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Deolal P, Scholz J, Ren K, Bragulat-Teixidor H, Otsuka S. Sculpting nuclear envelope identity from the endoplasmic reticulum during the cell cycle. Nucleus 2024; 15:2299632. [PMID: 38238284 PMCID: PMC10802211 DOI: 10.1080/19491034.2023.2299632] [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: 10/18/2023] [Accepted: 12/21/2023] [Indexed: 01/23/2024] Open
Abstract
The nuclear envelope (NE) regulates nuclear functions, including transcription, nucleocytoplasmic transport, and protein quality control. While the outer membrane of the NE is directly continuous with the endoplasmic reticulum (ER), the NE has an overall distinct protein composition from the ER, which is crucial for its functions. During open mitosis in higher eukaryotes, the NE disassembles during mitotic entry and then reforms as a functional territory at the end of mitosis to reestablish nucleocytoplasmic compartmentalization. In this review, we examine the known mechanisms by which the functional NE reconstitutes from the mitotic ER in the continuous ER-NE endomembrane system during open mitosis. Furthermore, based on recent findings indicating that the NE possesses unique lipid metabolism and quality control mechanisms distinct from those of the ER, we explore the maintenance of NE identity and homeostasis during interphase. We also highlight the potential significance of membrane junctions between the ER and NE.
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Affiliation(s)
- Pallavi Deolal
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Vienna, Austria
- Medical University of Vienna, Center for Medical Biochemistry, Department of Molecular Biology, Vienna, Austria
| | - Julia Scholz
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Vienna, Austria
- Medical University of Vienna, Center for Medical Biochemistry, Department of Molecular Biology, Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Kaike Ren
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Vienna, Austria
- Medical University of Vienna, Center for Medical Biochemistry, Department of Molecular Biology, Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Helena Bragulat-Teixidor
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Vienna, Austria
- Medical University of Vienna, Center for Medical Biochemistry, Department of Molecular Biology, Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Shotaro Otsuka
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Vienna, Austria
- Medical University of Vienna, Center for Medical Biochemistry, Department of Molecular Biology, Vienna, Austria
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2
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Lima JT, Ferreira JG. Mechanobiology of the nucleus during the G2-M transition. Nucleus 2024; 15:2330947. [PMID: 38533923 DOI: 10.1080/19491034.2024.2330947] [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: 11/30/2023] [Accepted: 03/09/2024] [Indexed: 03/28/2024] Open
Abstract
Cellular behavior is continuously influenced by mechanical forces. These forces span the cytoskeleton and reach the nucleus, where they trigger mechanotransduction pathways that regulate downstream biochemical events. Therefore, the nucleus has emerged as a regulator of cellular response to mechanical stimuli. Cell cycle progression is regulated by cyclin-CDK complexes. Recent studies demonstrated these biochemical pathways are influenced by mechanical signals, highlighting the interdependence of cellular mechanics and cell cycle regulation. In particular, the transition from G2 to mitosis (G2-M) shows significant changes in nuclear structure and organization, ranging from nuclear pore complex (NPC) and nuclear lamina disassembly to chromosome condensation. The remodeling of these mechanically active nuclear components indicates that mitotic entry is particularly sensitive to forces. Here, we address how mechanical forces crosstalk with the nucleus to determine the timing and efficiency of the G2-M transition. Finally, we discuss how the deregulation of nuclear mechanics has consequences for mitosis.
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Affiliation(s)
- Joana T Lima
- Epithelial Polarity and Cell Division Laboratory, Instituto de Investigação e Inovação em Saúde (i3S), Porto, Portugal
- Departamento de Biomedicina, Unidade de Biologia Experimental, Faculdade de Medicina do Porto, Porto, Portugal
- Programa Doutoral em Biomedicina, Faculdade de Medicina, Universidade do Porto, Porto, Portugal
| | - Jorge G Ferreira
- Epithelial Polarity and Cell Division Laboratory, Instituto de Investigação e Inovação em Saúde (i3S), Porto, Portugal
- Departamento de Biomedicina, Unidade de Biologia Experimental, Faculdade de Medicina do Porto, Porto, Portugal
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3
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McPhee M, Dellaire G, Ridgway ND. Mechanisms for assembly of the nucleoplasmic reticulum. Cell Mol Life Sci 2024; 81:415. [PMID: 39367888 PMCID: PMC11455740 DOI: 10.1007/s00018-024-05437-3] [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: 06/28/2024] [Revised: 08/22/2024] [Accepted: 09/03/2024] [Indexed: 10/07/2024]
Abstract
The nuclear envelope consists of an outer membrane connected to the endoplasmic reticulum, an inner membrane facing the nucleoplasm and a perinuclear space separating the two bilayers. The inner and outer nuclear membranes are physically connected at nuclear pore complexes that mediate selective communication and transfer of materials between the cytoplasm and nucleus. The spherical shape of the nuclear envelope is maintained by counterbalancing internal and external forces applied by cyto- and nucleo-skeletal networks, and the nuclear lamina and chromatin that underly the inner nuclear membrane. Despite its apparent rigidity, the nuclear envelope can invaginate to form an intranuclear membrane network termed the nucleoplasmic reticulum (NR) consisting of Type-I NR contiguous with the inner nuclear membrane and Type-II NR containing both the inner and outer nuclear membranes. The NR extends deep into the nuclear interior potentially facilitating communication and exchanges between the nuclear interior and the cytoplasm. This review details the evidence that NR intrusions that regulate cytoplasmic communication and genome maintenance are the result of a dynamic interplay between membrane biogenesis and remodelling, and physical forces exerted on the nuclear lamina derived from the cyto- and nucleo-skeletal networks.
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Affiliation(s)
- Michael McPhee
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, NS, B3H4R2, Canada
| | - Graham Dellaire
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, NS, B3H4R2, Canada
- Department of Pathology, Dalhousie University, Halifax, NS, B3H4R2, Canada
| | - Neale D Ridgway
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, NS, B3H4R2, Canada.
- Department of Pediatrics, Atlantic Research Centre, Dalhousie University, Halifax, NS, B3H4R2, Canada.
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4
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Białek W, Hryniewicz-Jankowska A, Czechowicz P, Sławski J, Collawn JF, Czogalla A, Bartoszewski R. The lipid side of unfolded protein response. Biochim Biophys Acta Mol Cell Biol Lipids 2024; 1869:159515. [PMID: 38844203 DOI: 10.1016/j.bbalip.2024.159515] [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: 02/28/2024] [Revised: 04/16/2024] [Accepted: 05/31/2024] [Indexed: 06/12/2024]
Abstract
Although our current knowledge of the molecular crosstalk between the ER stress, the unfolded protein response (UPR), and lipid homeostasis remains limited, there is increasing evidence that dysregulation of either protein or lipid homeostasis profoundly affects the other. Most research regarding UPR signaling in human diseases has focused on the causes and consequences of disrupted protein folding. The UPR itself consists of very complex pathways that function to not only maintain protein homeostasis, but just as importantly, modulate lipid biogenesis to allow the ER to adjust and promote cell survival. Lipid dysregulation is known to activate many aspects of the UPR, but the complexity of this crosstalk remains a major research barrier. ER lipid disequilibrium and lipotoxicity are known to be important contributors to numerous human pathologies, including insulin resistance, liver disease, cardiovascular diseases, neurodegenerative diseases, and cancer. Despite their medical significance and continuous research, however, the molecular mechanisms that modulate lipid synthesis during ER stress conditions, and their impact on cell fate decisions, remain poorly understood. Here we summarize the current view on crosstalk and connections between altered lipid metabolism, ER stress, and the UPR.
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Affiliation(s)
- Wojciech Białek
- Department of Biophysics, Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland
| | | | - Paulina Czechowicz
- Department of Biophysics, Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland
| | - Jakub Sławski
- Department of Biophysics, Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland
| | - James F Collawn
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, USA
| | - Aleksander Czogalla
- Department of Cytobiochemistry, Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland
| | - Rafał Bartoszewski
- Department of Biophysics, Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland.
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5
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Ptak C, Rehman S, Wozniak RW. Mechanisms of nuclear envelope expansion. Curr Opin Cell Biol 2024; 91:102425. [PMID: 39250858 DOI: 10.1016/j.ceb.2024.102425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2024] [Revised: 08/12/2024] [Accepted: 08/14/2024] [Indexed: 09/11/2024]
Abstract
In actively dividing eukaryotic cells, the nuclear envelope membrane (NEM) expands during the cell cycle to accommodate increases in nuclear volume and formation of two nuclei as a cell passes through mitosis to form daughter cells. NEM expansion is driven by glycerophospholipid (GPL) synthesis that is regulated by the lipin family of phosphatidic acid phosphatases (PAPs). How, and when during the cell cycle, PAPs regulate membrane expansion differs between organisms undergoing a closed or open mitosis. Here, we discuss recent studies that shed light on the mechanisms of NE expansion. Moreover, we examine evidence that NEM expansion not only employs GPLs synthesized in the ER but also lipids whose synthesis is regulated by events at the inner nuclear membrane.
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Affiliation(s)
- Christopher Ptak
- Department of Cell Biology, University of Alberta, Edmonton, Alberta, Canada
| | - Saif Rehman
- Department of Cell Biology, University of Alberta, Edmonton, Alberta, Canada
| | - Richard W Wozniak
- Department of Cell Biology, University of Alberta, Edmonton, Alberta, Canada.
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6
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Jiang X, Wang H, Nie K, Gao Y, Chen S, Tang Y, Wang Z, Su H, Dong H. Targeting lipid droplets and lipid droplet-associated proteins: a new perspective on natural compounds against metabolic diseases. Chin Med 2024; 19:120. [PMID: 39232826 PMCID: PMC11373146 DOI: 10.1186/s13020-024-00988-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2024] [Accepted: 08/22/2024] [Indexed: 09/06/2024] Open
Abstract
BACKGROUND Lipid droplet (LD) is a metabolically active organelle, which changes dynamically with the metabolic state and energy requirements of cells. Proteins that either insert into the LD phospholipid monolayer or are present in the cytoplasm, playing a crucial role in lipid homeostasis and signaling regulation, are known as LD-associated proteins. METHODS The keywords "lipid droplets" and "metabolic diseases" were used to obtain literature on LD metabolism and pathological mechanism. After searching databases including Scopus, OVID, Web of Science, and PubMed from 2013 to 2024 using terms like "lipid droplets", "lipid droplet-associated proteins", "fatty liver disease", "diabetes", "diabetic kidney disease", "obesity", "atherosclerosis", "hyperlipidemia", "natural drug monomers" and "natural compounds", the most common natural compounds were identified in about 954 articles. Eventually, a total of 91 studies of 10 natural compounds reporting in vitro or in vivo studies were refined and summarized. RESULTS The most frequently used natural compounds include Berberine, Mangostin, Capsaicin, Caffeine, Genistein, Epigallocatechin-3-gallate, Chlorogenic acid, Betaine, Ginsenoside, Resveratrol. These natural compounds interact with LD-associated proteins and help ameliorate abnormal LDs in various metabolic diseases. CONCLUSION Natural compounds involved in the regulation of LDs and LD-associated proteins hold promise for treating metabolic diseases. Further research into these interactions may lead to new therapeutic applications.
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Affiliation(s)
- Xinyue Jiang
- Institute of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hongzhan Wang
- Institute of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Kexin Nie
- Institute of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yang Gao
- Institute of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Shen Chen
- Institute of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yueheng Tang
- Department of Rehabilitation Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zhi Wang
- Department of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hao Su
- Department of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hui Dong
- Institute of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
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7
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Samardak K, Bâcle J, Moriel-Carretero M. Behind the stoNE wall: A fervent activity for nuclear lipids. Biochimie 2024:S0300-9084(24)00179-2. [PMID: 39111564 DOI: 10.1016/j.biochi.2024.08.002] [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: 04/09/2024] [Revised: 08/01/2024] [Accepted: 08/02/2024] [Indexed: 09/27/2024]
Abstract
The four main types of biomolecules are nucleic acids, proteins, carbohydrates and lipids. The knowledge about their respective interactions is as important as the individual understanding of each of them. However, while, for example, the interaction of proteins with the other three groups is extensively studied, that of nucleic acids and lipids is, in comparison, very poorly explored. An iconic paradigm of physical (and likely functional) proximity between DNA and lipids is the case of the genomic DNA in eukaryotes: enclosed within the nucleus by two concentric lipid bilayers, the wealth of implications of this interaction, for example in genome stability, remains underassessed. Nuclear lipid-related phenotypes have been observed for 50 years, yet in most cases kept as mere anecdotical descriptions. In this review, we will bring together the evidence connecting lipids with both the nuclear envelope and the nucleoplasm, and will make critical analyses of these descriptions. Our exploration establishes a scenario in which lipids irrefutably play a role in nuclear homeostasis.
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Affiliation(s)
- Kseniya Samardak
- Centre de Recherche en Biologie cellulaire de Montpellier (CRBM) UMR5237, Université de Montpellier, Centre National de La Recherche Scientifique, 34293 Montpellier Cedex 5, France
| | - Janélie Bâcle
- Centre de Recherche en Biologie cellulaire de Montpellier (CRBM) UMR5237, Université de Montpellier, Centre National de La Recherche Scientifique, 34293 Montpellier Cedex 5, France
| | - María Moriel-Carretero
- Centre de Recherche en Biologie cellulaire de Montpellier (CRBM) UMR5237, Université de Montpellier, Centre National de La Recherche Scientifique, 34293 Montpellier Cedex 5, France.
