1
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Sanovec O, Frolikova M, Kraus V, Vondrakova J, Qasemi M, Spevakova D, Simonik O, Moritz L, Caswell DL, Liska F, Ded L, Cerny J, Avidor-Reiss T, Hammoud SS, Schorle H, Postlerova P, Steger K, Komrskova K. Protamine 2 Deficiency Results In Septin 12 Abnormalities. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.28.596175. [PMID: 38854089 PMCID: PMC11160614 DOI: 10.1101/2024.05.28.596175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
There is a well-established link between abnormal sperm chromatin states and poor motility, however, how these two processes are interdependent is unknown. Here, we identified a possible mechanistic insight by showing that Protamine 2, a nuclear DNA packaging protein in sperm, directly interacts with cytoskeletal protein Septin 12, which is associated with sperm motility. Septin 12 has several isoforms, and we show, that in the Prm2 -/- sperm, the short one (Mw 36 kDa) is mislocalized, while two long isoforms (Mw 40 and 41 kDa) are unexpectedly lost in Prm2 -/- sperm chromatin-bound protein fractions. Septin 12 co-immunoprecipitated with Protamine 2 in the testicular cell lysate of WT mice and with Lamin B1/B2/B3 in co-transfected HEK cells despite we did not observe changes in Lamin B2/B3 protein or SUN4 expression in Prm2 -/- testes. Furthermore, the Prm2 -/- sperm have on average a smaller sperm nucleus and aberrant acrosome biogenesis. In humans, patients with low sperm motility (asthenozoospermia) have imbalanced histone- protamine 1/2 ratio and modified levels of cytoskeletal proteins. We detected retained Septin 12 isoforms (Mw 40 and 41 kDa) in the sperm membrane, chromatin-bound and tubulin/mitochondria protein fractions, which was not true for healthy normozoospermic men. In conclusion, our findings expand the current knowledge regarding the connection between Protamine 2 and Septin 12 expression and localization, resulting in low sperm motility and morphological abnormalities.
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2
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Li Y, Zhu J, Yu Z, Li H, Jin X. The role of Lamin B2 in human diseases. Gene 2023; 870:147423. [PMID: 37044185 DOI: 10.1016/j.gene.2023.147423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 04/02/2023] [Accepted: 04/05/2023] [Indexed: 04/14/2023]
Abstract
Lamin B2 (LMNB2), on the inner side of the nuclear envelope, constitutes the nuclear skeleton by connecting with other nuclear proteins. LMNB2 is involved in a wide range of nuclear functions, including DNA replication and stability, regulation of chromatin, and nuclear stiffness. Moreover, LMNB2 regulates several cellular processes, such as tissue development, cell cycle, cellular proliferation and apoptosis, chromatin localization and stability, and DNA methylation. Besides, the influence of abnormal expression and mutations of LMNB2 has been gradually discovered in cancers and laminopathies. Therefore, this review summarizes the recent advances of LMNB2-associated biological roles in physiological or pathological conditions, with a particular emphasis on cancers and laminopathies, as well as the potential mechanism of LMNB2 in related cancers.
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Affiliation(s)
- Yuxuan Li
- Department of Hepatobiliary and Pancreatic Surgery, Ningbo Medical Center of LiHuiLi Hospital, Ningbo University, Ningbo, Zhejiang 315040, P.R. China; Department of Biochemistry and Molecular Biology, Zhejiang Key Laboratory of Pathophysiology, Health Science Center, Ningbo University, Ningbo, Zhejiang 315211, P.R. China
| | - Jie Zhu
- Department of Hepatobiliary and Pancreatic Surgery, Ningbo Medical Center of LiHuiLi Hospital, Ningbo University, Ningbo, Zhejiang 315040, P.R. China; Department of Biochemistry and Molecular Biology, Zhejiang Key Laboratory of Pathophysiology, Health Science Center, Ningbo University, Ningbo, Zhejiang 315211, P.R. China
| | - Zongdong Yu
- Department of Hepatobiliary and Pancreatic Surgery, Ningbo Medical Center of LiHuiLi Hospital, Ningbo University, Ningbo, Zhejiang 315040, P.R. China; Department of Biochemistry and Molecular Biology, Zhejiang Key Laboratory of Pathophysiology, Health Science Center, Ningbo University, Ningbo, Zhejiang 315211, P.R. China
| | - Hong Li
- Department of Hepatobiliary and Pancreatic Surgery, Ningbo Medical Center of LiHuiLi Hospital, Ningbo University, Ningbo, Zhejiang 315040, P.R. China; Department of Biochemistry and Molecular Biology, Zhejiang Key Laboratory of Pathophysiology, Health Science Center, Ningbo University, Ningbo, Zhejiang 315211, P.R. China.
| | - Xiaofeng Jin
- Department of Hepatobiliary and Pancreatic Surgery, Ningbo Medical Center of LiHuiLi Hospital, Ningbo University, Ningbo, Zhejiang 315040, P.R. China; Department of Biochemistry and Molecular Biology, Zhejiang Key Laboratory of Pathophysiology, Health Science Center, Ningbo University, Ningbo, Zhejiang 315211, P.R. China.
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3
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Nuclear envelope assembly and dynamics during development. Semin Cell Dev Biol 2023; 133:96-106. [PMID: 35249812 DOI: 10.1016/j.semcdb.2022.02.028] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 02/22/2022] [Accepted: 02/25/2022] [Indexed: 01/22/2023]
Abstract
The nuclear envelope (NE) protects but also organizes the eukaryotic genome. In this review we will discuss recent literature on how the NE disassembles and reassembles, how it varies in surface area and protein composition and how this translates into chromatin organization and gene expression in the context of animal development.
