1
|
Varasteh T, Lima MS, Silva TA, da Cruz MLR, Ahmadi RA, Atella GC, Attias M, Swings J, de Souza W, Thompson FL, Thompson CC. The dispersant Corexit 9500 and (dispersed) oil are lethal to coral endosymbionts. MARINE POLLUTION BULLETIN 2024; 203:116491. [PMID: 38754321 DOI: 10.1016/j.marpolbul.2024.116491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Revised: 04/30/2024] [Accepted: 05/09/2024] [Indexed: 05/18/2024]
Abstract
Endosymbionts (Symbiodiniaceae) play a vital role in the health of corals. Seawater pollution can harm these endosymbionts and dispersants used during oil spill cleanup can be extremely toxic to these organisms. Here, we examined the impact of oil and a specific dispersant, Corexit-9500, on two representative endosymbionts - Symbiodinium and Cladocopium - from the Southwestern endemic coral Mussismilia braziliensis. The survival and photosynthetic potential of the endosymbionts decreased dramatically after exposure to the dispersant and oil by ~25 % after 2 h and ~50 % after 7 days. Low concentrations of dispersant (0.005 ml/l) and dispersed oil (Polycyclic Aromatic Hydrocarbons, 1132 μg/l; Total Petroleum Hydrocarbons, 595 μg/l) proved highly toxic to both Symbiodinium and Cladocopium. These levels triggered a reduction in growth rate, cell size, and cell wall thickness. After a few hours of exposure, cellular organelles were damaged or destroyed. These acute toxic effects underline the fragile nature of coral endosymbionts.
Collapse
Affiliation(s)
- Tooba Varasteh
- Laboratory of Microbiology, Biology Institute, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Michele S Lima
- Laboratory of Microbiology, Biology Institute, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Tatiana A Silva
- Laboratory of Celullar Ultrastructure Hertha Meyer, Biophysics Institute Carlos Chagas Filho, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Maria Luíza R da Cruz
- Laboratory of Microbiology, Biology Institute, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Reza Amir Ahmadi
- Laboratory of Microbiology, Biology Institute, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Georgia C Atella
- Laboratory of Lipids Biochemistry and Lipoprotein, Biochemistry Institute Leopoldo de Meis, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Marcia Attias
- Laboratory of Celullar Ultrastructure Hertha Meyer, Biophysics Institute Carlos Chagas Filho, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Jean Swings
- Laboratory of Microbiology, Biology Institute, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Wanderley de Souza
- Laboratory of Celullar Ultrastructure Hertha Meyer, Biophysics Institute Carlos Chagas Filho, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Fabiano L Thompson
- Laboratory of Microbiology, Biology Institute, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil.
| | - Cristiane C Thompson
- Laboratory of Microbiology, Biology Institute, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil.
| |
Collapse
|
2
|
Cabodevilla AG, Son N, Goldberg IJ. Intracellular lipase and regulation of the lipid droplet. Curr Opin Lipidol 2024; 35:85-92. [PMID: 38447014 PMCID: PMC10919935 DOI: 10.1097/mol.0000000000000918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/08/2024]
Abstract
PURPOSE OF REVIEW Lipid droplets are increasingly recognized as distinct intracellular organelles that have functions exclusive to the storage of energetic lipids. Lipid droplets modulate macrophage inflammatory phenotype, control the availability of energy for muscle function, store excess lipid, sequester toxic lipids, modulate mitochondrial activity, and allow transfer of fatty acids between tissues. RECENT FINDINGS There have been several major advances in our understanding of the formation, dissolution, and function of this organelle during the past two years. These include new information on movement and partition of amphipathic proteins between the cytosol and lipid droplet surface, molecular determinants of lipid droplet formation, and pathways leading to lipid droplet hydrophobic lipid formation. Rapid advances in mitochondrial biology have also begun to define differences in their function and partnering with lipid droplets to modulate lipid storage versus oxidation. SUMMARY This relationship of lipid droplets biology and cellular function provides new understanding of an important cellular organelle that influences muscle function, adipose lipid storage, and diseases of lipotoxicity.
Collapse
Affiliation(s)
- Ainara G Cabodevilla
- Division of Endocrinology, New York University Grossman School of Medicine, New York, New York, USA
| | | | | |
Collapse
|
3
|
Salzer U, Mairhofer M, De Franceschi L. Rainer Prohaska (1943-2022). Am J Hematol 2024; 99:144-145. [PMID: 37867398 DOI: 10.1002/ajh.27139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 10/07/2023] [Indexed: 10/24/2023]
Affiliation(s)
- Ulrich Salzer
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Vienna, Austria
- Center for Medical Biochemistry, Medical University of Vienna, Vienna, Austria
| | - Mario Mairhofer
- Medical Department of Hematology and Oncology, Johannes Kepler University, Linz, Austria
| | | |
Collapse
|
4
|
Hammoudeh N, Soukkarieh C, Murphy DJ, Hanano A. Mammalian lipid droplets: structural, pathological, immunological and anti-toxicological roles. Prog Lipid Res 2023; 91:101233. [PMID: 37156444 DOI: 10.1016/j.plipres.2023.101233] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 04/30/2023] [Accepted: 05/05/2023] [Indexed: 05/10/2023]
Abstract
Mammalian lipid droplets (LDs) are specialized cytosolic organelles consisting of a neutral lipid core surrounded by a membrane made up of a phospholipid monolayer and a specific population of proteins that varies according to the location and function of each LD. Over the past decade, there have been significant advances in the understanding of LD biogenesis and functions. LDs are now recognized as dynamic organelles that participate in many aspects of cellular homeostasis plus other vital functions. LD biogenesis is a complex, highly-regulated process with assembly occurring on the endoplasmic reticulum although aspects of the underpinning molecular mechanisms remain elusive. For example, it is unclear how many enzymes participate in the biosynthesis of the neutral lipid components of LDs and how this process is coordinated in response to different metabolic cues to promote or suppress LD formation and turnover. In addition to enzymes involved in the biosynthesis of neutral lipids, various scaffolding proteins play roles in coordinating LD formation. Despite their lack of ultrastructural diversity, LDs in different mammalian cell types are involved in a wide range of biological functions. These include roles in membrane homeostasis, regulation of hypoxia, neoplastic inflammatory responses, cellular oxidative status, lipid peroxidation, and protection against potentially toxic intracellular fatty acids and lipophilic xenobiotics. Herein, the roles of mammalian LDs and their associated proteins are reviewed with a particular focus on their roles in pathological, immunological and anti-toxicological processes.
Collapse
Affiliation(s)
- Nour Hammoudeh
- Department of Animal Biology, Faculty of Sciences, University of Damascus, Damascus, Syria
| | - Chadi Soukkarieh
- Department of Animal Biology, Faculty of Sciences, University of Damascus, Damascus, Syria
| | - Denis J Murphy
- School of Applied Sciences, University of South Wales, Pontypridd, CF37 1DL, Wales, United Kingdom..
| | - Abdulsamie Hanano
- Department of Molecular Biology and Biotechnology, Atomic Energy Commission of Syria (AECS), P.O. Box 6091, Damascus, Syria..
| |
Collapse
|
5
|
Sun Y, Heng J, Liu F, Zhang S, Liu P. Isolation and proteomic study of fish liver lipid droplets. BIOPHYSICS REPORTS 2023; 9:120-133. [PMID: 38028150 PMCID: PMC10648235 DOI: 10.52601/bpr.2023.230004] [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: 02/26/2023] [Accepted: 06/02/2023] [Indexed: 12/01/2023] Open
Abstract
Lipid droplets (LDs) are a neutral lipid storage organelle that is conserved in almost all species. Excessive storage of neutral lipids in LDs is directly associated with many metabolic syndromes. Zebrafish is a better model animal for the study of LD biology due to its transparent embryonic stage compared to other organisms. However, the study of LDs in fish has been difficult due to the lack of specific LD marker proteins and the limitation of purification technology. In this paper, the purification and proteomic analysis of liver LDs of fish including zebrafish and Carassius auratus were performed for the first time. 259 and 267 proteins were identified respectively. Besides most of the identified proteins were reported in previous LD proteomes of mammals, indicating the similarity between mammal and fish LDs. We also identified many unique proteins of liver LDs in fish that are involved in the regulation of LD dynamics. Through morphological and biochemical analysis, we found that the marker protein Plin2 of zebrafish LD was located on LDs in Huh7 cells. These results will facilitate further study of LDs in fish and liver metabolic diseases using fish as a model animal.
Collapse
Affiliation(s)
- Yuwei Sun
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jian Heng
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
- Institute of Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China
| | - Feng Liu
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
- Institute of Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shuyan Zhang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Pingsheng Liu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| |
Collapse
|
6
|
Komatsu T, Matsui I, Yokoyama H. Structural and mutational studies suggest key residues to determine whether stomatin SPFH domains form dimers or trimers. Biochem Biophys Rep 2022; 32:101384. [DOI: 10.1016/j.bbrep.2022.101384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 11/06/2022] [Indexed: 11/13/2022] Open
|
7
|
Wang X, Gou Z, Lv JJ, Zuo Y. A novel coumarin-TPA based fluorescent probe for turn-on hypochlorite detection and lipid-droplet-polarity bioimaging in cancer cells. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 279:121481. [PMID: 35691171 DOI: 10.1016/j.saa.2022.121481] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 05/31/2022] [Accepted: 06/04/2022] [Indexed: 06/15/2023]
Abstract
A novel fluorescent compound, named C-TPA, based on coumarin (acceptor) and triphenylamine (donor) was facilely designed and fabricated through a one-step Suzuki coupling reaction. As a donor group, triphenylamine can efficiently enhance the fluorescence intensity and photostability of coumarin, and thus improve the detection efficiency. C-TPA-S was obtained from C-TPA treated with Lawesson's reagent and C-TPA-S can be used for the turn-on detection of hypochlorite through oxidative desulfurization with a low detection limit of 0.12 μM. Moreover, the intramolecular charge transfer process between the donor and acceptor group endows C-TPA with solvatochromism property and makes C-TPA a good candidate for polarity detection. The C-TPA with bright green fluorescence was highly efficient for imaging the microenvironment of polarity both in living cells and tissues with high selectivity and photostability, which can be applied in the diagnosis for the cancer cells.
Collapse
Affiliation(s)
- Xuefeng Wang
- College of Chemistry and Pharmaceutical Sciences, Qingdao Agricultural University, Qingdao, Shandong 266109, PR China
| | - Zhiming Gou
- School of Chemistry and Chemical Engineering, School of Materials Science and Engineering, University of Jinan, Jinan, Shandong 250022, PR China
| | - Jing-Jing Lv
- Key Laboratory of Carbon Materials of Zhejiang Province, Institute of New Materials and Industrial Technologies, Wenzhou University, Wenzhou, Zhejiang 325035, PR China
| | - Yujing Zuo
- School of Chemistry and Chemical Engineering, School of Materials Science and Engineering, University of Jinan, Jinan, Shandong 250022, PR China
| |
Collapse
|
8
|
Stomatin modulates adipogenesis through the ERK pathway and regulates fatty acid uptake and lipid droplet growth. Nat Commun 2022; 13:4174. [PMID: 35854007 PMCID: PMC9296665 DOI: 10.1038/s41467-022-31825-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 07/01/2022] [Indexed: 11/08/2022] Open
Abstract
Regulation of fatty acid uptake, lipid production and storage, and metabolism of lipid droplets (LDs), is closely related to lipid homeostasis, adipocyte hypertrophy and obesity. We report here that stomatin, a major constituent of lipid raft, participates in adipogenesis and adipocyte maturation by modulating related signaling pathways. In adipocyte-like cells, increased stomatin promotes LD growth or enlargements by facilitating LD-LD fusion. It also promotes fatty acid uptake from extracellular environment by recruiting effector molecules, such as FAT/CD36 translocase, to lipid rafts to promote internalization of fatty acids. Stomatin transgenic mice fed with high-fat diet exhibit obesity, insulin resistance and hepatic impairments; however, such phenotypes are not seen in transgenic animals fed with regular diet. Inhibitions of stomatin by gene knockdown or OB-1 inhibit adipogenic differentiation and LD growth through downregulation of PPARγ pathway. Effects of stomatin on PPARγ involves ERK signaling; however, an alternate pathway may also exist. Stomatin is a component of lipid rafts. Here, Wu et al. show that stomatin modulates the differentiation and functions of adipocytes by regulating adipogenesis signaling and fatty acid influx such that with excessive calorie intake, increased stomatin induces adiposity.
Collapse
|
9
|
Brink JTR, Fourie R, Sebolai O, Albertyn J, Pohl CH. The role of lipid droplets in microbial pathogenesis. J Med Microbiol 2021; 70. [PMID: 34184983 DOI: 10.1099/jmm.0.001383] [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] [Indexed: 12/18/2022] Open
Abstract
The nonpolar lipids present in cells are mainly triacylglycerols and steryl esters. When cells are provided with an abundance of nutrients, these storage lipids accumulate. As large quantities of nonpolar lipids cannot be integrated into membranes, they are isolated from the cytosolic environment in lipid droplets. As specialized, inducible cytoplasmic organelles, lipid droplets have functions beyond the regulation of lipid metabolism, in cell signalling and activation, membrane trafficking and control of inflammatory mediator synthesis and secretion. Pathogens, including fungi, viruses, parasites, or intracellular bacteria can induce and may benefit from lipid droplets in infected cells. Here we review biogenesis of lipid droplets as well as the role of lipid droplets in the pathogenesis of selected viruses, bacteria, protists and yeasts.