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8
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Ernst R, Renne MF, Jain A, von der Malsburg A. Endoplasmic Reticulum Membrane Homeostasis and the Unfolded Protein Response. Cold Spring Harb Perspect Biol 2024; 16:a041400. [PMID: 38253414 PMCID: PMC11293554 DOI: 10.1101/cshperspect.a041400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
The endoplasmic reticulum (ER) is the key organelle for membrane biogenesis. Most lipids are synthesized in the ER, and most membrane proteins are first inserted into the ER membrane before they are transported to their target organelle. The composition and properties of the ER membrane must be carefully controlled to provide a suitable environment for the insertion and folding of membrane proteins. The unfolded protein response (UPR) is a powerful signaling pathway that balances protein and lipid production in the ER. Here, we summarize our current knowledge of how aberrant compositions of the ER membrane, referred to as lipid bilayer stress, trigger the UPR.
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Affiliation(s)
- Robert Ernst
- Medical Biochemistry and Molecular Biology, Medical Faculty, Saarland University, 66421 Homburg, Germany
- Preclinical Center for Molecular Signaling (PZMS), Medical Faculty, Saarland University, 66421 Homburg, Germany
| | - Mike F Renne
- Medical Biochemistry and Molecular Biology, Medical Faculty, Saarland University, 66421 Homburg, Germany
- Preclinical Center for Molecular Signaling (PZMS), Medical Faculty, Saarland University, 66421 Homburg, Germany
| | - Aamna Jain
- Medical Biochemistry and Molecular Biology, Medical Faculty, Saarland University, 66421 Homburg, Germany
- Preclinical Center for Molecular Signaling (PZMS), Medical Faculty, Saarland University, 66421 Homburg, Germany
| | - Alexander von der Malsburg
- Medical Biochemistry and Molecular Biology, Medical Faculty, Saarland University, 66421 Homburg, Germany
- Preclinical Center for Molecular Signaling (PZMS), Medical Faculty, Saarland University, 66421 Homburg, Germany
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9
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Zhu Y, Tong X, Xue J, Qiu H, Zhang D, Zheng DQ, Tu ZC, Ye C. Phospholipid biosynthesis modulates nucleotide metabolism and reductive capacity. Nat Chem Biol 2024:10.1038/s41589-024-01689-z. [PMID: 39060393 DOI: 10.1038/s41589-024-01689-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 07/02/2024] [Indexed: 07/28/2024]
Abstract
Phospholipid and nucleotide syntheses are fundamental metabolic processes in eukaryotic organisms, with their dysregulation implicated in various disease states. Despite their importance, the interplay between these pathways remains poorly understood. Using genetic and metabolic analyses in Saccharomyces cerevisiae, we elucidate how cytidine triphosphate usage in the Kennedy pathway for phospholipid synthesis influences nucleotide metabolism and redox balance. We find that deficiencies in the Kennedy pathway limit nucleotide salvage, prompting compensatory activation of de novo nucleotide synthesis and the pentose phosphate pathway. This metabolic shift enhances the production of antioxidants such as NADPH and glutathione. Moreover, we observe that the Kennedy pathway for phospholipid synthesis is inhibited during replicative aging, indicating its role in antioxidative defense as an adaptive mechanism in aged cells. Our findings highlight the critical role of phospholipid synthesis pathway choice in the integrative regulation of nucleotide metabolism, redox balance and membrane properties for cellular defense.
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Affiliation(s)
- Yibing Zhu
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, China
| | - Xiaomeng Tong
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, China
| | - Jingyuan Xue
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, China
| | - Hong Qiu
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, China
| | - Dan Zhang
- Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Dao-Qiong Zheng
- Ocean College, Zhejiang University, Zhoushan, China
- Hainan Institute, Zhejiang University, Sanya, China
| | - Zong-Cai Tu
- National R&D Center for Freshwater Fish Processing, Jiangxi Normal University, Nanchang, China
| | - Cunqi Ye
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, China.
- Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China.
- Hainan Institute, Zhejiang University, Sanya, China.
- National R&D Center for Freshwater Fish Processing, Jiangxi Normal University, Nanchang, China.
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10
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Liu CH, Shen PC, Lin WJ, Liu HC, Tsai MH, Huang TY, Chen IC, Lai YL, Wang YD, Hung MC, Cheng WC. LipidSig 2.0: integrating lipid characteristic insights into advanced lipidomics data analysis. Nucleic Acids Res 2024; 52:W390-W397. [PMID: 38709887 PMCID: PMC11223864 DOI: 10.1093/nar/gkae335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 03/29/2024] [Accepted: 04/16/2024] [Indexed: 05/08/2024] Open
Abstract
In the field of lipidomics, where the complexity of lipid structures and functions presents significant analytical challenges, LipidSig stands out as the first web-based platform providing integrated, comprehensive analysis for efficient data mining of lipidomic datasets. The upgraded LipidSig 2.0 (https://lipidsig.bioinfomics.org/) simplifies the process and empowers researchers to decipher the complex nature of lipids and link lipidomic data to specific characteristics and biological contexts. This tool markedly enhances the efficiency and depth of lipidomic research by autonomously identifying lipid species and assigning 29 comprehensive characteristics upon data entry. LipidSig 2.0 accommodates 24 data processing methods, streamlining diverse lipidomic datasets. The tool's expertise in automating intricate analytical processes, including data preprocessing, lipid ID annotation, differential expression, enrichment analysis, and network analysis, allows researchers to profoundly investigate lipid properties and their biological implications. Additional innovative features, such as the 'Network' function, offer a system biology perspective on lipid interactions, and the 'Multiple Group' analysis aids in examining complex experimental designs. With its comprehensive suite of features for analyzing and visualizing lipid properties, LipidSig 2.0 positions itself as an indispensable tool for advanced lipidomics research, paving the way for new insights into the role of lipids in cellular processes and disease development.
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Affiliation(s)
- Chia-Hsin Liu
- Cancer Biology and Precision Therapeutics Center, China Medical University, Taichung 404328, Taiwan
| | - Pei-Chun Shen
- Cancer Biology and Precision Therapeutics Center, China Medical University, Taichung 404328, Taiwan
| | - Wen-Jen Lin
- Cancer Biology and Precision Therapeutics Center, China Medical University, Taichung 404328, Taiwan
- School of Medicine, China Medical University, Taichung 404328, Taiwan
| | - Hsiu-Cheng Liu
- Cancer Biology and Precision Therapeutics Center, China Medical University, Taichung 404328, Taiwan
| | - Meng-Hsin Tsai
- Cancer Biology and Precision Therapeutics Center, China Medical University, Taichung 404328, Taiwan
| | - Tzu-Ya Huang
- Cancer Biology and Precision Therapeutics Center, China Medical University, Taichung 404328, Taiwan
| | - I-Chieh Chen
- Cancer Biology and Precision Therapeutics Center, China Medical University, Taichung 404328, Taiwan
| | - Yo-Liang Lai
- Department of Radiation Oncology, China Medical University, Taichung 404328, Taiwan
| | - Yu-De Wang
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung 404328, Taiwan
- Department of Urology, China Medical University, Taichung 404328, Taiwan
| | - Mien-Chie Hung
- Cancer Biology and Precision Therapeutics Center, China Medical University, Taichung 404328, Taiwan
- Institute of Biochemistry and Molecular Biology, China Medical University, Taichung 404328, Taiwan
- Molecular Medicine Center, China Medical University Hospital, China Medical University, Taichung 404328, Taiwan
- Department of Biotechnology, Asia University, Taichung 413305, Taiwan
| | - Wei-Chung Cheng
- Cancer Biology and Precision Therapeutics Center, China Medical University, Taichung 404328, Taiwan
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung 404328, Taiwan
- The Ph.D. program for Cancer Biology and Drug Discovery, China Medical University and Academia Sinica, Taichung 404328, Taiwan
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11
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Wang K, Xu H, Zou R, Zeng G, Yuan Y, Zhu X, Zhao X, Li J, Zhang L. PCYT1A deficiency disturbs fatty acid metabolism and induces ferroptosis in the mouse retina. BMC Biol 2024; 22:134. [PMID: 38858683 PMCID: PMC11165903 DOI: 10.1186/s12915-024-01932-y] [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: 12/09/2023] [Accepted: 06/04/2024] [Indexed: 06/12/2024] Open
Abstract
BACKGROUND Inherited retinal dystrophies (IRDs) are a group of debilitating visual disorders characterized by the progressive degeneration of photoreceptors, which ultimately lead to blindness. Among the causes of this condition, mutations in the PCYT1A gene, which encodes the rate-limiting enzyme responsible for phosphatidylcholine (PC) de novo synthesis via the Kennedy pathway, have been identified. However, the precise mechanisms underlying the association between PCYT1A mutations and IRDs remain unclear. To address this knowledge gap, we focused on elucidating the functions of PCYT1A in the retina. RESULTS We found that PCYT1A is highly expressed in Müller glial (MG) cells in the inner nuclear layer (INL) of the retina. Subsequently, we generated a retina-specific knockout mouse model in which the Pcyt1a gene was targeted (Pcyt1a-RKO or RKO mice) to investigate the molecular mechanisms underlying IRDs caused by PCYT1A mutations. Our findings revealed that the deletion of Pcyt1a resulted in retinal degenerative phenotypes, including reduced scotopic electroretinogram (ERG) responses and progressive degeneration of photoreceptor cells, accompanied by loss of cells in the INL. Furthermore, through proteomic and bioinformatic analyses, we identified dysregulated retinal fatty acid metabolism and activation of the ferroptosis signalling pathway in RKO mice. Importantly, we found that PCYT1A deficiency did not lead to an overall reduction in PC synthesis within the retina. Instead, this deficiency appeared to disrupt free fatty acid metabolism and ultimately trigger ferroptosis. CONCLUSIONS This study reveals a novel mechanism by which mutations in PCYT1A contribute to the development of IRDs, shedding light on the interplay between fatty acid metabolism and retinal degenerative diseases, and provides new insights into the treatment of IRDs.
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Affiliation(s)
- Kaifang Wang
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, Center for Medical Genetics, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610072, Sichuan, China
| | - Huijuan Xu
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, Center for Medical Genetics, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610072, Sichuan, China
- Qinghai Provincial Key Laboratory of Tibetan Medicine Research, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, 810008, Qinghai, China
| | - Rong Zou
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, Center for Medical Genetics, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610072, Sichuan, China
| | - Guangqun Zeng
- The People's Hospital of Pengzhou, Chengdu, 611930, Sichuan, China
| | - Ye Yuan
- Medical Center Hospital of Qionglai City, Chengdu, 611530, Sichuan, China
| | - Xianjun Zhu
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, Center for Medical Genetics, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610072, Sichuan, China
- Qinghai Provincial Key Laboratory of Tibetan Medicine Research, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, 810008, Qinghai, China
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, 610072, Sichuan, China
| | - Xiaohui Zhao
- The People's Hospital of Pengzhou, Chengdu, 611930, Sichuan, China.
| | - Jie Li
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, Center for Medical Genetics, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610072, Sichuan, China.
- Department of Ophthalmology, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610072, Sichuan, China.
| | - Lin Zhang
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, Center for Medical Genetics, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610072, Sichuan, China.
- Qinghai Provincial Key Laboratory of Tibetan Medicine Research, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, 810008, Qinghai, China.
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, 610072, Sichuan, China.
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12
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Sefik E, Duan K, Li Y, Sholar B, Evans L, Pincus J, Ammar Z, Murphy MM, Klaiman C, Saulnier CA, Pulver SL, Goldman-Yassen AE, Guo Y, Walker EF, Li L, Mulle JG, Shultz S. Structural deviations of the posterior fossa and the cerebellum and their cognitive links in a neurodevelopmental deletion syndrome. Mol Psychiatry 2024:10.1038/s41380-024-02584-8. [PMID: 38744992 DOI: 10.1038/s41380-024-02584-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 04/16/2024] [Accepted: 04/23/2024] [Indexed: 05/16/2024]
Abstract
High-impact genetic variants associated with neurodevelopmental disorders provide biologically-defined entry points for mechanistic investigation. The 3q29 deletion (3q29Del) is one such variant, conferring a 40-100-fold increased risk for schizophrenia, as well as high risk for autism and intellectual disability. However, the mechanisms leading to neurodevelopmental disability remain largely unknown. Here, we report the first in vivo quantitative neuroimaging study in individuals with 3q29Del (N = 24) and neurotypical controls (N = 1608) using structural MRI. Given prior radiology reports of posterior fossa abnormalities in 3q29Del, we focused our investigation on the cerebellum and its tissue-types and lobules. Additionally, we compared the prevalence of cystic/cyst-like malformations of the posterior fossa between 3q29Del and controls and examined the association between neuroanatomical findings and quantitative traits to probe gene-brain-behavior relationships. 3q29Del participants had smaller cerebellar cortex volumes than controls, before and after correction for intracranial volume (ICV). An anterior-posterior gradient emerged in finer grained lobule-based and voxel-wise analyses. 3q29Del participants also had larger cerebellar white matter volumes than controls following ICV-correction and displayed elevated rates of posterior fossa arachnoid cysts and mega cisterna magna findings independent of cerebellar volume. Cerebellar white matter and subregional gray matter volumes were associated with visual-perception and visual-motor integration skills as well as IQ, while cystic/cyst-like malformations yielded no behavioral link. In summary, we find that abnormal development of cerebellar structures may represent neuroimaging-based biomarkers of cognitive and sensorimotor function in 3q29Del, adding to the growing evidence identifying cerebellar pathology as an intersection point between syndromic and idiopathic forms of neurodevelopmental disabilities.