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4
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Knockdown of Lamin B1 and the Corresponding Lamin B Receptor Leads to Changes in Heterochromatin State and Senescence Induction in Malignant Melanoma. Cells 2022; 11:cells11142154. [PMID: 35883595 PMCID: PMC9321645 DOI: 10.3390/cells11142154] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 07/02/2022] [Accepted: 07/05/2022] [Indexed: 11/17/2022] Open
Abstract
Modifications in nuclear structures of cells are implicated in several diseases including cancer. They result in changes in nuclear activity, structural dynamics and cell signalling. However, the role of the nuclear lamina and related proteins in malignant melanoma is still unknown. Its molecular characterisation might lead to a deeper understanding and the development of new therapy approaches. In this study, we analysed the functional effects of dysregulated nuclear lamin B1 (LMNB1) and its nuclear receptor (LBR). According to their cellular localisation and function, we revealed that these genes are crucially involved in nuclear processes like chromatin organisation. RNA sequencing and differential gene expression analysis after knockdown of LMNB1 and LBR revealed their implication in important cellular processes driving ER stress leading to senescence and changes in chromatin state, which were also experimentally validated. We determined that melanoma cells need both molecules independently to prevent senescence. Hence, downregulation of both molecules in a BRAFV600E melanocytic senescence model as well as in etoposide-treated melanoma cells indicates both as potential senescence markers in melanoma. Our findings suggest that LMNB1 and LBR influence senescence and affect nuclear processes like chromatin condensation and thus are functionally relevant for melanoma progression.
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5
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Abstract
Lamins interact with a host of nuclear membrane proteins, transcription factors, chromatin regulators, signaling molecules, splicing factors, and even chromatin itself to form a nuclear subcompartment, the nuclear lamina, that is involved in a variety of cellular processes such as the governance of nuclear integrity, nuclear positioning, mitosis, DNA repair, DNA replication, splicing, signaling, mechanotransduction and -sensation, transcriptional regulation, and genome organization. Lamins are the primary scaffold for this nuclear subcompartment, but interactions with lamin-associated peptides in the inner nuclear membrane are self-reinforcing and mutually required. Lamins also interact, directly and indirectly, with peripheral heterochromatin domains called lamina-associated domains (LADs) and help to regulate dynamic 3D genome organization and expression of developmentally regulated genes.
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Affiliation(s)
- Xianrong Wong
- Laboratory of Developmental and Regenerative Biology, Skin Research Institute of Singapore, Agency for Science, Technology and Research (A∗STAR), Singapore 138648
| | - Ashley J Melendez-Perez
- Department of Biological Chemistry and Center for Epigenetics, Johns Hopkins University of Medicine, Baltimore, Maryland 21205, USA
| | - Karen L Reddy
- Department of Biological Chemistry and Center for Epigenetics, Johns Hopkins University of Medicine, Baltimore, Maryland 21205, USA
- Sidney Kimmel Cancer Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, USA
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6
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Serrano JB, Martins F, Pereira CD, van Pelt AMM, da Cruz E Silva OAB, Rebelo S. TorsinA Is Functionally Associated with Spermatogenesis. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2019; 25:221-228. [PMID: 30246678 DOI: 10.1017/s1431927618015179] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
TorsinA is a member of the AAA+ superfamily of adenosine triphosphatases. These AAA+ proteins have numerous biological functions, including vesicle fusion, cytoskeleton dynamics, intracellular trafficking, protein folding, and degradation as well as organelle biogenesis. Of particular interest is torsinA, which is mainly located in the endoplasmic reticulum (ER) and nuclear envelope (NE). Interestingly, mutations in the TOR1A gene (the gene encoding torsinA) are associated with DYT1 dystonia and with the preferential localization of mutated torsinA at the NE, where it is associated with lamina-associated polypeptide 1. A bioinformatics study of the torsinA interactome revealed reproductive processes to be highly relevant, as proteins in this class were found to interact with the former. Interestingly, the torsin protein family had never been previously described to be associated with the mammalian spermatogenic process. Histological staining of torsinA in human testis tissue revealed a granular cytoplasmic localization in mid- and late spermatocytes. We further sought to understand this newly discovered expression of torsinA in the meiotic phase of human spermatogenesis by studying its specific subcellular distribution. TorsinA is not present in the ER as commonly described. The proposal that torsinA might relocate to the pro-acrosomal vesicles in the Golgi apparatus is discussed.
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Affiliation(s)
- Joana B Serrano
- 1Neuroscience and Signalling Laboratory,Department of Medical Sciences,Institute of Biomedicine (iBiMED),University of Aveiro,3810-193 Aveiro,Portugal
| | - Filipa Martins
- 1Neuroscience and Signalling Laboratory,Department of Medical Sciences,Institute of Biomedicine (iBiMED),University of Aveiro,3810-193 Aveiro,Portugal
| | - Cátia D Pereira
- 1Neuroscience and Signalling Laboratory,Department of Medical Sciences,Institute of Biomedicine (iBiMED),University of Aveiro,3810-193 Aveiro,Portugal
| | - Ans M M van Pelt
- 2Center for Reproductive Medicine, Research Institute Reproduction and Development, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
| | - Odete A B da Cruz E Silva
- 1Neuroscience and Signalling Laboratory,Department of Medical Sciences,Institute of Biomedicine (iBiMED),University of Aveiro,3810-193 Aveiro,Portugal
| | - Sandra Rebelo
- 1Neuroscience and Signalling Laboratory,Department of Medical Sciences,Institute of Biomedicine (iBiMED),University of Aveiro,3810-193 Aveiro,Portugal
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7
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Pereira CD, Serrano JB, Martins F, da Cruz E Silva OAB, Rebelo S. Nuclear envelope dynamics during mammalian spermatogenesis: new insights on male fertility. Biol Rev Camb Philos Soc 2019; 94:1195-1219. [PMID: 30701647 DOI: 10.1111/brv.12498] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 01/04/2019] [Accepted: 01/08/2019] [Indexed: 02/06/2023]
Abstract
The production of highly specialized spermatozoa from undifferentiated spermatogonia is a strictly organized and programmed process requiring extensive restructuring of the entire cell. One of the most remarkable cellular transformations accompanying the various phases of spermatogenesis is the profound remodelling of the nuclear architecture, in which the nuclear envelope (NE) seems to be crucially involved. In recent years, several proteins from the distinct layers forming the NE (i.e. the inner and outer nuclear membranes as well as the nuclear lamina) have been associated with meiosis and/or spermiogenesis in different mammalian species. Among these are A- and B-type lamins, Dpy-19-like protein 2 (DPY19L2), lamin B receptor (LBR), lamina-associated polypeptide 1 (LAP1), LAP2/emerin/MAN1 (LEM) domain-containing proteins, spermatogenesis-associated 46 (SPATA46) and diverse elements of the linker of nucleoskeleton and cytoskeleton (LINC) complex, namely Sad-1/UNC-84 homology (SUN) and Klarsicht/ANC-1/Syne-1 homology (KASH) domain-containing proteins. Herein, we summarize the current state of the art on the cellular and subcellular distribution of NE proteins expressed during mammalian spermatogenesis, and discuss the latest research developments regarding their testis-specific functions. This review provides a comprehensive and innovative overview of the NE network as a regulatory platform and as an essential determinant of efficient meiotic chromosome recombination as well as spermiogenesis-associated nuclear remodelling and differentiation in mammalian male germline cells. Thus, this review provides important novel insights on the biological relevance of NE proteins for male fertility.
