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Nair A, Khanna J, Kler J, Ragesh R, Sengupta K. Nuclear envelope and chromatin choreography direct cellular differentiation. Nucleus 2025; 16:2449520. [PMID: 39943681 PMCID: PMC11834525 DOI: 10.1080/19491034.2024.2449520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2024] [Revised: 12/28/2024] [Accepted: 12/30/2024] [Indexed: 02/20/2025] Open
Abstract
The nuclear envelope plays an indispensable role in the spatiotemporal organization of chromatin and transcriptional regulation during the intricate process of cell differentiation. This review outlines the distinct regulatory networks between nuclear envelope proteins, transcription factors and epigenetic modifications in controlling the expression of cell lineage-specific genes during differentiation. Nuclear lamina with its associated nuclear envelope proteins organize heterochromatin via Lamina-Associated Domains (LADs), proximal to the nuclear periphery. Since nuclear lamina is mechanosensitive, we critically examine the impact of extracellular forces on differentiation outcomes. The nuclear envelope is spanned by nuclear pore complexes which, in addition to their central role in transport, are associated with chromatin organization. Furthermore, mutations in the nuclear envelope proteins disrupt differentiation, resulting in developmental disorders. Investigating the underlying nuclear envelope controlled regulatory mechanisms of chromatin remodelling during lineage commitment will accelerate our fundamental understanding of developmental biology and regenerative medicine.
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Affiliation(s)
- Anjitha Nair
- Chromosome Biology Lab (CBL), Indian Institute of Science Education and Research (IISER) Pune, Maharashtra, India
| | - Jayati Khanna
- Chromosome Biology Lab (CBL), Indian Institute of Science Education and Research (IISER) Pune, Maharashtra, India
| | - Jashan Kler
- Chromosome Biology Lab (CBL), Indian Institute of Science Education and Research (IISER) Pune, Maharashtra, India
| | - Rohith Ragesh
- Chromosome Biology Lab (CBL), Indian Institute of Science Education and Research (IISER) Pune, Maharashtra, India
| | - Kundan Sengupta
- Chromosome Biology Lab (CBL), Indian Institute of Science Education and Research (IISER) Pune, Maharashtra, India
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2
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Kotb NM, Ulukaya G, Ramamoorthy A, Park LS, Tang J, Hasson D, Rangan P. TORC1-driven translation of Nucleoporin44A promotes chromatin remodeling and germ cell-to-maternal transition in Drosophila. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2025:2025.03.14.643309. [PMID: 40161787 PMCID: PMC11952567 DOI: 10.1101/2025.03.14.643309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/02/2025]
Abstract
Oocyte specification is a critical developmental transition that requires the coordinated repression of germ cell-specific genes and activation of the maternal program to support embryogenesis. In Drosophila, the timely repression of germ cell and early oogenesis genes is essential for this transition, yet the mechanisms that coordinate this process remain unclear. Here, we uncover an unexpected translation-chromatin axis, where transient Target of Rapamycin Complex 1 (TORC1)-driven translation triggers chromatin remodeling, ensuring irreversible oocyte fate commitment. Through a screen, we identified ribosome biogenesis regulators, including Zinc finger protein RP-8 (Zfrp8) and TORC1 components, as key mediators of gene silencing. We show that TORC1 activity increases during oocyte specification, and disrupting ribosome biogenesis, translation, or TORC1 function prevents proper heterochromatin formation, leading to epigenetic instability. Polysome-seq analysis of zfrp8-depleted ovaries revealed that Zfrp8 is required for the translation of Nucleoporin 44A (Nup44A), a key nuclear pore complex (NPC) component. Given the role of the NPC in chromatin organization, independent disruption of Nup44A results in defective silencing of the germ cell and early oogenesis genes. Our findings reveal a mechanism in which translation-driven NPC remodeling coordinates heterochromatin establishment, facilitating the germ cell-to-maternal transition and ensuring proper oocyte fate commitment.
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Affiliation(s)
- Noor M. Kotb
- Department of Biomedical Sciences/Wadsworth Center, University at Albany State University of New York (SUNY), Albany, New York 12202, USA
- Department of Cell, Developmental, and Regenerative Biology, Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NewYork 10029, USA
- Current address, Hologic Diagenode, 400 Morris Avenue, Suite 101, Denville, New Jersey 07834, USA
| | - Gulay Ulukaya
- Bioinformatics for Next-Generation Sequencing (BiNGS) Core, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Anupriya Ramamoorthy
- Department of Cell, Developmental, and Regenerative Biology, Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NewYork 10029, USA
| | - Lina Seojin Park
- Department of Cell, Developmental, and Regenerative Biology, Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NewYork 10029, USA
| | - Julia Tang
- Department of Cell, Developmental, and Regenerative Biology, Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NewYork 10029, USA
| | - Dan Hasson
- Bioinformatics for Next-Generation Sequencing (BiNGS) Core, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
- Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Prashanth Rangan
- Department of Cell, Developmental, and Regenerative Biology, Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NewYork 10029, USA
- Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
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3
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Bettedi L, Zhang Y, Yang S, Lilly MA. Unveiling GATOR2 Function: Novel Insights from Drosophila Research. Cells 2024; 13:1795. [PMID: 39513902 PMCID: PMC11545208 DOI: 10.3390/cells13211795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2024] [Revised: 10/03/2024] [Accepted: 10/16/2024] [Indexed: 11/16/2024] Open
Abstract
The multiprotein Target of Rapamycin (TOR) Complex 1 (TORC1) is a serine/threonine kinase that stimulates anabolic metabolism and suppresses catabolism. Deregulation of TORC1 is implicated in various human pathologies, including cancer, epilepsy, and neurodegenerative disorders. The Gap Activity Towards Rags (GATOR) complex contains two subcomplexes: GATOR1, which inhibits TORC1 activity; and GATOR2, which counteracts GATOR1s function. Structural and biochemical studies have elucidated how GATOR1 regulates TORC1 activity by acting as a GTPase activating protein for Rag GTPase. However, while cryogenic electron microscopy has determined that the structure of the multi-protein GATOR2 complex is conserved from yeast to humans, how GATOR2 inhibits GATOR1 remains unclear. Here, we describe recent whole-animal studies in Drosophila that have yielded novel insights into GATOR2 function, including identifying a novel role for the GATOR2 subunit WDR59, redefining the core proteins sufficient for GATOR2 activity, and defining a TORC1-independent role for GATOR2 in the regulation of the lysosomal autophagic endomembrane system. Additionally, the recent characterization of a novel methionine receptor in Drosophila that acts through the GATOR2 complex suggests an attractive model for the evolution of species-specific nutrient sensors. Research on GATOR2 function in Drosophila highlights how whole-animal genetic models can be used to dissect intracellular signaling pathways to identify tissue-specific functions and functional redundancies that may be missed in studies confined to rapidly proliferating cell lines.
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Affiliation(s)
- Lucia Bettedi
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA; (L.B.); (S.Y.)
| | - Yingbiao Zhang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, Qingdao 266000, China;
| | - Shu Yang
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA; (L.B.); (S.Y.)
| | - Mary A. Lilly
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA; (L.B.); (S.Y.)
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4
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Rios-Valencia DG, Estrada K, Calderón-Gallegos A, Tirado-Mendoza R, Bobes RJ, Laclette JP, Cabrera-Bravo M. Effect of Hydroxyurea on Morphology, Proliferation, and Protein Expression on Taenia crassiceps WFU Strain. Int J Mol Sci 2024; 25:6061. [PMID: 38892261 PMCID: PMC11172544 DOI: 10.3390/ijms25116061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 05/22/2024] [Accepted: 05/23/2024] [Indexed: 06/21/2024] Open
Abstract
Flatworms are known for their remarkable regenerative ability, one which depends on totipotent cells known as germinative cells in cestodes. Depletion of germinative cells with hydroxyurea (HU) affects the regeneration of the parasite. Here, we studied the reduction and recovery of germinative cells in T. crassiceps cysticerci after HU treatment (25 mM and 40 mM of HU for 6 days) through in vitro assays. Viability and morphological changes were evaluated. The recovery of cysticerci's mobility and morphology was evaluated at 3 and 6 days, after 6 days of treatment. The number of proliferative cells was evaluated using EdU. Our results show morphological changes in the size, shape, and number of evaginated cysticerci at the 40 mM dose. The mobility of cysticerci was lower after 6 days of HU treatment at both concentrations. On days 3 and 6 of recovery after 25 mM of HU treatment, a partial recovery of the proliferative cells was observed. Proteomic and Gene Ontology analyses identified modifications in protein groups related to DNA binding, DNA damage, glycolytic enzymes, cytoskeleton, skeletal muscle, and RNA binding.
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Affiliation(s)
- Diana G. Rios-Valencia
- Department of Microbiology and Parasitology, School of Medicine, Universidad Nacional Autónoma de México, Coyoacan, Mexico City 04510, Mexico; (D.G.R.-V.); (R.T.-M.)
| | - Karel Estrada
- Unit for Massive Sequencing and Bioinformatics, Biotechnology Institute, Universidad Nacional Autónoma de México, Coyoacan, Mexico City 04510, Mexico;
| | - Arturo Calderón-Gallegos
- Department of Immunology, Biomedical Research Institute, Universidad Nacional Autónoma de México, Coyoacán, Mexico City 04510, Mexico; (A.C.-G.); (R.J.B.)
| | - Rocío Tirado-Mendoza
- Department of Microbiology and Parasitology, School of Medicine, Universidad Nacional Autónoma de México, Coyoacan, Mexico City 04510, Mexico; (D.G.R.-V.); (R.T.-M.)
| | - Raúl J. Bobes
- Department of Immunology, Biomedical Research Institute, Universidad Nacional Autónoma de México, Coyoacán, Mexico City 04510, Mexico; (A.C.-G.); (R.J.B.)
| | - Juan P. Laclette
- Department of Immunology, Biomedical Research Institute, Universidad Nacional Autónoma de México, Coyoacán, Mexico City 04510, Mexico; (A.C.-G.); (R.J.B.)
| | - Margarita Cabrera-Bravo
- Department of Microbiology and Parasitology, School of Medicine, Universidad Nacional Autónoma de México, Coyoacan, Mexico City 04510, Mexico; (D.G.R.-V.); (R.T.-M.)