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Affiliation(s)
- Esra Sefik
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA
- Department of Psychology, Emory University, Atlanta, GA, USA
| | - Kuaikuai Duan
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
- Tri-institutional Center for Translational Research in Neuroimaging and Data Science, Georgia State University, Georgia Institute of Technology, Emory University, Atlanta, GA, USA
| | - Yiheng Li
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Brittney Sholar
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
- Marcus Autism Center, Children's Healthcare of Atlanta and Emory University School of Medicine, Atlanta, GA, USA
| | - Lindsey Evans
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
- Marcus Autism Center, Children's Healthcare of Atlanta and Emory University School of Medicine, Atlanta, GA, USA
| | - Jordan Pincus
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
- Marcus Autism Center, Children's Healthcare of Atlanta and Emory University School of Medicine, Atlanta, GA, USA
| | - Zeena Ammar
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
- Marcus Autism Center, Children's Healthcare of Atlanta and Emory University School of Medicine, Atlanta, GA, USA
| | - Melissa M Murphy
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Cheryl Klaiman
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
- Marcus Autism Center, Children's Healthcare of Atlanta and Emory University School of Medicine, Atlanta, GA, USA
| | - Celine A Saulnier
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
- Neurodevelopmental Assessment & Consulting Services, Atlanta, GA, USA
| | - Stormi L Pulver
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
- Marcus Autism Center, Children's Healthcare of Atlanta and Emory University School of Medicine, Atlanta, GA, USA
| | - Adam E Goldman-Yassen
- Department of Radiology, Children's Healthcare of Atlanta, Atlanta, GA, USA
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA, USA
| | - Ying Guo
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Elaine F Walker
- Department of Psychology, Emory University, Atlanta, GA, USA
| | - Longchuan Li
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
- Marcus Autism Center, Children's Healthcare of Atlanta and Emory University School of Medicine, Atlanta, GA, USA
| | - Jennifer G Mulle
- Department of Psychiatry, Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ, USA.
| | - Sarah Shultz
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA.
- Marcus Autism Center, Children's Healthcare of Atlanta and Emory University School of Medicine, Atlanta, GA, USA.
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13
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McPhee M, Lee J, Salsman J, Pinelli M, Di Cara F, Rosen K, Dellaire G, Ridgway ND. Nuclear lipid droplets in Caco2 cells originate from nascent precursors and in situ at the nuclear envelope. J Lipid Res 2024; 65:100540. [PMID: 38570093 PMCID: PMC11077042 DOI: 10.1016/j.jlr.2024.100540] [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: 07/11/2023] [Revised: 03/22/2024] [Accepted: 03/25/2024] [Indexed: 04/05/2024] Open
Abstract
Intestinal epithelial cells convert excess fatty acids into triglyceride (TAG) for storage in cytoplasmic lipid droplets and secretion in chylomicrons. Nuclear lipid droplets (nLDs) are present in intestinal cells but their origin and relationship to cytoplasmic TAG synthesis and secretion is unknown. nLDs and related lipid-associated promyelocytic leukemia structures (LAPS) were abundant in oleate-treated Caco2 but less frequent in other human colorectal cancer cell lines and mouse intestinal organoids. nLDs and LAPS in undifferentiated oleate-treated Caco2 cells harbored the phosphatidate phosphatase Lipin1, its product diacylglycerol, and CTP:phosphocholine cytidylyltransferase (CCT)α. CCTα knockout Caco2 cells had fewer but larger nLDs, indicating a reliance on de novo PC synthesis for assembly. Differentiation of Caco2 cells caused large nLDs and LAPS to form regardless of oleate treatment or CCTα expression. nLDs and LAPS in Caco2 cells did not associate with apoCIII and apoAI and formed dependently of microsomal triglyceride transfer protein expression and activity, indicating they are not derived from endoplasmic reticulum luminal LDs precursors. Instead, undifferentiated Caco2 cells harbored a constitutive pool of nLDs and LAPS in proximity to the nuclear envelope that expanded in size and number with oleate treatment. Inhibition of TAG synthesis did affect the number of nascent nLDs and LAPS but prevented their association with promyelocytic leukemia protein, Lipin1α, and diacylglycerol, which instead accumulated on the nuclear membranes. Thus, nLD and LAPS biogenesis in Caco2 cells is not linked to lipoprotein secretion but involves biogenesis and/or expansion of nascent nLDs by de novo lipid synthesis.
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Affiliation(s)
- Michael McPhee
- Depts of Pediatrics and Biochemistry & Molecular Biology, Atlantic Research Centre, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Jonghwa Lee
- Depts of Pediatrics and Biochemistry & Molecular Biology, Atlantic Research Centre, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Jayme Salsman
- Depts of Pathology and Biochemistry & Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Marinella Pinelli
- Dept of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Francesca Di Cara
- Dept of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Kirill Rosen
- Depts of Pediatrics and Biochemistry & Molecular Biology, Atlantic Research Centre, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Graham Dellaire
- Depts of Pathology and Biochemistry & Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada.
| | - Neale D Ridgway
- Depts of Pediatrics and Biochemistry & Molecular Biology, Atlantic Research Centre, Dalhousie University, Halifax, Nova Scotia, Canada.
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14
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Benarroch E. What Is the Role of Nuclear Envelope Proteins in Neurologic Disorders? Neurology 2024; 102:e209202. [PMID: 38330281 DOI: 10.1212/wnl.0000000000209202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 12/12/2023] [Indexed: 02/10/2024] Open
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15
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Gunn AL, Yashchenko AI, Dubrulle J, Johnson J, Hatch EM. A high-content screen reveals new regulators of nuclear membrane stability. Sci Rep 2024; 14:6013. [PMID: 38472343 PMCID: PMC10933478 DOI: 10.1038/s41598-024-56613-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Accepted: 03/08/2024] [Indexed: 03/14/2024] Open
Abstract
Nuclear membrane rupture is a physiological response to multiple in vivo processes, such as cell migration, that can cause extensive genome instability and upregulate invasive and inflammatory pathways. However, the underlying molecular mechanisms of rupture are unclear and few regulators have been identified. In this study, we developed a reporter that is size excluded from re-compartmentalization following nuclear rupture events. This allows for robust detection of factors influencing nuclear integrity in fixed cells. We combined this with an automated image analysis pipeline in a high-content siRNA screen to identify new proteins that both increase and decrease nuclear rupture frequency in cancer cells. Pathway analysis identified an enrichment of nuclear membrane and ER factors in our hits and we demonstrate that one of these, the protein phosphatase CTDNEP1, is required for nuclear stability. Analysis of known rupture determinants, including an automated quantitative analysis of nuclear lamina gaps, are consistent with CTDNEP1 acting independently of actin and nuclear lamina organization. Our findings provide new insights into the molecular mechanism of nuclear rupture and define a highly adaptable program for rupture analysis that removes a substantial barrier to new discoveries in the field.
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Affiliation(s)
- Amanda L Gunn
- Divisions of Basic Sciences and Human Biology, The Fred Hutchinson Cancer Center, Seattle, WA, USA
| | - Artem I Yashchenko
- Divisions of Basic Sciences and Human Biology, The Fred Hutchinson Cancer Center, Seattle, WA, USA
| | - Julien Dubrulle
- Cellular Imaging Shared Resource, The Fred Hutchinson Cancer Center, Seattle, WA, USA
| | - Jodiene Johnson
- Divisions of Basic Sciences and Human Biology, The Fred Hutchinson Cancer Center, Seattle, WA, USA
- Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, WA, USA
| | - Emily M Hatch
- Divisions of Basic Sciences and Human Biology, The Fred Hutchinson Cancer Center, Seattle, WA, USA.
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16
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Foster J, McPhee M, Yue L, Dellaire G, Pelech S, Ridgway ND. Lipid- and phospho-regulation of CTP:Phosphocholine Cytidylyltransferase α association with nuclear lipid droplets. Mol Biol Cell 2024; 35:ar33. [PMID: 38170618 PMCID: PMC10916874 DOI: 10.1091/mbc.e23-09-0354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 12/12/2023] [Accepted: 12/19/2023] [Indexed: 01/05/2024] Open
Abstract
Fatty acids stored in triacylglycerol-rich lipid droplets are assembled with a surface monolayer composed primarily of phosphatidylcholine (PC). Fatty acids stimulate PC synthesis by translocating CTP:phosphocholine cytidylyltransferase (CCT) α to the inner nuclear membrane, nuclear lipid droplets (nLD) and lipid associated promyelocytic leukemia (PML) structures (LAPS). Huh7 cells were used to identify how CCTα translocation onto these nuclear structures are regulated by fatty acids and phosphorylation of its serine-rich P-domain. Oleate treatment of Huh7 cells increased nLDs and LAPS that became progressively enriched in CCTα. In cells expressing the phosphatidic acid phosphatase Lipin1α or 1β, the expanded pool of nLDs and LAPS had a proportional increase in associated CCTα. In contrast, palmitate induced few nLDs and LAPS and inhibited the oleate-dependent translocation of CCTα without affecting total nLDs. Phospho-memetic or phospho-null mutations in the P-domain revealed that a 70% phosphorylation threshold, rather than site-specific phosphorylation, regulated CCTα association with nLDs and LAPS. In vitro candidate kinase and inhibitor studies in Huh7 cells identified cyclin-dependent kinase (CDK) 1 and 2 as putative P-domain kinases. In conclusion, CCTα translocation onto nLDs and LAPS is dependent on available surface area and fatty acid composition, as well as threshold phosphorylation of the P-domain potentially involving CDKs.
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Affiliation(s)
- Jason Foster
- Departments of Pediatrics and Biochemistry & Molecular Biology, Atlantic Research Centre, and
| | - Michael McPhee
- Departments of Pediatrics and Biochemistry & Molecular Biology, Atlantic Research Centre, and
| | - Lambert Yue
- Division of Neurology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada V6T 2B5
| | - Graham Dellaire
- Departments of Pathology and Biochemistry & Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada B3H4R2
| | - Steven Pelech
- Division of Neurology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada V6T 2B5
- Kinexus Bioinformatics Corporation, Vancouver, BC, Canada V6P 6T3
| | - Neale D. Ridgway
- Departments of Pediatrics and Biochemistry & Molecular Biology, Atlantic Research Centre, and
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17
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Zhang W, Li Y, Fung AA, Li Z, Jang H, Zha H, Chen X, Gao F, Wu JY, Sheng H, Yao J, Skowronska-Krawczyk D, Jain S, Shi L. Multi-molecular hyperspectral PRM-SRS microscopy. Nat Commun 2024; 15:1599. [PMID: 38383552 PMCID: PMC10881988 DOI: 10.1038/s41467-024-45576-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 01/26/2024] [Indexed: 02/23/2024] Open
Abstract
Lipids play crucial roles in many biological processes. Mapping spatial distributions and examining the metabolic dynamics of different lipid subtypes in cells and tissues are critical to better understanding their roles in aging and diseases. Commonly used imaging methods (such as mass spectrometry-based, fluorescence labeling, conventional optical imaging) can disrupt the native environment of cells/tissues, have limited spatial or spectral resolution, or cannot distinguish different lipid subtypes. Here we present a hyperspectral imaging platform that integrates a Penalized Reference Matching algorithm with Stimulated Raman Scattering (PRM-SRS) microscopy. Using this platform, we visualize and identify high density lipoprotein particles in human kidney, a high cholesterol to phosphatidylethanolamine ratio inside granule cells of mouse hippocampus, and subcellular distributions of sphingosine and cardiolipin in human brain. Our PRM-SRS displays unique advantages of enhanced chemical specificity, subcellular resolution, and fast data processing in distinguishing lipid subtypes in different organs and species.
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Affiliation(s)
- Wenxu Zhang
- Shu Chien-Gene Lay Dept. of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Yajuan Li
- Shu Chien-Gene Lay Dept. of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Anthony A Fung
- Shu Chien-Gene Lay Dept. of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Zhi Li
- Shu Chien-Gene Lay Dept. of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Hongje Jang
- Shu Chien-Gene Lay Dept. of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Honghao Zha
- Shu Chien-Gene Lay Dept. of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Xiaoping Chen
- Dept. of Neurology, Northwestern University School of Medicine, Chicago, IL, USA
| | - Fangyuan Gao
- Center for Translational Vision Research, School of Medicine, University of California Irvine, Irvine, CA, USA
| | - Jane Y Wu
- Dept. of Neurology, Northwestern University School of Medicine, Chicago, IL, USA
| | - Huaxin Sheng
- Dept. of Anesthesiology, Duke University School of Medicine, Durham, NC, USA
| | - Junjie Yao
- Dept. of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Dorota Skowronska-Krawczyk
- Center for Translational Vision Research, School of Medicine, University of California Irvine, Irvine, CA, USA
| | - Sanjay Jain
- Dept. of Medicine, Washington University in St. Louis, St. Louis, MO, USA
- Dept. of Pathology & Immunology, Washington University in St. Louis, St. Louis, MO, USA
- Dept. of Pediatrics, Washington University in St. Louis, St. Louis, MO, USA
| | - Lingyan Shi
- Shu Chien-Gene Lay Dept. of Bioengineering, University of California San Diego, La Jolla, CA, USA.
