomes and the nuclear envelope. Mutations in genes encoding LEM-D proteins cause human laminopathies that are associated with tissue-restricted pathologies. Drosophila has five genes that encode proteins with LEM homology. Using yeast two-hybrid analyses, we demonstrate that four encode proteins that bind Drosophila (d)BAF. In addition to dBAF, dMAN1 associates with lamins, the LEM-D protein Bocksbeutel, and the receptor-regulated Smads, demonstrating parallel protein interactions with vertebrate homologs. P-element mobilization was used to generate null dMAN1 alleles. These mutants showed decreased viability, with surviving adults displaying male sterility, decreased female fertility, wing patterning and positioning defects, flightlessness, and locomotion difficulties that became more severe with age. Increased phospho-Smad staining in dMAN1 mutant wing discs is consistent with a role in transforming growth factor (TGF)-beta/bone morphogenic protein (BMP) signaling. The tissue-specific, age-enhanced dMAN1 mutant phenotypes are reminiscent of human laminopathies, suggesting that studies in Drosophila will provide insights into lamina dysfunction associated with disease.
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36
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Abstract
The nuclear lamina consists of a meshwork of lamins and lamina-associated proteins, which provide mechanical support, control size and shape of the nucleus, and mediate the attachment of chromatin to the nuclear envelope. Abnormal nuclear shapes are observed in aging cells of humans and nematode worms. The expression of laminDelta50, a constitutively active lamin A splicing variant in Hutchinson-Gilford progeria syndrome patients, leads to the lobulation of the nuclear envelope accompanied by DNA damage, and loss of heterochromatin. So far, it has been unclear whether these age-related changes are laminDelta50 specific or whether proteins that affect nuclear shape such as KUGELKERN or LAMIN B in general play a causative role in senescence. Here we show that in adult Drosophila flies, the size of the nuclei increases with age and the nuclei assume an aberrant shape. Moreover, induced expression of the farnesylated lamina proteins Lamin B and Kugelkern cause aberrant nuclear shapes and reduce the lifespan of adult flies. The shorter lifespan correlates with an early decline in age-dependent locomotor behaviour. Expression of kugelkern or lamin B in mammalian cells induces a nuclear lobulation phenotype in conjunction with DNA damage, and changes in histone modification similar to that found in cells expressing laminDelta50 or in cells from aged individuals. We conclude that lobulation of the nuclear membrane induced by the insertion of farnesylated lamina-proteins can lead to aging-like phenotypes.
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Affiliation(s)
- Annely Brandt
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Allianz, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany.
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37
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Abstract
Nuclear pore complexes (NPCs) are multisubunit protein entities embedded into the nuclear envelope (NE). Here, we examine the in vivo dynamics of the essential Drosophila nucleoporin Nup107 and several other NE-associated proteins during NE and NPCs disassembly and reassembly that take place within each mitosis. During both the rapid mitosis of syncytial embryos and the more conventional mitosis of larval neuroblasts, Nup107 is gradually released from the NE, but it remains partially confined to the nuclear (spindle) region up to late prometaphase, in contrast to nucleoporins detected by wheat germ agglutinin and lamins. We provide evidence that in all Drosophila cells, a structure derived from the NE persists throughout metaphase and early anaphase. Finally, we examined the dynamics of the spindle checkpoint proteins Mad2 and Mad1. During mitotic exit, Mad2 and Mad1 are actively imported back from the cytoplasm into the nucleus after the NE and NPCs have reformed, but they reassociate with the NE only later in G1, concomitantly with the recruitment of the basket nucleoporin Mtor (the Drosophila orthologue of vertebrate Tpr). Surprisingly, Drosophila Nup107 shows no evidence of localization to kinetochores, despite the demonstrated importance of this association in mammalian cells.