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Affiliation(s)
- Cátia D Pereira
- Department of Medical Sciences, Neuroscience and Signalling Laboratory, Institute for Biomedicine (iBiMED), University of Aveiro, 3810-193 Aveiro, Portugal
| | - Joana B Serrano
- Department of Medical Sciences, Neuroscience and Signalling Laboratory, Institute for Biomedicine (iBiMED), University of Aveiro, 3810-193 Aveiro, Portugal
| | - Filipa Martins
- Department of Medical Sciences, Neuroscience and Signalling Laboratory, Institute for Biomedicine (iBiMED), University of Aveiro, 3810-193 Aveiro, Portugal
| | - Odete A B da Cruz E Silva
- Department of Medical Sciences, Neuroscience and Signalling Laboratory, Institute for Biomedicine (iBiMED), University of Aveiro, 3810-193 Aveiro, Portugal.,The Discovery CTR, University of Aveiro Campus, 3810-193 Aveiro, Portugal
| | - Sandra Rebelo
- Department of Medical Sciences, Neuroscience and Signalling Laboratory, Institute for Biomedicine (iBiMED), University of Aveiro, 3810-193 Aveiro, Portugal
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8
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Paci M, Elkhatib R, Longepied G, Bourgeois P, Ray PF, Levy N, Mitchell MJ, Metzler-Guillemain C. The involvement of the nuclear lamina in human and rodent spermiogenesis: a systematic review. Basic Clin Androl 2018; 28:7. [PMID: 29946470 PMCID: PMC6008938 DOI: 10.1186/s12610-018-0072-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 04/19/2018] [Indexed: 12/11/2022] Open
Abstract
The nuclear lamina (NL) is a filamentous protein meshwork, composed essentially of lamins, situated between the inner nuclear membrane and the chromatin. The NL is a component of the nuclear envelope, interacts with a wide range of proteins and is required for normal nuclear structure and physiological development. During spermiogenesis the spermatid nucleus is elongated, and dramatically reduced in size with protamines replacing histones to produce a highly compacted chromatin. There is mounting evidence from studies in human and rodent, that the NL plays an important role in mammalian spermatid differentiation during spermiogenesis. In this review, we summarize and discuss the data available in the literature regarding the involvement of lamins and their direct or indirect partners in normal and abnormal human spermiogenesis.
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Affiliation(s)
- Marine Paci
- 1Aix Marseille Univ, Inserm, MMG, U1251, Marseille Medical Genetics, 13385 Marseille, France.,APHM Hôpital La Conception, Pôle femmes-Parents-enfants, Centre Clinico-Biologique d'Assistance Médicale à la Procréation-CECOS, 13385 Marseille Cedex 5, France
| | - Razan Elkhatib
- 1Aix Marseille Univ, Inserm, MMG, U1251, Marseille Medical Genetics, 13385 Marseille, France
| | - Guy Longepied
- 1Aix Marseille Univ, Inserm, MMG, U1251, Marseille Medical Genetics, 13385 Marseille, France
| | - Patrice Bourgeois
- 1Aix Marseille Univ, Inserm, MMG, U1251, Marseille Medical Genetics, 13385 Marseille, France
| | - Pierre F Ray
- 3Genetic Epigenetic and Therapies of Infertility, Institute for Advanced Biosciences, Inserm U1209, CNRS UMR 5309, Université Grenoble Alpes, CHU Grenoble Alpes, F-38000 Grenoble, France
| | - Nicolas Levy
- 1Aix Marseille Univ, Inserm, MMG, U1251, Marseille Medical Genetics, 13385 Marseille, France
| | - Michael J Mitchell
- 1Aix Marseille Univ, Inserm, MMG, U1251, Marseille Medical Genetics, 13385 Marseille, France
| | - Catherine Metzler-Guillemain
- 1Aix Marseille Univ, Inserm, MMG, U1251, Marseille Medical Genetics, 13385 Marseille, France.,APHM Hôpital La Conception, Pôle femmes-Parents-enfants, Centre Clinico-Biologique d'Assistance Médicale à la Procréation-CECOS, 13385 Marseille Cedex 5, France
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9
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Elkhatib RA, Paci M, Boissier R, Longepied G, Auguste Y, Achard V, Bourgeois P, Levy N, Branger N, Mitchell MJ, Metzler-Guillemain C. LEM-domain proteins are lost during human spermiogenesis but BAF and BAF-L persist. Reproduction 2017; 154:387-401. [PMID: 28684548 DOI: 10.1530/rep-17-0358] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 06/10/2017] [Accepted: 07/06/2017] [Indexed: 12/22/2022]
Abstract
During spermiogenesis the spermatid nucleus is elongated, and dramatically reduced in size with protamines replacing histones to produce a highly compacted chromatin. After fertilisation, this process is reversed in the oocyte to form the male pronucleus. Emerging evidence, including the coordinated loss of the nuclear lamina (NL) and the histones, supports the involvement of the NL in spermatid nuclear remodelling, but how the NL links to the chromatin is not known. In somatic cells, interactions between the NL and the chromatin have been demonstrated: LEM-domain proteins and LBR interact with the NL and respectively, the chromatin proteins BAF and HP1. We therefore sought to characterise the lamina-chromatin interface during spermiogenesis, by investigating the localisation of six LEM-domain proteins, two BAF proteins and LBR, in human spermatids and spermatozoa. Using RT-PCR, IF and western blotting, we show that six of the proteins tested are present in spermatids: LEMD1, LEMD2 (a short isoform), ANKLE2, LAP2β, BAF and BAF-L, and three absent: Emerin, LBR and LEMD3. The full-length LEMD2 isoform, required for nuclear integrity in somatic cells, is absent. In spermatids, no protein localised to the nuclear periphery, but five were nucleoplasmic, receding towards the posterior nuclear pole as spermatids matured. Our study therefore establishes that the lamina-chromatin interface in human spermatids is radically distinct from that defined in somatic cells. In ejaculated spermatozoa, we detected only BAF and BAF-L, suggesting that they might contribute to the shaping of the spermatozoon nucleus and, after fertilisation, its transition to the male pronucleus.