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18
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Zhao J, He C, Fan X, Wang L, Zhao L, Liu H, Shen W, Jiang S, Pei K, Gao J, Qi Y, Liu Y, Zhao J, Zhang R, Lu C, Tong J, Huai J. Tripeptidyl peptidase II coordinates the homeostasis of calcium and lipids in the central nervous system and its depletion causes presenile dementia in female mice through calcium/lipid dyshomeostasis-induced autophagic degradation of CYP19A1. Theranostics 2024; 14:1390-1429. [PMID: 38389851 PMCID: PMC10879859 DOI: 10.7150/thno.92571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 01/19/2024] [Indexed: 02/24/2024] Open
Abstract
Rationale: Tripeptidyl peptidase II (TPP2) has been proven to be related to human immune and neurological diseases. It is generally considered as a cytosolic protein which forms the largest known protease complex in eukaryotic cells to operate mostly downstream of proteasomes for degradation of longer peptides. However, this canonical function of TPP2 cannot explain its role in a wide variety of biological and pathogenic processes. The mechanistic interrelationships and hierarchical order of these processes have yet to be clarified. Methods: Animals, cells, plasmids, and viruses established and/or used in this study include: TPP2 knockout mouse line, TPP2 conditional knockout mouse lines (different neural cell type oriented), TRE-TPP2 knockin mouse line on the C57BL/6 background; 293T cells with depletion of TPP2, ATF6, IRE1, PERK, SYVN1, UCHL1, ATG5, CEPT1, or CCTα, respectively; 293T cells stably expressing TPP2, TPP2 S449A, TPP2 S449T, or CCTα-KDEL proteins on the TPP2-depleted background; Plasmids for eukaryotic transient expression of rat CYP19A1-Flag, CYP19A1 S118A-Flag, CYP19A1 S118D-Flag, Sac I ML GFP Strand 11 Long, OMMGFP 1-10, G-CEPIA1er, GCAMP2, CEPIA3mt, ACC-GFP, or SERCA1-GFP; AAV2 carrying the expression cassette of mouse CYP19A1-3 X Flag-T2A-ZsGreen. Techniques used in this study include: Flow cytometry, Immunofluorescence (IF) staining, Immunohistochemical (IHC) staining, Luxol fast blue (LFB) staining, β-galactosidase staining, Lipid droplet (LD) staining, Calcium (Ca2+) staining, Stimulated emission depletion (STED) imaging, Transmission electron microscopic imaging, Two-photon imaging, Terminal deoxynucleotidyl transferase (TdT) dUTP nick-end Labeling (TUNEL) assay, Bromodeoxyuridine (BrdU) assay, Enzymatic activity assay, Proximity ligation assay (PLA), In vivo electrophysiological recording, Long-term potentiation (LTP) recording, Split-GFP-based mitochondria-associated membrane (MAM) detection, Immunoprecipitation (IP), Cellular fractionation, In situ hybridization, Semi-quantitative RT-PCR, Immunoblot, Mass spectrometry-based lipidomics, metabolomics, proteomics, Primary hippocampal neuron culture and Morris water maze (MWM) test. Results: We found that TPP2, independent of its enzymatic activity, plays a crucial role in maintaining the homeostasis of intracellular Ca2+ and phosphatidylcholine (PC) in the central nervous system (CNS) of mice. In consistence with the critical importance of Ca2+ and PC in the CNS, TPP2 gene ablation causes presenile dementia in female mice, which is closely associated with Ca2+/PC dysregulation-induced endoplasmic reticulum (ER) stress, abnormal autophagic degradation of CYP19A1 (aromatase), and estrogen depletion. This work therefore uncovers a new role of TPP2 in lipogenesis and neurosteroidogenesis which is tightly related to cognitive function of adult female mice. Conclusion: Our study reveals a crucial role of TPP2 in controlling homeostasis of Ca2+ and lipids in CNS, and its deficiency causes sexual dimorphism in dementia. Thus, this study is not only of great significance for elucidating the pathogenesis of dementia and its futural treatment, but also for interpreting the role of TPP2 in other systems and their related disorders.
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Affiliation(s)
- Jin Zhao
- The Second Affiliated Hospital of Xinxiang Medical University (Henan Mental Hospital), Xinxiang, 453000, PR China
- Institute of Psychiatry and Neuroscience, Xinxiang Medical University, Xinxiang, 453003, PR China
| | - Chengtong He
- The Second Affiliated Hospital of Xinxiang Medical University (Henan Mental Hospital), Xinxiang, 453000, PR China
- Institute of Psychiatry and Neuroscience, Xinxiang Medical University, Xinxiang, 453003, PR China
| | - Xueyu Fan
- The Second Affiliated Hospital of Xinxiang Medical University (Henan Mental Hospital), Xinxiang, 453000, PR China
- Institute of Psychiatry and Neuroscience, Xinxiang Medical University, Xinxiang, 453003, PR China
| | - Lin Wang
- The Second Affiliated Hospital of Xinxiang Medical University (Henan Mental Hospital), Xinxiang, 453000, PR China
- Institute of Psychiatry and Neuroscience, Xinxiang Medical University, Xinxiang, 453003, PR China
| | - Liao Zhao
- The Second Affiliated Hospital of Xinxiang Medical University (Henan Mental Hospital), Xinxiang, 453000, PR China
- Institute of Psychiatry and Neuroscience, Xinxiang Medical University, Xinxiang, 453003, PR China
| | - Hui Liu
- The Second Affiliated Hospital of Xinxiang Medical University (Henan Mental Hospital), Xinxiang, 453000, PR China
- Institute of Psychiatry and Neuroscience, Xinxiang Medical University, Xinxiang, 453003, PR China
| | - Wujun Shen
- The Second Affiliated Hospital of Xinxiang Medical University (Henan Mental Hospital), Xinxiang, 453000, PR China
- Institute of Psychiatry and Neuroscience, Xinxiang Medical University, Xinxiang, 453003, PR China
| | - Sanwei Jiang
- Henan International Key Laboratory for Noninvasive Neuromodulation, Department of Physiology & Pathology, Xinxiang Medical University, Xinxiang, PR China
| | - Kaixuan Pei
- The Second Affiliated Hospital of Xinxiang Medical University (Henan Mental Hospital), Xinxiang, 453000, PR China
- Institute of Psychiatry and Neuroscience, Xinxiang Medical University, Xinxiang, 453003, PR China
| | - Jingjing Gao
- The Second Affiliated Hospital of Xinxiang Medical University (Henan Mental Hospital), Xinxiang, 453000, PR China
- Institute of Psychiatry and Neuroscience, Xinxiang Medical University, Xinxiang, 453003, PR China
| | - Yawei Qi
- The Second Affiliated Hospital of Xinxiang Medical University (Henan Mental Hospital), Xinxiang, 453000, PR China
- Institute of Psychiatry and Neuroscience, Xinxiang Medical University, Xinxiang, 453003, PR China
| | - Yang Liu
- The Second Affiliated Hospital of Xinxiang Medical University (Henan Mental Hospital), Xinxiang, 453000, PR China
- Institute of Psychiatry and Neuroscience, Xinxiang Medical University, Xinxiang, 453003, PR China
| | - Junqiang Zhao
- The Second Affiliated Hospital of Xinxiang Medical University (Henan Mental Hospital), Xinxiang, 453000, PR China
| | - Ruiling Zhang
- The Second Affiliated Hospital of Xinxiang Medical University (Henan Mental Hospital), Xinxiang, 453000, PR China
| | - Chengbiao Lu
- The Second Affiliated Hospital of Xinxiang Medical University (Henan Mental Hospital), Xinxiang, 453000, PR China
- Institute of Psychiatry and Neuroscience, Xinxiang Medical University, Xinxiang, 453003, PR China
- Henan International Key Laboratory for Noninvasive Neuromodulation, Department of Physiology & Pathology, Xinxiang Medical University, Xinxiang, PR China
- Senior author for electrophysiological experiments and related analysis
| | - Jia Tong
- The Second Affiliated Hospital of Xinxiang Medical University (Henan Mental Hospital), Xinxiang, 453000, PR China
- Institute of Psychiatry and Neuroscience, Xinxiang Medical University, Xinxiang, 453003, PR China
| | - Jisen Huai
- The Second Affiliated Hospital of Xinxiang Medical University (Henan Mental Hospital), Xinxiang, 453000, PR China
- Institute of Psychiatry and Neuroscience, Xinxiang Medical University, Xinxiang, 453003, PR China
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19
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Deng Y, Zhu H, Wang Y, Dong Y, Du J, Yu Q, Li M. The Endoplasmic Reticulum-Plasma Membrane Tethering Protein Ice2 Controls Lipid Droplet Size via the Regulation of Phosphatidylcholine in Candida albicans. J Fungi (Basel) 2024; 10:87. [PMID: 38276033 PMCID: PMC10817647 DOI: 10.3390/jof10010087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 01/13/2024] [Accepted: 01/17/2024] [Indexed: 01/27/2024] Open
Abstract
Lipid droplets (LDs) are intracellular organelles that play important roles in cellular lipid metabolism; they change their sizes and numbers in response to both intracellular and extracellular signals. Changes in LD size reflect lipid synthesis and degradation and affect many cellular activities, including energy supply and membrane synthesis. Here, we focused on the function of the endoplasmic reticulum-plasma membrane tethering protein Ice2 in LD dynamics in the fungal pathogen Candida albicans (C. albicans). Nile red staining and size quantification showed that the LD size increased in the ice2Δ/Δ mutant, indicating the critical role of Ice2 in the regulation of LD dynamics. A lipid content analysis further demonstrated that the mutant had lower phosphatidylcholine levels. As revealed with GFP labeling and fluorescence microscopy, the methyltransferase Cho2, which is involved in phosphatidylcholine synthesis, had poorer localization in the plasma membrane in the mutant than in the wild-type strain. Interestingly, the addition of the phosphatidylcholine precursor choline led to the recovery of normal-sized LDs in the mutant. These results indicated that Ice2 regulates LD size by controlling intracellular phosphatidylcholine levels and that endoplasmic reticulum-plasma membrane tethering proteins play a role in lipid metabolism regulation in C. albicans. This study provides significant findings for further investigation of the lipid metabolism in fungi.
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Affiliation(s)
| | | | | | | | | | | | - Mingchun Li
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China; (Y.D.); (H.Z.); (Y.W.); (Y.D.); (J.D.)
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20
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Shulman D, Dubnov S, Zorbaz T, Madrer N, Paldor I, Bennett DA, Seshadri S, Mufson EJ, Greenberg DS, Loewenstein Y, Soreq H. Sex-specific declines in cholinergic-targeting tRNA fragments in the nucleus accumbens in Alzheimer's disease. Alzheimers Dement 2023; 19:5159-5172. [PMID: 37158312 PMCID: PMC10632545 DOI: 10.1002/alz.13095] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 03/21/2023] [Indexed: 05/10/2023]
Abstract
INTRODUCTION Females with Alzheimer's disease (AD) suffer accelerated dementia and loss of cholinergic neurons compared to males, but the underlying mechanisms are unknown. Seeking causal contributors to both these phenomena, we pursued changes in transfer RNS (tRNA) fragments (tRFs) targeting cholinergic transcripts (CholinotRFs). METHODS We analyzed small RNA-sequencing (RNA-Seq) data from the nucleus accumbens (NAc) brain region which is enriched in cholinergic neurons, compared to hypothalamic or cortical tissues from AD brains; and explored small RNA expression in neuronal cell lines undergoing cholinergic differentiation. RESULTS NAc CholinotRFs of mitochondrial genome origin showed reduced levels that correlated with elevations in their predicted cholinergic-associated mRNA targets. Single-cell RNA seq from AD temporal cortices showed altered sex-specific levels of cholinergic transcripts in diverse cell types; inversely, human-originated neuroblastoma cells under cholinergic differentiation presented sex-specific CholinotRF elevations. DISCUSSION Our findings support CholinotRFs contributions to cholinergic regulation, predicting their involvement in AD sex-specific cholinergic loss and dementia.
