1
|
Fu X, Zhang S, Liu P. Co-immunoprecipitation for identifying protein-protein interaction on lipid droplets. BIOPHYSICS REPORTS 2024; 10:102-110. [PMID: 38774355 PMCID: PMC11103721 DOI: 10.52601/bpr.2024.240007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2024] [Accepted: 02/23/2024] [Indexed: 05/24/2024] Open
Abstract
The lipid droplet (LD) is a conserved organelle that exists in almost all organisms, ranging from bacteria to mammals. Dysfunctions in LDs are linked to a range of human metabolic syndromes. The formation of protein complexes on LDs is crucial for maintaining their function. Investigating how proteins interact on LDs is essential for understanding the role of LDs. We have developed an effective method to uncover protein-protein interactions and protein complexes specifically on LDs. In this method, we conduct co-immunoprecipitation (co-IP) experiments using LD proteins extracted directly from isolated LDs, rather than utilizing proteins from cell lysates. To elaborate, we begin by purifying LDs with high-quality and extracting LD-associated proteins. Subsequently, the co-IP experiment is performed on these LD-associated proteins directly, which would enhance the co-IP experiment specificity of LD-associated proteins. This method enables researchers to directly unveil protein complexes on LDs and gain deeper insights into the functional roles of proteins associated with LDs.
Collapse
Affiliation(s)
- Xiaochuan Fu
- Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shuyan Zhang
- Institute of Infectious Diseases, Beijing Key Laboratory of Emerging Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing 100015, China
- Beijing Institute of Infectious Diseases, Beijing 100015, China
| | - Pingsheng Liu
- Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| |
Collapse
|
2
|
Makiyama T, Obama T, Watanabe Y, Chatani M, Azetsu Y, Kawaguchi K, Imanaka T, Itabe H. Behavior of intracellular lipid droplets during cell division in HuH7 hepatoma cells. Exp Cell Res 2023; 433:113855. [PMID: 37995922 DOI: 10.1016/j.yexcr.2023.113855] [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: 06/23/2023] [Revised: 11/16/2023] [Accepted: 11/16/2023] [Indexed: 11/25/2023]
Abstract
Intracellular lipid droplets (LDs) are ubiquitous organelles found in many cell types. During mitosis, membranous organelles, including mitochondria, are divided into small pieces and transferred to daughter cells; however, the process of LD transfer to daughter cells is not fully elucidated. Herein, we investigated the behavior of LDs during mitosis in HuH7 human hepatoma cells. While fragments of the Golgi apparatus were scattered in the cytosol during mitosis, intracellular LDs retained their size and spherical morphology as they translocated to the two daughter cells. LDs were initially distributed throughout the cell during prophase but positioned outside the spindle in metaphase, aligning at the far sides of the centrioles. A similar distribution of LDs during mitosis was observed in another hepatocarcinoma HepG2 cells. When the spindle was disrupted by nocodazole treatment or never in mitosis gene A-related kinase 2A knockdown, LDs were localized in the area outside the chromosomes, suggesting that spindle formation is not necessary for LD localization at metaphase. The amount of major LD protein perilipin 2 reduced while LDs were enriched in perilipin 3 during mitosis, indicating the potential alteration of LD protein composition. Conclusively, the behavior of LDs during mitosis is distinct from that of other organelles in hepatocytes.
Collapse
Affiliation(s)
- Tomohiko Makiyama
- Department of Biological Chemistry, Showa University Graduate School of Pharmacy, 1-5-8 Hatanodai, Shinagawa, Tokyo, 142-8555, Japan.