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Parnaik VK. Role of Nuclear Lamins in Nuclear Organization, Cellular Signaling, and Inherited Diseases. International Review of Cell and Molecular Biology 2008; 266:157-206. [DOI: 10.1016/s1937-6448(07)66004-3] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Muñoz-Alarcón A, Pavlovic M, Wismar J, Schmitt B, Eriksson M, Kylsten P, Dushay MS. Characterization of lamin mutation phenotypes in Drosophila and comparison to human laminopathies. PLoS One 2007; 2:e532. [PMID: 17565385 PMCID: PMC1885830 DOI: 10.1371/journal.pone.0000532] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2007] [Accepted: 05/18/2007] [Indexed: 11/19/2022] Open
Abstract
Lamins are intermediate filament proteins that make up the nuclear lamina, a matrix underlying the nuclear membrane in all metazoan cells that is important for nuclear form and function. Vertebrate A-type lamins are expressed in differentiating cells, while B-type lamins are expressed ubiquitously. Drosophila has two lamin genes that are expressed in A- and B-type patterns, and it is assumed that similarly expressed lamins perform similar functions. However, Drosophila and vertebrate lamins are not orthologous, and their expression patterns evolved independently. It is therefore of interest to examine the effects of mutations in lamin genes. Mutations in the mammalian lamin A/C gene cause a range of diseases, collectively called laminopathies, that include muscular dystrophies and premature aging disorders. We compared the sequences of lamin genes from different species, and we have characterized larval and adult phenotypes in Drosophila bearing mutations in the lam gene that is expressed in the B-type pattern. Larvae move less and show subtle muscle defects, and surviving lam adults are flightless and walk like aged wild-type flies, suggesting that lam phenotypes might result from neuromuscular defects, premature aging, or both. The resemblance of Drosophila lam phenotypes to human laminopathies suggests that some lamin functions may be performed by differently expressed genes in flies and mammals. Such still-unknown functions thus would not be dependent on lamin gene expression pattern, suggesting the presence of other lamin functions that are expression dependent. Our results illustrate a complex interplay between lamin gene expression and function through evolution.
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Affiliation(s)
- Andrés Muñoz-Alarcón
- Department of Life Sciences, Södertörns högskola, Huddinge, Sweden
- Department of Biosciences and Nutrition, Karolinska Institute, Stockholm, Sweden
| | - Maja Pavlovic
- Department of Life Sciences, Södertörns högskola, Huddinge, Sweden
- Department of Biosciences and Nutrition, Karolinska Institute, Stockholm, Sweden
| | - Jasmine Wismar
- Max-Planck-Institut für Hirnforschung, Abteilung Neurochemie, Frankfurt, Germany
| | - Bertram Schmitt
- Max-Planck-Institut für Hirnforschung, Abteilung Neurochemie, Frankfurt, Germany
| | - Maria Eriksson
- Department of Biosciences and Nutrition, Karolinska Institute, Stockholm, Sweden
| | - Per Kylsten
- Department of Life Sciences, Södertörns högskola, Huddinge, Sweden
| | - Mitchell S. Dushay
- Department of Life Sciences, Södertörns högskola, Huddinge, Sweden
- Department of Comparative Physiology, EBC, Uppsala University, Uppsala, Sweden
- * To whom correspondence should be addressed. E-mail:
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40
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Abstract
Lamins are the main component of the nuclear lamina and considered to be the ancestors of all intermediate filament proteins. They are localized mainly at the nuclear periphery where they form protein complexes with integral proteins of the nuclear inner membrane, transcriptional regulators, histones and chromatin modifiers. Studying lamins in invertebrate species has unique advantages including the smaller number of lamin genes in the invertebrate genomes and powerful genetic analyses in Caenorhabditis elegans and Drosophila melanogaster. These simpler nuclear lamina systems allow direct analyses of their structure and functions. Here we give an overview of recent advances in the field of invertebrate nuclear lamins with special emphasis on their evolution, assembly and functions.
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Affiliation(s)
- Shai Melcer
- Department of Genetics, The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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41
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Abstract
Lamins are the major structural proteins of the nucleus in an animal cell. In addition to being essential for nuclear integrity and assembly, lamins are involved in the organization of nuclear processes such as DNA replication, transcription and repair. Mutations in the human lamin A gene lead to highly debilitating genetic disorders that primarily affect muscle, adipose, bone or neuronal tissues and also cause premature ageing syndromes. Mutant lamins alter nuclear integrity and hinder signalling pathways involved in muscle differentiation and adipocyte differentiation, suggesting tissue-specific roles for lamins. Furthermore, cells expressing mutant lamins are impaired in their response to DNA damaging agents. Recent reports indicate that certain lamin mutations act in a dominant negative manner to cause nuclear defects and cellular toxicity, and suggest a possible role for aberrant lamins in normal ageing processes.
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Affiliation(s)
- Veena K Parnaik
- Centre for Cellular and Molecular Biology, Hyderabad, India.
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