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Affiliation(s)
- Dana Shulman
- The Edmond & Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
- The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
- The Rachel and Selim Benin School of Computer Science and Engineering, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Serafima Dubnov
- The Edmond & Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
- The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Tamara Zorbaz
- The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Nimrod Madrer
- The Edmond & Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
- The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Iddo Paldor
- The Neurosurgery Department, Shaare Zedek Medical Center, Jerusalem 9103102, Israel
| | - David A. Bennett
- Rush Alzheimer's Disease Center, Rush University Medical Center, 600 South Paulina, Suite 1028, Chicago, IL 60612, USA
| | - Sudha Seshadri
- UT Health Medical Arts & Research Center, San Antonio , TX 78229, USA
| | - Elliott J. Mufson
- Barrow Neurological Institute, St. Joseph's Medical Center, Phoenix, AZ, 85013, USA
| | - David S. Greenberg
- The Edmond & Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
- The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Yonatan Loewenstein
- The Edmond & Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
- The Department of Neurobiology, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
- The Department of Cognitive Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
- The Federmann Center for the Study of Rationality, Jerusalem 9190401, Israel
| | - Hermona Soreq
- The Edmond & Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
- The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
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21
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Guo Y, Liu F, Guo Y, Qu Y, Zhang Z, Yao J, Xu J, Li J. Untargeted Lipidomics Analysis Unravels the Different Metabolites in the Fat Body of Mated Bumblebee ( Bombus terrestris) Queens. Int J Mol Sci 2023; 24:15408. [PMID: 37895088 PMCID: PMC10607666 DOI: 10.3390/ijms242015408] [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: 09/12/2023] [Revised: 10/11/2023] [Accepted: 10/17/2023] [Indexed: 10/29/2023] Open
Abstract
The fat body has important functions in energy, fertility, and immunity. In female insects, mating stimulates physiological, behavioral, and gene expression changes. However, it remains unclear whether the metabolites in the fat body are affected after the bumblebee (Bombus terrestris) queen mates. Here, the ultrastructure and lipid metabolites in fat body of mated queens were compared with those of virgins. The fat body weight of mated bumblebee queens was significantly increased, and the adipocytes were filled with lipid droplets. Using LC-MS/MS-based untargeted lipidomics, 949 and 748 differential metabolites were identified in the fat body of virgin and mated bumblebee queens, respectively, in positive and negative ion modes. Most lipid metabolites were decreased, especially some biomembrane components. In order to explore the relationship between the structures of lipid droplets and metabolite accumulation, transmission electron microscopy and fluorescence microscopy were used to observe the fat body ultrastructure. The size/area of lipid droplets was larger, and the fusion of lipid droplets was increased in the mated queen's fat body. These enlarged lipid droplets may store more energy and nutrients. The observed differences in lipid metabolites in the fat body of queens contribute to understanding the regulatory network of bumblebees post mating.
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Affiliation(s)
| | | | | | | | | | | | | | - Jilian Li
- State Key Laboratory of Resource Insects, Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Y.G.); (F.L.); (Y.G.); (Y.Q.); (Z.Z.); (J.Y.); (J.X.)
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22
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Gunn AL, Yashchenko AI, Dubrulle J, Johnson J, Hatch EM. A high-content screen reveals new regulators of nuclear membrane stability. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.30.542944. [PMID: 37398267 PMCID: PMC10312541 DOI: 10.1101/2023.05.30.542944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Nuclear membrane rupture is a physiological response to multiple in vivo processes, such as cell migration, that can cause extensive genome instability and upregulate invasive and inflammatory pathways. However, the underlying molecular mechanisms of rupture are unclear and few regulators have been identified. In this study, we developed a reporter that is size excluded from re-compartmentalization following nuclear rupture events. This allows for robust detection of factors influencing nuclear integrity in fixed cells. We combined this with an automated image analysis pipeline in a high-content siRNA screen to identify new proteins that both increase and decrease nuclear rupture frequency in cancer cells. Pathway analysis identified an enrichment of nuclear membrane and ER factors in our hits and we demonstrate that one of these, the protein phosphatase CTDNEP1, is required for nuclear stability. Further analysis of known rupture contributors, including a newly developed automated quantitative analysis of nuclear lamina gaps, strongly suggests that CTDNEP1 acts in a new pathway. Our findings provide new insights into the molecular mechanism of nuclear rupture and define a highly adaptable program for rupture analysis that removes a substantial barrier to new discoveries in the field.
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Affiliation(s)
- Amanda L. Gunn
- Divisions of Basic Sciences and Human Biology, The Fred Hutchinson Cancer Center, 1100 Fairview Ave, Seattle, Washington 98109, USA
| | - Artem I. Yashchenko
- Divisions of Basic Sciences and Human Biology, The Fred Hutchinson Cancer Center, 1100 Fairview Ave, Seattle, Washington 98109, USA
| | - Julien Dubrulle
- Cellular Imaging Shared Resource, The Fred Hutchinson Cancer Center, 1100 Fairview Ave, Seattle, Washington 98109, USA
| | - Jodiene Johnson
- Divisions of Basic Sciences and Human Biology, The Fred Hutchinson Cancer Center, 1100 Fairview Ave, Seattle, Washington 98109, USA
| | - Emily M. Hatch
- Divisions of Basic Sciences and Human Biology, The Fred Hutchinson Cancer Center, 1100 Fairview Ave, Seattle, Washington 98109, USA
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23
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Lee S, Carrasquillo Rodríguez JW, Merta H, Bahmanyar S. A membrane-sensing mechanism links lipid metabolism to protein degradation at the nuclear envelope. J Cell Biol 2023; 222:e202304026. [PMID: 37382667 PMCID: PMC10309186 DOI: 10.1083/jcb.202304026] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/22/2023] [Accepted: 06/02/2023] [Indexed: 06/30/2023] Open
Abstract
Lipid composition determines organelle identity; however, whether the lipid composition of the inner nuclear membrane (INM) domain of the ER contributes to its identity is not known. Here, we show that the INM lipid environment of animal cells is under local control by CTDNEP1, the master regulator of the phosphatidic acid phosphatase lipin 1. Loss of CTDNEP1 reduces association of an INM-specific diacylglycerol (DAG) biosensor and results in a decreased percentage of polyunsaturated containing DAG species. Alterations in DAG metabolism impact the levels of the resident INM protein Sun2, which is under local proteasomal regulation. We identify a lipid-binding amphipathic helix (AH) in the nucleoplasmic domain of Sun2 that prefers membrane packing defects. INM dissociation of the Sun2 AH is linked to its proteasomal degradation. We suggest that direct lipid-protein interactions contribute to sculpting the INM proteome and that INM identity is adaptable to lipid metabolism, which has broad implications on disease mechanisms associated with the nuclear envelope.
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Affiliation(s)
- Shoken Lee
- Department of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | | | - Holly Merta
- Department of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Shirin Bahmanyar
- Department of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT, USA
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24
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Cheng LC, Zhang X, Baboo S, Nguyen JA, Martinez-Bartolomé S, Loose E, Diedrich J, Yates JR, Gerace L. Comparative membrane proteomics reveals diverse cell regulators concentrated at the nuclear envelope. Life Sci Alliance 2023; 6:e202301998. [PMID: 37433644 PMCID: PMC10336727 DOI: 10.26508/lsa.202301998] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 06/23/2023] [Accepted: 06/26/2023] [Indexed: 07/13/2023] Open
Abstract
The nuclear envelope (NE) is a subdomain of the ER with prominent roles in nuclear organization, which are largely mediated by its distinctive protein composition. We developed methods to reveal low-abundance transmembrane (TM) proteins concentrated at the NE relative to the peripheral ER. Using label-free proteomics that compared isolated NEs with cytoplasmic membranes, we first identified proteins with apparent NE enrichment. In subsequent authentication, ectopically expressed candidates were analyzed by immunofluorescence microscopy to quantify their targeting to the NE in cultured cells. Ten proteins from a validation set were found to associate preferentially with the NE, including oxidoreductases, enzymes for lipid biosynthesis, and regulators of cell growth and survival. We determined that one of the validated candidates, the palmitoyltransferase Zdhhc6, modifies the NE oxidoreductase Tmx4 and thereby modulates its NE levels. This provides a functional rationale for the NE concentration of Zdhhc6. Overall, our methodology has revealed a group of previously unrecognized proteins concentrated at the NE and additional candidates. Future analysis of these can potentially unveil new mechanistic pathways associated with the NE.
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Affiliation(s)
- Li-Chun Cheng
- Department of Molecular Medicine, Scripps Research, La Jolla, CA, USA
| | - Xi Zhang
- Department of Molecular Medicine, Scripps Research, La Jolla, CA, USA
| | - Sabyasachi Baboo
- Department of Molecular Medicine, Scripps Research, La Jolla, CA, USA
| | - Julie A Nguyen
- Department of Molecular Medicine, Scripps Research, La Jolla, CA, USA
| | | | - Esther Loose
- Department of Molecular Medicine, Scripps Research, La Jolla, CA, USA
| | - Jolene Diedrich
- Department of Molecular Medicine, Scripps Research, La Jolla, CA, USA
| | - John R Yates
- Department of Molecular Medicine, Scripps Research, La Jolla, CA, USA
| | - Larry Gerace
- Department of Molecular Medicine, Scripps Research, La Jolla, CA, USA
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25
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Pilon M, Ruiz M. PAQR proteins and the evolution of a superpower: Eating all kinds of fats: Animals rely on evolutionarily conserved membrane homeostasis proteins to compensate for dietary variation. Bioessays 2023; 45:e2300079. [PMID: 37345585 DOI: 10.1002/bies.202300079] [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: 05/05/2023] [Revised: 06/06/2023] [Accepted: 06/07/2023] [Indexed: 06/23/2023]
Abstract
Recently published work showed that members of the PAQR protein family are activated by cell membrane rigidity and contribute to our ability to eat a wide variety of diets. Cell membranes are primarily composed of phospholipids containing dietarily obtained fatty acids, which poses a challenge to membrane properties because diets can vary greatly in their fatty acid composition and could impart opposite properties to the cellular membranes. In particular, saturated fatty acids (SFAs) can pack tightly and form rigid membranes (like butter at room temperature) while unsaturated fatty acids (UFAs) form more fluid membranes (like vegetable oils). Proteins of the PAQR protein family, characterized by the presence of seven transmembrane domains and a cytosolic N-terminus, contribute to membrane homeostasis in bacteria, yeasts, and animals. These proteins respond to membrane rigidity by stimulating fatty acid desaturation and incorporation of UFAs into phospholipids and explain the ability of animals to thrive on diets with widely varied fat composition. Also see the video abstract here: https://youtu.be/6ckcvaDdbQg.
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Affiliation(s)
- Marc Pilon
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Mario Ruiz
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
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26
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Saik NO, Ptak C, Rehman S, Aitchison JD, Montpetit B, Wozniak RW. SUMOylation at the inner nuclear membrane facilitates nuclear envelope biogenesis during mitosis. J Cell Biol 2023; 222:e202208137. [PMID: 37398994 PMCID: PMC10318406 DOI: 10.1083/jcb.202208137] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 03/24/2023] [Accepted: 05/15/2023] [Indexed: 07/04/2023] Open
Abstract
As eukaryotic cells progress through cell division, the nuclear envelope (NE) membrane must expand to accommodate the formation of progeny nuclei. In Saccharomyces cerevisiae, closed mitosis allows visualization of NE biogenesis during mitosis. During this period, the SUMO E3 ligase Siz2 binds the inner nuclear membrane (INM) and initiates a wave of INM protein SUMOylation. Here, we show these events increase INM levels of phosphatidic acid (PA), an intermediate of phospholipid biogenesis, and are necessary for normal mitotic NE membrane expansion. The increase in INM PA is driven by the Siz2-mediated inhibition of the PA phosphatase Pah1. During mitosis, this results from the binding of Siz2 to the INM and dissociation of Spo7 and Nem1, a complex required for the activation of Pah1. As cells enter interphase, the process is then reversed by the deSUMOylase Ulp1. This work further establishes a central role for temporally controlled INM SUMOylation in coordinating processes, including membrane expansion, that regulate NE biogenesis during mitosis.
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Affiliation(s)
- Natasha O. Saik
- Department of Cell Biology, University of Alberta, Edmonton, Alberta, Canada
| | - Christopher Ptak
- Department of Cell Biology, University of Alberta, Edmonton, Alberta, Canada
| | - Saif Rehman
- Department of Cell Biology, University of Alberta, Edmonton, Alberta, Canada
| | - John D. Aitchison
- Department of Cell Biology, University of Alberta, Edmonton, Alberta, Canada
- Seattle Children’s Research Institute, Seattle, WA, USA
- Department of Pediatrics and Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Ben Montpetit
- Department of Cell Biology, University of Alberta, Edmonton, Alberta, Canada
- Department of Viticulture and Enology, University of California Davis, Davis, CA, USA
| | - Richard W. Wozniak
- Department of Cell Biology, University of Alberta, Edmonton, Alberta, Canada
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27
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Sosa Ponce ML, Remedios MH, Moradi-Fard S, Cobb JA, Zaremberg V. SIR telomere silencing depends on nuclear envelope lipids and modulates sensitivity to a lysolipid. J Cell Biol 2023; 222:e202206061. [PMID: 37042812 PMCID: PMC10103788 DOI: 10.1083/jcb.202206061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 11/29/2022] [Accepted: 03/24/2023] [Indexed: 04/13/2023] Open
Abstract
The nuclear envelope (NE) is important in maintaining genome organization. The role of lipids in communication between the NE and telomere regulation was investigated, including how changes in lipid composition impact gene expression and overall nuclear architecture. Yeast was treated with the non-metabolizable lysophosphatidylcholine analog edelfosine, known to accumulate at the perinuclear ER. Edelfosine induced NE deformation and disrupted telomere clustering but not anchoring. Additionally, the association of Sir4 at telomeres decreased. RNA-seq analysis showed altered expression of Sir-dependent genes located at sub-telomeric (0-10 kb) regions, consistent with Sir4 dispersion. Transcriptomic analysis revealed that two lipid metabolic circuits were activated in response to edelfosine, one mediated by the membrane sensing transcription factors, Spt23/Mga2, and the other by a transcriptional repressor, Opi1. Activation of these transcriptional programs resulted in higher levels of unsaturated fatty acids and the formation of nuclear lipid droplets. Interestingly, cells lacking Sir proteins displayed resistance to unsaturated-fatty acids and edelfosine, and this phenotype was connected to Rap1.
