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Singh J, Sanghavi P, Mallik R. Microtubule motor driven interactions of lipid droplets: Specificities and opportunities. Front Cell Dev Biol 2022; 10:893375. [PMID: 36200039 PMCID: PMC9527339 DOI: 10.3389/fcell.2022.893375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 09/05/2022] [Indexed: 11/29/2022] Open
Abstract
Lipid Droplets (LDs) are evolutionarily conserved cellular organelles that store neutral lipids such as triacylglycerol and cholesterol-esters. Neutral lipids are enclosed within the limiting membrane of the LD, which is a monolayer of phospholipids and is therefore fundamentally different from the bilayer membrane enclosing most other organelles. LDs have long been viewed as a storehouse of lipids needed on demand for generating energy and membranes inside cells. Outside this classical view, we are now realizing that LDs have significant roles in protein sequestration, supply of signalling lipids, viral replication, lipoprotein production and many other functions of important physiological consequence. To execute such functions, LDs must often exchange lipids and proteins with other organelles (e.g., the ER, lysosomes, mitochondria) via physical contacts. But before such exchanges can occur, how does a micron-sized LD with limited ability to diffuse around find its cognate organelle? There is growing evidence that motor protein driven motion of LDs along microtubules may facilitate such LD-organelle interactions. We will summarize some aspects of LD motion leading to LD-organelle contacts, how these change with metabolic state and pathogen infections, and also ask how these pathways could perhaps be targeted selectively in the context of disease and drug delivery. Such a possibility arises because the binding of motor proteins to the monolayer membrane on LDs could be different from motor binding to the membrane on other cellular organelles.
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Affiliation(s)
- Jagjeet Singh
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
- *Correspondence: Roop Mallik, ; Jagjeet Singh,
| | - Paulomi Sanghavi
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
| | - Roop Mallik
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India
- *Correspondence: Roop Mallik, ; Jagjeet Singh,
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Chowdary PD, Che DL, Zhang K, Cui B. Retrograde NGF axonal transport--motor coordination in the unidirectional motility regime. Biophys J 2016; 108:2691-703. [PMID: 26039170 DOI: 10.1016/j.bpj.2015.04.036] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Revised: 04/26/2015] [Accepted: 04/29/2015] [Indexed: 10/23/2022] Open
Abstract
We present a detailed motion analysis of retrograde nerve growth factor (NGF) endosomes in axons to show that mechanical tugs-of-war and intracellular motor regulation are complimentary features of the near-unidirectional endosome directionality. We used quantum dots to fluorescently label NGF and acquired trajectories of retrograde quantum-dot-NGF-endosomes with <20-nm accuracy at 32 Hz in microfluidic neuron cultures. Using a combination of transient motion analysis and Bayesian parsing, we partitioned the trajectories into sustained periods of retrograde (dynein-driven) motion, constrained pauses, and brief anterograde (kinesin-driven) reversals. The data shows many aspects of mechanical tugs-of-war and multiple-motor mechanics in NGF-endosome transport. However, we found that stochastic mechanical models based on in vitro parameters cannot simulate the experimental data, unless the microtubule-binding affinity of kinesins on the endosome is tuned down by 10 times. Specifically, the simulations suggest that the NGF-endosomes are driven on average by 5-6 active dyneins and 1-2 downregulated kinesins. This is also supported by the dynamics of endosomes detaching under load in axons, showcasing the cooperativity of multiple dyneins and the subdued activity of kinesins. We discuss the possible motor coordination mechanism consistent with motor regulation and tugs-of-war for future investigations.
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Affiliation(s)
| | - Daphne L Che
- Department of Chemistry, Stanford University, Stanford, California
| | - Kai Zhang
- Department of Chemistry, Stanford University, Stanford, California
| | - Bianxiao Cui
- Department of Chemistry, Stanford University, Stanford, California.