Collapse
Affiliation(s)
- Jacobus T R Brink
- Department of Microbiology and Biochemistry, University of the Free State, Bloemfontein, South Africa
| | - Ruan Fourie
- Department of Microbiology and Biochemistry, University of the Free State, Bloemfontein, South Africa
| | - Olihile Sebolai
- Department of Microbiology and Biochemistry, University of the Free State, Bloemfontein, South Africa
| | - Jacobus Albertyn
- Department of Microbiology and Biochemistry, University of the Free State, Bloemfontein, South Africa
| | - Carolina H Pohl
- Department of Microbiology and Biochemistry, University of the Free State, Bloemfontein, South Africa
| |
Collapse
|
10
|
Rab18 binds PLIN2 and ACSL3 to mediate lipid droplet dynamics. Biochim Biophys Acta Mol Cell Biol Lipids 2021; 1866:158923. [PMID: 33713834 DOI: 10.1016/j.bbalip.2021.158923] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 02/26/2021] [Accepted: 03/05/2021] [Indexed: 01/16/2023]
Abstract
Lipid droplet (LD) is a vital organelle governing lipid homeostasis and Rab18 has been linked to lipid metabolism. However, the mechanisms of Rab18-mediated LD dynamics in myoblast cells remain elusive. Here, we report that Rab18 plays an important role in oleic acid (OA)-induced LD accumulation in mouse myoblast C2C12 cells. Rab18 was translocated from the endoplasmic reticulum (ER) to LDs during LD accumulation, which was regulated by perilipin 2 (PLIN2), a major LD protein. LD-associated Rab18 bound with the C terminus of PLIN2 and the LD localization of Rab18 was diminished when PLIN2 was depleted. Moreover, loss of function of Rab18 led to reduced triacylglycerol (TAG) level and fewer but larger LDs. In contrast, overexpression of Rab18 resulted in elevated TAG content and LD number. Furthermore, LD-associated Rab18 interacted with acyl-CoA synthetase long-chain family member 3 (ACSL3), which in turn promoted the LD localization of this protein. These data show that Rab18 interacts with PLIN2 and forms a complex with PLIN2 and ACSL3, which plays a critical role in LD accumulation and dynamics of myoblast cells.
Collapse
|
11
|
Veerabagu M, Rinne PLH, Skaugen M, Paul LK, van der Schoot C. Lipid Body Dynamics in Shoot Meristems: Production, Enlargement, and Putative Organellar Interactions and Plasmodesmal Targeting. FRONTIERS IN PLANT SCIENCE 2021; 12:674031. [PMID: 34367200 PMCID: PMC8335594 DOI: 10.3389/fpls.2021.674031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 06/14/2021] [Indexed: 05/20/2023]
Abstract
Post-embryonic cells contain minute lipid bodies (LBs) that are transient, mobile, engage in organellar interactions, and target plasmodesmata (PD). While LBs can deliver γ-clade 1,3-β-glucanases to PD, the nature of other cargo is elusive. To gain insight into the poorly understood role of LBs in meristems, we investigated their dynamics by microscopy, gene expression analyzes, and proteomics. In developing buds, meristems accumulated LBs, upregulated several LB-specific OLEOSIN genes and produced OLEOSINs. During bud maturation, the major gene OLE6 was strongly downregulated, OLEOSINs disappeared from bud extracts, whereas lipid biosynthesis genes were upregulated, and LBs were enlarged. Proteomic analyses of the LB fraction of dormant buds confirmed that OLEOSINs were no longer present. Instead, we identified the LB-associated proteins CALEOSIN (CLO1), Oil Body Lipase 1 (OBL1), Lipid Droplet Interacting Protein (LDIP), Lipid Droplet Associated Protein1a/b (LDAP1a/b) and LDAP3a/b, and crucial components of the OLEOSIN-deubiquitinating and degradation machinery, such as PUX10 and CDC48A. All mRFP-tagged LDAPs localized to LBs when transiently expressed in Nicotiana benthamiana. Together with gene expression analyzes, this suggests that during bud maturation, OLEOSINs were replaced by LDIP/LDAPs at enlarging LBs. The LB fraction contained the meristem-related actin7 (ACT7), "myosin XI tail-binding" RAB GTPase C2A, an LB/PD-associated γ-clade 1,3-β-glucanase, and various organelle- and/or PD-localized proteins. The results are congruent with a model in which LBs, motorized by myosin XI-k/1/2, traffic on F-actin, transiently interact with other organelles, and deliver a diverse cargo to PD.
Collapse
Affiliation(s)
- Manikandan Veerabagu
- Faculty of Biosciences, Department of Plant Sciences, Norwegian University of Life Sciences, Ås, Norway
| | - Päivi L. H. Rinne
- Faculty of Biosciences, Department of Plant Sciences, Norwegian University of Life Sciences, Ås, Norway
| | - Morten Skaugen
- Faculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Laju K. Paul
- Faculty of Biosciences, Department of Plant Sciences, Norwegian University of Life Sciences, Ås, Norway
| | - Christiaan van der Schoot
- Faculty of Biosciences, Department of Plant Sciences, Norwegian University of Life Sciences, Ås, Norway
- *Correspondence: Christiaan van der Schoot
| |
Collapse
|
12
|
Leyland B, Zarka A, Didi-Cohen S, Boussiba S, Khozin-Goldberg I. High Resolution Proteome of Lipid Droplets Isolated from the Pennate Diatom Phaeodactylum tricornutum (Bacillariophyceae) Strain pt4 provides mechanistic insights into complex intracellular coordination during nitrogen deprivation. JOURNAL OF PHYCOLOGY 2020; 56:1642-1663. [PMID: 32779202 DOI: 10.1111/jpy.13063] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 05/14/2020] [Accepted: 07/12/2020] [Indexed: 05/08/2023]
Abstract
Lipid droplets (LDs) are an organelle conserved amongst all eukaryotes, consisting of a neutral lipid core surrounded by a polar lipid monolayer. Many species of microalgae accumulate LDs in response to stress conditions, such as nitrogen starvation. Here, we report the isolation and proteomic profiling of LD proteins from the model oleaginous pennate diatom Phaeodactylum tricornutum, strain Pt4 (UTEX 646). We also provide a quantitative description of LD morphological ontogeny, and fatty acid content. Novel cell disruption and LD isolation methods, combined with suspension-trapping and nanoflow liquid chromatography coupled to high resolution mass spectrometry, yielded an unprecedented number of LD proteins. Predictive annotation of the LD proteome suggests a broad assemblage of proteins with diverse functions, including lipid metabolism and vesicle trafficking, as well as ribosomal and proteasomal machinery. These proteins provide mechanistic insights into LD processes, and evidence for interactions between LDs and other organelles. We identify for the first time several key steps in diatom LD-associated triacylglycerol biosynthesis. Bioinformatic analyses of the LD proteome suggests multiple protein targeting mechanisms, including amphipathic helices, post-translational modifications, and translocation machinery. This work corroborates recent findings from other strains of P. tricornutum, other diatoms, and other eukaryotic organisms, suggesting that the fundamental proteins orchestrating LDs are conserved, and represent an ancient component of the eukaryotic endomembrane system. We postulate a comprehensive model of nitrogen starvation-induced diatom LDs on a molecular scale, and provide a wealth of candidates for metabolic engineering, with the potential to eventually customize LD contents.
Collapse
Affiliation(s)
- Ben Leyland
- The Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology, Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Sede Boker Campus, Be'er Sheva, 84990, Israel
| | - Aliza Zarka
- The Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology, Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Sede Boker Campus, Be'er Sheva, 84990, Israel
| | - Shoshana Didi-Cohen
- The Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology, Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Sede Boker Campus, Be'er Sheva, 84990, Israel
| | - Sammy Boussiba
- The Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology, Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Sede Boker Campus, Be'er Sheva, 84990, Israel
| | - Inna Khozin-Goldberg
- The Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology, Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Sede Boker Campus, Be'er Sheva, 84990, Israel
| |
Collapse
|
13
|
Chua NK, Coates HW, Brown AJ. Squalene monooxygenase: a journey to the heart of cholesterol synthesis. Prog Lipid Res 2020; 79:101033. [DOI: 10.1016/j.plipres.2020.101033] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 04/21/2020] [Accepted: 04/24/2020] [Indexed: 02/07/2023]
|
14
|
Yokoyama H, Suzuki K, Hara K, Matsui I, Hashimoto H. Inactive dimeric structure of the protease domain of stomatin operon partner protein. ACTA CRYSTALLOGRAPHICA SECTION D-STRUCTURAL BIOLOGY 2020; 76:515-520. [PMID: 32496213 DOI: 10.1107/s2059798320005021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 04/09/2020] [Indexed: 11/11/2022]
Abstract
The N-terminal region of the stomatin operon partner protein (STOPP) PH1510 (1510-N) from the hyperthermophilic archaeon Pyrococcus horikoshii is a serine protease with a catalytic Ser-Lys dyad (Ser97 and Lys138) and specifically cleaves the C-terminal hydrophobic region of the p-stomatin PH1511. In a form of human hemolytic anemia known as hereditary stomatocytosis, stomatin is deficient in the erythrocyte membrane owing to mis-trafficking. Stomatin is thought to act as an oligomeric scaffolding protein to support cell membranes. The cleavage of stomatin by STOPP might be involved in a regulatory system. Several crystal structures of 1510-N have previously been determined: the wild type, the K138A mutant and its complex with a substrate peptide. Here, the crystal structure of the S97A mutant of 1510-N (1510-N S97A) was determined at 2.25 Å resolution. The structure contained two 1510-N S97A molecules in the asymmetric unit. On the superposition of one monomer of the 1510-N S97A and wild-type dimers, the S97A Cα atom of the other monomer of 1510-N S97A deviated by 23 Å from that of the wild type. This result indicates that 1510-N can greatly change the form of its dimer. Because of crystallographic symmetry in space group P65, a sixfold helical structure is constructed using the 1510-N dimer as a basic unit. This helical structure may be common to STOPP structures.
Collapse
Affiliation(s)
- Hideshi Yokoyama
- Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
| | - Kana Suzuki
- School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Kodai Hara
- School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Ikuo Matsui
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan
| | - Hiroshi Hashimoto
- School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| |
Collapse
|
15
|
Yokoyama H, Matsui I. The lipid raft markers stomatin, prohibitin, flotillin, and HflK/C (SPFH)-domain proteins form an operon with NfeD proteins and function with apolar polyisoprenoid lipids. Crit Rev Microbiol 2020; 46:38-48. [PMID: 31983249 DOI: 10.1080/1040841x.2020.1716682] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
SPFH-domain proteins are found in almost all organisms across three domains: archaea, bacteria, and eukaryotes. In eukaryotic organelles, their subfamilies exhibit overlapping distribution and functions; thus, the rationality of annotation to discriminate these subfamilies remains unclear. In this review, the binding ability of prokaryotic SPFH-domain proteins towards nonpolar polyisoprenoides such as squalene and lycopene, rather than cholesterol, is discussed. The hydrophobic region at the C-terminus of SPFH-domain proteins constitutes the main region that binds apolar polyisoprenoid lipids as well as cholesterol and substantively contributes towards lipid raft formation as these regions are self-assembled together with specific lipids. Because the scaffolding proteins caveolins show common topological properties with SPFH-domain proteins such as stomatin and flotillin, the α-helical segments of stomatin proteins can flexibly move along with the membrane surface, with such movement potentially leading to membrane bending via lipid raft clustering through the formation of high order homo-oligomeric complexes of SPFH-domain proteins. We also discuss the functional significance and ancient origin of SPFH-domain proteins and the NfeD protein (STOPP) operon, which can be traced back to the ancient living cells that diverged and evolved to archaea and bacteria. Based on the molecular mechanism whereby the STOPP-protease degrades the C-terminal hydrophobic clusters of SPFH-domain proteins, it is conceivable that STOPP-protease might control the physicochemical properties of lipid rafts.
Collapse
Affiliation(s)
- Hideshi Yokoyama
- Department of Medical and Life Sciences, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda, Chiba, Japan
| | - Ikuo Matsui
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
| |
Collapse
|
16
|
Chen Y, Frost S, Khushi M, Cantrill LC, Yu H, Arthur JW, Bright RK, Groblewski GE, Byrne JA. Delayed recruiting of TPD52 to lipid droplets - evidence for a "second wave" of lipid droplet-associated proteins that respond to altered lipid storage induced by Brefeldin A treatment. Sci Rep 2019; 9:9790. [PMID: 31278300 PMCID: PMC6611826 DOI: 10.1038/s41598-019-46156-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2018] [Accepted: 06/18/2019] [Indexed: 12/27/2022] Open
Abstract
Tumor protein D52 (TPD52) is amplified and overexpressed in breast and prostate cancers which are frequently characterised by dysregulated lipid storage and metabolism. TPD52 expression increases lipid storage in mouse 3T3 fibroblasts, and co-distributes with the Golgi marker GM130 and lipid droplets (LDs). We examined the effects of Brefeldin A (BFA), a fungal metabolite known to disrupt the Golgi structure, in TPD52-expressing 3T3 cells, and in human AU565 and HMC-1-8 breast cancer cells that endogenously express TPD52. Five-hour BFA treatment reduced median LD numbers, but increased LD sizes. TPD52 knockdown decreased both LD sizes and numbers, and blunted BFA's effects on LD numbers. Following BFA treatment for 1-3 hours, TPD52 co-localised with the trans-Golgi network protein syntaxin 6, but after 5 hours BFA treatment, TPD52 showed increased co-localisation with LDs, which was disrupted by microtubule depolymerising agent nocodazole. BFA treatment also increased perilipin (PLIN) family protein PLIN3 but reduced PLIN2 detection at LDs in TPD52-expressing 3T3 cells, with PLIN3 recruitment to LDs preceding that of TPD52. An N-terminally deleted HA-TPD52 mutant (residues 40-184) almost exclusively targeted to LDs in both vehicle and BFA treated cells. In summary, delayed recruitment of TPD52 to LDs suggests that TPD52 participates in a temporal hierarchy of LD-associated proteins that responds to altered LD packaging requirements induced by BFA treatment.