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Affiliation(s)
| | | | - Sarah Moradi-Fard
- Departments of Biochemistry and Molecular Biology and Oncology, Cumming School of Medicine, Robson DNA Science Centre, Arnie Charbonneau Cancer Institute, Calgary, Canada
| | - Jennifer A. Cobb
- Departments of Biochemistry and Molecular Biology and Oncology, Cumming School of Medicine, Robson DNA Science Centre, Arnie Charbonneau Cancer Institute, Calgary, Canada
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, Canada
| | - Vanina Zaremberg
- Department of Biological Sciences, University of Calgary, Calgary, Canada
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28
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Dymond MK. A Membrane Biophysics Perspective on the Mechanism of Alcohol Toxicity. Chem Res Toxicol 2023. [PMID: 37186813 DOI: 10.1021/acs.chemrestox.3c00039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Motivations for understanding the underlying mechanisms of alcohol toxicity range from economical to toxicological and clinical. On the one hand, acute alcohol toxicity limits biofuel yields, and on the other hand, acute alcohol toxicity provides a vital defense mechanism to prevent the spread of disease. Herein the role that stored curvature elastic energy (SCE) in biological membranes might play in alcohol toxicity is discussed, for both short and long-chain alcohols. Structure-toxicity relationships for alcohols ranging from methanol to hexadecanol are collated, and estimates of alcohol toxicity per alcohol molecule in the cell membrane are made. The latter reveal a minimum toxicity value per molecule around butanol before alcohol toxicity per molecule increases to a maximum around decanol and subsequently decreases again. The impact of alcohol molecules on the lamellar to inverse hexagonal phase transition temperature (TH) is then presented and used as a metric to assess the impact of alcohol molecules on SCE. This approach suggests the nonmonotonic relationship between alcohol toxicity and chain length is consistent with SCE being a target of alcohol toxicity. Finally, in vivo evidence for SCE-driven adaptations to alcohol toxicity in the literature are discussed.
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Affiliation(s)
- Marcus K Dymond
- Chemistry Research and Enterprise Group, University of Brighton, Huxley Building, Lewes Road, Brighton BN2 4GJ, United Kingdom
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29
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Ruiz M, Devkota R, Kaper D, Ruhanen H, Busayavalasa K, Radović U, Henricsson M, Käkelä R, Borén J, Pilon M. AdipoR2 recruits protein interactors to promote fatty acid elongation and membrane fluidity. J Biol Chem 2023:104799. [PMID: 37164154 DOI: 10.1016/j.jbc.2023.104799] [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: 10/26/2022] [Revised: 04/28/2023] [Accepted: 04/29/2023] [Indexed: 05/12/2023] Open
Abstract
The human AdipoR2 and its C. elegans homolog PAQR-2 are multi-pass plasma membrane proteins that protect cells against membrane rigidification. However, how AdipoR2 promotes membrane fluidity mechanistically is not clear. Using 13C-labelled fatty acids, we show that AdipoR2 can promote the elongation and incorporation of membrane-fluidizing polyunsaturated fatty acids into phospholipids. To elucidate the molecular basis of these activities, we performed immunoprecipitations of tagged AdipoR2 and PAQR-2 expressed in HEK293 cells or whole C. elegans, respectively, and identified co-immunoprecipitated proteins using mass spectroscopy. We found that several of the evolutionarily conserved AdipoR2/PAQR-2 interactors are important for fatty acid elongation and incorporation into phospholipids. We experimentally verified some of these interactions, namely with the dehydratase HACD3 that is essential for the third of four steps in long-chain fatty acid elongation, and ACSL4 that is important for activation of unsaturated fatty acids and their channeling into phospholipids. We conclude that AdipoR2 and PAQR-2 can recruit protein interactors to promote the production and incorporation of unsaturated fatty acids into phospholipids.
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Affiliation(s)
- Mario Ruiz
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Ranjan Devkota
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Delaney Kaper
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Hanna Ruhanen
- Helsinki University Lipidomics Unit, Helsinki Institute of Life Science, Biocenter Finland, Helsinki, Finland; Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Kiran Busayavalasa
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Uroš Radović
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Marcus Henricsson
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Reijo Käkelä
- Helsinki University Lipidomics Unit, Helsinki Institute of Life Science, Biocenter Finland, Helsinki, Finland; Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Jan Borén
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Marc Pilon
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden.
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30
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Zhu J, Meng W, Man Lam S, Shui G, Huang X. Phosphatidylcholine deficiency increases ferroptosis susceptibility in the C. elegans germline. J Genet Genomics 2023; 50:318-329. [PMID: 36933794 DOI: 10.1016/j.jgg.2023.03.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 02/15/2023] [Accepted: 03/06/2023] [Indexed: 03/18/2023]
Abstract
Ferroptosis, a regulated and iron-dependent form of cell death characterized by peroxidation of membrane phospholipids, has tremendous potential for the therapy of human diseases. The causal link between phospholipid homeostasis and ferroptosis is incompletely understood. Here, we reveal that spin-4, a previously identified regulator of the "B12-one-carbon cycle-phosphatidylcholine (PC)" pathway, sustains germline development and fertility by ensuring PC sufficiency in the nematode Caenorhabditis elegans. Mechanistically, SPIN-4 regulates lysosomal activity which is required for B12-associated PC synthesis. PC deficiency-induced sterility can be rescued by reducing the levels of polyunsaturated fatty acids (PUFAs), reactive oxygen species (ROS) , and redox-active iron, which indicates that the sterility is mediated by germline ferroptosis. These results highlight the critical role of PC homeostasis in ferroptosis susceptibility and offer a new target for pharmacological approaches.
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Affiliation(s)
- Jinglin Zhu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wei Meng
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Sin Man Lam
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Guanghou Shui
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xun Huang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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31
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Dorighello G, McPhee M, Halliday K, Dellaire G, Ridgway N. Differential contributions of phosphotransferases CEPT1 and CHPT1 to phosphatidylcholine homeostasis and lipid droplet biogenesis. J Biol Chem 2023; 299:104578. [PMID: 36871755 PMCID: PMC10166788 DOI: 10.1016/j.jbc.2023.104578] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 02/21/2023] [Accepted: 02/25/2023] [Indexed: 03/06/2023] Open
Abstract
The CDP-choline (Kennedy) pathway culminates with the synthesis of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) by choline/ethanolamine phosphotransferase 1 (CEPT1) in the endoplasmic reticulum (ER), and PC synthesis by choline phosphotransferase 1 (CHPT1) in the Golgi apparatus. Whether the PC and PE synthesized by CEPT1 and CHPT1 in the ER and Golgi apparatus has different cellular functions has not been formally addressed. Here we used CRISPR editing to generate CEPT1-and CHPT1-knockout (KO) U2OS cells to assess the differential contribution of the enzymes to feed-back regulation of nuclear CTP:phosphocholine cytidylyltransferase (CCT)α, the rate-limiting enzyme in PC synthesis, and lipid droplet (LD) biogenesis. We found that CEPT1-KO cells had a 50% and 80% reduction in PC and PE synthesis, respectively, while PC synthesis in CHPT1-KO cells was also reduced by 50%. CEPT1 knockout caused the post-transcriptional induction of CCTα protein expression as well as its dephosphorylation and constitutive localization on the inner nuclear membrane and nucleoplasmic reticulum. This activated CCTα phenotype was prevented by incubating CEPT1-KO cells with PC liposomes to restore end-product inhibition. Additionally, we determined that CEPT1 was in close proximity to cytoplasmic LDs, and CEPT1 knockout resulted in the accumulation of small cytoplasmic LDs, as well as increased nuclear LDs enriched in CCTα. In contrast, CHPT1 knockout had no effect on CCTα regulation or LD biogenesis. Thus, CEPT1 and CHPT1 contribute equally to PC synthesis; however, only PC synthesized by CEPT1 in the ER regulates CCTα and the biogenesis of cytoplasmic and nuclear LDs.
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Affiliation(s)
- Gabriel Dorighello
- Depts of Pediatrics and Biochemistry & Molecular Biology, Atlantic Research Centre, Dalhousie University, Halifax, Nova Scotia Canada B3H4R2
| | - Michael McPhee
- Depts of Pediatrics and Biochemistry & Molecular Biology, Atlantic Research Centre, Dalhousie University, Halifax, Nova Scotia Canada B3H4R2
| | - Katie Halliday
- Depts of Pediatrics and Biochemistry & Molecular Biology, Atlantic Research Centre, Dalhousie University, Halifax, Nova Scotia Canada B3H4R2
| | - Graham Dellaire
- Depts of Pediatrics and Biochemistry & Molecular Biology, Atlantic Research Centre, Dalhousie University, Halifax, Nova Scotia Canada B3H4R2; Depts of Pathology and Biochemistry & Molecular Biology, Dalhousie University, Halifax, Nova Scotia Canada B3H4R2
| | - NealeD Ridgway
- Depts of Pediatrics and Biochemistry & Molecular Biology, Atlantic Research Centre, Dalhousie University, Halifax, Nova Scotia Canada B3H4R2.
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Shulman D, Dubnov S, Zorbaz T, Madrer N, Paldor I, Bennett DA, Seshadri S, Mufson EJ, Greenberg DS, Loewenstein Y, Soreq H. Sex-specific declines in cholinergic-targeting tRNA fragments in the nucleus accumbens in Alzheimer's disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.08.527612. [PMID: 36798311 PMCID: PMC9934682 DOI: 10.1101/2023.02.08.527612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Introduction Females with Alzheimer's disease (AD) suffer accelerated dementia and loss of cholinergic neurons compared to males, but the underlying mechanisms are unknown. Seeking causal contributors to both these phenomena, we pursued changes in tRNA fragments (tRFs) targeting cholinergic transcripts (CholinotRFs). Methods We analyzed small RNA-sequencing data from the nucleus accumbens (NAc) brain region which is enriched in cholinergic neurons, compared to hypothalamic or cortical tissues from AD brains; and explored small RNA expression in neuronal cell lines undergoing cholinergic differentiation. Results NAc CholinotRFs of mitochondrial genome origin showed reduced levels that correlated with elevations in their predicted cholinergic-associated mRNA targets. Single cell RNA seq from AD temporal cortices showed altered sex-specific levels of cholinergic transcripts in diverse cell types; inversely, human-originated neuroblastoma cells under cholinergic differentiation presented sex-specific CholinotRF elevations. Discussion Our findings support CholinotRFs contributions to cholinergic regulation, predicting their involvement in AD sex-specific cholinergic loss and dementia.
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Affiliation(s)
- Dana Shulman
- The Edmond & Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
- The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
- The Rachel and Selim Benin School of Computer Science and Engineering, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Serafima Dubnov
- The Edmond & Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
- The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Tamara Zorbaz
- The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Nimrod Madrer
- The Edmond & Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
- The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Iddo Paldor
- The Neurosurgery Department, Shaare Zedek Medical Center, Jerusalem 9103102, Israel
| | - David A. Bennett
- Rush Alzheimer’s Disease Center, Rush University Medical Center, 600 South Paulina, Suite 1028, Chicago, IL 60612, USA
| | - Sudha Seshadri
- UT Health Medical Arts & Research Center, San Antonio, TX 78229, USA
| | - Elliott J. Mufson
- Barrow Neurological Institute, St. Joseph’s Medical Center, Phoenix, AZ, 85013, USA
| | - David S. Greenberg
- The Edmond & Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
- The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Yonatan Loewenstein
- The Edmond & Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
- The Department of Neurobiology, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
- The Department of Cognitive Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
- The Federmann Center for the Study of Rationality, Jerusalem 9190401, Israel
| | - Hermona Soreq
- The Edmond & Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
- The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
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Cheng LC, Zhang X, Baboo S, Nguyen JA, Martinez-Bartolomé S, Loose E, Diedrich J, Yates JR, Gerace L. Comparative membrane proteomics reveals diverse cell regulators concentrated at the nuclear envelope. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.13.528342. [PMID: 36824861 PMCID: PMC9949040 DOI: 10.1101/2023.02.13.528342] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
The nuclear envelope (NE) is a subdomain of the ER with prominent roles in nuclear organization, largely mediated by its distinctive protein composition. We developed methods to reveal novel, low abundance transmembrane (TM) proteins concentrated at the NE relative to the peripheral ER. Using label-free proteomics that compared isolated NEs to cytoplasmic membranes, we first identified proteins with apparent NE enrichment. In subsequent authentication, ectopically expressed candidates were analyzed by immunofluorescence microscopy to quantify their targeting to the NE in cultured cells. Ten proteins from a validation set were found to associate preferentially with the NE, including oxidoreductases, enzymes for lipid biosynthesis and regulators of cell growth and survival. We determined that one of the validated candidates, the palmitoyltransferase Zdhhc6, modifies the NE oxidoreductase Tmx4 and thereby modulates its NE levels. This provides a functional rationale for the NE concentration of Zdhhc6. Overall, our methodology has revealed a group of previously unrecognized proteins concentrated at the NE and additional candidates. Future analysis of these can potentially unveil new mechanistic pathways associated with the NE.