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5
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Li Y, Bertozzi A, Mann MRW, Kühn B. Interdependent changes of nuclear lamins, nuclear pore complexes, and ploidy regulate cellular regeneration and stress response in the heart. Nucleus 2023; 14:2246310. [PMID: 37606283 PMCID: PMC10446781 DOI: 10.1080/19491034.2023.2246310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 07/28/2023] [Accepted: 08/04/2023] [Indexed: 08/23/2023] Open
Abstract
In adult mammals, many heart muscle cells (cardiomyocytes) are polyploid, do not proliferate (post-mitotic), and, consequently, cannot contribute to heart regeneration. In contrast, fetal and neonatal heart muscle cells are diploid, proliferate, and contribute to heart regeneration. We have identified interdependent changes of the nuclear lamina, nuclear pore complexes, and DNA-content (ploidy) in heart muscle cell maturation. These results offer new perspectives on how cells alter their nuclear transport and, with that, their gene regulation in response to extracellular signals. We present how changes of the nuclear lamina alter nuclear pore complexes in heart muscle cells. The consequences of these changes for cellular regeneration and stress response in the heart are discussed.
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Affiliation(s)
- Yao Li
- Division of Pediatric Cardiology, Pediatric Institute for Heart Regeneration and Therapeutics (I-HRT), UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA, USA
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Alberto Bertozzi
- Division of Pediatric Cardiology, Pediatric Institute for Heart Regeneration and Therapeutics (I-HRT), UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA, USA
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Mellissa RW Mann
- Department of Obstetrics, Gynaecology and Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Magee-Womens Research Institute, Pittsburgh, PA, USA
| | - Bernhard Kühn
- Division of Pediatric Cardiology, Pediatric Institute for Heart Regeneration and Therapeutics (I-HRT), UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA, USA
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- McGowan Institute of Regenerative Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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6
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Wdr59 promotes or inhibits TORC1 activity depending on cellular context. Proc Natl Acad Sci U S A 2023; 120:e2212330120. [PMID: 36577058 PMCID: PMC9910487 DOI: 10.1073/pnas.2212330120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Target of Rapamycin Complex I (TORC1) is a central regulator of metabolism in eukaryotes that responds to a wide array of negative and positive inputs. The GTPase-activating protein toward Rags (GATOR) signaling pathway acts upstream of TORC1 and is comprised of two subcomplexes. The trimeric GATOR1 complex inhibits TORC1 activity in response to amino acid limitation by serving as a GTPase-activating protein (GAP) for the TORC1 activator RagA/B, a component of the lysosomally located Rag GTPase. The multi-protein GATOR2 complex inhibits the activity of GATOR1 and thus promotes TORC1 activation. Here we report that Wdr59, originally assigned to the GATOR2 complex based on studies performed in tissue culture cells, unexpectedly has a dual function in TORC1 regulation in Drosophila. We find that in the ovary and the eye imaginal disc brain complex, Wdr59 inhibits TORC1 activity by opposing the GATOR2-dependent inhibition of GATOR1. Conversely, in the Drosophila fat body, Wdr59 promotes the accumulation of the GATOR2 component Mio and is required for TORC1 activation. Similarly, in mammalian HeLa cells, Wdr59 prevents the proteolytic destruction of GATOR2 proteins Mio and Wdr24. Consistent with the reduced levels of the TORC1-activating GATOR2 complex, Wdr59KOs HeLa cells have reduced TORC1 activity which is restored along with GATOR2 protein levels upon proteasome inhibition. Taken together, our data support the model that the Wdr59 component of the GATOR2 complex functions to promote or inhibit TORC1 activity depending on cellular context.
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7
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Gu X, Jouandin P, Lalgudi PV, Binari R, Valenstein ML, Reid MA, Allen AE, Kamitaki N, Locasale JW, Perrimon N, Sabatini DM. Sestrin mediates detection of and adaptation to low-leucine diets in Drosophila. Nature 2022; 608:209-216. [PMID: 35859173 PMCID: PMC10112710 DOI: 10.1038/s41586-022-04960-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 06/09/2022] [Indexed: 12/28/2022]
Abstract
Mechanistic target of rapamycin complex 1 (mTORC1) regulates cell growth and metabolism in response to multiple nutrients, including the essential amino acid leucine1. Recent work in cultured mammalian cells established the Sestrins as leucine-binding proteins that inhibit mTORC1 signalling during leucine deprivation2,3, but their role in the organismal response to dietary leucine remains elusive. Here we find that Sestrin-null flies (Sesn-/-) fail to inhibit mTORC1 or activate autophagy after acute leucine starvation and have impaired development and a shortened lifespan on a low-leucine diet. Knock-in flies expressing a leucine-binding-deficient Sestrin mutant (SesnL431E) have reduced, leucine-insensitive mTORC1 activity. Notably, we find that flies can discriminate between food with or without leucine, and preferentially feed and lay progeny on leucine-containing food. This preference depends on Sestrin and its capacity to bind leucine. Leucine regulates mTORC1 activity in glial cells, and knockdown of Sesn in these cells reduces the ability of flies to detect leucine-free food. Thus, nutrient sensing by mTORC1 is necessary for flies not only to adapt to, but also to detect, a diet deficient in an essential nutrient.
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Affiliation(s)
- Xin Gu
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA.
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.
| | - Patrick Jouandin
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.
- Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA.
| | - Pranav V Lalgudi
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Rich Binari
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
- Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA
| | - Max L Valenstein
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Michael A Reid
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC, USA
| | - Annamarie E Allen
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC, USA
| | - Nolan Kamitaki
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
- Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Biomedical Informatics, Harvard Medical School, Boston, MA, USA
| | - Jason W Locasale
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC, USA
| | - Norbert Perrimon
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.
- Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA.
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8
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Loissell-Baltazar YA, Dokudovskaya S. SEA and GATOR 10 Years Later. Cells 2021; 10:cells10102689. [PMID: 34685669 PMCID: PMC8534245 DOI: 10.3390/cells10102689] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/30/2021] [Accepted: 10/03/2021] [Indexed: 12/17/2022] Open
Abstract
The SEA complex was described for the first time in yeast Saccharomyces cerevisiae ten years ago, and its human homologue GATOR complex two years later. During the past decade, many advances on the SEA/GATOR biology in different organisms have been made that allowed its role as an essential upstream regulator of the mTORC1 pathway to be defined. In this review, we describe these advances in relation to the identification of multiple functions of the SEA/GATOR complex in nutrient response and beyond and highlight the consequence of GATOR mutations in cancer and neurodegenerative diseases.
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9
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Gonzalez-Estevez A, Verrico A, Orniacki C, Reina-San-Martin B, Doye V. Integrity of the short arm of the nuclear pore Y-complex is required for mouse embryonic stem cell growth and differentiation. J Cell Sci 2021; 134:268378. [PMID: 34037234 DOI: 10.1242/jcs.258340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 04/19/2021] [Indexed: 11/20/2022] Open
Abstract
Many cellular processes, ranging from cell division to differentiation, are controlled by nuclear pore complexes (NPCs). However, studying the contributions of individual NPC subunits to these processes in vertebrates has long been impeded by their complexity and the lack of efficient genetic tools. Here, we use genome editing in mouse embryonic stem cells (mESCs) to characterize the role of NPC structural components, focusing on the short arm of the Y-complex that comprises Nup85, Seh1 and Nup43. We show that Seh1 and Nup43, although dispensable in pluripotent mESCs, are required for their normal cell growth rates, their viability upon differentiation and for the maintenance of proper NPC density. mESCs with an N-terminally truncated Nup85 mutation (in which interaction with Seh1 is greatly impaired) feature a similar reduction of NPC density. However, their proliferation and differentiation are unaltered, indicating that it is the integrity of the Y-complex, rather than the number of NPCs, that is critical to ensure these processes.
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Affiliation(s)
- Alba Gonzalez-Estevez
- Université de Paris, Centre National de la Recherche Scientifique, Institut Jacques Monod, F-75006 Paris, France.,Ecole Doctorale BioSPC, Université de Paris, Paris, France
| | - Annalisa Verrico
- Université de Paris, Centre National de la Recherche Scientifique, Institut Jacques Monod, F-75006 Paris, France
| | - Clarisse Orniacki
- Université de Paris, Centre National de la Recherche Scientifique, Institut Jacques Monod, F-75006 Paris, France.,Ecole Doctorale BioSPC, Université de Paris, Paris, France
| | - Bernardo Reina-San-Martin
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch 67404, France.,Inserm U 1258, Illkirch 67404, France.,Centre National de la Recherche Scientifique UMR (Unité Mixte de Recherche) 7104, Illkirch 67404, France.,Université de Strasbourg, Illkirch 67404, France
| | - Valérie Doye
- Université de Paris, Centre National de la Recherche Scientifique, Institut Jacques Monod, F-75006 Paris, France.,Ecole Doctorale BioSPC, Université de Paris, Paris, France
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10
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Abstract
Nuclear pore complexes are multiprotein channels that span the nuclear envelope, which connects the nucleus to the cytoplasm. In addition to their main role in the regulation of nucleocytoplasmic molecule exchange, it has become evident that nuclear pore complexes and their components also have multiple transport-independent functions. In recent years, an increasing number of studies have reported the involvement of nuclear pore complex components in embryogenesis, cell differentiation and tissue-specific processes. Here, we review the findings that highlight the dynamic nature of nuclear pore complexes and their roles in many cell type-specific functions during development and tissue homeostasis.