Collapse
Affiliation(s)
- Yuyan Chen
- Molecular Oncology Laboratory, Children's Cancer Research Unit, Kids Research, The Children's Hospital at Westmead, Westmead, NSW, 2145, Australia.
- The University of Sydney Discipline of Child and Adolescent Health, The Children's Hospital at Westmead, Westmead, NSW, 2145, Australia.
| | - Sarah Frost
- Molecular Oncology Laboratory, Children's Cancer Research Unit, Kids Research, The Children's Hospital at Westmead, Westmead, NSW, 2145, Australia
- The University of Sydney Discipline of Child and Adolescent Health, The Children's Hospital at Westmead, Westmead, NSW, 2145, Australia
| | - Matloob Khushi
- Bioinformatics Unit, Children's Medical Research Institute, The University of Sydney, Westmead, NSW, 2145, Australia
- The University of Sydney School of Information Technologies, Darlington, NSW, 2008, Australia
| | - Laurence C Cantrill
- The University of Sydney Discipline of Child and Adolescent Health, The Children's Hospital at Westmead, Westmead, NSW, 2145, Australia
- Kids Research Microscope Facility, The Children's Hospital at Westmead, Westmead, NSW, 2145, Australia
| | - Hong Yu
- Cell Imaging Facility, Westmead Institute for Medical Research, Westmead, NSW, 2145, Australia
| | - Jonathan W Arthur
- Bioinformatics Unit, Children's Medical Research Institute, The University of Sydney, Westmead, NSW, 2145, Australia
| | - Robert K Bright
- Department of Immunology and Molecular Microbiology and TTUHSC Cancer Center, Texas Tech University Health Sciences Center, Lubbock, Texas, 79430, USA
| | - Guy E Groblewski
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
| | - Jennifer A Byrne
- Molecular Oncology Laboratory, Children's Cancer Research Unit, Kids Research, The Children's Hospital at Westmead, Westmead, NSW, 2145, Australia.
- The University of Sydney Discipline of Child and Adolescent Health, The Children's Hospital at Westmead, Westmead, NSW, 2145, Australia.
| |
Collapse
|
17
|
Zhang C, Liu P. The New Face of the Lipid Droplet: Lipid Droplet Proteins. Proteomics 2018; 19:e1700223. [DOI: 10.1002/pmic.201700223] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Revised: 08/13/2018] [Indexed: 12/20/2022]
Affiliation(s)
- Congyan Zhang
- National Laboratory of BiomacromoleculesCAS Center for Excellence in BiomacromoleculesInstitute of BiophysicsChinese Academy of Sciences Beijing 100101 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Pingsheng Liu
- National Laboratory of BiomacromoleculesCAS Center for Excellence in BiomacromoleculesInstitute of BiophysicsChinese Academy of Sciences Beijing 100101 China
- University of Chinese Academy of Sciences Beijing 100049 China
| |
Collapse
|
18
|
Liu Y, Xu S, Zhang C, Zhu X, Hammad MA, Zhang X, Christian M, Zhang H, Liu P. Hydroxysteroid dehydrogenase family proteins on lipid droplets through bacteria, C. elegans, and mammals. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1863:881-894. [DOI: 10.1016/j.bbalip.2018.04.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 04/18/2018] [Accepted: 04/21/2018] [Indexed: 02/08/2023]
|
19
|
Vallochi AL, Teixeira L, Oliveira KDS, Maya-Monteiro CM, Bozza PT. Lipid Droplet, a Key Player in Host-Parasite Interactions. Front Immunol 2018; 9:1022. [PMID: 29875768 PMCID: PMC5974170 DOI: 10.3389/fimmu.2018.01022] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 04/24/2018] [Indexed: 12/18/2022] Open
Abstract
Lipid droplets (lipid bodies, LDs) are dynamic organelles that have important roles in regulating lipid metabolism, energy homeostasis, cell signaling, membrane trafficking, and inflammation. LD biogenesis, composition, and functions are highly regulated and may vary according to the stimuli, cell type, activation state, and inflammatory environment. Increased cytoplasmic LDs are frequently observed in leukocytes and other cells in a number of infectious diseases. Accumulating evidence reveals LDs participation in fundamental mechanisms of host-pathogen interactions, including cell signaling and immunity. LDs are sources of eicosanoid production, and may participate in different aspects of innate signaling and antigen presentation. In addition, intracellular pathogens evolved mechanisms to subvert host metabolism and may use host LDs, as ways of immune evasion and nutrients source. Here, we review mechanisms of LDs biogenesis and their contributions to the infection progress, and discuss the latest discoveries on mechanisms and pathways involving LDs roles as regulators of the immune response to protozoan infection.
Collapse
Affiliation(s)
- Adriana Lima Vallochi
- Laboratório de Imunofarmacologia, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| | | | | | | | - Patricia T. Bozza
- Laboratório de Imunofarmacologia, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| |
Collapse
|
20
|
Abstract
Lipid droplets (LDs) are ubiquitous fat storage organelles and play key roles in lipid metabolism and energy homeostasis; in addition, they contribute to protein storage, folding, and degradation. However, a role for LDs in the nervous system remains largely unexplored. We discuss evidence supporting an intimate functional connection between LDs and motor neuron disease (MND) pathophysiology, examining how LD functions in systemic energy homeostasis, in neuron-glia metabolic coupling, and in protein folding and clearance may affect or contribute to disease pathology. An integrated understanding of LD biology and neurodegeneration may open the way for new therapeutic interventions.
Collapse
Affiliation(s)
- Giuseppa Pennetta
- Euan MacDonald Centre for Motor Neuron Disease Research, University of Edinburgh, Edinburgh EH8 9XD, UK; Centre for Integrative Physiology, University of Edinburgh, Edinburgh EH8 9XD, UK.
| | - Michael A Welte
- Department of Biology, University of Rochester, Rochester, NY 14627, USA
| |
Collapse
|
21
|
de Almeida PE, Toledo DAM, Rodrigues GSC, D'Avila H. Lipid Bodies as Sites of Prostaglandin E2 Synthesis During Chagas Disease: Impact in the Parasite Escape Mechanism. Front Microbiol 2018; 9:499. [PMID: 29616011 PMCID: PMC5869919 DOI: 10.3389/fmicb.2018.00499] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 03/05/2018] [Indexed: 12/22/2022] Open
Abstract
During Chagas disease, the Trypanosoma cruzi can induce some changes in the host cells in order to escape or manipulate the host immune response. The modulation of the lipid metabolism in the host phagocytes or in the parasite itself is one feature that has been observed. The goal of this mini review is to discuss the mechanisms that regulate intracellular lipid body (LB) biogenesis in the course of this parasite infection and their meaning to the pathophysiology of the disease. The interaction host–parasite induces LB (or lipid droplet) formation in a Toll-like receptor 2-dependent mechanism in macrophages and is enhanced by apoptotic cell uptake. Simultaneously, there is a lipid accumulation in the parasite due to the incorporation of host fatty acids. The increase in the LB accumulation during infection is correlated with an increase in the synthesis of PGE2 within the host cells and the parasite LBs. Moreover, the treatment with fatty acid synthase inhibitor C75 or non-steroidal anti-inflammatory drugs such as NS-398 and aspirin inhibited the LB biogenesis and also induced the down modulation of the eicosanoid production and the parasite replication. These findings show that LBs are organelles up modulated during the course of infection. Furthermore, the biogenesis of the LB is involved in the lipid mediator generation by both the macrophages and the parasite triggering escape mechanisms.
Collapse
Affiliation(s)
- Patrícia E de Almeida
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, Juiz de Fora, Brazil
| | | | - Gabriel S C Rodrigues
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, Juiz de Fora, Brazil
| | - Heloisa D'Avila
- Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, Juiz de Fora, Brazil
| |
Collapse
|
22
|
Inloes JM, Kiosses WB, Wang H, Walther TC, Farese RV, Cravatt BF. Functional Contribution of the Spastic Paraplegia-Related Triglyceride Hydrolase DDHD2 to the Formation and Content of Lipid Droplets. Biochemistry 2017; 57:827-838. [PMID: 29278326 DOI: 10.1021/acs.biochem.7b01028] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Deleterious mutations in the serine lipase DDHD2 are a causative basis of complex hereditary spastic paraplegia (HSP, subtype SPG54) in humans. We recently found that DDHD2 is a principal triglyceride hydrolase in the central nervous system (CNS) and that genetic deletion of this enzyme in mice leads to ectopic lipid droplet (LD) accumulation in neurons throughout the brain. Nonetheless, how HSP-related mutations in DDHD2 relate to triglyceride metabolism and LD formation remains poorly understood. Here, we have characterized a set of HSP-related mutations in DDHD2 and found that they disrupt triglyceride hydrolase activity in vitro and impair the capacity of DDHD2 to protect cells from LD accumulation following exposure to free fatty acid, an outcome that was also observed with a DDHD2-selective inhibitor. We furthermore isolated and characterized LDs from brain tissue of DDHD2-/- mice, revealing that they contain both established LD-associated proteins identified previously in other organs and CNS-enriched proteins, including several proteins with genetic links to human neurological disease. These data, taken together, indicate that the genetic inactivation of DDHD2, as caused by HSP-associated mutations, substantially perturbs lipid homeostasis and the formation and content of LDs, underscoring the importance of triglyceride metabolism for normal CNS function and the key role that DDHD2 plays in this process.
Collapse
Affiliation(s)
- Jordon M Inloes
- Department of Chemical Physiology, The Skaggs Institute for Chemical Biology, The Scripps Research Institute , La Jolla, California 92037, United States
| | - William B Kiosses
- Department of Molecular Medicine, The Skaggs Institute for Chemical Biology, The Scripps Research Institute , La Jolla, California 92037, United States
| | - Huajin Wang
- University Libraries, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States.,Department of Biological Sciences, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States.,Department of Genetics and Complex Diseases, Harvard T. H. Chan School of Public Health , Boston, Massachusetts 02115, United States.,Department of Cell Biology, Harvard Medical School , Boston, Massachusetts 02115, United States
| | - Tobias C Walther
- Department of Genetics and Complex Diseases, Harvard T. H. Chan School of Public Health , Boston, Massachusetts 02115, United States.,Department of Cell Biology, Harvard Medical School , Boston, Massachusetts 02115, United States.,Broad Institute of Harvard and MIT , Cambridge, Massachusetts 02142, United States.,Howard Hughes Medical Institute , Boston, Massachusetts 02115, United States
| | - Robert V Farese
- Department of Genetics and Complex Diseases, Harvard T. H. Chan School of Public Health , Boston, Massachusetts 02115, United States.,Department of Cell Biology, Harvard Medical School , Boston, Massachusetts 02115, United States.,Broad Institute of Harvard and MIT , Cambridge, Massachusetts 02142, United States
| | - Benjamin F Cravatt
- Department of Chemical Physiology, The Skaggs Institute for Chemical Biology, The Scripps Research Institute , La Jolla, California 92037, United States
| |
Collapse
|
23
|
Feeding-fasting dependent recruitment of membrane microdomain proteins to lipid droplets purified from the liver. PLoS One 2017; 12:e0183022. [PMID: 28800633 PMCID: PMC5553754 DOI: 10.1371/journal.pone.0183022] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 07/30/2017] [Indexed: 01/23/2023] Open
Abstract
Lipid droplets (LDs) are cellular stores of neutral fat that facilitate lipid and protein trafficking in response to metabolic cues. Unlike other vesicles, the phospholipid membrane on the LD is a monolayer. Interestingly, this monolayer membrane has free cholesterol, and may therefore contain lipid microdomains that serve as a platform for assembling proteins involved in signal transduction, cell polarity, pathogen entry etc. In support of this, cell culture studies have detected microdomain-associated "raftophilic" proteins on LDs. However, the physiological significance of this observation has been unclear. Here we show that two proteins (Flotillin-1 and SNAP23) that bind to membrane microdomains associate differently with LDs purified from rat liver depending on the feeding/fasting state of the animal. Flotillin-1 increases on LDs in the fed state, possibly because LDs interact with the endoplasmic reticulum (ER), facilitating supply of flotillin-1 from ER to LDs. Interestingly, this increase in flotillin-1 is correlated with an increase in free cholesterol on the LDs in fed state. In opposite behaviour to flotillin-1, SNAP23 increases on LDs in the fasted state and this appears to mediate LD-mitochondria interactions. Such LD-mitochondria interactions may provide fatty acids to mitochondria for promoting beta-oxidation in hepatocytes in response to fasting. Our work brings out physiologically relevant aspects of lipid droplet biology that are different from, and may not be entirely possible to replicate and study in cell culture.