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Affiliation(s)
- Li-Chun Cheng
- Department of Molecular Medicine, Scripps Research, 10550 N Torrey Pines Rd, La Jolla CA, USA
| | - Xi Zhang
- Department of Molecular Medicine, Scripps Research, 10550 N Torrey Pines Rd, La Jolla CA, USA
| | - Sabyasachi Baboo
- Department of Molecular Medicine, Scripps Research, 10550 N Torrey Pines Rd, La Jolla CA, USA
| | - Julie A Nguyen
- Department of Molecular Medicine, Scripps Research, 10550 N Torrey Pines Rd, La Jolla CA, USA
| | | | - Esther Loose
- Department of Molecular Medicine, Scripps Research, 10550 N Torrey Pines Rd, La Jolla CA, USA
| | - Jolene Diedrich
- Department of Molecular Medicine, Scripps Research, 10550 N Torrey Pines Rd, La Jolla CA, USA
| | - John R Yates
- Department of Molecular Medicine, Scripps Research, 10550 N Torrey Pines Rd, La Jolla CA, USA
| | - Larry Gerace
- Department of Molecular Medicine, Scripps Research, 10550 N Torrey Pines Rd, La Jolla CA, USA
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Fanani ML, Ambroggio EE. Phospholipases and Membrane Curvature: What Is Happening at the Surface? MEMBRANES 2023; 13:190. [PMID: 36837693 PMCID: PMC9965983 DOI: 10.3390/membranes13020190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 01/27/2023] [Accepted: 01/31/2023] [Indexed: 06/18/2023]
Abstract
In this revision work, we emphasize the close relationship between the action of phospholipases and the modulation of membrane curvature and curvature stress resulting from this activity. The alteration of the tridimensional structure of membranes upon the action of phospholipases is analyzed based on studies on model lipid membranes. The transient unbalance of both compositional and physical membrane properties between the hemilayers upon phospholipase activity lead to curvature tension and the catalysis of several membrane-related processes. Several proteins' membrane-bound and soluble forms are susceptible to regulation by the curvature stress induced by phospholipase action, which has important consequences in cell signaling. Additionally, the modulation of membrane fusion by phospholipase products regulates membrane dynamics in several cellular scenarios. We commented on vesicle fusion in the Golgi-endoplasmic system, synaptic vesicle fusion to the plasma membrane, viral membrane fusion to host cell plasma membrane and gametes membrane fusion upon acrosomal reaction. Furthermore, we explored the modulation of membrane fusion by the asymmetric adsorption of amphiphilic drugs. A deep understanding of the relevance of lipid membrane structure, particularly membrane curvature and curvature stress, on different cellular events leads to the challenge of its regulation, which may become a powerful tool for pharmacological therapy.
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Affiliation(s)
- María Laura Fanani
- Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba X5000HUA, Argentina
- Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), CONICET, Haya de la Torre y Medina Allende, Ciudad Universitaria, Córdoba X5000HUA, Argentina
| | - Ernesto Esteban Ambroggio
- Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba X5000HUA, Argentina
- Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), CONICET, Haya de la Torre y Medina Allende, Ciudad Universitaria, Córdoba X5000HUA, Argentina
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35
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Wang D, He Z, Liu M, Jin Y, Zhao J, Zhou R, Wu C, Qin J. Exogenous fatty acid renders the improved salt tolerance in Zygosaccharomyces rouxii by altering lipid metabolism. Lebensm Wiss Technol 2023. [DOI: 10.1016/j.lwt.2023.114579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
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36
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Nuclear envelope assembly and dynamics during development. Semin Cell Dev Biol 2023; 133:96-106. [PMID: 35249812 DOI: 10.1016/j.semcdb.2022.02.028] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 02/22/2022] [Accepted: 02/25/2022] [Indexed: 01/22/2023]
Abstract
The nuclear envelope (NE) protects but also organizes the eukaryotic genome. In this review we will discuss recent literature on how the NE disassembles and reassembles, how it varies in surface area and protein composition and how this translates into chromatin organization and gene expression in the context of animal development.
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37
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Xu Z, Tong Q, Lv W, Xiao Y, Wang Z. Phosphocholine cytidylyltransferase MoPct1 is crucial for vegetative growth, conidiation, and appressorium-mediated plant infection by Magnaporthe oryzae. Front Microbiol 2023; 14:1136168. [PMID: 37213497 PMCID: PMC10196169 DOI: 10.3389/fmicb.2023.1136168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Accepted: 04/12/2023] [Indexed: 05/23/2023] Open
Abstract
Phosphatidylcholine (PC) plays crucial biological roles in eukaryotic cells. In Saccharomyces cerevisiae, apart from phosphatidylethanolamine (PE) methylation pathway, PC is also synthesized via CDP-choline pathway. Phosphocholine cytidylyltransferase Pct1 is the rate-limiting enzyme to catalyze the conversion from phosphocholine to CDP-choline in this pathway. Here, we report the identification and functional characterization of an ortholog of the budding yeast PCT1 in Magnaporthe oryzae, named MoPCT1. Targeted gene deletion mutants of MoPCT1 were impaired in vegetative growth, conidiation, appressorium turgor accumulation and cell wall integrity. Also, the mutants were severely compromised in appressorium-mediated penetration, infectious growth and pathogenicity. Western blot analysis revealed that cell autophagy was activated by the deletion of MoPCT1 under nutrient-rich conditions. Moreover, we found several key genes in PE methylation pathway, such as MoCHO2, MoOPI3, and MoPSD2, were significantly up-regulated in the ΔMopct1 mutants, indicating that a pronounced compensation effect exists between the two PC biosynthesis pathways in M. oryzae. Interestingly, in the ΔMopct1 mutants, histone H3 was hypermethylated and expression levels of several methionine cycling-related genes were significantly up-regulated, suggesting that MoPCT1 is involved in histone H3 methylation and methionine metabolism. Taken together, we conclude that the phosphocholine cytidylyltransferase coding gene MoPCT1 plays important roles in vegetative growth, conidiation and appressorium-mediated plant infection by M. oryzae.
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38
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Anand D, Chaudhuri A. Grease in the Nucleus: Insights into the Dynamic Life of Nuclear Membranes. J Membr Biol 2022; 256:137-145. [PMID: 36331589 PMCID: PMC10082704 DOI: 10.1007/s00232-022-00272-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 09/20/2022] [Indexed: 11/06/2022]
Abstract
AbstractNucleus is at the center stage of cellular drama orchestrated in the life of a cell and the nucleoplasm is surrounded by a double membranous compartment constituting the Nuclear membrane/envelope (NE) that separates it from the cytoplasm in nucleated cells. The initial understanding of the NE was that of a border security entity between the nucleus and the cytoplasm, separating gene regulation and transcription in the nucleus from translation in the cytoplasm. However, the discovery of a wide array of inherited diseases caused by mutations in genes encoding proteins that reside or interact with NE diverted the interest into deciphering the lipid-protein-rich environment of the NE. Today, the NE is considered a dynamic organelle which forms a functional linkage between the nucleus and the rest of the cell. The exposure of NE to constant mechanical constraints by its connectivity to the large polymer network of the lamina and chromatin on one side, and to the cytoskeleton on the other side results, in a variety of shape changes. We discuss two such deformation, the formation of nuclear blebs and nucleoplasmic reticulum (NER). Although the protein and the lipid composition of NE comprises a small fraction of the total lipid-protein load of the cell, the ability to define the lipid-protein composition of Inner nuclear membrane (INM) and Outer nuclear membrane (ONM) with precision is crucial for obtaining a deeper mechanistic understanding of their lipid-protein interaction and the various signaling pathways that are triggered by them. In addition, this allows us to further understand the direct and indirect roles of NE machinery in the chromosomal organization and gene regulation.
Graphical Abstract
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Affiliation(s)
- Deepak Anand
- The Microbiology Group, Department of Biology, Biology Building, Lund University, Sölvegatan 35, 223 62, Lund, Sweden
| | - Arunima Chaudhuri
- Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine, Lund University, Sölvegatan 19, 223 62, Lund, Sweden.
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39
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Leveraging orthology within maize and Arabidopsis QTL to identify genes affecting natural variation in gravitropism. Proc Natl Acad Sci U S A 2022; 119:e2212199119. [PMID: 36161933 PMCID: PMC9546580 DOI: 10.1073/pnas.2212199119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Plants typically orient their organs with respect to the Earth's gravity field by a dynamic process called gravitropism. To discover conserved genetic elements affecting seedling root gravitropism, we measured the process in a set of Zea mays (maize) recombinant inbred lines with machine vision and compared the results with those obtained in a similar study of Arabidopsis thaliana. Each of the several quantitative trait loci that we mapped in both species spanned many hundreds of genes, too many to test individually for causality. We reasoned that orthologous genes may be responsible for natural variation in monocot and dicot root gravitropism. If so, pairs of orthologous genes affecting gravitropism may be present within the maize and Arabidopsis QTL intervals. A reciprocal comparison of sequences within the QTL intervals identified seven pairs of such one-to-one orthologs. Analysis of knockout mutants demonstrated a role in gravitropism for four of the seven: CCT2 functions in phosphatidylcholine biosynthesis, ATG5 functions in membrane remodeling during autophagy, UGP2 produces the substrate for cellulose and callose polymer extension, and FAMA is a transcription factor. Automated phenotyping enabled this discovery of four naturally varying components of a conserved process (gravitropism) by making it feasible to conduct the same large-scale experiment in two species.
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40
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Shen Z, Lengyel M, Niethammer P. The yellow brick road to nuclear membrane mechanotransduction. APL Bioeng 2022; 6:021501. [PMID: 35382443 PMCID: PMC8967412 DOI: 10.1063/5.0080371] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 03/09/2022] [Indexed: 02/06/2023] Open
Abstract
The nuclear membrane may function as a mechanosensory surface alongside the plasma membrane. In this Review, we discuss how this idea emerged, where it currently stands, and point out possible implications, without any claim of comprehensiveness.
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Affiliation(s)
| | - Miklós Lengyel
- Cell Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
| | - Philipp Niethammer
- Cell Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
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41
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Fang W, Zhu Y, Yang S, Tong X, Ye C. Reciprocal regulation of phosphatidylcholine synthesis and H3K36 methylation programs metabolic adaptation. Cell Rep 2022; 39:110672. [PMID: 35417718 DOI: 10.1016/j.celrep.2022.110672] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 01/14/2022] [Accepted: 03/22/2022] [Indexed: 11/17/2022] Open
Abstract
Phospholipid biosynthesis plays a role in mediating membrane-to-histone communication that influences metabolic decisions. Upon nutrient deprivation, phospholipid methylation generates a starvation signal in the form of S-adenosylmethionine (SAM) depletion, leading to dynamic changes in histone methylation. Here we show that the SAM-responsive methylation of H3K36 is critical for metabolic adaptation to nutrient starvation in the budding yeast Saccharomyces cerevisiae. We find that mutants deficient in H3K36 methylation exhibit defects in membrane integrity and pyrimidine metabolism and lose viability quickly under starvation. Adjusting the synthesis of phospholipids potently rewires metabolic pathways for nucleotide synthesis and boosts the production of antioxidants, ameliorating the defects resulting from the loss of H3K36 methylation. We further demonstrate that H3K36 methylation reciprocally regulates phospholipid synthesis by influencing redox balance. Our study illustrates an adaptive mechanism whereby phospholipid synthesis entails a histone modification to reprogram metabolism for adaptation in a eukaryotic model organism.
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Affiliation(s)
- Wen Fang
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, China
| | - Yibing Zhu
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, China
| | - Sen Yang
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, China
| | - Xiaomeng Tong
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, China
| | - Cunqi Ye
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, China; Kidney Disease Center, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.
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42
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Coupling lipid synthesis with nuclear envelope remodeling. Trends Biochem Sci 2022; 47:52-65. [PMID: 34556392 PMCID: PMC9943564 DOI: 10.1016/j.tibs.2021.08.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 08/12/2021] [Accepted: 08/25/2021] [Indexed: 01/10/2023]
Abstract
The nuclear envelope (NE) is a protective barrier to the genome, yet its membranes undergo highly dynamic remodeling processes that are necessary for cell growth and maintenance. While mechanisms by which proteins promote NE remodeling are emerging, the types of bilayer lipids and the lipid-protein interactions that define and sculpt nuclear membranes remain elusive. The NE is continuous with the endoplasmic reticulum (ER) and recent evidence suggests that lipids produced in the ER are harnessed to remodel nuclear membranes. In this review, we examine new roles for lipid species made proximally within the ER and locally at the NE to control NE dynamics. We further explore how the biosynthesis of lipids coordinates NE remodeling to ensure genome protection.