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Affiliation(s)
| | - Marine Paci
- Aix Marseille UnivINSERM, GMGF, UMR_S 910, Marseille, France
- APHM Hôpital La ConceptionGynépôle, Laboratoire de Biologie de la Reproduction-CECOS, Marseille Cedex 5, France
| | - Romain Boissier
- APHM Hôpital La ConceptionService d'Urologie, Marseille Cedex 5, France
| | - Guy Longepied
- Aix Marseille UnivINSERM, GMGF, UMR_S 910, Marseille, France
| | - Yasmina Auguste
- Aix Marseille UnivINSERM, GMGF, UMR_S 910, Marseille, France
| | - Vincent Achard
- APHM Hôpital La ConceptionGynépôle, Laboratoire de Biologie de la Reproduction-CECOS, Marseille Cedex 5, France
- Aix-Marseille UnivUniv Avignon, CNRS, IRD, IMBE, UMR7263, Marseille France
| | | | - Nicolas Levy
- Aix Marseille UnivINSERM, GMGF, UMR_S 910, Marseille, France
| | - Nicolas Branger
- APHM Hôpital La ConceptionService d'Urologie, Marseille Cedex 5, France
| | | | - Catherine Metzler-Guillemain
- Aix Marseille UnivINSERM, GMGF, UMR_S 910, Marseille, France
- APHM Hôpital La ConceptionGynépôle, Laboratoire de Biologie de la Reproduction-CECOS, Marseille Cedex 5, France
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10
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Mitchell M. The nuclear lamina during human spermiogenesis. Orphanet J Rare Dis 2015. [PMCID: PMC4652502 DOI: 10.1186/1750-1172-10-s2-o22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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11
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Camozzi D, Capanni C, Cenni V, Mattioli E, Columbaro M, Squarzoni S, Lattanzi G. Diverse lamin-dependent mechanisms interact to control chromatin dynamics. Focus on laminopathies. Nucleus 2015; 5:427-40. [PMID: 25482195 PMCID: PMC4164485 DOI: 10.4161/nucl.36289] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Interconnected functional strategies govern chromatin dynamics in eukaryotic cells. In this context, A and B type lamins, the nuclear intermediate filaments, act on diverse platforms involved in tissue homeostasis. On the nuclear side, lamins elicit large scale or fine chromatin conformational changes, affect DNA damage response factors and transcription factor shuttling. On the cytoplasmic side, bridging-molecules, the LINC complex, associate with lamins to coordinate chromatin dynamics with cytoskeleton and extra-cellular signals.
Consistent with such a fine tuning, lamin mutations and/or defects in their expression or post-translational processing, as well as mutations in lamin partner genes, cause a heterogeneous group of diseases known as laminopathies. They include muscular dystrophies, cardiomyopathy, lipodystrophies, neuropathies, and progeroid syndromes. The study of chromatin dynamics under pathological conditions, which is summarized in this review, is shedding light on the complex and fascinating role of the nuclear lamina in chromatin regulation.
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Affiliation(s)
- Daria Camozzi
- a CNR Institute for Molecular Genetics; Unit of Bologna and SC Laboratory of Musculoskeletal Cell Biology; Rizzoli Orthopedic Institute; Bologna, Italy
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12
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Peter A, Khandekar S, Deakin JE, Stick R. A peculiar lamin in a peculiar mammal: Expression of lamin LIII in platypus (Ornithorhynchus anatinus). Eur J Cell Biol 2015. [PMID: 26213206 DOI: 10.1016/j.ejcb.2015.07.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Platypus (Ornithorhynchus anatinus) holds a unique phylogenetic position at the base of the mammalian lineage due to an amalgamation of mammalian and sauropsid-like features. Here we describe the set of four lamin genes for platypus. Lamins are major components of the nuclear lamina, which constitutes a main component of the nucleoskeleton and is involved in a wide range of nuclear functions. Vertebrate evolution was accompanied by an increase in the number of lamin genes from a single gene in their closest relatives, the tunicates and cephalochordates, to four genes in the vertebrate lineage. Of the four genes the LIII gene is characterized by the presence of two alternatively spliced CaaX-encoding exons. In amphibians and fish LIII is the major lamin protein in oocytes and early embryos. The LIII gene is conserved throughout the vertebrate lineage, with the notable exception of marsupials and placental mammals, which have lost the LIII gene. Here we show that platypus has retained an LIII gene, albeit with a significantly altered structure and with a radically different expression pattern. The platypus LIII gene contains only a single CaaX-encoding exon and the head domain together with coil 1a and part of coil1b of the platypus LIII protein is replaced by a novel short non-helical N-terminus. It is expressed exclusively in the testis. These features resemble those of male germ cell-specific lamins in placental mammals, in particular those of lamin C2. Our data suggest (i) that the specific functions of LIII, which it fulfills in all other vertebrates, is no longer required in mammals and (ii) once it had been freed from these functions has undergone structural alterations and has adopted a new functionality in monotremes.