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Affiliation(s)
- Valeria Guglielmi
- Development, Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
- NCI-Designated Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | | | - Maximiliano A D'Angelo
- Development, Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
- NCI-Designated Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
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11
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Yang S, Zhang Y, Ting CY, Bettedi L, Kim K, Ghaniam E, Lilly MA. The Rag GTPase Regulates the Dynamic Behavior of TSC Downstream of Both Amino Acid and Growth Factor Restriction. Dev Cell 2020; 55:272-288.e5. [PMID: 32898476 PMCID: PMC7657977 DOI: 10.1016/j.devcel.2020.08.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 06/30/2020] [Accepted: 08/10/2020] [Indexed: 01/09/2023]
Abstract
The dysregulation of the metabolic regulator TOR complex I (TORC1) contributes to a wide array of human pathologies. Tuberous sclerosis complex (TSC) is a potent inhibitor of TORC1. Here, we demonstrate that the Rag GTPase acts in both the amino-acid-sensing and growth factor signaling pathways to control TORC1 activity through the regulation of TSC dynamics in HeLa cells and Drosophila. We find that TSC lysosomal-cytosolic exchange increases in response to both amino acid and growth factor restriction. Moreover, the rate of exchange mirrors TSC function, with depletions of the Rag GTPase blocking TSC lysosomal mobility and rescuing TORC1 activity. Finally, we show that the GATOR2 complex controls the phosphorylation of TSC2, which is essential for TSC exchange. Our data support the model that the amino acid and growth factor signaling pathways converge on the Rag GTPase to inhibit TORC1 activity through the regulation of TSC dynamics.
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Affiliation(s)
- Shu Yang
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yingbiao Zhang
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Chun-Yuan Ting
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Lucia Bettedi
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kuikwon Kim
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Elena Ghaniam
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Mary A Lilly
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
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12
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Khan AU, Qu R, Ouyang J, Dai J. Role of Nucleoporins and Transport Receptors in Cell Differentiation. Front Physiol 2020; 11:239. [PMID: 32308628 PMCID: PMC7145948 DOI: 10.3389/fphys.2020.00239] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 03/02/2020] [Indexed: 12/20/2022] Open
Abstract
Bidirectional molecular movements between the nucleus and cytoplasm take place through nuclear pore complexes (NPCs) embedded in the nuclear membrane. These macromolecular structures are composed of several nucleoporins, which form seven different subcomplexes based on their biochemical affinity. These nucleoporins are integral components of the complex, not only allowing passive transport but also interacting with importin, exportin, and other molecules that are required for transport of protein in various cellular processes. Transport of different proteins is carried out either dependently or independently on transport receptors. As well as facilitating nucleocytoplasmic transport, nucleoporins also play an important role in cell differentiation, possibly by their direct gene interaction. This review will cover the general role of nucleoporins (whether its dependent or independent) and nucleocytoplasmic transport receptors in cell differentiation.
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13
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Hinnant TD, Merkle JA, Ables ET. Coordinating Proliferation, Polarity, and Cell Fate in the Drosophila Female Germline. Front Cell Dev Biol 2020; 8:19. [PMID: 32117961 PMCID: PMC7010594 DOI: 10.3389/fcell.2020.00019] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 01/10/2020] [Indexed: 01/05/2023] Open
Abstract
Gametes are highly specialized cell types produced by a complex differentiation process. Production of viable oocytes requires a series of precise and coordinated molecular events. Early in their development, germ cells are an interconnected group of mitotically dividing cells. Key regulatory events lead to the specification of mature oocytes and initiate a switch to the meiotic cell cycle program. Though the chromosomal events of meiosis have been extensively studied, it is unclear how other aspects of oocyte specification are temporally coordinated. The fruit fly, Drosophila melanogaster, has long been at the forefront as a model system for genetics and cell biology research. The adult Drosophila ovary continuously produces germ cells throughout the organism’s lifetime, and many of the cellular processes that occur to establish oocyte fate are conserved with mammalian gamete development. Here, we review recent discoveries from Drosophila that advance our understanding of how early germ cells balance mitotic exit with meiotic initiation. We discuss cell cycle control and establishment of cell polarity as major themes in oocyte specification. We also highlight a germline-specific organelle, the fusome, as integral to the coordination of cell division, cell polarity, and cell fate in ovarian germ cells. Finally, we discuss how the molecular controls of the cell cycle might be integrated with cell polarity and cell fate to maintain oocyte production.
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Affiliation(s)
- Taylor D Hinnant
- Department of Biology, East Carolina University, Greenville, NC, United States
| | - Julie A Merkle
- Department of Biology, University of Evansville, Evansville, IN, United States
| | - Elizabeth T Ables
- Department of Biology, East Carolina University, Greenville, NC, United States
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14
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Kim YI, Nam IK, Um JY, Choe SK. Regulatory role of Wdr24 in autophagy activity during zebrafish embryogenesis. Mol Cell Toxicol 2018. [DOI: 10.1007/s13273-019-0010-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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15
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Preston CC, Storm EC, Leonard RJ, Faustino RS. Emerging roles for nucleoporins in reproductive cellular physiology 1. Can J Physiol Pharmacol 2018; 97:257-264. [PMID: 30388388 DOI: 10.1139/cjpp-2018-0436] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Nucleoporins are a specialized subset of nuclear proteins that comprise the nuclear pore complex and regulate nucleocytoplasmic transport. Recent demonstrations of roles for individual nucleoporins in multiple paradigms of differentiation via mechanisms independent of nuclear trafficking represent conceptual advances in understanding the contributions of nucleoporins to cellular development. Among these, a functional role for nucleoporins in reproductive fitness and gametogenesis has been identified, supported by robust models and clinical studies that leverage the power of next generation sequencing technology to identify reproductive-disease-associated mutations in specific nucleoporins. Proper nucleoporin function manifests in different ways during oogenesis and spermatogenesis. However, nonhuman models of gametogenesis may not recapitulate human mechanisms, which may confound translational interpretation and relevance. To circumvent these limitations, identification of reproductive pathologies in patients, combined with next generation sequencing approaches and advanced in silico tools, offers a powerful approach to investigate the potential function of nucleoporins in human reproduction. Ultimately, elucidating the role of nucleoporins in reproductive biology will provide opportunities for predictive, diagnostic, and therapeutic strategies to address reproductive disorders.
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Affiliation(s)
- Claudia C Preston
- a Genetics and Genomics, Sanford Research, 2301 E. 60th Street N., Sioux Falls, SD 57104, USA
| | - Emily C Storm
- a Genetics and Genomics, Sanford Research, 2301 E. 60th Street N., Sioux Falls, SD 57104, USA
| | - Riley J Leonard
- a Genetics and Genomics, Sanford Research, 2301 E. 60th Street N., Sioux Falls, SD 57104, USA
| | - Randolph S Faustino
- a Genetics and Genomics, Sanford Research, 2301 E. 60th Street N., Sioux Falls, SD 57104, USA.,b Department of Pediatrics, Sanford School of Medicine of the University of South Dakota, 1400 W. 22nd Street, Sioux Falls, SD 57105, USA
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16
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Ma Y, Silveri L, LaCava J, Dokudovskaya S. Tumor suppressor NPRL2 induces ROS production and DNA damage response. Sci Rep 2017; 7:15311. [PMID: 29127423 PMCID: PMC5681675 DOI: 10.1038/s41598-017-15497-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 10/23/2017] [Indexed: 02/07/2023] Open
Abstract
The SEA/GATOR complex is an essential regulator of the mTORC1 pathway. In mammals the GATOR1 complex is composed of the proteins DEPDC5, NPRL2 and NPRL3. GATOR1 serves as an mTORC1 inhibitor and activates the mTORC1-modulating RagA GTPase. However, several GATOR members have mTORC1 independent functions. Here we characterize mammalian cells overexpressing the GATOR1 component NPRL2. We demonstrate that, in the cells with active p53, ectopic expression of NPRL2 induces NOX2-dependent production of reactive oxygen species and DNA damage. Overexpressed NPRL2 accumulates in the nucleus, together with apoptosis-inducing factor (AIF). These events are accompanied by phosphorylation of p53, activation of a DNA-damage response and cell cycle arrest in G1 phase, followed by apoptosis. In the cells negative for active p53, NPRL2 ectopic expression leads to activation of CHK1 or CHK2 kinases and cell cycle arrest in S or G2/M phases. Combined, these results demonstrate a new role for the NPRL2, distinct from its function in mTORC1 regulation.
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Affiliation(s)
- Yinxing Ma
- CNRS UMR 8126, Université Paris-Sud 11, Institut Gustave Roussy, 114, rue Edouard Vaillant, 94805, Villejuif, France
| | - Licia Silveri
- CNRS UMR 8126, Université Paris-Sud 11, Institut Gustave Roussy, 114, rue Edouard Vaillant, 94805, Villejuif, France
| | - John LaCava
- Laboratory of Cellular and Structural Biology, The Rockefeller University, New York, New York, USA.,Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York, 10016, USA
| | - Svetlana Dokudovskaya
- CNRS UMR 8126, Université Paris-Sud 11, Institut Gustave Roussy, 114, rue Edouard Vaillant, 94805, Villejuif, France.
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17
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Peng L, Wang L, Yang YF, Zou MM, He WY, Wang Y, Wang Q, Vasseur L, You MS. Transcriptome profiling of the Plutella xylostella (Lepidoptera: Plutellidae) ovary reveals genes involved in oogenesis. Gene 2017; 637:90-99. [PMID: 28916376 DOI: 10.1016/j.gene.2017.09.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 07/21/2017] [Accepted: 09/08/2017] [Indexed: 01/23/2023]
Abstract
BACKGROUND As a specialized organ, the insect ovary performs valuable functions by ensuring fecundity and population survival. Oogenesis is the complex physiological process resulting in the production of mature eggs, which are involved in epigenetic programming, germ cell behavior, cell cycle regulation, etc. Identification of the genes involved in ovary development and oogenesis is critical to better understand the reproductive biology and screening for the potential molecular targets in Plutella xylostella, a worldwide destructive pest of economically major crops. RESULTS Based on transcriptome sequencing, a total of 7.88Gb clean nucleotides was obtained, with 19,934 genes and 1861 new transcripts being identified. Expression profiling indicated that 61.7% of the genes were expressed (FPKM≥1) in the P. xylostella ovary. GO annotation showed that the pathways of multicellular organism reproduction and multicellular organism reproduction process, as well as gamete generation and chorion were significantly enriched. Processes that were most likely relevant to reproduction included the spliceosome, ubiquitin mediated proteolysis, endocytosis, PI3K-Akt signaling pathway, insulin signaling pathway, cAMP signaling pathway, and focal adhesion were identified in the top 20 'highly represented' KEGG pathways. Functional genes involved in oogenesis were further analyzed and validated by qRT-PCR to show their potential predominant roles in P. xylostella reproduction. CONCLUSIONS Our newly developed P. xylostella ovary transcriptome provides an overview of the gene expression profiling in this specialized tissue and the functional gene network closely related to the ovary development and oogenesis. This is the first genome-wide transcriptome dataset of P. xylostella ovary that includes a subset of functionally activated genes. This global approach will be the basis for further studies on molecular mechanisms of P. xylostella reproduction aimed at screening potential molecular targets for integrated pest management.