Collapse
|
24
|
Onal G, Kutlu O, Gozuacik D, Dokmeci Emre S. Lipid Droplets in Health and Disease. Lipids Health Dis 2017; 16:128. [PMID: 28662670 PMCID: PMC5492776 DOI: 10.1186/s12944-017-0521-7] [Citation(s) in RCA: 155] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 06/16/2017] [Indexed: 12/16/2022] Open
Abstract
Lipids are essential building blocks synthesized by complex molecular pathways and deposited as lipid droplets (LDs) in cells. LDs are evolutionary conserved organelles found in almost all organisms, from bacteria to mammals. They are composed of a hydrophobic neutral lipid core surrounding by a phospholipid monolayer membrane with various decorating proteins. Degradation of LDs provide metabolic energy for divergent cellular processes such as membrane synthesis and molecular signaling. Lipolysis and autophagy are two main catabolic pathways of LDs, which regulate lipid metabolism and, thereby, closely engaged in many pathological conditons. In this review, we first provide an overview of the current knowledge on the structural properties and the biogenesis of LDs. We further focus on the recent findings of their catabolic mechanism by lipolysis and autophagy as well as their connection ragarding the regulation and function. Moreover, we discuss the relevance of LDs and their catabolism-dependent pathophysiological conditions.
Collapse
Affiliation(s)
- Gizem Onal
- Department of Medical Biology, Hacettepe University, 06100, Ankara, Turkey
| | - Ozlem Kutlu
- Nanotechnology Research and Application Center (SUNUM) & Center of Excellence for Functional Surfaces and Interfaces for Nano Diagnostics (EFSUN), Sabanci University, 34956, Istanbul, Turkey
| | - Devrim Gozuacik
- Molecular Biology, Genetics, and Bioengineering Program & Center of Excellence for Functional Surfaces and Interfaces for Nano Diagnostics (EFSUN), Sabanci University, 34956, Istanbul, Turkey
| | - Serap Dokmeci Emre
- Department of Medical Biology, Hacettepe University, 06100, Ankara, Turkey.
| |
Collapse
|
25
|
Structure-function analysis of human stomatin: A mutation study. PLoS One 2017; 12:e0178646. [PMID: 28575093 PMCID: PMC5456319 DOI: 10.1371/journal.pone.0178646] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 05/16/2017] [Indexed: 12/27/2022] Open
Abstract
Stomatin is an ancient, widely expressed, oligomeric, monotopic membrane protein that is associated with cholesterol-rich membranes/lipid rafts. It is part of the SPFH superfamily including stomatin-like proteins, prohibitins, flotillin/reggie proteins, bacterial HflK/C proteins and erlins. Biochemical features such as palmitoylation, oligomerization, and hydrophobic “hairpin” structure show similarity to caveolins and other integral scaffolding proteins. Recent structure analyses of the conserved PHB/SPFH domain revealed amino acid residues and subdomains that appear essential for the structure and function of stomatin. To test the significance of these residues and domains, we exchanged or deleted them, expressed respective GFP-tagged mutants, and studied their subcellular localization, molecular dynamics and biochemical properties. We show that stomatin is a cholesterol binding protein and that at least two domains are important for the association with cholesterol-rich membranes. The conserved, prominent coiled-coil domain is necessary for oligomerization, while association with cholesterol-rich membranes is also involved in oligomer formation. FRAP analyses indicate that the C-terminus is the dominant entity for lateral mobility and binding site for the cortical actin cytoskeleton.
Collapse
|
26
|
Hung YH, Carreiro AL, Buhman KK. Dgat1 and Dgat2 regulate enterocyte triacylglycerol distribution and alter proteins associated with cytoplasmic lipid droplets in response to dietary fat. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1862:600-614. [PMID: 28249764 PMCID: PMC5503214 DOI: 10.1016/j.bbalip.2017.02.014] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 01/31/2017] [Accepted: 02/24/2017] [Indexed: 12/16/2022]
Abstract
Enterocytes, the absorptive cells of the small intestine, mediate efficient absorption of dietary fat (triacylglycerol, TAG). The digestive products of dietary fat are taken up by enterocytes, re-esterified into TAG, and packaged on chylomicrons (CMs) for secretion into blood or temporarily stored within cytoplasmic lipid droplets (CLDs). Altered enterocyte TAG distribution impacts susceptibility to high fat diet associated diseases, but molecular mechanisms directing TAG toward these fates are unclear. Two enzymes, acyl CoA: diacylglycerol acyltransferase 1 (Dgat1) and Dgat2, catalyze the final, committed step of TAG synthesis within enterocytes. Mice with intestine-specific overexpression of Dgat1 (Dgat1Int) or Dgat2 (Dgat2Int), or lack of Dgat1 (Dgat1-/-), were previously found to have altered intestinal TAG secretion and storage. We hypothesized that varying intestinal Dgat1 and Dgat2 levels alters TAG distribution in subcellular pools for CM synthesis as well as the morphology and proteome of CLDs. To test this we used ultrastructural and proteomic methods to investigate intracellular TAG distribution and CLD-associated proteins in enterocytes from Dgat1Int, Dgat2Int, and Dgat1-/- mice 2h after a 200μl oral olive oil gavage. We found that varying levels of intestinal Dgat1 and Dgat2 altered TAG pools involved in CM assembly and secretion, the number or size of CLDs present in enterocytes, and the enterocyte CLD proteome. Overall, these results support a model where Dgat1 and Dgat2 function coordinately to regulate the process of dietary fat absorption by preferentially synthesizing TAG for incorporation into distinct subcellular TAG pools in enterocytes.
Collapse
Affiliation(s)
- Yu-Han Hung
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907, USA
| | - Alicia L Carreiro
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907, USA
| | - Kimberly K Buhman
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907, USA.
| |
Collapse
|
27
|
Meyers A, Chourey K, Weiskittel TM, Pfiffner S, Dunlap JR, Hettich RL, Dalhaimer P. The protein and neutral lipid composition of lipid droplets isolated from the fission yeast, Schizosaccharomyces pombe. J Microbiol 2017; 55:112-122. [PMID: 28120187 DOI: 10.1007/s12275-017-6205-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 10/04/2016] [Accepted: 10/20/2016] [Indexed: 12/17/2022]
Abstract
Lipid droplets consist of a core of neutral lipids surrounded by a phospholipid monolayer with bound proteins. Much of the information on lipid droplet function comes from proteomic and lipodomic studies that identify the components of droplets isolated from organisms throughout the phylogenetic tree. Here, we add to that important inventory by reporting lipid droplet factors from the fission yeast, Schizosaccharomyces pombe. Unique to this study was the fact that cells were cultured in three different environments: 1) late log growth phase in glucose-based media, 2) stationary phase in glucosebased media, and 3) late log growth phase in media containing oleic acid. We confirmed colocalization of major factors with lipid droplets using live-cell fluorescent microscopy. We also analyzed droplets from each of the three conditions for sterol ester (SE) and triacylglycerol (TAG) content, along with their respective fatty acid compositions. We identified a previously undiscovered lipid droplet protein, Vip1p, which affects droplet size distribution. The results provide further insight into the workings of these ubiquitous organelles.
Collapse
Affiliation(s)
- Alex Meyers
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN, 37996-2200, USA
| | - Karuna Chourey
- Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Taylor M Weiskittel
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN, 37996-2200, USA
| | - Susan Pfiffner
- Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, 37996, USA
| | - John R Dunlap
- Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, 37996, USA.,Advanced Microscopy and Imaging Center, University of Tennessee, Knoxville, TN, 37996, USA
| | | | - Paul Dalhaimer
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN, 37996-2200, USA. .,Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, 37996, USA. .,Institute of Biomedical Engineering, University of Tennessee, Knoxville, TN, 37996, USA.
| |
Collapse
|
28
|
Lee JH, Hsieh CF, Liu HW, Chen CY, Wu SC, Chen TW, Hsu CS, Liao YH, Yang CY, Shyu JF, Fischer WB, Lin CH. Lipid raft-associated stomatin enhances cell fusion. FASEB J 2016; 31:47-59. [PMID: 27663861 DOI: 10.1096/fj.201600643r] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 09/07/2016] [Indexed: 01/25/2023]
Abstract
Membrane fusions that occur during vesicle transport, virus infection, and tissue development, involve receptors that mediate membrane contact and initiate fusion and effectors that execute membrane reorganization and fusion pore formation. Some of these fusogenic receptors/effectors are preferentially recruited to lipid raft membrane microdomains. Therefore, major constituents of lipid rafts, such as stomatin, may be involved in the regulation of cell-cell fusion. Stomatin produced in cells can be released to the extracellular environment, either through protein refolding to pass across lipid bilayer or through exosome trafficking. We report that cells expressing more stomatin or exposed to exogenous stomatin are more prone to undergoing cell fusion. During osteoclastogenesis, depletion of stomatin inhibited cell fusion but had little effect on tartrate-resistant acid phosphatase production. Moreover, in stomatin transgenic mice, increased cell fusion leading to enhanced bone resorption and subsequent osteoporosis were observed. With its unique molecular topology, stomatin forms molecular assembly within lipid rafts or on the appositional plasma membranes, and promotes membrane fusion by modulating fusogenic protein engagement.-Lee, J.-H., Hsieh, C.-F., Liu, H.-W., Chen, C.-Y., Wu, S.-C., Chen, T.-W., Hsu, C.-S., Liao, Y.-H., Yang, C.-Y., Shyu, J.-F., Fischer, W. B., Lin, C.-H. Lipid raft-associated stomatin enhances cell fusion.
Collapse
Affiliation(s)
- Jui-Hao Lee
- Taiwan International Graduate Program in Molecular Medicine, National Yang-Ming University and Academia Sinica, Taipei, Taiwan.,Institute of Microbiology and Immunology.,Institute of Biochemistry and Molecular Biology
| | | | - Hong-Wen Liu
- Institute of Microbiology and Immunology.,Chong Hin Loon Memorial Cancer and Biotherapy Research Center, and
| | - Chin-Yau Chen
- Institute of Microbiology and Immunology.,Department of Surgery, I-Lan, Taiwan
| | - Shao-Chin Wu
- Institute of Biophotonics, National Yang-Ming University, Taipei, Taiwan
| | - Tung-Wei Chen
- Institute of Biophotonics, National Yang-Ming University, Taipei, Taiwan
| | | | - Yu-Hsiu Liao
- Institute of Biophotonics, National Yang-Ming University, Taipei, Taiwan
| | - Chih-Yung Yang
- Department of Education and Research, Taipei City Hospital, Taipei, Taiwan; and
| | - Jia-Fwu Shyu
- Department of Biology and Anatomy, National Defense Medical Center, Taipei, Taiwan
| | - Wolfgang B Fischer
- Institute of Biophotonics, National Yang-Ming University, Taipei, Taiwan
| | - Chi-Hung Lin
- Taiwan International Graduate Program in Molecular Medicine, National Yang-Ming University and Academia Sinica, Taipei, Taiwan; .,Institute of Microbiology and Immunology.,Institute of Biophotonics, National Yang-Ming University, Taipei, Taiwan
| |
Collapse
|
29
|
Zhang S, Wang Y, Cui L, Deng Y, Xu S, Yu J, Cichello S, Serrero G, Ying Y, Liu P. Morphologically and Functionally Distinct Lipid Droplet Subpopulations. Sci Rep 2016; 6:29539. [PMID: 27386790 PMCID: PMC4937419 DOI: 10.1038/srep29539] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 06/20/2016] [Indexed: 12/12/2022] Open
Abstract
Lipid droplet (LD), a multi-functional organelle, is often found to associate with other cellular membranous structures and vary in size in a given cell, which may be related to their functional diversity. Here we established a method to separate LD subpopulations from isolated CHO K2 LDs into three different size categories. The subpopulation with smallest LDs was nearly free of ER and other membranous structures while those with larger LDs contained intact ER. These distinct subpopulations of LDs differed in their protein composition and ability to recruit proteins. This method was also applicable to LDs obtained from other sources, such as Huh7 cells, mouse liver and brown adipose tissue, et al. We developed an in vitro assay requiring only isolated LDs, Coenzyme A, and ATP to drive lipid synthesis. The LD subpopulation nearly depleted of ER was able to incorporate fatty acids into triacylglycerol and phospholipids. Together, our data demonstrate that LDs in a given cell are heterogeneous in size and function, and suggest that LDs are one of cellular lipid synthetic organelles.
Collapse
Affiliation(s)
- Shuyan Zhang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Yang Wang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Liujuan Cui
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.,School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Yaqin Deng
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shimeng Xu
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jinhai Yu
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Simon Cichello
- School of Life Sciences, La Trobe University, Melbourne Victoria 3086, Australia
| | | | - Yunshu Ying
- University of Texas Southwestern Medical Center, Dallas 75390, USA
| | - Pingsheng Liu
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| |
Collapse
|
30
|
Chen Y, Frost S, Byrne JA. Dropping in on the lipid droplet- tumor protein D52 (TPD52) as a new regulator and resident protein. Adipocyte 2016; 5:326-32. [PMID: 27617178 DOI: 10.1080/21623945.2016.1148835] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 01/15/2016] [Accepted: 01/20/2016] [Indexed: 02/06/2023] Open
Abstract
Lipid droplets are essential for both the storage and retrieval of excess cellular nutrients, and their biology is regulated by a diverse range of cellular proteins, some of which function at the lipid droplet. Numerous studies have characterized lipid droplet proteomes in different organisms and cell types, and RNAi whole genome screening studies have examined the genetic regulation of lipid storage in C. elegans and D. melanogaster. While tumor protein D52 (TPD52) did not emerge from earlier studies as a strong candidate, exogenous expression of human TPD52 in cultured cells resulted in significantly increased numbers of lipid droplets, and oleic acid supplementation increased TPD52 detection at both lipid droplets and the Golgi apparatus. These results suggest that direct testing of proteins that are infrequently but recurrently identified in proteomic and RNAi screening studies may identify novel lipid droplet regulators. While the analysis of these possibly lower-abundance or itinerant lipid droplet proteins may be more technically challenging, such proteins could facilitate a more detailed interrogation of emerging aspects of lipid droplet biology.