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Affiliation(s)
- Annette Peter
- Department of Cell Biology, FB2, University of Bremen, P.O. Box 33 04 40, 28334 Bremen, Germany
| | - Shaunak Khandekar
- Cellular and Molecular Pharmacology, Louvain Drug Research Institute, Université catholique de Louvain, avenue E. Mounier 73 bte B1.73.05, B-1200 Brussels, Belgium.
| | - Janine E Deakin
- Research School of Biology, ANU College of Medicine, Biology and Environment, Canberra, Australia.
| | - Reimer Stick
- Department of Cell Biology, FB2, University of Bremen, P.O. Box 33 04 40, 28334 Bremen, Germany.
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13
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Elkhatib R, Longepied G, Paci M, Achard V, Grillo JM, Levy N, Mitchell MJ, Metzler-Guillemain C. Nuclear envelope remodelling during human spermiogenesis involves somatic B-type lamins and a spermatid-specific B3 lamin isoform. Mol Hum Reprod 2015; 21:225-36. [PMID: 25477337 DOI: 10.1093/molehr/gau111] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The nuclear lamina (NL) is a filamentous protein meshwork, composed essentially of lamins, situated between the inner nuclear membrane and the chromatin. There is mounting evidence that the NL plays a role in spermatid differentiation during spermiogenesis. The mouse spermatid NL is composed of the ubiquitous lamin B1 and the spermatid-specific lamin B3, an N-terminally truncated isoform of lamin B2. However, nothing is known about the NL in human spermatids. We therefore investigated the expression pattern and localization of A-type lamins (A, C and C2) and B-type lamins (B1, B2 and B3) during human spermiogenesis. Here, we show that a lamin B3 transcript is present in human spermatids and that B-type lamins are the only lamins detectable in human spermatids. We determine that, as shown for their mouse counterparts, human lamin B3, but not lamin B2, induces strong nuclear deformation, when ectopically expressed in HeLa cells. Co-immunofluorescence revealed that, in human spermatids, B-type lamins are present at the nuclear periphery, except in the region covered by the acrosome, and that as the spermatid matures the B-type lamins recede towards the posterior pole. Only lamin B1 remains detectable on 33-47% of ejaculated spermatozoa. On spermatozoa selected for normal head density, however, this fell to <6%, suggesting that loss of the NL signal may be linked to complete sperm nucleus compaction. The similarities revealed between lamin expression during human and rodent spermiogenesis, strengthen evidence that the NL and lamin B3 have conserved functions during the intense remodelling of the mammalian spermatid nucleus.
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Affiliation(s)
- Razan Elkhatib
- Aix Marseille Université, INSERM, GMGF UMR_S 910, 13385, Marseille, France
| | - Guy Longepied
- Aix Marseille Université, INSERM, GMGF UMR_S 910, 13385, Marseille, France
| | - Marine Paci
- Aix Marseille Université, INSERM, GMGF UMR_S 910, 13385, Marseille, France APHM Hôpital La Conception, Gynépôle, Laboratoire de Biologie de la Reproduction-CECOS, 13385 Marseille Cedex 5, France
| | - Vincent Achard
- APHM Hôpital La Conception, Gynépôle, Laboratoire de Biologie de la Reproduction-CECOS, 13385 Marseille Cedex 5, France
| | - Jean-Marie Grillo
- APHM Hôpital La Conception, Gynépôle, Laboratoire de Biologie de la Reproduction-CECOS, 13385 Marseille Cedex 5, France Aix Marseille Université, Laboratoire de Biogénotoxicologie et Mutagenèse Environnementale, EA 1784 - Fédération de Recherche CNRS no 3098 Ecosystèmes Continentaux et Risques Environnementaux, 13385 Marseille Cedex 5, France
| | - Nicolas Levy
- Aix Marseille Université, INSERM, GMGF UMR_S 910, 13385, Marseille, France
| | - Michael J Mitchell
- Aix Marseille Université, INSERM, GMGF UMR_S 910, 13385, Marseille, France
| | - Catherine Metzler-Guillemain
- Aix Marseille Université, INSERM, GMGF UMR_S 910, 13385, Marseille, France APHM Hôpital La Conception, Gynépôle, Laboratoire de Biologie de la Reproduction-CECOS, 13385 Marseille Cedex 5, France
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14
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Mu W, Starmer J, Fedoriw AM, Yee D, Magnuson T. Repression of the soma-specific transcriptome by Polycomb-repressive complex 2 promotes male germ cell development. Genes Dev 2014; 28:2056-69. [PMID: 25228648 PMCID: PMC4173155 DOI: 10.1101/gad.246124.114] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Using conditional mutagenesis to remove the core PRC2 subunits EED and SUZ12 during male germ cell development, Mu et al. identified a requirement for PRC2 in both mitotic and meiotic germ cells. Mutant spermatocytes exhibited ectopic expression of somatic lamins and an abnormal distribution of SUN1 proteins on the nuclear envelope. These defects were coincident with abnormal chromosome dynamics, affecting homologous chromosome pairing and synapsis. Polycomb-repressive complex 2 (PRC2) catalyzes the methylation of histone H3 Lys27 (H3K27) and functions as a critical epigenetic regulator of both stem cell pluripotency and somatic differentiation, but its role in male germ cell development is unknown. Using conditional mutagenesis to remove the core PRC2 subunits EED and SUZ12 during male germ cell development, we identified a requirement for PRC2 in both mitotic and meiotic germ cells. We observed a paucity of mutant spermatogonial stem cells (SSCs), which appears independent of repression of the known cell cycle inhibitors Ink4a/Ink4b/Arf. Moreover, mutant spermatocytes exhibited ectopic expression of somatic lamins and an abnormal distribution of SUN1 proteins on the nuclear envelope. These defects were coincident with abnormal chromosome dynamics, affecting homologous chromosome pairing and synapsis. We observed acquisition of H3K27me3 on stage-specific genes during meiotic progression, indicating a requirement for PRC2 in regulating the meiotic transcriptional program. Together, these data demonstrate that transcriptional repression of soma-specific genes by PRC2 facilitates homeostasis and differentiation during mammalian spermatogenesis.