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Affiliation(s)
- Lu Peng
- State Key Laboratory of Ecological Pest Control for Fujian-Taiwan Crops and College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Fujian-Taiwan Joint Innovation Centre for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Key Laboratory of Integrated Pest Management for Fujian-Taiwan Crops, Ministry of Agriculture, Fuzhou 350002, China; Fujian Provincial Key Laboratory of Insect Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Lei Wang
- State Key Laboratory of Ecological Pest Control for Fujian-Taiwan Crops and College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Fujian-Taiwan Joint Innovation Centre for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Key Laboratory of Integrated Pest Management for Fujian-Taiwan Crops, Ministry of Agriculture, Fuzhou 350002, China; Fujian Provincial Key Laboratory of Insect Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Yi-Fan Yang
- State Key Laboratory of Ecological Pest Control for Fujian-Taiwan Crops and College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Fujian-Taiwan Joint Innovation Centre for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Key Laboratory of Integrated Pest Management for Fujian-Taiwan Crops, Ministry of Agriculture, Fuzhou 350002, China; Fujian Provincial Key Laboratory of Insect Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Ming-Min Zou
- State Key Laboratory of Ecological Pest Control for Fujian-Taiwan Crops and College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Fujian-Taiwan Joint Innovation Centre for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Key Laboratory of Integrated Pest Management for Fujian-Taiwan Crops, Ministry of Agriculture, Fuzhou 350002, China; Fujian Provincial Key Laboratory of Insect Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Wei-Yi He
- State Key Laboratory of Ecological Pest Control for Fujian-Taiwan Crops and College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Fujian-Taiwan Joint Innovation Centre for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Key Laboratory of Integrated Pest Management for Fujian-Taiwan Crops, Ministry of Agriculture, Fuzhou 350002, China; Fujian Provincial Key Laboratory of Insect Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Yue Wang
- State Key Laboratory of Ecological Pest Control for Fujian-Taiwan Crops and College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Fujian-Taiwan Joint Innovation Centre for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Key Laboratory of Integrated Pest Management for Fujian-Taiwan Crops, Ministry of Agriculture, Fuzhou 350002, China; Fujian Provincial Key Laboratory of Insect Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Qing Wang
- State Key Laboratory of Ecological Pest Control for Fujian-Taiwan Crops and College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Fujian-Taiwan Joint Innovation Centre for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Key Laboratory of Integrated Pest Management for Fujian-Taiwan Crops, Ministry of Agriculture, Fuzhou 350002, China; Fujian Provincial Key Laboratory of Insect Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Liette Vasseur
- State Key Laboratory of Ecological Pest Control for Fujian-Taiwan Crops and College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Fujian-Taiwan Joint Innovation Centre for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Key Laboratory of Integrated Pest Management for Fujian-Taiwan Crops, Ministry of Agriculture, Fuzhou 350002, China; Fujian Provincial Key Laboratory of Insect Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Department of Biological Sciences, Brock University, St. Catharines, Ontario L2S 3A1, Canada
| | - Min-Sheng You
- State Key Laboratory of Ecological Pest Control for Fujian-Taiwan Crops and College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Fujian-Taiwan Joint Innovation Centre for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Key Laboratory of Integrated Pest Management for Fujian-Taiwan Crops, Ministry of Agriculture, Fuzhou 350002, China; Fujian Provincial Key Laboratory of Insect Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
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18
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Spatial Activation of TORC1 Is Regulated by Hedgehog and E2F1 Signaling in the Drosophila Eye. Dev Cell 2017; 42:363-375.e4. [PMID: 28829944 DOI: 10.1016/j.devcel.2017.07.020] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 06/17/2017] [Accepted: 07/23/2017] [Indexed: 01/20/2023]
Abstract
Target of rapamycin complex 1 (TORC1) regulates cell growth in response to nutrients and growth factors. Although TORC1 signaling has been thoroughly studied at the cellular level, the regulation of TORC1 in multicellular tissues and organs has remained elusive. Here we found that TORC1 is selectively activated in the second mitotic wave (SMW), the terminal synchronous cell division, of the developing Drosophila eye. We demonstrated that Hedgehog (Hh) signaling regulates TORC1 through E2F1 and the cyclin D/Cdk4 complex in the SMW, and this regulation is independent from insulin and amino acid signaling pathways. TORC1 is necessary for the proper G1/S transition of the cells, and the activation of TORC1 rescues the cell-cycle defect of Hh signaling-deficient cells in the SMW. Based on this evolutionarily conserved regulation of TORC1 by Hh signaling, we propose that Hh-dependent developmental signaling pathways spatially regulate TORC1 activity in multicellular organisms.
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19
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Wei Y, Reveal B, Cai W, Lilly MA. The GATOR1 Complex Regulates Metabolic Homeostasis and the Response to Nutrient Stress in Drosophila melanogaster. G3 (BETHESDA, MD.) 2016; 6:3859-3867. [PMID: 27672113 PMCID: PMC5144957 DOI: 10.1534/g3.116.035337] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 09/15/2016] [Indexed: 02/06/2023]
Abstract
TORC1 regulates metabolism and growth in response to a large array of upstream inputs. The evolutionarily conserved trimeric GATOR1 complex inhibits TORC1 activity in response to amino acid limitation. In humans, the GATOR1 complex has been implicated in a wide array of pathologies including cancer and hereditary forms of epilepsy. However, the precise role of GATOR1 in animal physiology remains largely undefined. Here, we characterize null mutants of the GATOR1 components nprl2, nprl3, and iml1 in Drosophila melanogaster We demonstrate that all three mutants have inappropriately high baseline levels of TORC1 activity and decreased adult viability. Consistent with increased TORC1 activity, GATOR1 mutants exhibit a cell autonomous increase in cell growth. Notably, escaper nprl2 and nprl3 mutant adults have a profound locomotion defect. In line with a nonautonomous role in the regulation of systemic metabolism, expressing the Nprl3 protein in the fat body, a nutrient storage organ, and hemocytes but not muscles and neurons rescues the motility of nprl3 mutants. Finally, we show that nprl2 and nprl3 mutants fail to activate autophagy in response to amino acid limitation and are extremely sensitive to both amino acid and complete starvation. Thus, in Drosophila, in addition to maintaining baseline levels of TORC1 activity, the GATOR1 complex has retained a critical role in the response to nutrient stress. In summary, the TORC1 inhibitor GATOR1 contributes to multiple aspects of the development and physiology of Drosophila.
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Affiliation(s)
- Youheng Wei
- Cell Biology and Neurobiology Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892
| | - Brad Reveal
- Cell Biology and Neurobiology Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892
| | - Weili Cai
- Cell Biology and Neurobiology Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892
| | - Mary A Lilly
- Cell Biology and Neurobiology Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892
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20
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Tucker EJ, Grover SR, Bachelot A, Touraine P, Sinclair AH. Premature Ovarian Insufficiency: New Perspectives on Genetic Cause and Phenotypic Spectrum. Endocr Rev 2016; 37:609-635. [PMID: 27690531 DOI: 10.1210/er.2016-1047] [Citation(s) in RCA: 153] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Premature ovarian insufficiency (POI) is one form of female infertility, defined by loss of ovarian activity before the age of 40 and characterized by amenorrhea (primary or secondary) with raised gonadotropins and low estradiol. POI affects up to one in 100 females, including one in 1000 before the age of 30. Substantial evidence suggests a genetic basis for POI; however, the majority of cases remain unexplained, indicating that genes likely to be associated with this condition are yet to be discovered. This review discusses the current knowledge of the genetic basis of POI. We highlight genes typically known to cause syndromic POI that can be responsible for isolated POI. The role of mouse models in understanding POI pathogenesis is discussed, and a thorough list of candidate POI genes is provided. Identifying a genetic basis for POI has multiple advantages, such as enabling the identification of presymptomatic family members who can be offered counseling and cryopreservation of eggs before depletion, enabling personalized treatment based on the cause of an individual's condition, and providing better understanding of disease mechanisms that ultimately aid the development of improved treatments.