Collapse
|
31
|
Chen TW, Liu HW, Liou YJ, Lee JH, Lin CH. Over-expression of stomatin causes syncytium formation in nonfusogenic JEG-3 choriocarcinoma placental cells. Cell Biol Int 2016; 40:926-33. [PMID: 27306251 DOI: 10.1002/cbin.10636] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 06/11/2016] [Indexed: 11/09/2022]
Abstract
Placental trophoblast differentiation involves the continuous fusion of mononuclear cytotrophoblasts. However, except for syncytin, little is known about the detailed mechanisms underlying trophoblast fusion. A previous study indicated that lipid rafts play an important role in HTLV-1 syncytium formation. To identify proteins that may be involved in placental trophoblast differentiation, we examined stomatin, an important lipid-raft protein that localizes to detergent-resistant membrane domains. The syncytium and human chorionic gonadotropin (β-hCG; a marker of placental trophoblast differentiation) were visualized by immunofluorescence staining. We found that overexpression of stomatin in the nonfusogenic JEG-3 cell line caused syncytium formation and increased the fusion index of cells. Treating these cells with N(6) ,2'-O-dibutyryladenosine 3',5'-cyclic monophosphate further increased cell fusion by stomatin. β-hCG was found in a few JEG-3 cells overexpressing stomatin at 48 h, and its levels increased dramatically at 72 h along with the formation of the multinuclear syncytium. RNA interference was used to decrease stomatin expression in BeWo cells, a fusogenic human choriocarcinoma cell line. After knockdown for 72 h, stomatin levels decreased by almost 95%. The fusion indexes of control and stomatin-knockdown cells at 72 h were 9.4 and 6.5%, respectively. Our data indicated that stomatin could trigger syncytium formation and upregulate β-hCG for cell fusion in nonfusogenic JEG-3 cells. Downregulation of stomatin slightly inhibited the fusion index of fusogenic BeWo cells. Thus, these data suggested that stomatin plays an important role in trophoblast differentiation.
Collapse
Affiliation(s)
- Tung-Wei Chen
- Institute of Biophotonics, National Yang-Ming University, No. 155, Sec. 2, Linong, Street, Taipei, Taiwan, 112,, ROC
| | - Hong-Wen Liu
- Institute of Microbiology and Immunology, National Yang-Ming University, No. 155, Sec. 2, Linong Street, Taipei, Taiwan, 112,, ROC
| | - Yi-Jia Liou
- Institute of Microbiology and Immunology, National Yang-Ming University, No. 155, Sec. 2, Linong Street, Taipei, Taiwan, 112,, ROC
| | - Jui-Hao Lee
- Institute of Microbiology and Immunology, National Yang-Ming University, No. 155, Sec. 2, Linong Street, Taipei, Taiwan, 112,, ROC.,Institute of Biochemistry, National Yang-Ming University, No. 155, Sec. 2, Linong Street, Taipei, Taiwan, 112,, ROC.,Taiwan International Graduate Program in Molecular Medicine, National Yang-Ming University and Academia Sinica, No. 155, Sec. 2, Linong Street, Taipei, Taiwan, 112,, ROC
| | - Chi-Hung Lin
- Institute of Biophotonics, National Yang-Ming University, No. 155, Sec. 2, Linong, Street, Taipei, Taiwan, 112,, ROC.,Institute of Microbiology and Immunology, National Yang-Ming University, No. 155, Sec. 2, Linong Street, Taipei, Taiwan, 112,, ROC.,Department of Health, New Taipei City Government, Taipei, Taiwan
| |
Collapse
|
32
|
Boldt K, van Reeuwijk J, Lu Q, Koutroumpas K, Nguyen TMT, Texier Y, van Beersum SEC, Horn N, Willer JR, Mans DA, Dougherty G, Lamers IJC, Coene KLM, Arts HH, Betts MJ, Beyer T, Bolat E, Gloeckner CJ, Haidari K, Hetterschijt L, Iaconis D, Jenkins D, Klose F, Knapp B, Latour B, Letteboer SJF, Marcelis CL, Mitic D, Morleo M, Oud MM, Riemersma M, Rix S, Terhal PA, Toedt G, van Dam TJP, de Vrieze E, Wissinger Y, Wu KM, Apic G, Beales PL, Blacque OE, Gibson TJ, Huynen MA, Katsanis N, Kremer H, Omran H, van Wijk E, Wolfrum U, Kepes F, Davis EE, Franco B, Giles RH, Ueffing M, Russell RB, Roepman R. An organelle-specific protein landscape identifies novel diseases and molecular mechanisms. Nat Commun 2016; 7:11491. [PMID: 27173435 PMCID: PMC4869170 DOI: 10.1038/ncomms11491] [Citation(s) in RCA: 178] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 04/01/2016] [Indexed: 01/12/2023] Open
Abstract
Cellular organelles provide opportunities to relate biological mechanisms to disease. Here we use affinity proteomics, genetics and cell biology to interrogate cilia: poorly understood organelles, where defects cause genetic diseases. Two hundred and seventeen tagged human ciliary proteins create a final landscape of 1,319 proteins, 4,905 interactions and 52 complexes. Reverse tagging, repetition of purifications and statistical analyses, produce a high-resolution network that reveals organelle-specific interactions and complexes not apparent in larger studies, and links vesicle transport, the cytoskeleton, signalling and ubiquitination to ciliary signalling and proteostasis. We observe sub-complexes in exocyst and intraflagellar transport complexes, which we validate biochemically, and by probing structurally predicted, disruptive, genetic variants from ciliary disease patients. The landscape suggests other genetic diseases could be ciliary including 3M syndrome. We show that 3M genes are involved in ciliogenesis, and that patient fibroblasts lack cilia. Overall, this organelle-specific targeting strategy shows considerable promise for Systems Medicine. Mutations in proteins that localize to primary cilia cause devastating diseases, yet the primary cilium is a poorly understood organelle. Here the authors use interaction proteomics to identify a network of human ciliary proteins that provides new insights into several biological processes and diseases.
Collapse
Affiliation(s)
- Karsten Boldt
- Medical Proteome Center, Institute for Ophthalmic Research, University of Tuebingen, 72074 Tuebingen, Germany
| | - Jeroen van Reeuwijk
- Department of Human Genetics and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
| | - Qianhao Lu
- Biochemie Zentrum Heidelberg (BZH), University of Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.,Cell Networks, Bioquant, Ruprecht-Karl University of Heidelberg, Im Neuenheimer Feld 267, 69120 Heidelberg, Germany
| | - Konstantinos Koutroumpas
- Institute of Systems and Synthetic Biology, Genopole, CNRS, Université d'Evry, 91030 Evry, France
| | - Thanh-Minh T Nguyen
- Department of Human Genetics and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
| | - Yves Texier
- Medical Proteome Center, Institute for Ophthalmic Research, University of Tuebingen, 72074 Tuebingen, Germany.,Department of Molecular Epigenetics, Helmholtz Center Munich, Center for Integrated Protein Science, 81377 Munich, Germany
| | - Sylvia E C van Beersum
- Department of Human Genetics and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
| | - Nicola Horn
- Medical Proteome Center, Institute for Ophthalmic Research, University of Tuebingen, 72074 Tuebingen, Germany
| | - Jason R Willer
- Center for Human Disease Modeling, Duke University, Durham, North Carolina 27701, USA
| | - Dorus A Mans
- Department of Human Genetics and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
| | - Gerard Dougherty
- Department of General Pediatrics, University Children's Hospital Muenster, 48149 Muenster, Germany
| | - Ideke J C Lamers
- Department of Human Genetics and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
| | - Karlien L M Coene
- Department of Human Genetics and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
| | - Heleen H Arts
- Department of Human Genetics and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
| | - Matthew J Betts
- Biochemie Zentrum Heidelberg (BZH), University of Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.,Cell Networks, Bioquant, Ruprecht-Karl University of Heidelberg, Im Neuenheimer Feld 267, 69120 Heidelberg, Germany
| | - Tina Beyer
- Medical Proteome Center, Institute for Ophthalmic Research, University of Tuebingen, 72074 Tuebingen, Germany
| | - Emine Bolat
- Department of Human Genetics and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
| | - Christian Johannes Gloeckner
- German Center for Neurodegenerative Diseases (DZNE) within the Helmholz Association, Otfried-Müller Strasse 23, 72076 Tuebingen, Germany
| | - Khatera Haidari
- Department of Nephrology and Hypertension, Regenerative Medicine Center, University Medical Center Utrecht, 3584 CT Utrecht, The Netherlands
| | - Lisette Hetterschijt
- Department of Otorhinolaryngology and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
| | - Daniela Iaconis
- Telethon Institute of Genetics and Medicine, TIGEM 80078, Italy
| | - Dagan Jenkins
- Molecular Medicine Unit and Birth Defects Research Centre, UCL Institute of Child Health, London, WC1N 1EH, UK
| | - Franziska Klose
- Medical Proteome Center, Institute for Ophthalmic Research, University of Tuebingen, 72074 Tuebingen, Germany
| | - Barbara Knapp
- Cell and Matrix Biology, Inst. of Zoology, Johannes Gutenberg University of Mainz, 55122 Mainz, Germany
| | - Brooke Latour
- Department of Human Genetics and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
| | - Stef J F Letteboer
- Department of Human Genetics and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
| | - Carlo L Marcelis
- Department of Human Genetics and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
| | - Dragana Mitic
- Cambridge Cell Networks Ltd, St John's Innovation Centre, Cowley Road, Cambridge, CB4 0WS, UK
| | - Manuela Morleo
- Telethon Institute of Genetics and Medicine, TIGEM 80078, Italy.,Department of Translational Medicine Federico II University, 80131 Naples, Italy
| | - Machteld M Oud
- Department of Human Genetics and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
| | - Moniek Riemersma
- Department of Human Genetics and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
| | - Susan Rix
- Molecular Medicine Unit and Birth Defects Research Centre, UCL Institute of Child Health, London, WC1N 1EH, UK
| | - Paulien A Terhal
- Department of Genetics, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands
| | - Grischa Toedt
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Teunis J P van Dam
- Centre for Molecular and Biomolecular Informatics and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Geert Grooteplein Zuid 26-28, 6525 GA Nijmegen, The Netherlands
| | - Erik de Vrieze
- Department of Otorhinolaryngology and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
| | - Yasmin Wissinger
- Medical Proteome Center, Institute for Ophthalmic Research, University of Tuebingen, 72074 Tuebingen, Germany
| | - Ka Man Wu
- Department of Human Genetics and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
| | - Gordana Apic
- Cambridge Cell Networks Ltd, St John's Innovation Centre, Cowley Road, Cambridge, CB4 0WS, UK
| | - Philip L Beales
- Molecular Medicine Unit and Birth Defects Research Centre, UCL Institute of Child Health, London, WC1N 1EH, UK
| | - Oliver E Blacque
- School of Biomolecular &Biomed Science, Conway Institute, University College Dublin, Dublin 4, Ireland
| | - Toby J Gibson
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Martijn A Huynen
- Centre for Molecular and Biomolecular Informatics and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Geert Grooteplein Zuid 26-28, 6525 GA Nijmegen, The Netherlands
| | - Nicholas Katsanis
- Center for Human Disease Modeling, Duke University, Durham, North Carolina 27701, USA
| | - Hannie Kremer
- Department of Otorhinolaryngology and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
| | - Heymut Omran
- Department of General Pediatrics, University Children's Hospital Muenster, 48149 Muenster, Germany
| | - Erwin van Wijk
- Department of Otorhinolaryngology and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
| | - Uwe Wolfrum
- Cell and Matrix Biology, Inst. of Zoology, Johannes Gutenberg University of Mainz, 55122 Mainz, Germany
| | - François Kepes
- Institute of Systems and Synthetic Biology, Genopole, CNRS, Université d'Evry, 91030 Evry, France
| | - Erica E Davis
- Center for Human Disease Modeling, Duke University, Durham, North Carolina 27701, USA
| | - Brunella Franco
- Telethon Institute of Genetics and Medicine, TIGEM 80078, Italy.,Department of Translational Medicine Federico II University, 80131 Naples, Italy
| | - Rachel H Giles
- Department of Nephrology and Hypertension, Regenerative Medicine Center, University Medical Center Utrecht, 3584 CT Utrecht, The Netherlands
| | - Marius Ueffing
- Medical Proteome Center, Institute for Ophthalmic Research, University of Tuebingen, 72074 Tuebingen, Germany
| | - Robert B Russell
- Biochemie Zentrum Heidelberg (BZH), University of Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.,Cell Networks, Bioquant, Ruprecht-Karl University of Heidelberg, Im Neuenheimer Feld 267, 69120 Heidelberg, Germany
| | - Ronald Roepman
- Department of Human Genetics and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525 GA Nijmegen, The Netherlands
| | | |
Collapse
|
33
|
Lipid droplet-associated proteins in atherosclerosis (Review). Mol Med Rep 2016; 13:4527-34. [PMID: 27082419 PMCID: PMC4878557 DOI: 10.3892/mmr.2016.5099] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 01/29/2016] [Indexed: 01/01/2023] Open
Abstract
Accumulation of atherosclerotic plaques in arterial walls leads to major cardiovascular diseases and stroke. Macrophages/foam cells are central components of atherosclerotic plaques, which populate the arterial wall in order to remove harmful modified low‑density lipoprotein (LDL) particles, resulting in the accumulation of lipids, mostly LDL‑derived cholesterol ester, in cytosolic lipid droplets (LDs). At present, LDs are recognized as dynamic organelles that govern cellular metabolic processes. LDs consist of an inner core of neutral lipids surrounded by a monolayer of phospholipids and free cholesterol, and contain LD‑associated proteins (LDAPs) that regulate LD functions. Foam cells are characterized by an aberrant accumulation of cytosolic LDs, and are considered a hallmark of atherosclerotic lesions through all stages of development. Previous studies have investigated the mechanisms underlying foam cell formation, aiming to discover therapeutic strategies that target foam cells and intervene against atherosclerosis. It is well established that LDAPs have a major role in the pathogenesis of metabolic diseases caused by dysfunction of lipid metabolism, and several studies have linked LDAPs to the development of atherosclerosis. In this review, several foam cell‑targeting pathways have been described, with an emphasis on the role of LDAPs in cholesterol mobilization from macrophages. In addition, the potential of LDAPs as therapeutic targets to prevent the progression and/or facilitate the regression of the disease has been discussed.