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Affiliation(s)
- Weipeng Mu
- Department of Genetics, Carolina Center for Genome Sciences, Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599, USA
| | - Joshua Starmer
- Department of Genetics, Carolina Center for Genome Sciences, Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599, USA
| | - Andrew M Fedoriw
- Department of Genetics, Carolina Center for Genome Sciences, Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599, USA
| | - Della Yee
- Department of Genetics, Carolina Center for Genome Sciences, Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599, USA
| | - Terry Magnuson
- Department of Genetics, Carolina Center for Genome Sciences, Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599, USA
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15
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Jahn D, Schramm S, Benavente R, Alsheimer M. Dynamic properties of meiosis-specific lamin C2 and its impact on nuclear envelope integrity. Nucleus 2014. [DOI: 10.4161/nucl.11800] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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16
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Wong X, Luperchio TR, Reddy KL. NET gains and losses: the role of changing nuclear envelope proteomes in genome regulation. Curr Opin Cell Biol 2014; 28:105-20. [PMID: 24886773 DOI: 10.1016/j.ceb.2014.04.005] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Revised: 03/21/2014] [Accepted: 04/11/2014] [Indexed: 01/13/2023]
Abstract
In recent years, our view of the nucleus has changed considerably with an increased awareness of the roles dynamic higher order chromatin structure and nuclear organization play in nuclear function. More recently, proteomics approaches have identified differential expression of nuclear lamina and nuclear envelope transmembrane (NET) proteins. Many NETs have been implicated in a range of developmental disorders as well as cell-type specific biological processes, including genome organization and nuclear morphology. While further studies are needed, it is clear that the differential nuclear envelope proteome contributes to cell-type specific nuclear identity and functions. This review discusses the importance of proteome diversity at the nuclear periphery and highlights the putative roles of NET proteins, with a focus on nuclear architecture.
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Affiliation(s)
- Xianrong Wong
- Johns Hopkins University, School of Medicine, Department of Biological Chemistry and Center for Epigenetics, 855N. Wolfe St., Rangos 574, Baltimore, MD 21044, United States
| | - Teresa R Luperchio
- Johns Hopkins University, School of Medicine, Department of Biological Chemistry and Center for Epigenetics, 855N. Wolfe St., Rangos 574, Baltimore, MD 21044, United States
| | - Karen L Reddy
- Johns Hopkins University, School of Medicine, Department of Biological Chemistry and Center for Epigenetics, 855N. Wolfe St., Rangos 574, Baltimore, MD 21044, United States.
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17
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Abstract
Gametogenesis combines two important features: reduction of the genome content from diploid to haploid by carefully partitioning chromosomes, and the subsequent differentiation into fertilization-competent gametes, which in males is characterized by profound nuclear restructuring. These are quite difficult tasks and require a tight coordination of different cellular mechanisms. Recent studies in the field established a key role for LINC complexes in both meiosis and sperm head formation. LINC complexes comprise SUN and KASH domain proteins that form nuclear envelope (NE) bridges, linking the nucleoskeleton to the cytoskeleton. They are well known for their crucial roles in diverse cellular and developmental processes, such as nuclear positioning and cell polarization. In this review, we highlight key roles ascribed to LINC complexes and to the nucleocytoskeletal connection in gametogenesis. First, we give a short overview about the general features of LINC components and the profound reorganization of the NE in germ cells. We then focus on specific roles of LINC complexes in meiotic chromosome dynamics and their impact on pairing, synapsis, and recombination. Finally, we provide an update of the mechanisms controlling sperm head formation and discuss the role of sperm-specific LINC complexes in nuclear shaping and their relation to specialized cytoskeletal structures that form concurrently with nuclear restructuring and sperm elongation.
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Affiliation(s)
- Martin P Kracklauer
- Department of Physiology, Wayne State University Medical School, Detroit, Michigan, USA
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18
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Abstract
Lamins are the major components of the nuclear lamina, a filamentous layer found at the interphase between chromatin and the inner nuclear membrane. The lamina supports the nuclear envelope and provides anchorage sites for chromatin. Lamins and their associated proteins are required for most nuclear activities, mitosis, and for linking the nucleoskeleton to the network of cytoskeletal filaments. Mutations in lamins and their associated proteins give rise to a wide range of diseases, collectively called laminopathies. This review focuses on the evolution of the lamin protein family. Evolution from basal metazoans to man will be described on the basis of protein sequence comparisons and analyses of their gene structure. Lamins are the founding members of the family of intermediate filament proteins. How genes encoding cytoplasmic IF proteins could have arisen from the archetypal lamin gene progenitor, can be inferred from a comparison of the respective gene structures. The lamin/IF protein family seems to be restricted to the metazoans. In general, invertebrate genomes harbor only a single lamin gene encoding a B-type lamin. The archetypal lamin gene structure found in basal metazoans is conserved up to the vertebrate lineage. The completely different structure of lamin genes in Caenorhabditis and Drosophila are exceptions rather than the rule within their systematic groups. However, variation in the length of the coiled-coil forming central domain might be more common than previously anticipated. The increase in the number of lamin genes in vertebrates can be explained by two rounds of genome duplication. The origin of lamin A by exon shuffling might explain the processing of prelamin A to the mature non-isoprenylated form of lamin A. By alternative splicing the number of vertebrate lamin proteins has increased even further. Lamin C, an alternative splice form of the LMNA gene, is restricted to mammals. Amphibians and mammals express germline-specific lamins that differ in their protein structure from that of somatic lamins. Evidence is provided that there exist lamin-like proteins outside the metazoan lineage.