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Chughtai AA, Kaššák F, Kostrouchová M, Novotný JP, Krause MW, Saudek V, Kostrouch Z, Kostrouchová M. Perilipin-related protein regulates lipid metabolism in C. elegans. PeerJ 2015; 3:e1213. [PMID: 26357594 PMCID: PMC4562238 DOI: 10.7717/peerj.1213] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 08/05/2015] [Indexed: 01/08/2023] Open
Abstract
Perilipins are lipid droplet surface proteins that contribute to fat metabolism by controlling the access of lipids to lipolytic enzymes. Perilipins have been identified in organisms as diverse as metazoa, fungi, and amoebas but strikingly not in nematodes. Here we identify the protein encoded by the W01A8.1 gene in Caenorhabditis elegans as the closest homologue and likely orthologue of metazoan perilipin. We demonstrate that nematode W01A8.1 is a cytoplasmic protein residing on lipid droplets similarly as human perilipins 1 and 2. Downregulation or elimination of W01A8.1 affects the appearance of lipid droplets resulting in the formation of large lipid droplets localized around the dividing nucleus during the early zygotic divisions. Visualization of lipid containing structures by CARS microscopy in vivo showed that lipid-containing structures become gradually enlarged during oogenesis and relocate during the first zygotic division around the dividing nucleus. In mutant embryos, the lipid containing structures show defective intracellular distribution in subsequent embryonic divisions and become gradually smaller during further development. In contrast to embryos, lipid-containing structures in enterocytes and in epidermal cells of adult animals are smaller in mutants than in wild type animals. Our results demonstrate the existence of a perilipin-related regulation of fat metabolism in nematodes and provide new possibilities for functional studies of lipid metabolism.
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Affiliation(s)
- Ahmed Ali Chughtai
- Institute of Cellular Biology and Pathology, First Faculty of Medicine, Charles University in Prague , Albertov, Prague , Czech Republic
| | - Filip Kaššák
- Institute of Cellular Biology and Pathology, First Faculty of Medicine, Charles University in Prague , Albertov, Prague , Czech Republic
| | - Markéta Kostrouchová
- Institute of Cellular Biology and Pathology, First Faculty of Medicine, Charles University in Prague , Albertov, Prague , Czech Republic ; Department of Pathology, Third Faculty of Medicine, Charles University in Prague , Ruská, Prague , Czech Republic
| | - Jan Philipp Novotný
- Institute of Cellular Biology and Pathology, First Faculty of Medicine, Charles University in Prague , Albertov, Prague , Czech Republic
| | - Michael W Krause
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health , Bethesda, MD , USA
| | - Vladimír Saudek
- University of Cambridge Metabolic Research Laboratories, Wellcome Trust-Medical Research Council, Institute of Metabolic Science , Cambridge , UK
| | - Zdenek Kostrouch
- Institute of Cellular Biology and Pathology, First Faculty of Medicine, Charles University in Prague , Albertov, Prague , Czech Republic
| | - Marta Kostrouchová
- Institute of Cellular Biology and Pathology, First Faculty of Medicine, Charles University in Prague , Albertov, Prague , Czech Republic
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Ally S, Larson AG, Barlan K, Rice SE, Gelfand VI. Opposite-polarity motors activate one another to trigger cargo transport in live cells. ACTA ACUST UNITED AC 2010; 187:1071-82. [PMID: 20038680 PMCID: PMC2806283 DOI: 10.1083/jcb.200908075] [Citation(s) in RCA: 158] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Intracellular transport is typically bidirectional, consisting of a series of back and forth movements. Kinesin-1 and cytoplasmic dynein require each other for bidirectional transport of intracellular cargo along microtubules; i.e., inhibition or depletion of kinesin-1 abolishes dynein-driven cargo transport and vice versa. Using Drosophila melanogaster S2 cells, we demonstrate that replacement of endogenous kinesin-1 or dynein with an unrelated, peroxisome-targeted motor of the same directionality activates peroxisome transport in the opposite direction. However, motility-deficient versions of motors, which retain the ability to bind microtubules and hydrolyze adenosine triphosphate, do not activate peroxisome motility. Thus, any pair of opposite-polarity motors, provided they move along microtubules, can activate one another. These results demonstrate that mechanical interactions between opposite-polarity motors are necessary and sufficient for bidirectional organelle transport in live cells.
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Affiliation(s)
- Shabeen Ally
- Department of Cell and Molecular Biology, Northwestern University, Chicago, IL 60611, USA
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Fujii H, Ikura Y, Arimoto J, Sugioka K, Iezzoni JC, Park SH, Naruko T, Itabe H, Kawada N, Caldwell SH, Ueda M. Expression of perilipin and adipophilin in nonalcoholic fatty liver disease; relevance to oxidative injury and hepatocyte ballooning. J Atheroscler Thromb 2009; 16:893-901. [PMID: 20032580 DOI: 10.5551/jat.2055] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
AIMS Perilipin and adipophilin, PAT family proteins, play important roles in lipid metabolism. Although nonalcoholic fatty liver disease (NAFLD) is initiated by hepatocyte lipidation, little is known about the relationship between these proteins and hepatocellular injury. We investigated the expressions of perilipin and adipophilin and their relation to inflammation, fibrosis, hepatocellular ballooning, and oxidized phosphatidylcholine (oxPC) localization in human NAFLD. METHODS AND RESULTS Liver biopsies of nonalcoholic steatohepatitis (NASH, n=39) or simple steatosis (n=9) were studied by immunohistochemical techniques using anti-perilipin, anti-adipophilin and anti-oxPC antibodies. The severity of liver damage was histologically assessed by the Brunt system and NAFLD activity score (NAS). Enlarged hepatocytes usually containing Mallory-Denk bodies were defined as ballooned. Perilipin and adipophilin were detected on the rim of lipid droplets in both NASH and simple steatosis. Perilipin was more evident in larger lipid droplets while adipophilin expression was frequent in lipid droplets of ballooned hepatocytes. The frequency of adipophilin-positive ballooned hepatocytes was correlated to inflammation (Rs=0.72, p<0.0001), fibrosis (Rs=0.46, p=0.005), NAS (Rs=0.47, p=0.004) and oxPC-positive ballooned hepatocytes (Rs=0.35, p=0.033). CONCLUSIONS Expression patterns of perilipin and adipophilin in NASH livers varied with the size of lipid droplets. In partiew or, adipophilin expression in ballooned hepatocytes was closely associated with oxidative damage.