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Affiliation(s)
- Elena J Tucker
- Murdoch Children's Research Institute (E.J.T., S.R.G., A.H.S.), Royal Children's Hospital, Melbourne, VIC 3052 Australia; Department of Paediatrics (E.J.T., S.R.G., A.H.S.), University of Melbourne, Melbourne, VIC 3010, Australia; Department of Paediatric and Adolescent Gynaecology (S.R.G.), Royal Children's Hospital, Melbourne, VIC 3052, Australia; Assistance Publique Hôpitaux de Paris, (A.B., P.T.), IE3M, Université Pierre et Marie Curie, Paris 6 University, Department of Endocrinology and Reproductive Medicine, Centre de Référence des Maladies Endocriniennes Rares de la Croissance et des Pathologies Gynécologiques Rares, Pitié-Salpêtrière Hospital, Université Pierre et Marie Curie, 75013 Paris, France; Institut National de la Santé et de la Recherche Médicale (A.B., P.T.), 75654 Paris, France
| | - Sonia R Grover
- Murdoch Children's Research Institute (E.J.T., S.R.G., A.H.S.), Royal Children's Hospital, Melbourne, VIC 3052 Australia; Department of Paediatrics (E.J.T., S.R.G., A.H.S.), University of Melbourne, Melbourne, VIC 3010, Australia; Department of Paediatric and Adolescent Gynaecology (S.R.G.), Royal Children's Hospital, Melbourne, VIC 3052, Australia; Assistance Publique Hôpitaux de Paris, (A.B., P.T.), IE3M, Université Pierre et Marie Curie, Paris 6 University, Department of Endocrinology and Reproductive Medicine, Centre de Référence des Maladies Endocriniennes Rares de la Croissance et des Pathologies Gynécologiques Rares, Pitié-Salpêtrière Hospital, Université Pierre et Marie Curie, 75013 Paris, France; Institut National de la Santé et de la Recherche Médicale (A.B., P.T.), 75654 Paris, France
| | - Anne Bachelot
- Murdoch Children's Research Institute (E.J.T., S.R.G., A.H.S.), Royal Children's Hospital, Melbourne, VIC 3052 Australia; Department of Paediatrics (E.J.T., S.R.G., A.H.S.), University of Melbourne, Melbourne, VIC 3010, Australia; Department of Paediatric and Adolescent Gynaecology (S.R.G.), Royal Children's Hospital, Melbourne, VIC 3052, Australia; Assistance Publique Hôpitaux de Paris, (A.B., P.T.), IE3M, Université Pierre et Marie Curie, Paris 6 University, Department of Endocrinology and Reproductive Medicine, Centre de Référence des Maladies Endocriniennes Rares de la Croissance et des Pathologies Gynécologiques Rares, Pitié-Salpêtrière Hospital, Université Pierre et Marie Curie, 75013 Paris, France; Institut National de la Santé et de la Recherche Médicale (A.B., P.T.), 75654 Paris, France
| | - Philippe Touraine
- Murdoch Children's Research Institute (E.J.T., S.R.G., A.H.S.), Royal Children's Hospital, Melbourne, VIC 3052 Australia; Department of Paediatrics (E.J.T., S.R.G., A.H.S.), University of Melbourne, Melbourne, VIC 3010, Australia; Department of Paediatric and Adolescent Gynaecology (S.R.G.), Royal Children's Hospital, Melbourne, VIC 3052, Australia; Assistance Publique Hôpitaux de Paris, (A.B., P.T.), IE3M, Université Pierre et Marie Curie, Paris 6 University, Department of Endocrinology and Reproductive Medicine, Centre de Référence des Maladies Endocriniennes Rares de la Croissance et des Pathologies Gynécologiques Rares, Pitié-Salpêtrière Hospital, Université Pierre et Marie Curie, 75013 Paris, France; Institut National de la Santé et de la Recherche Médicale (A.B., P.T.), 75654 Paris, France
| | - Andrew H Sinclair
- Murdoch Children's Research Institute (E.J.T., S.R.G., A.H.S.), Royal Children's Hospital, Melbourne, VIC 3052 Australia; Department of Paediatrics (E.J.T., S.R.G., A.H.S.), University of Melbourne, Melbourne, VIC 3010, Australia; Department of Paediatric and Adolescent Gynaecology (S.R.G.), Royal Children's Hospital, Melbourne, VIC 3052, Australia; Assistance Publique Hôpitaux de Paris, (A.B., P.T.), IE3M, Université Pierre et Marie Curie, Paris 6 University, Department of Endocrinology and Reproductive Medicine, Centre de Référence des Maladies Endocriniennes Rares de la Croissance et des Pathologies Gynécologiques Rares, Pitié-Salpêtrière Hospital, Université Pierre et Marie Curie, 75013 Paris, France; Institut National de la Santé et de la Recherche Médicale (A.B., P.T.), 75654 Paris, France
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The GATOR2 Component Wdr24 Regulates TORC1 Activity and Lysosome Function. PLoS Genet 2016; 12:e1006036. [PMID: 27166823 PMCID: PMC4864241 DOI: 10.1371/journal.pgen.1006036] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 04/18/2016] [Indexed: 11/27/2022] Open
Abstract
TORC1 is a master regulator of metabolism in eukaryotes that responds to multiple upstream signaling pathways. The GATOR complex is a newly defined upstream regulator of TORC1 that contains two sub-complexes, GATOR1, which inhibits TORC1 activity in response to amino acid starvation and GATOR2, which opposes the activity of GATOR1. While the GATOR1 complex has been implicated in a wide array of human pathologies including cancer and hereditary forms of epilepsy, the in vivo relevance of the GATOR2 complex remains poorly understood in metazoans. Here we define the in vivo role of the GATOR2 component Wdr24 in Drosophila. Using a combination of genetic, biochemical, and cell biological techniques we demonstrate that Wdr24 has both TORC1 dependent and independent functions in the regulation of cellular metabolism. Through the characterization of a null allele, we show that Wdr24 is a critical effector of the GATOR2 complex that promotes the robust activation of TORC1 and cellular growth in a broad array of Drosophila tissues. Additionally, epistasis analysis between wdr24 and genes that encode components of the GATOR1 complex revealed that Wdr24 has a second critical function, the TORC1 independent regulation of lysosome dynamics and autophagic flux. Notably, we find that two additional members of the GATOR2 complex, Mio and Seh1, also have a TORC1 independent role in the regulation of lysosome function. These findings represent a surprising and previously unrecognized function of GATOR2 complex components in the regulation of lysosomes. Consistent with our findings in Drosophila, through the characterization of a wdr24-/- knockout HeLa cell line we determined that Wdr24 promotes lysosome acidification and autophagic flux in mammalian cells. Taken together our data support the model that Wdr24 is a key effector of the GATOR2 complex, required for both TORC1 activation and the TORC1 independent regulation of lysosomes. TORC1 is a conserved multi-protein complex that regulates metabolism and cell growth in response to many upstream inputs including nutrient availability. When amino acids are limiting, the GATOR1 complex inhibits TORC1 activation. The inhibition of TORC1 slows cellular metabolism and promotes cell survival during times of protein scarcity. A second critical response to amino acid limitation is the activation of autophagy. During autophagy cells degrade intracellular components in specialized membrane-bound organelles called autolysosomes that are formed when lysosomes fuse with autophagosomes. In times of nutrient stress, the process of autophagy allows proteins and other building blocks of the cell to be broken down and repurposed for vital cellular functions. Here we demonstrate that Wdr24, a component of the multi-protein GATOR2 complex, has a dual role in the regulation of cellular metabolism in Drosophila. First, Wdr24 is required to oppose the activity of the GATOR1 complex, thus activating TORC1 in a broad array of Drosophila tissues. Second, Wdr24 promotes the acidification of lysosomes and thus facilitates autophagic flux. Our data support the model that Wdr24 uses both TORC1 dependent and independent pathways to regulate cellular metabolism.
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Abstract
The oocyte is the sole source of the female genetic material that will be fertilized by sperm to form an embryo. Many extrinsic and intrinsic factors are critical for oocyte development and survival; however, these mediators are incompletely understood. In this issue of the JCI, Weinberg-Shukron et al. uncover a novel recessive missense mutation in the gene encoding nucleoporin-107 (NUP107) that results in abnormal ovarian development. Recapitulation of the human mutation in the Drosophila NUP107 ortholog resulted in poor follicular development and demonstrated an evolutionarily conserved and ovary-specific role of NUP107. While NUP107 is required for nuclear pore complex function in somatic cells of flies and women, this specific amino acid change appears only to be disruptive in the ovary. All together, these findings imply that missense mutations in other genes could be specifically disruptive of ovarian or testicular function, while leaving extragonadal function intact.
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23
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Weinberg-Shukron A, Renbaum P, Kalifa R, Zeligson S, Ben-Neriah Z, Dreifuss A, Abu-Rayyan A, Maatuk N, Fardian N, Rekler D, Kanaan M, Samson AO, Levy-Lahad E, Gerlitz O, Zangen D. A mutation in the nucleoporin-107 gene causes XX gonadal dysgenesis. J Clin Invest 2015; 125:4295-304. [PMID: 26485283 DOI: 10.1172/jci83553] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 09/03/2015] [Indexed: 11/17/2022] Open
Abstract
Ovarian development and maintenance are poorly understood; however, diseases that affect these processes can offer insights into the underlying mechanisms. XX female gonadal dysgenesis (XX-GD) is a rare, genetically heterogeneous disorder that is characterized by underdeveloped, dysfunctional ovaries, with subsequent lack of spontaneous pubertal development, primary amenorrhea, uterine hypoplasia, and hypergonadotropic hypogonadism. Here, we report an extended consanguineous family of Palestinian origin, in which 4 females exhibited XX-GD. Using homozygosity mapping and whole-exome sequencing, we identified a recessive missense mutation in nucleoporin-107 (NUP107, c.1339G>A, p.D447N). This mutation segregated with the XX-GD phenotype and was not present in available databases or in 150 healthy ethnically matched controls. NUP107 is a component of the nuclear pore complex, and the NUP107-associated protein SEH1 is required for oogenesis in Drosophila. In Drosophila, Nup107 knockdown in somatic gonadal cells resulted in female sterility, whereas males were fully fertile. Transgenic rescue of Drosophila females bearing the Nup107D364N mutation, which corresponds to the human NUP107 (p.D447N), resulted in almost complete sterility, with a marked reduction in progeny, morphologically aberrant eggshells, and disintegrating egg chambers, indicating defective oogenesis. These results indicate a pivotal role for NUP107 in ovarian development and suggest that nucleoporin defects may play a role in milder and more common conditions such as premature ovarian failure.
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Platani M, Trinkle-Mulcahy L, Porter M, Jeyaprakash AA, Earnshaw WC. Mio depletion links mTOR regulation to Aurora A and Plk1 activation at mitotic centrosomes. J Cell Biol 2015; 210:45-62. [PMID: 26124292 PMCID: PMC4494011 DOI: 10.1083/jcb.201410001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Coordination of cell growth and proliferation in response to nutrient supply is mediated by mammalian target of rapamycin (mTOR) signaling. In this study, we report that Mio, a highly conserved member of the SEACAT/GATOR2 complex necessary for the activation of mTORC1 kinase, plays a critical role in mitotic spindle formation and subsequent chromosome segregation by regulating the proper concentration of active key mitotic kinases Plk1 and Aurora A at centrosomes and spindle poles. Mio-depleted cells showed reduced activation of Plk1 and Aurora A kinase at spindle poles and an impaired localization of MCAK and HURP, two key regulators of mitotic spindle formation and known substrates of Aurora A kinase, resulting in spindle assembly and cytokinesis defects. Our results indicate that a major function of Mio in mitosis is to regulate the activation/deactivation of Plk1 and Aurora A, possibly by linking them to mTOR signaling in a pathway to promote faithful mitotic progression.