| | - Takashi Obama
- Department of Biological Chemistry, Showa University Graduate School of Pharmacy, 1-5-8 Hatanodai, Shinagawa, Tokyo, 142-8555, Japan
| | - Yuichi Watanabe
- Department of Biological Chemistry, Showa University Graduate School of Pharmacy, 1-5-8 Hatanodai, Shinagawa, Tokyo, 142-8555, Japan
| | - Masahiro Chatani
- Department of Pharmacology, Showa University School of Dentistry, 1-5-8 Hatanodai, Shinagawa, Tokyo, 142-8555, Japan; Pharmacological Research Center, Showa University, 1-5-8 Hatanodai, Shinagawa, Tokyo, 142-8555, Japan
| | - Yuki Azetsu
- Department of Pharmacology, Showa University School of Dentistry, 1-5-8 Hatanodai, Shinagawa, Tokyo, 142-8555, Japan; Pharmacological Research Center, Showa University, 1-5-8 Hatanodai, Shinagawa, Tokyo, 142-8555, Japan
| | - Kosuke Kawaguchi
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan
| | - Tsuneo Imanaka
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan; Faculty of Pharmaceutical Sciences, Hiroshima International University, 5-1-1 Hirokoshinkai, Kure City, Hiroshima, 737-0112, Japan
| | - Hiroyuki Itabe
- Department of Biological Chemistry, Showa University Graduate School of Pharmacy, 1-5-8 Hatanodai, Shinagawa, Tokyo, 142-8555, Japan
| |
Collapse
|
3
|
Papsdorf K, Miklas JW, Hosseini A, Cabruja M, Morrow CS, Savini M, Yu Y, Silva-García CG, Haseley NR, Murphy LM, Yao P, de Launoit E, Dixon SJ, Snyder MP, Wang MC, Mair WB, Brunet A. Lipid droplets and peroxisomes are co-regulated to drive lifespan extension in response to mono-unsaturated fatty acids. Nat Cell Biol 2023; 25:672-684. [PMID: 37127715 PMCID: PMC10185472 DOI: 10.1038/s41556-023-01136-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 03/23/2023] [Indexed: 05/03/2023]
Abstract
Dietary mono-unsaturated fatty acids (MUFAs) are linked to longevity in several species. But the mechanisms by which MUFAs extend lifespan remain unclear. Here we show that an organelle network involving lipid droplets and peroxisomes is critical for MUFA-induced longevity in Caenorhabditis elegans. MUFAs upregulate the number of lipid droplets in fat storage tissues. Increased lipid droplet number is necessary for MUFA-induced longevity and predicts remaining lifespan. Lipidomics datasets reveal that MUFAs also modify the ratio of membrane lipids and ether lipids-a signature associated with decreased lipid oxidation. In agreement with this, MUFAs decrease lipid oxidation in middle-aged individuals. Intriguingly, MUFAs upregulate not only lipid droplet number but also peroxisome number. A targeted screen identifies genes involved in the co-regulation of lipid droplets and peroxisomes, and reveals that induction of both organelles is optimal for longevity. Our study uncovers an organelle network involved in lipid homeostasis and lifespan regulation, opening new avenues for interventions to delay aging.
Collapse
Affiliation(s)
| | - Jason W Miklas
- Department of Genetics, Stanford University, Stanford, CA, USA
| | - Amir Hosseini
- Department of Genetics, Stanford University, Stanford, CA, USA
| | - Matias Cabruja
- Department of Genetics, Stanford University, Stanford, CA, USA
| | - Christopher S Morrow
- Department of Molecular Metabolism, Harvard T. H. Chan School of Public Health, Boston, MA, USA
| | - Marzia Savini
- Department of Molecular and Human Genetics, Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA
| | - Yong Yu
- Department of Molecular and Human Genetics, Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, China
| | - Carlos G Silva-García
- Department of Molecular Metabolism, Harvard T. H. Chan School of Public Health, Boston, MA, USA
| | | | | | - Pallas Yao
- Department of Molecular Metabolism, Harvard T. H. Chan School of Public Health, Boston, MA, USA
| | | | - Scott J Dixon
- Department of Biology, Stanford University, Stanford, CA, USA
| | | | - Meng C Wang
- Department of Molecular and Human Genetics, Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - William B Mair
- Department of Molecular Metabolism, Harvard T. H. Chan School of Public Health, Boston, MA, USA
| | - Anne Brunet
- Department of Genetics, Stanford University, Stanford, CA, USA.
- Glenn Laboratories for the Biology of Aging, Stanford University, Stanford, CA, USA.