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Affiliation(s)
- Hideki Fujii
- Department of Hepatology, Osaka City University Graduate School of Medicine, Japan
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Perttilä J, Merikanto K, Naukkarinen J, Surakka I, Martin NW, Tanhuanpää K, Grimard V, Taskinen MR, Thiele C, Salomaa V, Jula A, Perola M, Virtanen I, Peltonen L, Olkkonen VM. OSBPL10, a novel candidate gene for high triglyceride trait in dyslipidemic Finnish subjects, regulates cellular lipid metabolism. J Mol Med (Berl) 2009; 87:825-35. [PMID: 19554302 PMCID: PMC2707950 DOI: 10.1007/s00109-009-0490-z] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2009] [Revised: 05/14/2009] [Accepted: 05/25/2009] [Indexed: 11/25/2022]
Abstract
Analysis of variants in three genes encoding oxysterol-binding protein (OSBP) homologues (OSBPL2, OSBPL9, OSBPL10) in Finnish families with familial low high-density lipoprotein (HDL) levels (N = 426) or familial combined hyperlipidemia (N = 684) revealed suggestive linkage of OSBPL10 single-nucleotide polymorphisms (SNPs) with extreme end high triglyceride (TG; >90th percentile) trait. Prompted by this initial finding, we carried out association analysis in a metabolic syndrome subcohort (Genmets) of Health2000 examination survey (N = 2,138), revealing association of multiple OSBPL10 SNPs with high serum TG levels (>95th percentile). To investigate whether OSBPL10 could be the gene underlying the observed linkage and association, we carried out functional experiments in the human hepatoma cell line Huh7. Silencing of OSBPL10 increased the incorporation of [(3)H]acetate into cholesterol and both [(3)H]acetate and [(3)H]oleate into triglycerides and enhanced the accumulation of secreted apolipoprotein B100 in growth medium, suggesting that the encoded protein ORP10 suppresses hepatic lipogenesis and very-low-density lipoprotein production. ORP10 was shown to associate dynamically with microtubules, consistent with its involvement in intracellular transport or organelle positioning. The data introduces OSBPL10 as a gene whose variation may contribute to high triglyceride levels in dyslipidemic Finnish subjects and provides evidence for ORP10 as a regulator of cellular lipid metabolism.