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Affiliation(s)
- Melpomeni Platani
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, Scotland, UK
| | - Laura Trinkle-Mulcahy
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H8M5, Canada Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Ontario K1H8M5, Canada
| | - Michael Porter
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK
| | - A Arockia Jeyaprakash
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, Scotland, UK
| | - William C Earnshaw
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, Scotland, UK
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Dokudovskaya S, Rout MP. SEA you later alli-GATOR--a dynamic regulator of the TORC1 stress response pathway. J Cell Sci 2015; 128:2219-28. [PMID: 25934700 DOI: 10.1242/jcs.168922] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Cells constantly adapt to various environmental changes and stresses. The way in which nutrient and stress levels in a cell feed back to control metabolism and growth are, unsurprisingly, extremely complex, as responding with great sensitivity and speed to the 'feast or famine, slack or stress' status of its environment is a central goal for any organism. The highly conserved target of rapamycin complex 1 (TORC1) controls eukaryotic cell growth and response to a variety of signals, including nutrients, hormones and stresses, and plays the key role in the regulation of autophagy. A lot of attention has been paid recently to the factors in this pathway functioning upstream of TORC1. In this Commentary, we focus on a major, newly discovered upstream regulator of TORC1--the multiprotein SEA complex, also known as GATOR. We describe the structural and functional features of the yeast complex and its mammalian homolog, and their involvement in the regulation of the TORC1 pathway and TORC1-independent processes. We will also provide an overview of the consequences of GATOR deregulation in cancer and other diseases.
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Affiliation(s)
- Svetlana Dokudovskaya
- CNRS UMR 8126, Université Paris-Sud 11, Institut Gustave Roussy, 114, rue Edouard Vaillant, 94805, Villejuif, France
| | - Michael P Rout
- Laboratory of Cellular and Structural Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
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26
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Talamas JA, Capelson M. Nuclear envelope and genome interactions in cell fate. Front Genet 2015; 6:95. [PMID: 25852741 PMCID: PMC4365743 DOI: 10.3389/fgene.2015.00095] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 02/22/2015] [Indexed: 12/14/2022] Open
Abstract
The eukaryotic cell nucleus houses an organism’s genome and is the location within the cell where all signaling induced and development-driven gene expression programs are ultimately specified. The genome is enclosed and separated from the cytoplasm by the nuclear envelope (NE), a double-lipid membrane bilayer, which contains a large variety of trans-membrane and associated protein complexes. In recent years, research regarding multiple aspects of the cell nucleus points to a highly dynamic and coordinated concert of efforts between chromatin and the NE in regulation of gene expression. Details of how this concert is orchestrated and how it directs cell differentiation and disease are coming to light at a rapid pace. Here we review existing and emerging concepts of how interactions between the genome and the NE may contribute to tissue specific gene expression programs to determine cell fate.
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Affiliation(s)
- Jessica A Talamas
- Program in Epigenetics, Department of Cell and Developmental Biology, Smilow Center for Translational Research, Perelman School of Medicine, University of Pennsylvania Philadelphia, PA, USA
| | - Maya Capelson
- Program in Epigenetics, Department of Cell and Developmental Biology, Smilow Center for Translational Research, Perelman School of Medicine, University of Pennsylvania Philadelphia, PA, USA
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27
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TORC1 regulators Iml1/GATOR1 and GATOR2 control meiotic entry and oocyte development in Drosophila. Proc Natl Acad Sci U S A 2014; 111:E5670-7. [PMID: 25512509 DOI: 10.1073/pnas.1419156112] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
In single-cell eukaryotes the pathways that monitor nutrient availability are central to initiating the meiotic program and gametogenesis. In Saccharomyces cerevisiae an essential step in the transition to the meiotic cycle is the down-regulation of the nutrient-sensitive target of rapamycin complex 1 (TORC1) by the increased minichromosome loss 1/ GTPase-activating proteins toward Rags 1 (Iml1/GATOR1) complex in response to amino acid starvation. How metabolic inputs influence early meiotic progression and gametogenesis remains poorly understood in metazoans. Here we define opposing functions for the TORC1 regulatory complexes Iml1/GATOR1 and GATOR2 during Drosophila oogenesis. We demonstrate that, as is observed in yeast, the Iml1/GATOR1 complex inhibits TORC1 activity to slow cellular metabolism and drive the mitotic/meiotic transition in developing ovarian cysts. In iml1 germline depletions, ovarian cysts undergo an extra mitotic division before meiotic entry. The TORC1 inhibitor rapamycin can suppress this extra mitotic division. Thus, high TORC1 activity delays the mitotic/meiotic transition. Conversely, mutations in Tor, which encodes the catalytic subunit of the TORC1 complex, result in premature meiotic entry. Later in oogenesis, the GATOR2 components Mio and Seh1 are required to oppose Iml1/GATOR1 activity to prevent the constitutive inhibition of TORC1 and a block to oocyte growth and development. To our knowledge, these studies represent the first examination of the regulatory relationship between the Iml1/GATOR1 and GATOR2 complexes within the context of a multicellular organism. Our data imply that the central role of the Iml1/GATOR1 complex in the regulation of TORC1 activity in the early meiotic cycle has been conserved from single cell to multicellular organisms.
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Algret R, Fernandez-Martinez J, Shi Y, Kim SJ, Pellarin R, Cimermancic P, Cochet E, Sali A, Chait BT, Rout MP, Dokudovskaya S. Molecular architecture and function of the SEA complex, a modulator of the TORC1 pathway. Mol Cell Proteomics 2014; 13:2855-70. [PMID: 25073740 DOI: 10.1074/mcp.m114.039388] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The TORC1 signaling pathway plays a major role in the control of cell growth and response to stress. Here we demonstrate that the SEA complex physically interacts with TORC1 and is an important regulator of its activity. During nitrogen starvation, deletions of SEA complex components lead to Tor1 kinase delocalization, defects in autophagy, and vacuolar fragmentation. TORC1 inactivation, via nitrogen deprivation or rapamycin treatment, changes cellular levels of SEA complex members. We used affinity purification and chemical cross-linking to generate the data for an integrative structure modeling approach, which produced a well-defined molecular architecture of the SEA complex and showed that the SEA complex comprises two regions that are structurally and functionally distinct. The SEA complex emerges as a platform that can coordinate both structural and enzymatic activities necessary for the effective functioning of the TORC1 pathway.
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Affiliation(s)
- Romain Algret
- From the ‡CNRS UMR 8126, Université Paris-Sud 11, Institut Gustave Roussy, 114, rue Edouard Vaillant, 94805, Villejuif, France
| | - Javier Fernandez-Martinez
- §Laboratory of Cellular and Structural Biology, The Rockefeller University, 1230 York Avenue, New York, New York 10065
| | - Yi Shi
- ¶Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, 1230 York Avenue, New York, New York 10065
| | - Seung Joong Kim
- ‖Department of Bioengineering and Therapeutic Sciences, Department of Pharmaceutical Chemistry, and California Institute for Quantitative Biosciences (QB3), University of California, San Francisco, UCSF MC 2552, Byers Hall Room 503B, 1700 4th Street, San Francisco, California 94158-2330
| | - Riccardo Pellarin
- ‖Department of Bioengineering and Therapeutic Sciences, Department of Pharmaceutical Chemistry, and California Institute for Quantitative Biosciences (QB3), University of California, San Francisco, UCSF MC 2552, Byers Hall Room 503B, 1700 4th Street, San Francisco, California 94158-2330
| | - Peter Cimermancic
- ‖Department of Bioengineering and Therapeutic Sciences, Department of Pharmaceutical Chemistry, and California Institute for Quantitative Biosciences (QB3), University of California, San Francisco, UCSF MC 2552, Byers Hall Room 503B, 1700 4th Street, San Francisco, California 94158-2330
| | - Emilie Cochet
- From the ‡CNRS UMR 8126, Université Paris-Sud 11, Institut Gustave Roussy, 114, rue Edouard Vaillant, 94805, Villejuif, France
| | - Andrej Sali
- ‖Department of Bioengineering and Therapeutic Sciences, Department of Pharmaceutical Chemistry, and California Institute for Quantitative Biosciences (QB3), University of California, San Francisco, UCSF MC 2552, Byers Hall Room 503B, 1700 4th Street, San Francisco, California 94158-2330
| | - Brian T Chait
- ¶Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, 1230 York Avenue, New York, New York 10065
| | - Michael P Rout
- §Laboratory of Cellular and Structural Biology, The Rockefeller University, 1230 York Avenue, New York, New York 10065
| | - Svetlana Dokudovskaya
- From the ‡CNRS UMR 8126, Université Paris-Sud 11, Institut Gustave Roussy, 114, rue Edouard Vaillant, 94805, Villejuif, France;
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29
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Wei Y, Lilly MA. The TORC1 inhibitors Nprl2 and Nprl3 mediate an adaptive response to amino-acid starvation in Drosophila. Cell Death Differ 2014; 21:1460-8. [PMID: 24786828 DOI: 10.1038/cdd.2014.63] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 04/02/2014] [Accepted: 04/03/2014] [Indexed: 01/09/2023] Open
Abstract
Target of rapamycin complex 1 (TORC1) is a master regulator of metabolism in eukaryotes that integrates information from multiple upstream signaling pathways. In yeast, the Nitrogen permease regulators 2 and 3 (Npr2 and Npr3) mediate an essential response to amino-acid limitation upstream of TORC1. In mammals, the Npr2 ortholog, Nprl2, is a putative tumor suppressor gene that inhibits cell growth and enhances sensitivity to numerous anticancer drugs including cisplatin. However, the precise role of Nprl2 and Nprl3 in the regulation of metabolism in metazoans remains poorly defined. Here we demonstrate that the central importance of Nprl2 and Nprl3 in the response to amino-acid starvation has been conserved from single celled to multicellular animals. We find that in Drosophila Nprl2 and Nprl3 physically interact and are targeted to lysosomes and autolysosomes. Using oogenesis as a model system, we show that Nprl2 and Nprl3 inhibit TORC1 signaling in the female germline in response to amino-acid starvation. Moreover, the inhibition TORC1 by Nprl2/3 is critical to the preservation of female fertility during times of protein scarcity. In young egg chambers the failure to downregulate TORC1 in response to amino-acid limitation triggers apoptosis. Thus, our data suggest the presence of a metabolic checkpoint that initiates a cell death program when TORC1 activity remains inappropriately high during periods of amino-acid and/or nutrient scarcity in oogenesis. Finally, we demonstrate that Nprl2/3 work in concert with the TORC1 inhibitors Tsc1/2 to fine tune TORC1 activity during oogenesis and that Tsc1 is a critical downstream effector of Akt1 in the female germline.