- Wu Tsai Institute of Neurosciences, Stanford University, Stanford, CA, USA.
| |
Collapse
|
4
|
Application of Caenorhabditis elegans in Lipid Metabolism Research. Int J Mol Sci 2023; 24:ijms24021173. [PMID: 36674689 PMCID: PMC9860639 DOI: 10.3390/ijms24021173] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 01/01/2023] [Accepted: 01/05/2023] [Indexed: 01/11/2023] Open
Abstract
Over the last decade, the development and prevalence of obesity have posed a serious public health risk, which has prompted studies on the regulation of adiposity. With the ease of genetic manipulation, the diversity of the methods for characterizing body fat levels, and the observability of feeding behavior, Caenorhabditis elegans (C. elegans) is considered an excellent model for exploring energy homeostasis and the regulation of the cellular fat storage. In addition, the homology with mammals in the genes related to the lipid metabolism allows many aspects of lipid modulation by the regulators of the central nervous system to be conserved in this ideal model organism. In recent years, as the complex network of genes that maintain an energy balance has been gradually expanded and refined, the regulatory mechanisms of lipid storage have become clearer. Furthermore, the development of methods and devices to assess the lipid levels has become a powerful tool for studies in lipid droplet biology and the regulation of the nematode lipid metabolism. Herein, based on the rapid progress of C. elegans lipid metabolism-related studies, this review outlined the lipid metabolic processes, the major signaling pathways of fat storage regulation, and the primary experimental methods to assess the lipid content in nematodes. Therefore, this model system holds great promise for facilitating the understanding, management, and therapies of human obesity and other metabolism-related diseases.
Collapse
|
5
|
Castillo-Quan JI, Steinbaugh MJ, Fernández-Cárdenas LP, Pohl NK, Wu Z, Zhu F, Moroz N, Teixeira V, Bland MS, Lehrbach NJ, Moronetti L, Teufl M, Blackwell TK. An antisteatosis response regulated by oleic acid through lipid droplet-mediated ERAD enhancement. SCIENCE ADVANCES 2023; 9:eadc8917. [PMID: 36598980 PMCID: PMC9812393 DOI: 10.1126/sciadv.adc8917] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 11/23/2022] [Indexed: 05/19/2023]
Abstract
Although excessive lipid accumulation is a hallmark of obesity-related pathologies, some lipids are beneficial. Oleic acid (OA), the most abundant monounsaturated fatty acid (FA), promotes health and longevity. Here, we show that OA benefits Caenorhabditis elegans by activating the endoplasmic reticulum (ER)-resident transcription factor SKN-1A (Nrf1/NFE2L1) in a lipid homeostasis response. SKN-1A/Nrf1 is cleared from the ER by the ER-associated degradation (ERAD) machinery and stabilized when proteasome activity is low and canonically maintains proteasome homeostasis. Unexpectedly, OA increases nuclear SKN-1A levels independently of proteasome activity, through lipid droplet-dependent enhancement of ERAD. In turn, SKN-1A reduces steatosis by reshaping the lipid metabolism transcriptome and mediates longevity from OA provided through endogenous accumulation, reduced H3K4 trimethylation, or dietary supplementation. Our findings reveal an unexpected mechanism of FA signal transduction, as well as a lipid homeostasis pathway that provides strategies for opposing steatosis and aging, and may mediate some benefits of the OA-rich Mediterranean diet.
Collapse
Affiliation(s)
- Jorge Iván Castillo-Quan
- Section on Islet Cell and Regenerative Biology, Research Division, Joslin Diabetes Center, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Harvard Stem Cell Institute, Harvard Medical School, Boston, MA, USA
| | - Michael J. Steinbaugh
- Section on Islet Cell and Regenerative Biology, Research Division, Joslin Diabetes Center, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Harvard Stem Cell Institute, Harvard Medical School, Boston, MA, USA
| | - Laura Paulette Fernández-Cárdenas
- Section on Islet Cell and Regenerative Biology, Research Division, Joslin Diabetes Center, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Harvard Stem Cell Institute, Harvard Medical School, Boston, MA, USA
| | - Nancy K. Pohl
- Section on Islet Cell and Regenerative Biology, Research Division, Joslin Diabetes Center, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Harvard Stem Cell Institute, Harvard Medical School, Boston, MA, USA
| | - Ziyun Wu
- Section on Islet Cell and Regenerative Biology, Research Division, Joslin Diabetes Center, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Harvard Stem Cell Institute, Harvard Medical School, Boston, MA, USA
| | - Feimei Zhu
- Section on Islet Cell and Regenerative Biology, Research Division, Joslin Diabetes Center, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Harvard Stem Cell Institute, Harvard Medical School, Boston, MA, USA
| | - Natalie Moroz
- Section on Islet Cell and Regenerative Biology, Research Division, Joslin Diabetes Center, Boston, MA, USA
- Biology Department, Emmanuel College, Boston, MA, USA
| | - Veronica Teixeira
- Section on Islet Cell and Regenerative Biology, Research Division, Joslin Diabetes Center, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Harvard Stem Cell Institute, Harvard Medical School, Boston, MA, USA
| | - Monet S. Bland
- Section on Islet Cell and Regenerative Biology, Research Division, Joslin Diabetes Center, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Harvard Stem Cell Institute, Harvard Medical School, Boston, MA, USA
| | - Nicolas J. Lehrbach
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA
| | - Lorenza Moronetti
- Section on Islet Cell and Regenerative Biology, Research Division, Joslin Diabetes Center, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Harvard Stem Cell Institute, Harvard Medical School, Boston, MA, USA
| | - Magdalena Teufl
- Section on Islet Cell and Regenerative Biology, Research Division, Joslin Diabetes Center, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Harvard Stem Cell Institute, Harvard Medical School, Boston, MA, USA
| | - T. Keith Blackwell
- Section on Islet Cell and Regenerative Biology, Research Division, Joslin Diabetes Center, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Harvard Stem Cell Institute, Harvard Medical School, Boston, MA, USA
- Corresponding author.