Collapse
|
34
|
Wang Y, Zhou XM, Ma X, Du Y, Zheng L, Liu P. Construction of Nanodroplet/Adiposome and Artificial Lipid Droplets. ACS NANO 2016; 10:3312-3322. [PMID: 26910792 DOI: 10.1021/acsnano.5b06852] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The lipid droplet (LD) is a cellular organelle that consists of a neutral lipid core with a monolayer-phospholipid membrane and associated proteins. Recent LD studies demonstrate its importance in metabolic diseases and biofuel development. However, the mechanisms governing its formation and dynamics remain elusive. Therefore, we developed an in vitro system to facilitate the elucidation of these mechanisms. We generated sphere-shaped structures with a neutral lipid core and a monolayer-phospholipid membrane by mechanically mixing neutral lipids and phospholipids followed by a two-step purification. We named the nanodroplet "adiposome". We then recruited LD structure-like/resident proteins to the adiposome, including the bacterial MLDS, Caenorhabditis elegans MDT-28/PLIN-1, or mammalian perilipin-2. In addition, adipose triglyceride lipase (ATGL) and apolipoprotein A1 (apo A-I) were recruited to adiposome. We termed the functional protein-coated adiposomes, Artificial Lipid Droplets (ALDs). With this experimental system, different proteins can be recruited to build ALDs for some biological goals and potential usage in drug delivery.
Collapse
Affiliation(s)
- Yang Wang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences , Beijing 100101, China
| | - Xiao-Ming Zhou
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences , Beijing 100101, China
| | - Xuejing Ma
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences , Beijing 100101, China
- University of Chinese Academy of Sciences , Beijing 100049, China
| | - Yalan Du
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences , Beijing 100101, China
- Department of Histology and Embryology, University of South China , Hengyang, Hunan 421001, China
| | - Lemin Zheng
- The Institute of Cardiovascular Sciences and Institute of Systems Biomedicine, School of Basic Medical Sciences, and Key Laboratory of Molecular Cardiovascular Sciences of Ministry of Education, Peking University Health Science Center , Beijing 100191, China
| | - Pingsheng Liu
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences , Beijing 100101, China
- University of Chinese Academy of Sciences , Beijing 100049, China
| |
Collapse
|
35
|
Yan G, Li B, Xin X, Xu M, Ji G, Yu H. MicroRNA-34a Promotes Hepatic Stellate Cell Activation via Targeting ACSL1. Med Sci Monit 2015; 21:3008-15. [PMID: 26437572 PMCID: PMC4601392 DOI: 10.12659/msm.894000] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 04/13/2015] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND The incidence of liver fibrosis remains high due to the lack of effective therapies. Our previous work found that microRNA (miR)-34a expression was increased, while acy1-CoA synthetase long-chain family member1 (ACSL1) was decreased, in a dimethylnitrosamine (DNS)-induced hepatic fibrosis rat model. We hypothesized that miR-34a may play a role in the process of hepatic fibrosis by targeting ACSL1. MATERIAL AND METHODS From days 2 to 14, cultured primary hepatic stellate cells (HSCs) underwent cell morphology, immunocytochemical staining, and quantitative reverse transcription PCR (RT-qPCR) for alpha smooth muscle actin (a-SMA), desmin, rno-miR-34a, and ACSL1 expression. Wild-type and mutant luciferase reporter plasmids were constructed according to the predicted miR-34a binding site on the 3'-untranslated region (UTR) of the ACSL1 mRNA and then transfected into HEK293 cells. rno-miR-34a was silenced in HSCs to confirm that rno-miR-34a negatively regulates ACSL1 expression. mRNA and protein expression of α-SMA, type I collagen, and desmin were assayed in miR-34a-silenced HSCs. RESULTS HSCs were deemed quiescent during the first 3 days and activated after 10 days. rno-miR-34a expression increased, and ACSL1 expression decreased, from day 2 to 7 to 14. rno-miR-34a was shown to specifically bind to the 3'-UTR of ACSL1. miR-34a-silenced HSCs showed higher ACSL1and lower α-SMA, type I collagen, and desmin expression than that of matching negative controls and non-transfected cells. CONCLUSIONS miR-34a appears to play an important role in the process of liver fibrosis by targeting ACSL1 and may show promise as a therapeutic molecular target for hepatic fibrosis.
Collapse
Affiliation(s)
- Gangli Yan
- Department of Pathology, Changzheng Hospital, The Second Military Medical University, Shanghai, P.R. China
- Department of Neurology, The No. 161 People’s Liberation Army (PLA) Hospital, Wuhan, Hubei, P.R. China
| | - Binbin Li
- Department of Pathology, Changzheng Hospital, The Second Military Medical University, Shanghai, P.R. China
| | - Xuan Xin
- Department of Pathology, Changzheng Hospital, The Second Military Medical University, Shanghai, P.R. China
- Department of Pathology, The General Hospital of the Jinan Military Command, Jinan, Shandong, P.R. China
| | - Midie Xu
- Department of Pathology, Changzheng Hospital, The Second Military Medical University, Shanghai, P.R. China
| | - Guoqing Ji
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai, P.R. China
- Institutes of Biomedical Sciences, Fudan University, Shanghai, P.R. China
| | - Hongyu Yu
- Department of Pathology, Changzheng Hospital, The Second Military Medical University, Shanghai, P.R. China
| |
Collapse
|
36
|
Lipid droplets and associated proteins in the skin: basic research and clinical perspectives. Arch Dermatol Res 2015; 308:1-6. [PMID: 26437897 DOI: 10.1007/s00403-015-1599-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 09/19/2015] [Accepted: 09/21/2015] [Indexed: 10/23/2022]
Abstract
Lipid droplets (LDs), the major organelles handling fat storage, comprise a hydrophobic neutral lipid core surrounded by a phospholipid monolayer embedded with a protein miscellany. Although lipids of the stratum corneum are essential for the skin barrier, and progressive lipid accumulation culminating in cell disruption is the hallmark of sebaceous differentiation, only a few studies touched on skin LD and associated proteins so far. Here, after briefly introducing the basic facts about LD and associated proteins, we discuss how forthcoming studies may unveil novel players in skin lipid metabolism and candidate target proteins for treating skin diseases.
Collapse
|
37
|
Khan SA, Wollaston-Hayden EE, Markowski TW, Higgins L, Mashek DG. Quantitative analysis of the murine lipid droplet-associated proteome during diet-induced hepatic steatosis. J Lipid Res 2015; 56:2260-72. [PMID: 26416795 DOI: 10.1194/jlr.m056812] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Indexed: 01/17/2023] Open
Abstract
Hepatic steatosis is characterized by the accumulation of lipid droplets (LDs), which are composed of a neutral lipid core surrounded by a phospholipid monolayer embedded with many proteins. Although the LD-associated proteome has been investigated in multiple tissues and organisms, the dynamic changes in the murine LD-associated proteome in response to obesity and hepatic steatosis have not been studied. We characterized the hepatic LD-associated proteome of C57BL/6J male mouse livers following high-fat feeding using isobaric tagging for relative and absolute quantification. Of the 1,520 proteins identified with a 5% local false discovery rate, we report a total of 48 proteins that were increased and 52 proteins that were decreased on LDs in response to high-fat feeding. Most notably, ribosomal and endoplasmic reticulum proteins were increased and extracellular and cytosolic proteins were decreased in response to high-fat feeding. Additionally, many proteins involved in fatty acid catabolism or xenobiotic metabolism were enriched in the LD fraction following high-fat feeding. In contrast, proteins involved in glucose metabolism and liver X receptor or retinoid X receptor activation were decreased on LDs of high-fat-fed mice. This study provides insights into unique biological functions of hepatic LDs under normal and steatotic conditions.
Collapse
Affiliation(s)
- Salmaan Ahmed Khan
- Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN 55108
| | | | - Todd W Markowski
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455
| | - LeeAnn Higgins
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455
| | - Douglas G Mashek
- Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN 55108
| |
Collapse
|
38
|
Kamili A, Roslan N, Frost S, Cantrill LC, Wang D, Della-Franca A, Bright RK, Groblewski GE, Straub BK, Hoy AJ, Chen Y, Byrne JA. TPD52 expression increases neutral lipid storage within cultured cells. J Cell Sci 2015; 128:3223-38. [PMID: 26183179 DOI: 10.1242/jcs.167692] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2014] [Accepted: 07/10/2015] [Indexed: 12/12/2022] Open
Abstract
Tumor protein D52 (TPD52) is amplified and/or overexpressed in cancers of diverse cellular origins. Altered cellular metabolism (including lipogenesis) is a hallmark of cancer development, and protein-protein associations between TPD52 and known regulators of lipid storage, and differential TPD52 expression in obese versus non-obese adipose tissue, suggest that TPD52 might regulate cellular lipid metabolism. We found increased lipid droplet numbers in BALB/c 3T3 cell lines stably expressing TPD52, compared with control and TPD52L1-expressing cell lines. TPD52-expressing 3T3 cells showed increased fatty acid storage in triglyceride (from both de novo synthesis and uptake) and formed greater numbers of lipid droplets upon oleic acid supplementation than control cells. TPD52 colocalised with Golgi, but not endoplasmic reticulum (ER), markers and also showed partial colocalisation with lipid droplets coated with ADRP (also known as PLIN2), with a proportion of TPD52 being detected in the lipid droplet fraction. Direct interactions between ADRP and TPD52, but not TPD52L1, were demonstrated using the yeast two-hybrid system, with ADRP-TPD52 interactions confirmed using GST pulldown assays. Our findings uncover a new isoform-specific role for TPD52 in promoting intracellular lipid storage, which might be relevant to TPD52 overexpression in cancer.
Collapse
Affiliation(s)
- Alvin Kamili
- Molecular Oncology Laboratory, Children's Cancer Research Unit, Kids Research Institute, The Children's Hospital at Westmead, Westmead, New South Wales 2145, Australia
| | - Nuruliza Roslan
- Molecular Oncology Laboratory, Children's Cancer Research Unit, Kids Research Institute, The Children's Hospital at Westmead, Westmead, New South Wales 2145, Australia Discipline of Paediatrics and Child Health, University of Sydney, The Children's Hospital at Westmead, Westmead, New South Wales 2145, Australia
| | - Sarah Frost
- Molecular Oncology Laboratory, Children's Cancer Research Unit, Kids Research Institute, The Children's Hospital at Westmead, Westmead, New South Wales 2145, Australia Discipline of Paediatrics and Child Health, University of Sydney, The Children's Hospital at Westmead, Westmead, New South Wales 2145, Australia
| | - Laurence C Cantrill
- Discipline of Paediatrics and Child Health, University of Sydney, The Children's Hospital at Westmead, Westmead, New South Wales 2145, Australia Kids Research Institute Microscope Facility, The Children's Hospital at Westmead, Westmead, New South Wales 2145, Australia
| | - Dongwei Wang
- Kids Research Institute Microscope Facility, The Children's Hospital at Westmead, Westmead, New South Wales 2145, Australia
| | - Austin Della-Franca
- Molecular Oncology Laboratory, Children's Cancer Research Unit, Kids Research Institute, The Children's Hospital at Westmead, Westmead, New South Wales 2145, Australia Discipline of Paediatrics and Child Health, University of Sydney, The Children's Hospital at Westmead, Westmead, New South Wales 2145, Australia
| | - Robert K Bright
- Department of Immunology and Molecular Microbiology and TTUHSC Cancer Center, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - Guy E Groblewski
- Department of Nutritional Sciences, University of Wisconsin, Madison, WI 53706, USA
| | - Beate K Straub
- Department of General Pathology, Institute of Pathology, Heidelberg 69120, Germany
| | - Andrew J Hoy
- Discipline of Physiology, School of Medical Sciences and Bosch Institute and Boden Institute of Obesity, Nutrition, Exercise and Eating Disorders, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Yuyan Chen
- Molecular Oncology Laboratory, Children's Cancer Research Unit, Kids Research Institute, The Children's Hospital at Westmead, Westmead, New South Wales 2145, Australia Discipline of Paediatrics and Child Health, University of Sydney, The Children's Hospital at Westmead, Westmead, New South Wales 2145, Australia
| | - Jennifer A Byrne
- Molecular Oncology Laboratory, Children's Cancer Research Unit, Kids Research Institute, The Children's Hospital at Westmead, Westmead, New South Wales 2145, Australia Discipline of Paediatrics and Child Health, University of Sydney, The Children's Hospital at Westmead, Westmead, New South Wales 2145, Australia
| |
Collapse
|
39
|
Proteomic analysis of murine testes lipid droplets. Sci Rep 2015; 5:12070. [PMID: 26159641 PMCID: PMC4498221 DOI: 10.1038/srep12070] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 06/10/2015] [Indexed: 01/12/2023] Open
Abstract
Testicular Leydig cells contain abundant cytoplasmic lipid droplets (LDs) as a cholesteryl-ester store for releasing cholesterols as the precursor substrate for testosterone biosynthesis. Here, we identified the protein composition of testicular LDs purified from adult mice by using mass spectrometry and immunodetection. Among 337 proteins identified, 144 were previously detected in LD proteomes; 44 were confirmed by microscopy. Testicular LDs contained multiple Rab GTPases, chaperones, and proteins involved in glucuronidation, ubiquination and transport, many known to modulate LD formation and LD-related cellular functions. In particular, testicular LDs contained many members of both the perilipin family and classical lipase/esterase superfamily assembled predominately in adipocyte LDs. Thus, testicular LDs might be regulated similar to adipocyte LDs. Remarkably, testicular LDs contained a large number of classical enzymes for biosynthesis and metabolism of cholesterol and hormonal steroids, so steroidogenic reactions might occur on testicular LDs or the steroidogenic enzymes and products could be transferred through testicular LDs. These characteristics differ from the LDs in most other types of cells, so testicular LDs could be an active organelle functionally involved in steroidogenesis.