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43
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Abstract
The cell nucleus is best known as the container of the genome. Its envelope provides a barrier for passive macromolecule diffusion, which enhances the control of gene expression. As its largest and stiffest organelle, the nucleus also defines the minimal space requirements of a cell. Internal or external pressures that deform a cell to its physical limits cause a corresponding nuclear deformation. Evidence is consolidating that the nucleus, in addition to its genetic functions, serves as a physical sensing device for critical cell body deformation. Nuclear mechanotransduction allows cells to adapt their acute behaviors, mechanical stability, paracrine signaling, and fate to their physical surroundings. This review summarizes the basic chemical and mechanical properties of nuclear components, and how these properties are thought to be utilized for mechanosensing.
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Affiliation(s)
- Philipp Niethammer
- Cell Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA;
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44
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Romanauska A, Köhler A. Reprogrammed lipid metabolism protects inner nuclear membrane against unsaturated fat. Dev Cell 2021; 56:2562-2578.e3. [PMID: 34407429 PMCID: PMC8480995 DOI: 10.1016/j.devcel.2021.07.018] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 06/04/2021] [Accepted: 07/26/2021] [Indexed: 11/20/2022]
Abstract
The cell nucleus is surrounded by a double membrane. The lipid packing and viscosity of membranes is critical for their function and is tightly controlled by lipid saturation. Circuits regulating the lipid saturation of the outer nuclear membrane (ONM) and contiguous endoplasmic reticulum (ER) are known. However, how lipid saturation is controlled in the inner nuclear membrane (INM) has remained enigmatic. Using INM biosensors and targeted genetic manipulations, we show that increased lipid unsaturation causes a reprogramming of lipid storage metabolism across the nuclear envelope (NE). Cells induce lipid droplet (LD) formation specifically from the distant ONM/ER, whereas LD formation at the INM is suppressed. In doing so, unsaturated fatty acids are shifted away from the INM. We identify the transcription circuits that topologically reprogram LD synthesis and identify seipin and phosphatidic acid as critical effectors. Our study suggests a detoxification mechanism protecting the INM from excess lipid unsaturation. Biosensors detect lipid saturation dynamics of INM Increased lipid unsaturation induces LDs at ONM, but not at INM Opposing transcription circuits reprogram LD synthesis across the NE LDs detoxify unsaturated lipids to maintain INM integrity
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Affiliation(s)
- Anete Romanauska
- Max Perutz Labs, University of Vienna and Medical University of Vienna, Vienna Biocenter Campus (VBC), Dr. Bohr-Gasse 9/3, 1030 Vienna, Austria
| | - Alwin Köhler
- Max Perutz Labs, University of Vienna and Medical University of Vienna, Vienna Biocenter Campus (VBC), Dr. Bohr-Gasse 9/3, 1030 Vienna, Austria.
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Devkota R, Kaper D, Bodhicharla R, Henricsson M, Borén J, Pilon M. A genetic titration of membrane composition in Caenorhabditis elegans reveals its importance for multiple cellular and physiological traits. Genetics 2021; 219:iyab093. [PMID: 34125894 PMCID: PMC9335940 DOI: 10.1093/genetics/iyab093] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 06/08/2021] [Indexed: 12/21/2022] Open
Abstract
Communicating editor: B. Grant The composition and biophysical properties of cellular membranes must be tightly regulated to maintain the proper functions of myriad processes within cells. To better understand the importance of membrane homeostasis, we assembled a panel of five Caenorhabditis elegans strains that show a wide span of membrane composition and properties, ranging from excessively rich in saturated fatty acids (SFAs) and rigid to excessively rich in polyunsaturated fatty acids (PUFAs) and fluid. The genotypes of the five strain are, from most rigid to most fluid: paqr-1(tm3262); paqr-2(tm3410), paqr-2(tm3410), N2 (wild-type), mdt-15(et14); nhr-49(et8), and mdt-15(et14); nhr-49(et8); acs-13(et54). We confirmed the excess SFA/rigidity-to-excess PUFA/fluidity gradient using the methods of fluorescence recovery after photobleaching (FRAP) and lipidomics analysis. The five strains were then studied for a variety of cellular and physiological traits and found to exhibit defects in: permeability, lipid peroxidation, growth at different temperatures, tolerance to SFA-rich diets, lifespan, brood size, vitellogenin trafficking, oogenesis, and autophagy during starvation. The excessively rigid strains often exhibited defects in opposite directions compared to the excessively fluid strains. We conclude that deviation from wild-type membrane homeostasis is pleiotropically deleterious for numerous cellular/physiological traits. The strains introduced here should prove useful to further study the cellular and physiological consequences of impaired membrane homeostasis.
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Affiliation(s)
- Ranjan Devkota
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg S-405 30, Sweden
| | - Delaney Kaper
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg S-405 30, Sweden
| | - Rakesh Bodhicharla
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg S-405 30, Sweden
| | - Marcus Henricsson
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, University of Gothenburg, Gothenburg S-405 30, Sweden
| | - Jan Borén
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, University of Gothenburg, Gothenburg S-405 30, Sweden
| | - Marc Pilon
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg S-405 30, Sweden
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Bahja J, Dymond MK. Does membrane curvature elastic energy play a role in mediating oxidative stress in lipid membranes? Free Radic Biol Med 2021; 171:191-202. [PMID: 34000382 DOI: 10.1016/j.freeradbiomed.2021.05.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 05/10/2021] [Accepted: 05/11/2021] [Indexed: 02/06/2023]
Abstract
The effects of oxidative stress on cells are associated with a wide range of pathologies. Oxidative stress is predominantly initiated by the action of reactive oxygen species and/or lipoxygenases on polyunsaturated fatty acid containing lipids. The downstream products are oxidised phospholipids, bioactive aldehydes and a range of Schiff base by-products between aldehydes and lipids, or other biomacromolecules. In this review we assess the impact of oxidative stress on lipid membranes, focusing on the changes that occur to the curvature preference (lipid spontaneous curvature) and elastic properties of membranes, since these biophysical properties modulate phospholipid homeostasis. Studies show that the lipid products of oxidative stress reduce stored curvature elastic energy in membranes. Based upon this observation, we hypothesize that the effects of oxidative stress on lipid membranes will be reduced by compounds that increase stored curvature elastic energy. We find a strong correlation appears across literature studies that we have reviewed, such that many compounds like vitamin E, Curcumin, Coenzyme Q10 and vitamin A show behaviour consistent with this hypothesis. Finally, we consider whether age-related changes in lipid composition represent the homeostatic response of cells to compensate for the accumulation of in vivo lipid oxidation products.
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Affiliation(s)
- Julia Bahja
- Centre for Stress and Age-Related Disease, University of Brighton, Lewes Rd, Brighton, BN2 4GL, UK
| | - Marcus K Dymond
- Centre for Stress and Age-Related Disease, University of Brighton, Lewes Rd, Brighton, BN2 4GL, UK.
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Jacquemyn J, Foroozandeh J, Vints K, Swerts J, Verstreken P, Gounko NV, Gallego SF, Goodchild R. Torsin and NEP1R1-CTDNEP1 phosphatase affect interphase nuclear pore complex insertion by lipid-dependent and lipid-independent mechanisms. EMBO J 2021; 40:e106914. [PMID: 34313336 PMCID: PMC8408595 DOI: 10.15252/embj.2020106914] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 05/30/2021] [Accepted: 06/28/2021] [Indexed: 12/25/2022] Open
Abstract
The interphase nuclear envelope (NE) is extensively remodeled during nuclear pore complex (NPC) insertion. How this remodeling occurs and why it requires Torsin ATPases, which also regulate lipid metabolism, remains poorly understood. Here, we show that Drosophila Torsin (dTorsin) affects lipid metabolism via the NEP1R1‐CTDNEP1 phosphatase and the Lipin phosphatidic acid (PA) phosphatase. This includes that Torsins remove NEP1R1‐CTDNEP1 from the NE in fly and mouse cells, leading to subsequent Lipin exclusion from the nucleus. NEP1R1‐CTDNEP1 downregulation also restores nuclear pore membrane fusion in post‐mitotic dTorsinKO fat body cells. However, dTorsin‐associated nuclear pore defects do not correlate with lipidomic abnormalities and are not resolved by silencing of Lipin. Further testing confirmed that membrane fusion continues in cells with hyperactivated Lipin. It also led to the surprising finding that excessive PA metabolism inhibits recruitment of the inner ring complex Nup35 subunit, resulting in elongated channel‐like structures in place of mature nuclear pores. We conclude that the NEP1R1‐CTDNEP1 phosphatase affects interphase NPC biogenesis by lipid‐dependent and lipid‐independent mechanisms, explaining some of the pleiotropic effects of Torsins.
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Affiliation(s)
- Julie Jacquemyn
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Joyce Foroozandeh
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Katlijn Vints
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium.,VIB-KU Leuven Center for Brain & Disease Research, Electron Microscopy Platform & VIB-Bioimaging Core, Leuven, Belgium
| | - Jef Swerts
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Patrik Verstreken
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Natalia V Gounko
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium.,VIB-KU Leuven Center for Brain & Disease Research, Electron Microscopy Platform & VIB-Bioimaging Core, Leuven, Belgium
| | - Sandra F Gallego
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Rose Goodchild
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium
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48
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Dymond MK. Lipid monolayer spontaneous curvatures: A collection of published values. Chem Phys Lipids 2021; 239:105117. [PMID: 34265278 DOI: 10.1016/j.chemphyslip.2021.105117] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 07/03/2021] [Accepted: 07/09/2021] [Indexed: 11/24/2022]
Abstract
Lipid monolayer spontaneous curvatures (or lipid intrinsic curvatures) are one of several material properties of lipids that enable the stored curvature elastic energy in a lipid aggregate to be determined. Stored curvature elastic energy is important since it can modulate the function of membrane proteins and plays a role in the regulatory pathways of phospholipid homeostasis. Due to the large number of different lipid molecules that might theoretically exist in nature, very few lipid spontaneous curvatures have been determined. Herein the values of lipid spontaneous curvatures that exist in the literature are collected, alongside key experimental details. Where possible, trends in the data are discussed and finally, obvious gaps in the knowledge are signposted.
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Affiliation(s)
- Marcus K Dymond
- Chemistry Research and Enterprise Group, School of Pharmacy and Biomolecular Sciences, Huxley Building, University of Brighton, BN2 4GL, United Kingdom.
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49
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Gauthier BR, Comaills V. Nuclear Envelope Integrity in Health and Disease: Consequences on Genome Instability and Inflammation. Int J Mol Sci 2021; 22:ijms22147281. [PMID: 34298904 PMCID: PMC8307504 DOI: 10.3390/ijms22147281] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 07/02/2021] [Accepted: 07/04/2021] [Indexed: 12/11/2022] Open
Abstract
The dynamic nature of the nuclear envelope (NE) is often underestimated. The NE protects, regulates, and organizes the eukaryote genome and adapts to epigenetic changes and to its environment. The NE morphology is characterized by a wide range of diversity and abnormality such as invagination and blebbing, and it is a diagnostic factor for pathologies such as cancer. Recently, the micronuclei, a small nucleus that contains a full chromosome or a fragment thereof, has gained much attention. The NE of micronuclei is prone to collapse, leading to DNA release into the cytoplasm with consequences ranging from the activation of the cGAS/STING pathway, an innate immune response, to the creation of chromosomal instability. The discovery of those mechanisms has revolutionized the understanding of some inflammation-related diseases and the origin of complex chromosomal rearrangements, as observed during the initiation of tumorigenesis. Herein, we will highlight the complexity of the NE biology and discuss the clinical symptoms observed in NE-related diseases. The interplay between innate immunity, genomic instability, and nuclear envelope leakage could be a major focus in future years to explain a wide range of diseases and could lead to new classes of therapeutics.
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Affiliation(s)
- Benoit R. Gauthier
- Andalusian Center for Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucía-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain
- Correspondence: (B.R.G.); (V.C.)
| | - Valentine Comaills
- Andalusian Center for Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucía-University of Pablo de Olavide-University of Seville-CSIC, 41092 Seville, Spain
- Correspondence: (B.R.G.); (V.C.)
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50
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Abstract
The cell nucleus is best known as the container of the genome. Its envelope provides a barrier for passive macromolecule diffusion, which enhances the control of gene expression. As its largest and stiffest organelle, the nucleus also defines the minimal space requirements of a cell. Internal or external pressures that deform a cell to its physical limits cause a corresponding nuclear deformation. Evidence is consolidating that the nucleus, in addition to its genetic functions, serves as a physical sensing device for critical cell body deformation. Nuclear mechanotransduction allows cells to adapt their acute behaviors, mechanical stability, paracrine signaling, and fate to their physical surroundings. This review summarizes the basic chemical and mechanical properties of nuclear components, and how these properties are thought to be utilized for mechanosensing. Expected final online publication date for the Annual Review of Cell and Developmental Biology, Volume 37 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Philipp Niethammer
- Cell Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA;
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