| |
Collapse
|
6
|
Wang Y, Li C, Zhang J, Xu X, Fu L, Xu J, Zhu H, Hu Y, Li C, Wang M, Wu Y, Zou X, Liang B. Polyunsaturated fatty acids promote the rapid fusion of lipid droplets in Caenorhabditis elegans. J Biol Chem 2022; 298:102179. [PMID: 35752365 PMCID: PMC9352923 DOI: 10.1016/j.jbc.2022.102179] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 06/07/2022] [Accepted: 06/09/2022] [Indexed: 11/27/2022] Open
Abstract
Lipid droplets (LDs) are intracellular organelles that dynamically regulate lipids and energy homeostasis in the cell. LDs can grow through either local lipid synthesis or LD fusion. However, how lipids involving in LD fusion for LD growth is largely unknown. Here, we show that genetic mutation of acox-3 (acyl-CoA oxidase), maoc-1 (enoyl-CoA hydratase), dhs-28 (3-hydroxylacyl-CoA dehydrogenase), and daf-22 (3-ketoacyl-CoA thiolase), all involved in the peroxisomal β-oxidation pathway in Caenorhabditis elegans, led to rapid fusion of adjacent LDs to form giant LDs (gLDs). Mechanistically, we show that dysfunction of peroxisomal β-oxidation results in the accumulation of long-chain fatty acid-CoA and phosphocholine, which may activate the sterol-binding protein 1/sterol regulatory element-binding protein to promote gLD formation. Furthermore, we found that inactivation of either FAT-2 (delta-12 desaturase) or FAT-3 and FAT-1 (delta-15 desaturase and delta-6 desaturase, respectively) to block the biosynthesis of polyunsaturated fatty acids (PUFAs) with three or more double bonds (n≥3-PUFAs) fully repressed the formation of gLDs; in contrast, dietary supplementation of n≥3-PUFAs or phosphocholine bearing these PUFAs led to recovery of the formation of gLDs in peroxisomal β-oxidation-defective worms lacking PUFA biosynthesis. Thus, we conclude that n≥3-PUFAs, distinct from other well-known lipids and proteins, promote rapid LD fusion leading to LD growth.