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MESH Headings
- Cell Line, Tumor
- Cholesterol, HDL/blood
- Cholesterol, HDL/genetics
- Cholesterol, HDL/metabolism
- Female
- Finland
- Gene Silencing
- Hepatocytes/metabolism
- Humans
- Hyperlipidemia, Familial Combined/genetics
- Hyperlipidemia, Familial Combined/metabolism
- Lipid Metabolism
- Male
- Microtubules/chemistry
- Polymorphism, Single Nucleotide
- Receptors, Steroid/analysis
- Receptors, Steroid/genetics
- Receptors, Steroid/metabolism
- Triglycerides/blood
- Triglycerides/genetics
- Triglycerides/metabolism
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Affiliation(s)
- Julia Perttilä
- National Institute for Health and Welfare/Public Health Genomics Unit, Biomedicum, P.O. Box 104, 00251 Helsinki, Finland
- FIMM, Institute for Molecular Medicine Finland, University of Helsinki, P.O. Box 20, 00014 Helsinki, Finland
- Institute of Biomedicine/Anatomy, University of Helsinki, P.O. Box 63, 00014 Helsinki, Finland
| | - Krista Merikanto
- National Institute for Health and Welfare/Public Health Genomics Unit, Biomedicum, P.O. Box 104, 00251 Helsinki, Finland
- FIMM, Institute for Molecular Medicine Finland, University of Helsinki, P.O. Box 20, 00014 Helsinki, Finland
| | - Jussi Naukkarinen
- National Institute for Health and Welfare/Public Health Genomics Unit, Biomedicum, P.O. Box 104, 00251 Helsinki, Finland
- FIMM, Institute for Molecular Medicine Finland, University of Helsinki, P.O. Box 20, 00014 Helsinki, Finland
| | - Ida Surakka
- National Institute for Health and Welfare/Public Health Genomics Unit, Biomedicum, P.O. Box 104, 00251 Helsinki, Finland
- FIMM, Institute for Molecular Medicine Finland, University of Helsinki, P.O. Box 20, 00014 Helsinki, Finland
| | - Nicolas W. Martin
- National Institute for Health and Welfare/Public Health Genomics Unit, Biomedicum, P.O. Box 104, 00251 Helsinki, Finland
- Queensland Institute of Medical Research, 300 Herston Road, Brisbane, 4029 Australia
| | - Kimmo Tanhuanpää
- Light microscopy Unit, Institute of Biotechnology, University of Helsinki, 00014 Helsinki, Finland
| | - Vinciane Grimard
- Max-Planck-Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Marja-Riitta Taskinen
- Department of Medicine, Division of Cardiology, Helsinki University Hospital and Biomedicum, Haartmaninkatu 8, 00290 Helsinki, Finland
| | - Christoph Thiele
- Max-Planck-Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Veikko Salomaa
- Department of Chronic Disease Prevention, National Institute for Health and Welfare, P.O. Box 30, 00271 Helsinki, Finland
| | - Antti Jula
- National Institute for Health and Welfare, 20720 Turku, Finland
| | - Markus Perola
- National Institute for Health and Welfare/Public Health Genomics Unit, Biomedicum, P.O. Box 104, 00251 Helsinki, Finland
- FIMM, Institute for Molecular Medicine Finland, University of Helsinki, P.O. Box 20, 00014 Helsinki, Finland
| | - Ismo Virtanen
- Institute of Biomedicine/Anatomy, University of Helsinki, P.O. Box 63, 00014 Helsinki, Finland
| | - Leena Peltonen
- National Institute for Health and Welfare/Public Health Genomics Unit, Biomedicum, P.O. Box 104, 00251 Helsinki, Finland
- FIMM, Institute for Molecular Medicine Finland, University of Helsinki, P.O. Box 20, 00014 Helsinki, Finland
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, CB10 1SA UK
- Department of Medical Genetics, University of Helsinki, 00014 Helsinki, Finland
- The Broad Institute, Boston, MA 02142 USA
| | - Vesa M. Olkkonen
- National Institute for Health and Welfare/Public Health Genomics Unit, Biomedicum, P.O. Box 104, 00251 Helsinki, Finland
- FIMM, Institute for Molecular Medicine Finland, University of Helsinki, P.O. Box 20, 00014 Helsinki, Finland
- Institute of Biomedicine/Anatomy, University of Helsinki, P.O. Box 63, 00014 Helsinki, Finland
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Murphy S, Martin S, Parton RG. Lipid droplet-organelle interactions; sharing the fats. Biochim Biophys Acta Mol Cell Biol Lipids 2008; 1791:441-7. [PMID: 18708159 DOI: 10.1016/j.bbalip.2008.07.004] [Citation(s) in RCA: 186] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2008] [Revised: 06/09/2008] [Accepted: 07/18/2008] [Indexed: 12/20/2022]
Abstract
Lipid droplets (LDs) are key cellular organelles involved in lipid storage and mobilisation. While the major signalling cascades and many of the regulators of lipolysis have been identified, the cellular interactions involved in lipid mobilisation and release remain largely undefined. In non-adipocytes, LDs are small, mobile and interact with other cellular compartments. In contrast, adipocytes primarily contain very large, immotile LDs. The striking morphological differences between LDs in adipocytes and non-adipocytes suggest that key differences must exist in the manner in which LDs in different cell types interact with other organelles. Recent studies have highlighted the complexity of LD interactions, which can be both homotypic, with each other, and heterotypic, with other organelles. The molecules involved in these interactions are also now emerging, including Rab proteins, key regulators of membrane traffic, and caveolin, an integral membrane protein providing a functional link between the cell surface and LDs. Here we summarise recent insights into the cell biology of the LD particularly focussing on the homotypic and heterotypic interactions in both adipocytes and non-adipocytes. We speculate that these interactions may involve inter-organelle membrane contact sites or a hemi-fusion type mechanism to facilitate lipid transfer.
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Affiliation(s)
- Samantha Murphy
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland 4072, Australia
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