Collapse
|
40
|
Dichlberger A, Schlager S, Kovanen PT, Schneider WJ. Lipid droplets in activated mast cells - a significant source of triglyceride-derived arachidonic acid for eicosanoid production. Eur J Pharmacol 2015; 785:59-69. [PMID: 26164793 DOI: 10.1016/j.ejphar.2015.07.020] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Revised: 05/28/2015] [Accepted: 07/07/2015] [Indexed: 12/17/2022]
Abstract
Mast cells are potent effectors of immune reactions and key players in various inflammatory diseases such as atherosclerosis, asthma, and rheumatoid arthritis. The cellular defense response of mast cells represents a unique and powerful system, where external signals can trigger cell activation resulting in a stimulus-specific and highly coordinated release of a plethora of bioactive mediators. The arsenal of mediators encompasses preformed molecules stored in cytoplasmic secretory granules, as well as newly synthesized proteinaceous and lipid mediators. The release of mediators occurs in strict chronological order and requires proper coordination between the endomembrane system and various enzymatic machineries. For the generation of lipid mediators, cytoplasmic lipid droplets have been shown to function as a major intracellular pool of arachidonic acid, the precursor for eicosanoid biosynthesis. Recent studies have revealed that not only phospholipids in mast cell membranes, but also triglycerides in mast cell lipid droplets are a substrate source for eicosanoid formation. The present review summarizes current knowledge about mast cell lipid droplet biology, and discusses expansions and challenges of traditional mechanistic models for eicosanoid production.
Collapse
Affiliation(s)
- Andrea Dichlberger
- Wihuri Research Institute, Biomedicum Helsinki 1, Haartmaninkatu 8, 00290 Helsinki, Finland; Medical University of Vienna, Max F. Perutz Laboratories, Department of Medical Biochemistry, Dr. Bohrgasse 9/2, 1030 Vienna, Austria.
| | - Stefanie Schlager
- Medical University of Graz, Institute of Molecular Biology and Biochemistry, Harrachgasse 21, 8010 Graz, Austria; Medical University of Vienna, Max F. Perutz Laboratories, Department of Medical Biochemistry, Dr. Bohrgasse 9/2, 1030 Vienna, Austria
| | - Petri T Kovanen
- Wihuri Research Institute, Biomedicum Helsinki 1, Haartmaninkatu 8, 00290 Helsinki, Finland; Medical University of Vienna, Max F. Perutz Laboratories, Department of Medical Biochemistry, Dr. Bohrgasse 9/2, 1030 Vienna, Austria
| | - Wolfgang J Schneider
- Wihuri Research Institute, Biomedicum Helsinki 1, Haartmaninkatu 8, 00290 Helsinki, Finland; Medical University of Graz, Institute of Molecular Biology and Biochemistry, Harrachgasse 21, 8010 Graz, Austria; Medical University of Vienna, Max F. Perutz Laboratories, Department of Medical Biochemistry, Dr. Bohrgasse 9/2, 1030 Vienna, Austria
| |
Collapse
|
41
|
D’Aquila T, Sirohi D, Grabowski JM, Hedrick VE, Paul LN, Greenberg AS, Kuhn RJ, Buhman KK. Characterization of the proteome of cytoplasmic lipid droplets in mouse enterocytes after a dietary fat challenge. PLoS One 2015; 10:e0126823. [PMID: 25992653 PMCID: PMC4436333 DOI: 10.1371/journal.pone.0126823] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 04/08/2015] [Indexed: 01/23/2023] Open
Abstract
Dietary fat absorption by the small intestine is a multistep process that regulates the uptake and delivery of essential nutrients and energy. One step of this process is the temporary storage of dietary fat in cytoplasmic lipid droplets (CLDs). The storage and mobilization of dietary fat is thought to be regulated by proteins that associate with the CLD; however, mechanistic details of this process are currently unknown. In this study we analyzed the proteome of CLDs isolated from enterocytes harvested from the small intestine of mice following a dietary fat challenge. In this analysis we identified 181 proteins associated with the CLD fraction, of which 37 are associated with known lipid related metabolic pathways. We confirmed the localization of several of these proteins on or around the CLD through confocal and electron microscopy, including perilipin 3, apolipoprotein A-IV, and acyl-CoA synthetase long-chain family member 5. The identification of the enterocyte CLD proteome provides new insight into potential regulators of CLD metabolism and the process of dietary fat absorption.
Collapse
Affiliation(s)
- Theresa D’Aquila
- Department of Nutrition Science, Purdue University, West Lafayette, Indiana, United States of America
| | - Devika Sirohi
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
- Bindley Bioscience Center, Purdue University, West Lafayette, Indiana, United States of America
| | - Jeffrey M. Grabowski
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
- Department of Entomology, Purdue University, West Lafayette, Indiana, United States of America
| | - Victoria E. Hedrick
- Bindley Bioscience Center, Purdue University, West Lafayette, Indiana, United States of America
| | - Lake N. Paul
- Bindley Bioscience Center, Purdue University, West Lafayette, Indiana, United States of America
| | - Andrew S. Greenberg
- Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts, United States of America
| | - Richard J. Kuhn
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
- Bindley Bioscience Center, Purdue University, West Lafayette, Indiana, United States of America
| | - Kimberly K. Buhman
- Department of Nutrition Science, Purdue University, West Lafayette, Indiana, United States of America
- * E-mail:
| |
Collapse
|
42
|
Chlamydia trachomatis Infection Leads to Defined Alterations to the Lipid Droplet Proteome in Epithelial Cells. PLoS One 2015; 10:e0124630. [PMID: 25909443 PMCID: PMC4409204 DOI: 10.1371/journal.pone.0124630] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 03/16/2015] [Indexed: 11/19/2022] Open
Abstract
The obligate intracellular bacterium Chlamydia trachomatis is a major human pathogen and a main cause of genital and ocular diseases. During its intracellular cycle, C. trachomatis replicates inside a membrane-bound vacuole termed an “inclusion”. Acquisition of lipids (and other nutrients) from the host cell is a critical step in chlamydial replication. Lipid droplets (LD) are ubiquitous, ER-derived neutral lipid-rich storage organelles surrounded by a phospholipids monolayer and associated proteins. Previous studies have shown that LDs accumulate at the periphery of, and eventually translocate into, the chlamydial inclusion. These observations point out to Chlamydia-mediated manipulation of LDs in infected cells, which may impact the function and thereby the protein composition of these organelles. By means of a label-free quantitative mass spectrometry approach we found that the LD proteome is modified in the context of C. trachomatis infection. We determined that LDs isolated from C. trachomatis-infected cells were enriched in proteins related to lipid metabolism, biosynthesis and LD-specific functions. Interestingly, consistent with the observation that LDs intimately associate with the inclusion, a subset of inclusion membrane proteins co-purified with LD protein extracts. Finally, genetic ablation of LDs negatively affected generation of C. trachomatis infectious progeny, consistent with a role for LD biogenesis in optimal chlamydial growth.
Collapse
|
43
|
Lu J, Boeren S, van Hooijdonk T, Vervoort J, Hettinga K. Effect of the DGAT1 K232A genotype of dairy cows on the milk metabolome and proteome. J Dairy Sci 2015; 98:3460-9. [PMID: 25771043 DOI: 10.3168/jds.2014-8872] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 01/30/2015] [Indexed: 01/14/2023]
Abstract
Diglyceride O-acyltransferase 1 (DGAT1) is the enzyme that catalyzes the synthesis of triglycerides from diglycerides and acyl-coenzyme A. The DGAT1 K232A polymorphism was previously shown to have a significant influence on bovine milk production characteristics (milk yield, protein content, fat content, and fatty acid composition). The mechanism of this influence has, however, not been elucidated. In this study, metabolomics ((1)H-nuclear magnetic resonance) and proteomics (laser chromatography-tandem mass spectrometry) were applied to determine the serum and lipid metabolite composition and milk fat globule membrane proteome of milk samples from cows with the DGAT1 KK and AA genotypes. The milk samples from cows with the DGAT1 KK genotype contained more stomatin, sphingomyelin, choline, and carnitine, and less citrate, creatine or phosphocreatine, glycerol-phosphocholine, mannose-like sugar, acetyl sugar phosphate, uridine diphosphate (UDP)-related sugar, and orotic acid compared with milk samples from cows with the DGAT1 AA genotype. Based on these results, we propose that the differences between the DGAT1 genotypes may be related to stomatin-sphingomyelin lipid rafts as well as structural (cell membrane) differences in epithelial cells of the mammary gland. In conclusion, our study shows that, in addition to previously described changes in triglyceride composition, cows differing in DGAT1 polymorphism differ in their milk proteome and metabolome, which may help in further understanding the effect of the DGAT1 K232A polymorphism on milk production characteristics.
Collapse
Affiliation(s)
- Jing Lu
- Dairy Science and Technology, FQD group, Wageningen University, Bornse Weilanden 9, 6708 WG, Wageningen, the Netherlands; Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA, Wageningen, the Netherlands; Institute of Agro-Products Processing Science and Technology, Chinese Academy of Agricultural Sciences (CAAS), Beijing, China 100193
| | - Sjef Boeren
- Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA, Wageningen, the Netherlands
| | - Toon van Hooijdonk
- Dairy Science and Technology, FQD group, Wageningen University, Bornse Weilanden 9, 6708 WG, Wageningen, the Netherlands
| | - Jacques Vervoort
- Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA, Wageningen, the Netherlands
| | - Kasper Hettinga
- Dairy Science and Technology, FQD group, Wageningen University, Bornse Weilanden 9, 6708 WG, Wageningen, the Netherlands.
| |
Collapse
|
44
|
Gross DA, Silver DL. Cytosolic lipid droplets: from mechanisms of fat storage to disease. Crit Rev Biochem Mol Biol 2015; 49:304-26. [PMID: 25039762 DOI: 10.3109/10409238.2014.931337] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The lipid droplet (LD) is a phylogenetically conserved organelle. In eukaryotes, it is born from the endoplasmic reticulum, but unlike its parent organelle, LDs are the only known cytosolic organelles that are micellar in structure. LDs are implicated in numerous physiological and pathophysiological functions. Many aspects of the LD has captured the attention of diverse scientists alike and has recently led to an explosion in information on the LD biogenesis, expansion and fusion, identification of LD proteomes and diseases associated with LD biology. This review will provide a brief history of this fascinating organelle and provide some contemporary views of unanswered questions in LD biogenesis.
Collapse
Affiliation(s)
- David A Gross
- Program in Cardiovascular & Metabolic Disorders, Duke-NUS Graduate Medical School Singapore , Singapore , and
| | | |
Collapse
|
45
|
Dahlhoff M, Fröhlich T, Arnold GJ, Müller U, Leonhardt H, Zouboulis CC, Schneider MR. Characterization of the sebocyte lipid droplet proteome reveals novel potential regulators of sebaceous lipogenesis. Exp Cell Res 2014; 332:146-55. [PMID: 25523620 DOI: 10.1016/j.yexcr.2014.12.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Revised: 12/03/2014] [Accepted: 12/05/2014] [Indexed: 01/06/2023]
Abstract
Lipid metabolism depends on lipid droplets (LD), cytoplasmic structures surrounded by a protein-rich phospholipid monolayer. Although lipid synthesis is the hallmark of sebaceous gland cell differentiation, the LD-associated proteins of sebocytes have not been evaluated systematically. The LD fraction of SZ95 sebocytes was collected by density gradient centrifugation and associated proteins were analyzed by nanoliquid chromatography/tandem mass spectrometry. 54 proteins were significantly enriched in LD fractions, and 6 of them have not been detected previously in LDs. LD fractions contained high levels of typical LD-associated proteins as PLIN2/PLIN3, and most proteins belonged to functional categories characteristic for LD-associated proteins, indicating a reliable dataset. After confirming expression of transcripts encoding the six previously unidentified proteins by qRT-PCR in SZ95 sebocytes and in another sebocyte line (SebE6E7), we focused on two of these proteins, ALDH1A3 and EPHX4. While EPHX4 was localized almost exclusively on the surface of LDs, ALDH1A3 showed a more widespread localization that included additional cytoplasmic structures. siRNA-mediated downregulation revealed that depletion of EPHX4 increases LD size and sebaceous lipogenesis. Further studies on the roles of these proteins in sebocyte physiology and sebaceous lipogenesis may indicate novel strategies for the therapy of sebaceous gland-associated diseases such as acne.