Collapse
Affiliation(s)
- Yanli Wang
- Center for Life Sciences, School of Life Sciences, State Key Laboratory for Conservation and Utilization of Bio-Resources, Yunnan University, Kunming, Yunnan, China
| | - Chunxia Li
- Center for Life Sciences, School of Life Sciences, State Key Laboratory for Conservation and Utilization of Bio-Resources, Yunnan University, Kunming, Yunnan, China
| | - Jingjing Zhang
- Center for Life Sciences, School of Life Sciences, State Key Laboratory for Conservation and Utilization of Bio-Resources, Yunnan University, Kunming, Yunnan, China
| | - Xiumei Xu
- Center for Life Sciences, School of Life Sciences, State Key Laboratory for Conservation and Utilization of Bio-Resources, Yunnan University, Kunming, Yunnan, China
| | - Lin Fu
- Center for Life Sciences, School of Life Sciences, State Key Laboratory for Conservation and Utilization of Bio-Resources, Yunnan University, Kunming, Yunnan, China
| | - Jie Xu
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan province, Kunming Institute of Zoology, CAS, Kunming, Yunnan, China
| | - Hong Zhu
- Center for Life Sciences, School of Life Sciences, State Key Laboratory for Conservation and Utilization of Bio-Resources, Yunnan University, Kunming, Yunnan, China
| | - Ying Hu
- College of Chinese Materia Medica and Yunnan Key Laboratory of Southern Medicinal Utilization, Yunnan University of Chinese Medicine, Kunming, Yunnan, China
| | - Chengbin Li
- Center for Life Sciences, School of Life Sciences, State Key Laboratory for Conservation and Utilization of Bio-Resources, Yunnan University, Kunming, Yunnan, China
| | - Mengjie Wang
- Center for Life Sciences, School of Life Sciences, State Key Laboratory for Conservation and Utilization of Bio-Resources, Yunnan University, Kunming, Yunnan, China
| | - Yingjie Wu
- Shandong Provincial Hospital, School of Laboratory Animal & Shandong Laboratory Animal Center, Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong, China; Institute for Genome Engineered Animal Models of Human Diseases, National Center of Genetically Engineered Animal Models for International Research, Liaoning Provence Key Lab of Genome Engineered Animal Models Dalian Medical University, Dalian, Liaoning, China.
| | - Xiaoju Zou
- College of Chinese Materia Medica and Yunnan Key Laboratory of Southern Medicinal Utilization, Yunnan University of Chinese Medicine, Kunming, Yunnan, China.
| | - Bin Liang
- Center for Life Sciences, School of Life Sciences, State Key Laboratory for Conservation and Utilization of Bio-Resources, Yunnan University, Kunming, Yunnan, China.
| |
Collapse
|
7
|
Identification of Somatic Proteins in Haemonchus Contortus Infective Larvae (L 3) and Adults. Helminthologia 2022; 59:143-151. [PMID: 36118367 PMCID: PMC9444209 DOI: 10.2478/helm-2022-0017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 05/05/2022] [Indexed: 11/26/2022] Open
Abstract
Haemonchus contortus is considered the most pathogenic nematode in sheep production systems based on grazing. Comparing infective larvae (L3) with adult parasites can lead to the identification of proteins that play an important role in parasite-host interactions. In this study, we report a list of H. contortus somatic proteins and made a comparative analysis of somatic proteins of L3 and adult worms. L3 and adult parasites were subjected to protein extraction and subsequently to peptide fractionation. Peptides were analysed by mass spectrometry and LC-MS/MS data analysis. Data analysis and search on SEQUEST and MASCOT against H. contortus from the WormBase ParaSite database resulted in the identification of 775 unique peptide sequences corresponding to 227 proteins at 1 % FDR. From these, 18 proteins were specific to L3 and 63 to adult parasites. The gene ontology (GO) enrichment analysis of the proteins specific to L3 and adult worms to gain insight into cellular components, molecular functions and biological processes that affect the parasite-host interaction showed some differences between the two parasite stages. The list of proteins found provides a database to identify target proteins that could be useful as biomarkers of the infection or in the generation of anthelmintic drugs that inhibit proteins essential for the establishment of the infection and the survival of adult parasites. They can also serve as new candidates for vaccine research.
Collapse
|
8
|
Cao Z, Fung CW, Mak HY. A Flexible Network of Lipid Droplet Associated Proteins Support Embryonic Integrity of C. elegans. Front Cell Dev Biol 2022; 10:856474. [PMID: 35445028 PMCID: PMC9015696 DOI: 10.3389/fcell.2022.856474] [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] [Received: 01/17/2022] [Accepted: 03/16/2022] [Indexed: 11/13/2022] Open
Abstract
In addition to coordinating the storage and mobilization of neutral fat, lipid droplets (LDs) are conserved organelles that can accommodate additional cargos in order to support animal development. However, it is unclear if each type of cargo is matched with a specific subset of LDs. Here, we report that SEIP-1/seipin defines a subset of oocyte LDs that are required for proper eggshell formation in C. elegans. Using a photoconvertible fluorescent protein-based imaging assay, we found that SEIP-1 positive LDs were selectively depleted after fertilization, coincident of the formation of a lipid-rich permeability barrier of the eggshell. Loss of SEIP-1 function caused impenetrant embryonic arrest, which could be worsened by FAT-3/fatty acyl-CoA desaturase deficiency or suppressed by PLIN-1/Perilipin deficiency. The embryonic development of seip-1; plin-1 mutant in turn depended on the recruitment of RAB-18/Rab18 to LDs, which was not observed in wild type embryos. We propose that SEIP-1 dependent and independent mechanisms act in parallel to ensure the packaging and export of lipid-rich permeability barrier constituents, which involve LDs. The identity of these LDs, as defined by their associated proteins, exhibits unexpected plasticity that ultimately ensures the survival of embryos ex utero.