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Affiliation(s)
- Annette Peter
- Department for Cell Biology, University of Bremen, Bremen, Germany
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19
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Göb E, Schmitt J, Benavente R, Alsheimer M. Mammalian sperm head formation involves different polarization of two novel LINC complexes. PLoS One 2010; 5:e12072. [PMID: 20711465 PMCID: PMC2919408 DOI: 10.1371/journal.pone.0012072] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2010] [Accepted: 07/14/2010] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND LINC complexes are nuclear envelope bridging protein structures formed by interaction of SUN and KASH proteins. They physically connect the nucleus with the peripheral cytoskeleton and are critically involved in a variety of dynamic processes, such as nuclear anchorage, movement and positioning and meiotic chromosome dynamics. Moreover, they are shown to be essential for maintaining nuclear shape. FINDINGS Based on detailed expression analysis and biochemical approaches, we show here that during mouse sperm development, a terminal cell differentiation process characterized by profound morphogenic restructuring, two novel distinctive LINC complexes are established. They consist either of spermiogenesis-specific Sun3 and Nesprin1 or Sun1eta, a novel non-nuclear Sun1 isoform, and Nesprin3. We could find that these two LINC complexes specifically polarize to opposite spermatid poles likely linking to sperm-specific cytoskeletal structures. Although, as shown in co-transfection/immunoprecipitation experiments, SUN proteins appear to arbitrarily interact with various KASH partners, our study demonstrates that they actually are able to confine their binding to form distinct LINC complexes. CONCLUSIONS Formation of the mammalian sperm head involves assembly and different polarization of two novel spermiogenesis-specific LINC complexes. Together, our findings suggest that theses LINC complexes connect the differentiating spermatid nucleus to surrounding cytoskeletal structures to enable its well-directed shaping and elongation, which in turn is a critical parameter for male fertility.
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Affiliation(s)
- Eva Göb
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Johannes Schmitt
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Ricardo Benavente
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Manfred Alsheimer
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, Würzburg, Germany
- * E-mail:
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20
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Hermo L, Pelletier RM, Cyr DG, Smith CE. Surfing the wave, cycle, life history, and genes/proteins expressed by testicular germ cells. Part 4: intercellular bridges, mitochondria, nuclear envelope, apoptosis, ubiquitination, membrane/voltage-gated channels, methylation/acetylation, and transcription factors. Microsc Res Tech 2010; 73:364-408. [PMID: 19941288 DOI: 10.1002/jemt.20785] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
As germ cells divide and differentiate from spermatogonia to spermatozoa, they share a number of structural and functional features that are common to all generations of germ cells and these features are discussed herein. Germ cells are linked to one another by large intercellular bridges which serve to move molecules and even large organelles from the cytoplasm of one cell to another. Mitochondria take on different shapes and features and topographical arrangements to accommodate their specific needs during spermatogenesis. The nuclear envelope and pore complex also undergo extensive modifications concomitant with the development of germ cell generations. Apoptosis is an event that is normally triggered by germ cells and involves many proteins. It occurs to limit the germ cell pool and acts as a quality control mechanism. The ubiquitin pathway comprises enzymes that ubiquitinate as well as deubiquitinate target proteins and this pathway is present and functional in germ cells. Germ cells express many proteins involved in water balance and pH control as well as voltage-gated ion channel movement. In the nucleus, proteins undergo epigenetic modifications which include methylation, acetylation, and phosphorylation, with each of these modifications signaling changes in chromatin structure. Germ cells contain specialized transcription complexes that coordinate the differentiation program of spermatogenesis, and there are many male germ cell-specific differences in the components of this machinery. All of the above features of germ cells will be discussed along with the specific proteins/genes and abnormalities to fertility related to each topic.
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Affiliation(s)
- Louis Hermo
- Department of Anatomy and Cell Biology, Faculty of Medicine, McGill University, 3640 University Street, Montreal, QC Canada H3A 2B2.
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21
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Jahn D, Schramm S, Benavente R, Alsheimer M. Dynamic properties of meiosis-specific lamin C2 and its impact on nuclear envelope integrity. Nucleus 2010; 1:273-83. [PMID: 21327075 DOI: 10.4161/nucl.1.3.11800] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Revised: 03/12/2010] [Accepted: 03/15/2010] [Indexed: 11/19/2022] Open
Abstract
A hallmark of meiosis is the precise pairing and the stable physical connection (synapsis) of the homologous chromosomes. These processes are essential prerequisite for their proper segregation. Pairing of the homologs during meiotic prophase I critically depends on characteristic movements of chromosomes. These movements, in turn, require attachment of meiotic telomeres to the nuclear envelope and their subsequent dynamic repositioning. Dynamic repositioning of meiotic telomeres goes along with profound structural reorganization of the nuclear envelope. The short A-type lamin C2 is thought to play a critical role in this process due to its specific expression during meiotic prophase I and the unique localization surrounding telomere attachments. Consistent with this notion, here we provide compelling evidence that meiosis-specific lamin C2 features a significantly increased mobility compared to somatic lamins as revealed by photobleaching techniques. We show that this property can be clearly ascribed to the lack of the N-terminal head and the significantly shorter α-helical coil domain. Moreover, expression of lamin C2 in somatic cells induces nuclear deformations and alters the distribution of the endogenous nuclear envelope proteins lamin B1, LAP2, SUN1 and SUN2. Together, our data define lamin C2 as a "natural lamin deletion mutant" that confers unique properties to the nuclear envelope which would be essential for dynamic telomere repositioning during meiotic prophase I.