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Affiliation(s)
- Y Wei
- Cell Biology and Metabolism Program, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - M A Lilly
- Cell Biology and Metabolism Program, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
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30
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Niu X, Hong J, Zheng X, Melville DB, Knapik EW, Meng A, Peng J. The nuclear pore complex function of Sec13 protein is required for cell survival during retinal development. J Biol Chem 2014; 289:11971-11985. [PMID: 24627485 DOI: 10.1074/jbc.m114.547190] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Sec13 is a dual function protein, being a core component of both the COPII coat, which mediates protein trafficking from the endoplasmic reticulum to the Golgi apparatus, and the nuclear pore complex (NPC), which facilitates nucleo-cytoplasmic traffic. Here, we present a genetic model to differentiate the roles of these two functions of Sec13 in vivo. We report that sec13(sq198) mutant embryos develop small eyes that exhibit disrupted retinal lamination and that the mutant retina contains an excessive number of apoptotic cells. Surprisingly, we found that loss of COPII function by oligonucleotide-mediated gene knockdown of sec31a and sec31b or brefeldin A treatment did not disrupt retinal lamination, although it did result in digestive organ defects similar to those seen in sec13(sq198), suggesting that the digestive organ defects observed in sec13(sq198) are due to loss of COPII function, whereas the retinal lamination defects are due to loss of the NPC function. We showed that the retinal cells of sec13(sq198) failed to form proper nuclear pores, leading to a nuclear accumulation of total mRNA and abnormal activation of the p53-dependent apoptosis pathway, causing the retinal defect in sec13(sq198). Furthermore, we found that a mutant lacking Nup107, a key NPC-specific component, phenocopied the retinal lamination phenotype as observed in sec13(sq198). Our results demonstrate a requirement for the nuclear pore function of Sec13 in development of the retina and provide the first genetic evidence to differentiate the contributions of the NPC and the COPII functions of Sec13 during organogenesis.
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Affiliation(s)
- Xubo Niu
- Key Laboratory for Molecular Animal Nutrition, Ministry of Education, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Jian Hong
- Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Xiaofeng Zheng
- State Key Laboratory of Biomembrane and Membrane Engineering, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - David B Melville
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720-3370; Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee 37232
| | - Ela W Knapik
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee 37232
| | - Anming Meng
- State Key Laboratory of Biomembrane and Membrane Engineering, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Jinrong Peng
- Key Laboratory for Molecular Animal Nutrition, Ministry of Education, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.
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31
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Asakawa H, Yang HJ, Yamamoto TG, Ohtsuki C, Chikashige Y, Sakata-Sogawa K, Tokunaga M, Iwamoto M, Hiraoka Y, Haraguchi T. Characterization of nuclear pore complex components in fission yeast Schizosaccharomyces pombe. Nucleus 2014; 5:149-62. [PMID: 24637836 PMCID: PMC4049921 DOI: 10.4161/nucl.28487] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The nuclear pore complex (NPC) is an enormous proteinaceous complex composed of multiple copies of about 30 different proteins called nucleoporins. In this study, we analyzed the composition of the NPC in the model organism Schizosaccharomyces pombe using strains in which individual nucleoporins were tagged with GFP. We identified 31 proteins as nucleoporins by their localization to the nuclear periphery. Gene disruption analysis in previous studies coupled with gene disruption analysis in the present study indicates that 15 of these nucleoporins are essential for vegetative cell growth and the other 16 nucleoporins are non-essential. Among the 16 non-essential nucleoporins, 11 are required for normal progression through meiosis and their disruption caused abnormal spore formation or poor spore viability. Based on fluorescence measurements of GFP-fused nucleoporins, we estimated the composition of the NPC in S. pombe and found that the organization of the S. pombe NPC is largely similar to that of other organisms; a single NPC was estimated as being 45.8–47.8 MDa in size. We also used fluorescence measurements of single NPCs and quantitative western blotting to analyze the composition of the Nup107-Nup160 subcomplex, which plays an indispensable role in NPC organization and function. Our analysis revealed low amounts of Nup107 and Nup131 and high amounts of Nup132 in the Nup107-Nup160 subcomplex, suggesting that the composition of this complex in S. pombe may differ from that in S. cerevisiae and humans. Comparative analysis of NPCs in various organisms will lead to a comprehensive understanding of the functional architecture of the NPC.
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Affiliation(s)
- Haruhiko Asakawa
- Graduate School of Frontier Biosciences; Osaka University; Suita, Japan
| | - Hui-Ju Yang
- Graduate School of Frontier Biosciences; Osaka University; Suita, Japan
| | - Takaharu G Yamamoto
- Advanced ICT Research Institute Kobe; National Institute of Information and Communications Technology; Kobe, Japan
| | - Chizuru Ohtsuki
- Graduate School of Frontier Biosciences; Osaka University; Suita, Japan
| | - Yuji Chikashige
- Advanced ICT Research Institute Kobe; National Institute of Information and Communications Technology; Kobe, Japan; Graduate School of Science; Osaka University; Toyonaka, Japan
| | - Kumiko Sakata-Sogawa
- Department of Biological Information; Graduate School of Bioscience and Biotechnology; Tokyo Institute of Technology; Yokohama, Japan; RIKEN Center for Integrative Medical Sciences (IMS-RCAI); Yokohama, Japan
| | - Makio Tokunaga
- Department of Biological Information; Graduate School of Bioscience and Biotechnology; Tokyo Institute of Technology; Yokohama, Japan; RIKEN Center for Integrative Medical Sciences (IMS-RCAI); Yokohama, Japan
| | - Masaaki Iwamoto
- Advanced ICT Research Institute Kobe; National Institute of Information and Communications Technology; Kobe, Japan
| | - Yasushi Hiraoka
- Graduate School of Frontier Biosciences; Osaka University; Suita, Japan; Advanced ICT Research Institute Kobe; National Institute of Information and Communications Technology; Kobe, Japan; Graduate School of Science; Osaka University; Toyonaka, Japan
| | - Tokuko Haraguchi
- Graduate School of Frontier Biosciences; Osaka University; Suita, Japan; Advanced ICT Research Institute Kobe; National Institute of Information and Communications Technology; Kobe, Japan; Graduate School of Science; Osaka University; Toyonaka, Japan
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32
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Bui KH, von Appen A, DiGuilio AL, Ori A, Sparks L, Mackmull MT, Bock T, Hagen W, Andrés-Pons A, Glavy JS, Beck M. Integrated structural analysis of the human nuclear pore complex scaffold. Cell 2014; 155:1233-43. [PMID: 24315095 DOI: 10.1016/j.cell.2013.10.055] [Citation(s) in RCA: 271] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 08/22/2013] [Accepted: 10/02/2013] [Indexed: 11/28/2022]
Abstract
The nuclear pore complex (NPC) is a fundamental component of all eukaryotic cells that facilitates nucleocytoplasmic exchange of macromolecules. It is assembled from multiple copies of about 30 nucleoporins. Due to its size and complex composition, determining the structure of the NPC is an enormous challenge, and the overall architecture of the NPC scaffold remains elusive. In this study, we have used an integrated approach based on electron tomography, single-particle electron microscopy, and crosslinking mass spectrometry to determine the structure of a major scaffold motif of the human NPC, the Nup107 subcomplex, in both isolation and integrated into the NPC. We show that 32 copies of the Nup107 subcomplex assemble into two reticulated rings, one each at the cytoplasmic and nuclear face of the NPC. This arrangement may explain how changes of the diameter are realized that would accommodate transport of huge cargoes.
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Affiliation(s)
- Khanh Huy Bui
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, Meyerhofstrasse 1, 69117 Heidelberg, Germany
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33
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Nuclear pore complex composition: a new regulator of tissue-specific and developmental functions. Nat Rev Mol Cell Biol 2013; 13:687-99. [PMID: 23090414 DOI: 10.1038/nrm3461] [Citation(s) in RCA: 258] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Nuclear pore complexes (NPCs) are multiprotein aqueous channels that penetrate the nuclear envelope connecting the nucleus and the cytoplasm. NPCs consist of multiple copies of roughly 30 different proteins known as nucleoporins (NUPs). Due to their essential role in controlling nucleocytoplasmic transport, NPCs have traditionally been considered as structures of ubiquitous composition. The overall structure of the NPC is indeed conserved in all cells, but new evidence suggests that the protein composition of NPCs varies among cell types and tissues. Moreover, mutations in various nucleoporins result in tissue-specific diseases. These findings point towards a heterogeneity in NPC composition and function. This unexpected heterogeneity suggests that cells use a combination of different nucleoporins to assemble NPCs with distinct properties and specialized functions.