Collapse
Affiliation(s)
- Maik Dahlhoff
- Institute of Molecular Animal Breeding and Biotechnology, Gene Center, LMU Munich, Germany
| | - Thomas Fröhlich
- Laboratory for Functional Genome Analysis LAFUGA, Gene Center, LMU Munich, Germany
| | - Georg J Arnold
- Laboratory for Functional Genome Analysis LAFUGA, Gene Center, LMU Munich, Germany
| | - Udo Müller
- Human Biology and BioImaging, Department of Biology II, LMU Munich, Germany
| | - Heinrich Leonhardt
- Human Biology and BioImaging, Department of Biology II, LMU Munich, Germany
| | - Christos C Zouboulis
- Departments of Dermatology, Venereology, Allergology and Immunology, Dessau Medical Center, Dessau, Germany
| | - Marlon R Schneider
- Institute of Molecular Animal Breeding and Biotechnology, Gene Center, LMU Munich, Germany.
| |
Collapse
|
46
|
Moessinger C, Klizaite K, Steinhagen A, Philippou-Massier J, Shevchenko A, Hoch M, Ejsing CS, Thiele C. Two different pathways of phosphatidylcholine synthesis, the Kennedy Pathway and the Lands Cycle, differentially regulate cellular triacylglycerol storage. BMC Cell Biol 2014; 15:43. [PMID: 25491198 PMCID: PMC4293825 DOI: 10.1186/s12860-014-0043-3] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Accepted: 11/17/2014] [Indexed: 02/01/2023] Open
Abstract
Background Lipids are stored within cells in lipid droplets (LDs). They consist of a core of neutral lipids surrounded by a monolayer of phospholipids, predominantly phosphatidylcholine (PC). LDs are very dynamic and can rapidly change in size upon lipid uptake or release. These dynamics require a fast adaptation of LD surface. We have recently shown that two Lands cycle PC synthesizing enyzmes, LPCAT1 and LPCAT2 can localize to the LD surface. Results Here, we show that knock-down of both enzymes leads to an increase in LD size without changes in the total amount of neutral lipids, while interference with the de-novo Kennedy pathway PC biosynthesis is associated with changes in triacylglyceride synthesis. We show that function of LPCAT1 and 2 is conserved in Drosophila melanogaster by the ortholog CG32699. Furthermore we demonstrate that modulation of the LD pool by LPCAT1 influences the release of lipoprotein from liver cells. Conclusion Activity of the Kennedy pathway regulates the balance between phospholipids and neutral lipids, while the Lands cycle regulates lipid droplet size by regulating surface availability and influencing surface to volume ratio. Differences in lipid droplet size may account for differences in lipid dynamics and be relevant to understand lipid overload diseases. Electronic supplementary material The online version of this article (doi:10.1186/s12860-014-0043-3) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Christine Moessinger
- Life and Medical Sciences Institute, University of Bonn, Carl-Troll-Str. 31, 53115, Bonn, Germany. .,Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, D-01307, Dresden, Germany.
| | - Kristina Klizaite
- Life and Medical Sciences Institute, University of Bonn, Carl-Troll-Str. 31, 53115, Bonn, Germany.
| | - Almut Steinhagen
- Life and Medical Sciences Institute, University of Bonn, Carl-Troll-Str. 31, 53115, Bonn, Germany.
| | - Julia Philippou-Massier
- Life and Medical Sciences Institute, University of Bonn, Carl-Troll-Str. 31, 53115, Bonn, Germany. .,Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, D-01307, Dresden, Germany.
| | - Andrej Shevchenko
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, D-01307, Dresden, Germany.
| | - Michael Hoch
- Life and Medical Sciences Institute, University of Bonn, Carl-Troll-Str. 31, 53115, Bonn, Germany.
| | - Christer S Ejsing
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, 5230, Odense, Denmark.
| | - Christoph Thiele
- Life and Medical Sciences Institute, University of Bonn, Carl-Troll-Str. 31, 53115, Bonn, Germany.
| |
Collapse
|
47
|
Tuohetahuntila M, Spee B, Kruitwagen HS, Wubbolts R, Brouwers JF, van de Lest CH, Molenaar MR, Houweling M, Helms JB, Vaandrager AB. Role of long-chain acyl-CoA synthetase 4 in formation of polyunsaturated lipid species in hepatic stellate cells. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1851:220-30. [PMID: 25500141 DOI: 10.1016/j.bbalip.2014.12.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Revised: 11/17/2014] [Accepted: 12/01/2014] [Indexed: 02/02/2023]
Abstract
Hepatic stellate cell (HSC) activation is a critical step in the development of chronic liver disease. We previously observed that the levels of triacylglycerol (TAG) species containing long polyunsaturated fatty acids (PUFAs) are increased in in vitro activated HSCs. Here we investigated the cause and consequences of the rise in PUFA-TAGs by profiling enzymes involved in PUFA incorporation. We report that acyl CoA synthetase (ACSL) type 4, which has a preference for PUFAs, is the only upregulated ACSL family member in activated HSCs. Inhibition of the activity of ACSL4 by siRNA-mediated knockdown or addition of rosiglitazone specifically inhibited the incorporation of deuterated arachidonic acid (AA-d8) into TAG in HSCs. In agreement with this, ACSL4 was found to be partially localized around lipid droplets (LDs) in HSCs. Inhibition of ACSL4 also prevented the large increase in PUFA-TAGs in HSCs upon activation and to a lesser extent the increase of arachidonate-containing phosphatidylcholine species. Inhibition of ACSL4 by rosiglitazone was associated with an inhibition of HSC activation and prostaglandin secretion. Our combined data show that upregulation of ACSL4 is responsible for the increase in PUFA-TAG species during activation of HSCs, which may serve to protect cells against a shortage of PUFAs required for eicosanoid secretion.
Collapse
Affiliation(s)
- Maidina Tuohetahuntila
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine & Institute of Biomembranes, Utrecht University, Yalelaan 2, 3584 CM Utrecht, The Netherlands.
| | - Bart Spee
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 104, 3584 CM Utrecht, The Netherlands.
| | - Hedwig S Kruitwagen
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 104, 3584 CM Utrecht, The Netherlands.
| | - Richard Wubbolts
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine & Institute of Biomembranes, Utrecht University, Yalelaan 2, 3584 CM Utrecht, The Netherlands.
| | - Jos F Brouwers
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine & Institute of Biomembranes, Utrecht University, Yalelaan 2, 3584 CM Utrecht, The Netherlands.
| | - Chris H van de Lest
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine & Institute of Biomembranes, Utrecht University, Yalelaan 2, 3584 CM Utrecht, The Netherlands.
| | - Martijn R Molenaar
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine & Institute of Biomembranes, Utrecht University, Yalelaan 2, 3584 CM Utrecht, The Netherlands.
| | - Martin Houweling
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine & Institute of Biomembranes, Utrecht University, Yalelaan 2, 3584 CM Utrecht, The Netherlands.
| | - J Bernd Helms
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine & Institute of Biomembranes, Utrecht University, Yalelaan 2, 3584 CM Utrecht, The Netherlands.
| | - Arie B Vaandrager
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine & Institute of Biomembranes, Utrecht University, Yalelaan 2, 3584 CM Utrecht, The Netherlands.
| |
Collapse
|
48
|
Squalene mono-oxygenase, a key enzyme in cholesterol synthesis, is stabilized by unsaturated fatty acids. Biochem J 2014; 461:435-42. [PMID: 24840124 DOI: 10.1042/bj20131404] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
SM (squalene mono-oxygenase) catalyses the first oxygenation step in cholesterol synthesis, immediately before the formation of the steroid backbone at lanosterol. SM is an important control point in the pathway, and is regulated at the post-translational level by accelerated cholesterol-dependent ubiquitination and proteasomal degradation, which is associated with the accumulation of squalene. Using model cell systems, we report that SM is stabilized by unsaturated fatty acids. Treatment with unsaturated fatty acids such as oleate, but not saturated fatty acids, increased protein levels of SM or SM-N100-GFP (the first 100 amino acids of SM fused to GFP) at the post-translational level and partially overcame cholesterol-dependent degradation, as well as reversing cholesterol-dependent squalene accumulation. Maximum stabilization required activation of fatty acids, but not triacylglycerol or phosphatidylcholine synthesis. The mechanism of oleate-mediated stabilization appeared to occur through reduced ubiquitination by the E3 ubiquitin ligase MARCH6. Stabilization of a cholesterol biosynthetic enzyme by unsaturated fatty acids may help maintain a constant cholesterol/phospholipid ratio.
Collapse
|
49
|
Yokoyama H, Matsui I. Crystal structure of the stomatin operon partner protein from Pyrococcus horikoshii indicates the formation of a multimeric assembly. FEBS Open Bio 2014; 4:804-12. [PMID: 25349784 PMCID: PMC4208085 DOI: 10.1016/j.fob.2014.09.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Revised: 09/09/2014] [Accepted: 09/09/2014] [Indexed: 01/21/2023] Open
Abstract
The structure of C-terminal domain of stomatin operon partner protein PH1510 was determined. C-terminal domain of PH1510 (1510-C) forms a five-stranded β-barrel known as an OB-fold. 1510-C could assemble into multimers based on a dimer as a basic unit. 1510-C functions as a scaffold protein to form a multimeric assembly with stomatin.
Stomatin, prohibitin, flotillin, and HflK/C (SPFH) domain proteins are found in the lipid raft microdomains of various cellular membranes. Stomatin/STOPP (stomatin operon partner protein) gene pairs are present in both archaeal and bacterial species, and their protein products may be involved in the quality control of membrane proteins. In the present study, the crystal structure of the C-terminal soluble domain of STOPP PH1510 (1510-C) from the hyperthermophilic archaeon Pyrococcus horikoshii was determined at 2.4 Å resolution. The structure of 1510-C had a compact five-stranded β-barrel fold known as an oligosaccharide/oligonucleotide-binding fold (OB-fold). According to crystal packing, 1510-C could assemble into multimers based on a dimer as a basic unit. 1510-C also formed a large cylinder-like structure composed of 24 subunits or a large triangular prism-like structure composed of 12 subunits. These results indicate that 1510-C functions as a scaffold protein to form the multimeric assembly of STOPP and stomatin.
Collapse
Affiliation(s)
- Hideshi Yokoyama
- School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Ikuo Matsui
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan
| |
Collapse
|
50
|
Mannik J, Meyers A, Dalhaimer P. Isolation of cellular lipid droplets: two purification techniques starting from yeast cells and human placentas. J Vis Exp 2014:50981. [PMID: 24747783 PMCID: PMC4160924 DOI: 10.3791/50981] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Lipid droplets are dynamic organelles that can be found in most eukaryotic and certain prokaryotic cells. Structurally, the droplets consist of a core of neutral lipids surrounded by a phospholipid monolayer. One of the most useful techniques in determining the cellular roles of droplets has been proteomic identification of bound proteins, which can be isolated along with the droplets. Here, two methods are described to isolate lipid droplets and their bound proteins from two wide-ranging eukaryotes: fission yeast and human placental villous cells. Although both techniques have differences, the main method-- density gradient centrifugation--is shared by both preparations. This shows the wide applicability of the presented droplet isolation techniques. In the first protocol, yeast cells are converted into spheroplasts by enzymatic digestion of their cell walls. The resulting spheroplasts are then gently lysed in a loose-fitting homogenizer. Ficoll is added to the lysate to provide a density gradient, and the mixture is centrifuged three times. After the first spin, the lipid droplets are localized to the white-colored floating layer of the centrifuge tubes along with the endoplasmic reticulum (ER), the plasma membrane, and vacuoles. Two subsequent spins are used to remove these other three organelles. The result is a layer that has only droplets and bound proteins. In the second protocol, placental villous cells are isolated from human term placentas by enzymatic digestion with trypsin and DNase I. The cells are homogenized in a loose-fitting homogenizer. Low-speed and medium-speed centrifugation steps are used to remove unbroken cells, cellular debris, nuclei, and mitochondria. Sucrose is added to the homogenate to provide a density gradient and the mixture is centrifuged to separate the lipid droplets from the other cellular fractions. The purity of the lipid droplets in both protocols is confirmed by Western Blot analysis. The droplet fractions from both preps are suitable for subsequent proteomic and lipidomic analysis.
Collapse
Affiliation(s)
- Jaana Mannik
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee
| | - Alex Meyers
- Department of Chemical and Biomolecular Engineering, University of Tennessee
| | - Paul Dalhaimer
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee; Department of Chemical and Biomolecular Engineering, University of Tennessee;
| |
Collapse
|