Collapse
Affiliation(s)
- Zhe Cao
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Chun Wing Fung
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Ho Yi Mak
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong SAR, China
| |
Collapse
|
9
|
Hello from the other side: Membrane contact of lipid droplets with other organelles and subsequent functional implications. Prog Lipid Res 2021; 85:101141. [PMID: 34793861 DOI: 10.1016/j.plipres.2021.101141] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 11/10/2021] [Accepted: 11/10/2021] [Indexed: 02/06/2023]
Abstract
Lipid droplets (LDs) are ubiquitous organelles that play crucial roles in response to physiological and environmental cues. The identification of several neutral lipid synthesizing and regulatory protein complexes have propelled significant advance on the mechanisms of LD biogenesis in the endoplasmic reticulum (ER). Increasing evidence suggests that distinct proteins and regulatory factors, which localize to membrane contact sites (MCS), are involved not only in interorganellar lipid exchange and transport, but also function in other important cellular processes, including autophagy, mitochondrial dynamics and inheritance, ion signaling and inter-regulation of these MCS. More and more tethers and molecular determinants are associated to MCS and to a diversity of cellular and pathophysiological processes, demonstrating the dynamics and importance of these junctions in health and disease. The conjugation of lipids with proteins in supramolecular complexes is known to be paramount for many biological processes, namely membrane biosynthesis, cell homeostasis, regulation of organelle division and biogenesis, and cell growth. Ultimately, this physical organization allows the contact sites to function as crucial metabolic hubs that control the occurrence of chemical reactions. This leads to biochemical and metabolite compartmentalization for the purposes of energetic efficiency and cellular homeostasis. In this review, we will focus on the structural and functional aspects of LD-organelle interactions and how they ensure signaling exchange and metabolites transfer between organelles.
Collapse
|
10
|
Wilson MH, Ekker SC, Farber SA. Imaging cytoplasmic lipid droplets in vivo with fluorescent perilipin 2 and perilipin 3 knock-in zebrafish. eLife 2021; 10:e66393. [PMID: 34387191 PMCID: PMC8460263 DOI: 10.7554/elife.66393] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 08/10/2021] [Indexed: 12/26/2022] Open
Abstract
Cytoplasmic lipid droplets are highly dynamic storage organelles that are critical for cellular lipid homeostasis. While the molecular details of lipid droplet dynamics are a very active area of investigation, this work has been primarily performed in cultured cells. Taking advantage of the powerful transgenic and in vivo imaging opportunities available in zebrafish, we built a suite of tools to study lipid droplets in real time from the subcellular to the whole organism level. Fluorescently tagging the lipid droplet-associated proteins, perilipin 2 and perilipin 3, in the endogenous loci permits visualization of lipid droplets in the intestine, liver, and adipose tissue. Using these tools, we found that perilipin 3 is rapidly loaded on intestinal lipid droplets following a high-fat meal and later replaced by perilipin 2. These powerful new tools will facilitate studies on the role of lipid droplets in different tissues, under different genetic and physiological manipulations, and in a variety of human disease models.