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Bukovsky A, Caudle MR. Immunoregulation of follicular renewal, selection, POF, and menopause in vivo, vs. neo-oogenesis in vitro, POF and ovarian infertility treatment, and a clinical trial. Reprod Biol Endocrinol 2012; 10:97. [PMID: 23176151 PMCID: PMC3551781 DOI: 10.1186/1477-7827-10-97] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2012] [Accepted: 11/11/2012] [Indexed: 12/13/2022] Open
Abstract
The immune system plays an important role in the regulation of tissue homeostasis ("tissue immune physiology"). Function of distinct tissues during adulthood, including the ovary, requires (1) Renewal from stem cells, (2) Preservation of tissue-specific cells in a proper differentiated state, which differs among distinct tissues, and (3) Regulation of tissue quantity. Such morphostasis can be executed by the tissue control system, consisting of immune system-related components, vascular pericytes, and autonomic innervation. Morphostasis is established epigenetically, during morphogenetic (developmental) immune adaptation, i.e., during the critical developmental period. Subsequently, the tissues are maintained in a state of differentiation reached during the adaptation by a "stop effect" of resident and self renewing monocyte-derived cells. The later normal tissue is programmed to emerge (e.g., late emergence of ovarian granulosa cells), the earlier its function ceases. Alteration of certain tissue differentiation during the critical developmental period causes persistent alteration of that tissue function, including premature ovarian failure (POF) and primary amenorrhea. In fetal and adult human ovaries the ovarian surface epithelium cells called ovarian stem cells (OSC) are bipotent stem cells for the formation of ovarian germ and granulosa cells. Recently termed oogonial stem cells are, in reality, not stem but already germ cells which have the ability to divide. Immune system-related cells and molecules accompany asymmetric division of OSC resulting in the emergence of secondary germ cells, symmetric division, and migration of secondary germ cells, formation of new granulosa cells and fetal and adult primordial follicles (follicular renewal), and selection and growth of primary/preantral, and dominant follicles. The number of selected follicles during each ovarian cycle is determined by autonomic innervation. Morphostasis is altered with advancing age, due to degenerative changes of the immune system. This causes cessation of oocyte and follicular renewal at 38 +/-2 years of age due to the lack of formation of new granulosa cells. Oocytes in primordial follicles persisting after the end of the prime reproductive period accumulate genetic alterations resulting in an exponentially growing incidence of fetal trisomies and other genetic abnormalities with advanced maternal age. The secondary germ cells also develop in the OSC cultures derived from POF and aging ovaries. In vitro conditions are free of immune mechanisms, which prevent neo-oogenesis in vivo. Such germ cells are capable of differentiating in vitro into functional oocytes. This may provide fresh oocytes and genetically related children to women lacking the ability to produce their own follicular oocytes. Further study of "immune physiology" may help us to better understand ovarian physiology and pathology, including ovarian infertility caused by POF or by a lack of ovarian follicles with functional oocytes in aging ovaries. The observations indicating involvement of immunoregulation in physiological neo-oogenesis and follicular renewal from OSC during the fetal and prime reproductive periods are reviewed as well as immune system and age-independent neo-oogenesis and oocyte maturation in OSC cultures, perimenopausal alteration of homeostasis causing disorders of many tissues, and the first OSC culture clinical trial.
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Affiliation(s)
- Antonin Bukovsky
- The Institute of Biotechnology, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
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35
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Zheng X, Yang S, Han Y, Zhao X, Zhao L, Tian T, Tong J, Xu P, Xiong C, Meng A. Loss of zygotic NUP107 protein causes missing of pharyngeal skeleton and other tissue defects with impaired nuclear pore function in zebrafish embryos. J Biol Chem 2012; 287:38254-64. [PMID: 22965233 PMCID: PMC3488094 DOI: 10.1074/jbc.m112.408997] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Revised: 09/08/2012] [Indexed: 11/06/2022] Open
Abstract
The Nup107-160 multiprotein subcomplex is essential for the assembly of nuclear pore complexes. The developmental functions of individual constituents of this subcomplex in vertebrates remain elusive. In particular, it is unknown whether Nup107 plays an important role in development of vertebrate embryos. Zebrafish nup107 is maternally expressed and its zygotic expression becomes prominent in the head region and the intestine from 24 h postfertilization (hpf) onward. In this study, we generate a zebrafish mutant line, nup107(tsu068Gt), in which the nup107 locus is disrupted by an insertion of Tol2 transposon element in the first intron and as a result it fails to produce normal transcripts. Homozygous nup107(tsu068Gt) mutant embryos exhibit tissue-specific defects after 3 days postfertilization (dpf), including loss of the pharyngeal skeletons, degeneration of the intestine, absence of the swim bladder, and smaller eyes. These mutants die at 5-6 days. Extensive apoptosis occurs in the affected tissues, which is partially dependent on p53 apoptotic pathways. In cells of the defective tissues, FG-repeat nucleoporins are disturbed and nuclear pore number is reduced, leading to impaired translocation of mRNAs from the nucleus to the cytoplasm. Our findings shed new light on developmental function of Nup107 in vertebrates.
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Affiliation(s)
- Xiaofeng Zheng
- From the State Key Laboratory of Biomembrane and Membrane Engineering, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China and
| | - Shuyan Yang
- From the State Key Laboratory of Biomembrane and Membrane Engineering, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China and
- the Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yanchao Han
- From the State Key Laboratory of Biomembrane and Membrane Engineering, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China and
| | - Xinyi Zhao
- From the State Key Laboratory of Biomembrane and Membrane Engineering, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China and
| | - Long Zhao
- From the State Key Laboratory of Biomembrane and Membrane Engineering, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China and
| | - Tian Tian
- From the State Key Laboratory of Biomembrane and Membrane Engineering, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China and
| | - Jingyuan Tong
- From the State Key Laboratory of Biomembrane and Membrane Engineering, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China and
| | - Pengfei Xu
- From the State Key Laboratory of Biomembrane and Membrane Engineering, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China and
| | - Cong Xiong
- From the State Key Laboratory of Biomembrane and Membrane Engineering, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China and
| | - Anming Meng
- From the State Key Laboratory of Biomembrane and Membrane Engineering, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China and
- the Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
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36
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Azzam G, Smibert P, Lai EC, Liu JL. Drosophila Argonaute 1 and its miRNA biogenesis partners are required for oocyte formation and germline cell division. Dev Biol 2012; 365:384-94. [PMID: 22445511 DOI: 10.1016/j.ydbio.2012.03.005] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Revised: 03/05/2012] [Accepted: 03/07/2012] [Indexed: 11/16/2022]
Abstract
Argonaute 1 (Ago1) is a member of the Argonaute/PIWI protein family involved in small RNA-mediated gene regulation. In Drosophila, Ago1 plays a specific role in microRNA (miRNA) biogenesis and function. Previous studies have demonstrated that Ago1 regulates the fate of germline stem cells. However, the function of Ago1 in other aspects of oogenesis is still elusive. Here we report the function of Ago1 in developing egg chambers. We find that Ago1 protein is enriched in the oocytes and is also highly expressed in the cytoplasm of follicle cells. Clonal analysis of multiple ago1 mutant alleles shows that many mutant egg chambers contain only 8 nurse cells without an oocyte which is phenocopied in dicer-1, pasha and drosha mutants. Our results suggest that Ago1 and its miRNA biogenesis partners play a role in oocyte determination and germline cell division in Drosophila.
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Affiliation(s)
- Ghows Azzam
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, South Parks Road, University of Oxford, Oxford, UK
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37
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Miyamoto Y, Boag PR, Hime GR, Loveland KL. Regulated nucleocytoplasmic transport during gametogenesis. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2012; 1819:616-30. [PMID: 22326858 DOI: 10.1016/j.bbagrm.2012.01.015] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Revised: 01/23/2012] [Accepted: 01/24/2012] [Indexed: 12/13/2022]
Abstract
Gametogenesis is the process by which sperm or ova are produced in the gonads. It is governed by a tightly controlled series of gene expression events, with some common and others distinct for males and females. Nucleocytoplasmic transport is of central importance to the fidelity of gene regulation that is required to achieve the precisely regulated germ cell differentiation essential for fertility. In this review we discuss the physiological importance for gamete formation of the molecules involved in classical nucleocytoplasmic protein transport, including importins/karyopherins, Ran and nucleoporins. To address what functions/factors are conserved or specialized for these developmental processes between species, we compare knowledge from mice, flies and worms. The present analysis provides evidence of the necessity for and specificity of each nuclear transport factor and for nucleoporins during germ cell differentiation. This article is part of a Special Issue entitled: Nuclear Transport and RNA Processing.
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Affiliation(s)
- Yoichi Miyamoto
- Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, Victoria 3800, Australia.
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38
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Bukovsky A. Ovarian stem cell niche and follicular renewal in mammals. Anat Rec (Hoboken) 2011; 294:1284-306. [PMID: 21714105 DOI: 10.1002/ar.21422] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2011] [Accepted: 04/28/2011] [Indexed: 12/24/2022]
Abstract
Stem cell niche consists of perivascular compartment, which connects the stem cells to the immune and vascular systems. During embryonic period, extragonadal primordial germ cells colonize coelomic epithelium of developing gonads. Subsequently, ovarian stem cells (OSC) produce secondary germ cells under the influence of OSC niche, including immune system-related cells and hormonal signaling. The OSC in fetal and adult human ovaries serve as a source of germ and granulosa cells. Lack of either granulosa or germ cell niche will result in premature ovarian failure in spite of the presence of OSC. During perinatal period, the OSC transdifferentiate into fibroblast-like cells forming the ovarian tunica albuginea resistant to environmental threats. They represent mesenchymal precursors of epithelial OSC during adulthood. The follicular renewal during the prime reproductive period (PRP) ensures that there are fresh eggs available for a healthy progeny. End of PRP is followed by exponentially growing fetal genetic abnormalities. The OSC are present in adult, aging, and postmenopausal ovaries, and differentiate in vitro into new oocytes. During in vitro development of large isolated oocytes reaching 200 μm in diameter, an ancestral mechanism of premeiotic nurse cells, which operates during oogenesis in developing ovaries from invertebrates to mammalian species, is utilized. In vitro developed eggs could be used for autologous IVF treatment of premature ovarian failure. Such eggs are also capable to produce parthenogenetic embryos like some cultured follicular oocytes. The parthenotes produce embryonic stem cells derived from inner cell mass, and these cells can serve as autologous pluripotent stem cells.
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Affiliation(s)
- Antonin Bukovsky
- Institute of Biotechnology, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
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