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Affiliation(s)
- Daniel Jahn
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, Germany
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22
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von Moeller F, Barendziak T, Apte K, Goldberg MW, Stick R. Molecular characterization of Xenopus lamin LIV reveals differences in the lamin composition of sperms in amphibians and mammals. Nucleus 2010; 1:85-95. [PMID: 21327107 PMCID: PMC3035121 DOI: 10.4161/nucl.1.1.10517] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2009] [Revised: 11/04/2009] [Accepted: 11/04/2009] [Indexed: 02/06/2023] Open
Abstract
Lamins are nuclear intermediate filament proteins. They are involved in most nuclear activities and are essential for retaining the mechano-elastic properties of the nucleus. Somatic cells of vertebrates express lamins A, B1 and B2 while lamin LIII, a major component of the amphibian oocyte lamina is absent in mammals. The organization of the lamina of germ cells differs significantly from that of somatic cells. Mammalian spermatogenic cells express two short lamins, C2 and B3, that are splice isoforms of lamin A and B2, respectively. Here we identify the previously described Xenopus lamin LIV as splice variant of the lamin LIII gene. LIV contains 40 extra residues in coil 2A of the rod domain, which results in altered assembly properties. Xenopus lamin LIV and mammalian B3 assemble into short structures rather than into long IF-like filaments. Expression of lamin LIV is restricted to male germ cells suggesting that it might be the functional equivalent of mammalian lamin B3. We provide evidence that lamins C2 and B3 are restricted to the mammalian lineage and describe the lamin composition of Xenopus sperm. Our results show that the evolution of germ cell-specific lamins followed separate and distinctly different paths in amphibians and mammals.
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Affiliation(s)
| | - Tanja Barendziak
- Department of Cell Biology; University of Bremen; Bremen, Germany
| | - Ketaki Apte
- Department of Cell Biology; University of Bremen; Bremen, Germany
| | - Martin W Goldberg
- School of Biological and Biomedical Sciences; The University of Durham; Durham, UK
| | - Reimer Stick
- Department of Cell Biology; University of Bremen; Bremen, Germany
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23
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Lammerding J, Fong LG, Ji JY, Reue K, Stewart CL, Young SG, Lee RT. Lamins A and C but not lamin B1 regulate nuclear mechanics. J Biol Chem 2006; 281:25768-80. [PMID: 16825190 DOI: 10.1074/jbc.m513511200] [Citation(s) in RCA: 487] [Impact Index Per Article: 27.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Mutations in the nuclear envelope proteins lamins A and C cause a broad variety of human diseases, including Emery-Dreifuss muscular dystrophy, dilated cardiomyopathy, and Hutchinson-Gilford progeria syndrome. Cells lacking lamins A and C have reduced nuclear stiffness and increased nuclear fragility, leading to increased cell death under mechanical strain and suggesting a potential mechanism for disease. Here, we investigated the contribution of major lamin subtypes (lamins A, C, and B1) to nuclear mechanics by analyzing nuclear shape, nuclear dynamics over time, nuclear deformations under strain, and cell viability under prolonged mechanical stimulation in cells lacking both lamins A and C, cells lacking only lamin A (i.e. "lamin C-only" cells), cells lacking wild-type lamin B1, and wild-type cells. Lamin A/C-deficient cells exhibited increased numbers of misshapen nuclei and had severely reduced nuclear stiffness and decreased cell viability under strain. Lamin C-only cells had slightly abnormal nuclear shape and mildly reduced nuclear stiffness but no decrease in cell viability under strain. Interestingly, lamin B1-deficient cells exhibited normal nuclear mechanics despite having a significantly increased frequency of nuclear blebs. Our study indicates that lamins A and C are important contributors to the mechanical stiffness of nuclei, whereas lamin B1 contributes to nuclear integrity but not stiffness.
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Affiliation(s)
- Jan Lammerding
- Cardiovascular Division, Department of Medicine, and Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02139, USA.
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24
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Schütz W, Alsheimer M, Ollinger R, Benavente R. Nuclear envelope remodeling during mouse spermiogenesis: postmeiotic expression and redistribution of germline lamin B3. Exp Cell Res 2005; 307:285-91. [PMID: 15950617 DOI: 10.1016/j.yexcr.2005.03.023] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2004] [Revised: 03/07/2005] [Accepted: 03/14/2005] [Indexed: 11/30/2022]
Abstract
Lamins are members of a multigene family of structural nuclear envelope (NE) proteins. Differentiated mammalian somatic cells express lamins A, C, B1, and B2. The composition and organization of the nuclear lamina of mammalian spermatogenic cells differ significantly from that of somatic cells as they express lamin B1 as well as two short germ line-specific isoforms, namely lamins B3 and C2. Here we describe in detail the expression pattern and localization of lamin B3 during mouse spermatogenesis. By combining RT-PCR, immunoblotting, and immunofluorescence microscopy, we show that lamin B3 is selectively expressed during spermiogenesis (i.e., postmeiotic stages of spermatogenesis). In round spermatids, lamin B3 is distributed in the nuclear periphery and, notably, also in the nucleoplasm. In the course of spermiogenesis, lamin B3 becomes redistributed as it concentrates progressively to the posterior pole of spermatid nuclei. Our results show that during mammalian spermiogenesis the nuclear lamina is composed of B-type isoforms only, namely the ubiquitous lamin B1 and the germline-specific lamin B3. Lamin B3 is the first example of a mammalian lamin that is selectively expressed during postmeiotic stages of spermatogenesis.
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Affiliation(s)
- Wolfgang Schütz
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
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