Collapse
Affiliation(s)
- Meredith H Wilson
- Carnegie Institution for Science Department of EmbryologyBaltimoreUnited States
| | - Stephen C Ekker
- Department of Biochemistry and Molecular Biology, Mayo ClinicRochesterUnited States
| | - Steven A Farber
- Carnegie Institution for Science Department of EmbryologyBaltimoreUnited States
- Johns Hopkins University Department of BiologyBaltimoreUnited States
| |
Collapse
|
11
|
Motility Plays an Important Role in the Lifetime of Mammalian Lipid Droplets. Int J Mol Sci 2021; 22:ijms22083802. [PMID: 33916886 PMCID: PMC8067576 DOI: 10.3390/ijms22083802] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 03/25/2021] [Accepted: 04/01/2021] [Indexed: 01/31/2023] Open
Abstract
The lipid droplet is a kind of organelle that stores neutral lipids in cells. Recent studies have found that in addition to energy storage, lipid droplets also play an important role in biological processes such as resistance to stress, immunity, cell proliferation, apoptosis, and signal transduction. Lipid droplets are formed at the endoplasmic reticulum, and mature lipid droplets participate in various cellular processes. Lipid droplets are decomposed by lipase and lysosomes. In the life of a lipid droplet, the most important thing is to interact with other organelles, including the endoplasmic reticulum, mitochondria, peroxisomes, and autophagic lysosomes. The interaction between lipid droplets and other organelles requires them to be close to each other, which inevitably involves the motility of lipid droplets. In fact, through many microscopic observation techniques, researchers have discovered that lipid droplets are highly dynamic organelles that move quickly. This paper reviews the process of lipid droplet motility, focusing on explaining the molecular basis of lipid droplet motility, the factors that regulate lipid droplet motility, and the influence of motility on the formation and decomposition of lipid droplets. In addition, this paper also proposes several unresolved problems for lipid droplet motility. Finally, this paper makes predictions about the future research of lipid droplet motility.
Collapse
|
12
|
Wang C, Xia C, Zhu Y, Zhang H. Innovative fluorescent probes for in vivo visualization of biomolecules in living Caenorhabditis elegans. Cytometry A 2021; 99:560-574. [PMID: 33638604 DOI: 10.1002/cyto.a.24325] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 02/02/2021] [Accepted: 02/15/2021] [Indexed: 12/16/2022]
Abstract
Caenorhabditis elegans (C. elegans) as a well-established multicellular model organism has been widely used in the biological field for half a century. Its numerous advantages including small body size, rapid life cycle, high-reproductive rate, well-defined anatomy, and conserved genome, has made C. elegans one of the most successful multicellular model organisms. Discoveries obtained from the C. elegans model have made great contributions to research fields such as development, aging, biophysics, immunology, and neuroscience. Because of its transparent body and giant cell size, C. elegans is also an ideal subject for high resolution and high-throughput optical imaging and analysis. During the past decade, great advances have been made to develop biomolecule-targeting techniques for noninvasive optical imaging. These novel technologies expanded the toolbox for qualitative and quantitative analysis of biomolecules in C. elegans. In this review, we summarize recently developed fluorescent probes or labeling techniques for visualizing biomolecules at the cellular, subcellular or molecular scale by using C. elegans as the major model organism or designed specifically for the applications in C. elegans. Combining the technological advantages of the C. elegans model with the novel fluorescent labeling techniques will provide new horizons for high-efficiency quantitative optical analysis in live organisms.
Collapse
Affiliation(s)
- Chunxia Wang
- Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, Suzhou, China
| | - Chujie Xia
- Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, Suzhou, China
| | - Yi Zhu
- Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, Suzhou, China
| | - Huimin Zhang
- Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, Suzhou, China
| |
Collapse
|
13
|
Cui L, Liu P. Two Types of Contact Between Lipid Droplets and Mitochondria. Front Cell Dev Biol 2020; 8:618322. [PMID: 33385001 PMCID: PMC7769837 DOI: 10.3389/fcell.2020.618322] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 11/25/2020] [Indexed: 12/11/2022] Open
Abstract
Lipid droplets (LDs) and mitochondria are essential organelles involved in cellular lipid metabolism and energy homeostasis. Accumulated studies have revealed that the physical contact between these two organelles is important for their functions. Current understanding of the contact between cellular organelles is highly dynamic, fitting a "kiss-and-run" model. The same pattern of contact between LDs and mitochondria has been reported and several proteins are found to mediate this contact, such as perilipin1 (PLIN1) and PLIN5. Another format of the contact has also been found and termed anchoring. LD-anchored mitochondria (LDAM) are identified in oxidative tissues including brown adipose tissue (BAT), skeletal muscle, and heart muscle, and this anchoring between these two organelles is conserved from mouse to monkey. Moreover, this anchoring is generated during the brown/beige adipocyte differentiation. In this review, we will summarize previous studies on the interaction between LDs and mitochondria, categorize the types of the contacts into dynamic and stable/anchored, present their similarities and differences, discuss their potential distinct molecular mechanism, and finally propose a working hypothesis that may explain why and how cells use two patterns of contact between LDs and mitochondria.
Collapse
Affiliation(s)
- Liujuan Cui
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Pingsheng Liu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| |
Collapse
|