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Fernández-Del-Río L, Kelly ME, Contreras J, Bradley MC, James AM, Murphy MP, Payne GS, Clarke CF. Genes and lipids that impact uptake and assimilation of exogenous coenzyme Q in Saccharomyces cerevisiae. Free Radic Biol Med 2020; 154:105-118. [PMID: 32387128 PMCID: PMC7611304 DOI: 10.1016/j.freeradbiomed.2020.04.029] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 04/18/2020] [Accepted: 04/28/2020] [Indexed: 12/13/2022]
Abstract
Coenzyme Q (CoQ) is an essential player in the respiratory electron transport chain and is the only lipid-soluble antioxidant synthesized endogenously in mammalian and yeast cells. In humans, genetic mutations, pathologies, certain medical treatments, and aging, result in CoQ deficiencies, which are linked to mitochondrial, cardiovascular, and neurodegenerative diseases. The only strategy available for these patients is CoQ supplementation. CoQ supplements benefit a small subset of patients, but the poor solubility of CoQ greatly limits treatment efficacy. Consequently, the efficient delivery of CoQ to the mitochondria and restoration of respiratory function remains a major challenge. A better understanding of CoQ uptake and mitochondrial delivery is crucial to make this molecule a more efficient and effective therapeutic tool. In this study, we investigated the mechanism of CoQ uptake and distribution using the yeast Saccharomyces cerevisiae as a model organism. The addition of exogenous CoQ was tested for the ability to restore growth on non-fermentable medium in several strains that lack CoQ synthesis (coq mutants). Surprisingly, we discovered that the presence of CoQ biosynthetic intermediates impairs assimilation of CoQ into a functional respiratory chain in yeast cells. Moreover, a screen of 40 gene deletions considered to be candidates to prevent exogenous CoQ from rescuing growth of the CoQ-less coq2Δ mutant, identified six novel genes (CDC10, RTS1, RVS161, RVS167, VPS1, and NAT3) as necessary for efficient trafficking of CoQ to mitochondria. The proteins encoded by these genes represent essential steps in the pathways responsible for transport of exogenously supplied CoQ to its functional sites in the cell, and definitively associate CoQ distribution with endocytosis and intracellular vesicular trafficking pathways conserved from yeast to human cells.
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Affiliation(s)
- Lucía Fernández-Del-Río
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, University of California, Los Angeles, USA
| | - Miranda E Kelly
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, University of California, Los Angeles, USA
| | - Jaime Contreras
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, University of California, Los Angeles, USA
| | - Michelle C Bradley
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, University of California, Los Angeles, USA
| | - Andrew M James
- MRC Mitochondrial Biology Unit, University of Cambridge, UK
| | - Michael P Murphy
- MRC Mitochondrial Biology Unit, University of Cambridge, UK; Department of Medicine, University of Cambridge, UK
| | - Gregory S Payne
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, USA
| | - Catherine F Clarke
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, University of California, Los Angeles, USA.
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52
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Awad AM, Nag A, Pham NVB, Bradley MC, Jabassini N, Nathaniel J, Clarke CF. Intragenic suppressor mutations of the COQ8 protein kinase homolog restore coenzyme Q biosynthesis and function in Saccharomyces cerevisiae. PLoS One 2020; 15:e0234192. [PMID: 32479562 PMCID: PMC7263595 DOI: 10.1371/journal.pone.0234192] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Accepted: 05/20/2020] [Indexed: 11/18/2022] Open
Abstract
Saccharomyces cerevisiae Coq8 is a member of the ancient UbiB atypical protein kinase family. Coq8, and its orthologs UbiB, ABC1, ADCK3, and ADCK4, are required for the biosynthesis of coenzyme Q in yeast, E. coli, A. thaliana, and humans. Each Coq8 ortholog retains nine highly conserved protein kinase-like motifs, yet its functional role in coenzyme Q biosynthesis remains mysterious. Coq8 may function as an ATPase whose activity is stimulated by coenzyme Q intermediates and phospholipids. A key yeast point mutant expressing Coq8-A197V was previously shown to result in a coenzyme Q-less, respiratory deficient phenotype. The A197V substitution occurs in the crucial Ala-rich protein kinase-like motif I of yeast Coq8. Here we show that long-term cultures of mutants expressing Coq8-A197V produce spontaneous revertants with the ability to grow on medium containing a non-fermentable carbon source. Each revertant is shown to harbor a secondary intragenic suppressor mutation within the COQ8 gene. The intragenic suppressors restore the synthesis of coenzyme Q. One class of the suppressors fully restores the levels of coenzyme Q and key Coq polypeptides necessary for the maintenance and integrity of the high-molecular mass CoQ synthome (also termed complex Q), while the other class provides only a partial rescue. Mutants harboring the first class of suppressors grow robustly under respiratory conditions, while mutants containing the second class grow more slowly under these conditions. Our work provides insight into the function of this important yet still enigmatic Coq8 family.
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Affiliation(s)
- Agape M. Awad
- Department of Chemistry and Biochemistry, and the Molecular Biology Institute, University of California, Los Angeles, California, United States of America
| | - Anish Nag
- Department of Chemistry and Biochemistry, and the Molecular Biology Institute, University of California, Los Angeles, California, United States of America
| | - Nguyen V. B. Pham
- Department of Chemistry and Biochemistry, and the Molecular Biology Institute, University of California, Los Angeles, California, United States of America
| | - Michelle C. Bradley
- Department of Chemistry and Biochemistry, and the Molecular Biology Institute, University of California, Los Angeles, California, United States of America
| | - Nour Jabassini
- Department of Chemistry and Biochemistry, and the Molecular Biology Institute, University of California, Los Angeles, California, United States of America
| | - Juan Nathaniel
- Department of Chemistry and Biochemistry, and the Molecular Biology Institute, University of California, Los Angeles, California, United States of America
| | - Catherine F. Clarke
- Department of Chemistry and Biochemistry, and the Molecular Biology Institute, University of California, Los Angeles, California, United States of America
- * E-mail:
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53
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Zung N, Schuldiner M. New horizons in mitochondrial contact site research. Biol Chem 2020; 401:793-809. [PMID: 32324151 DOI: 10.1515/hsz-2020-0133] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 04/14/2020] [Indexed: 12/18/2022]
Abstract
Contact sites, areas where two organelles are held in close proximity through the action of molecular tethers, enable non-vesicular communication between compartments. Mitochondria have been center stage in the contact site field since the discovery of the first contact between mitochondria and the endoplasmic reticulum (ER) over 60 years ago. However, only now, in the last decade, has there been a burst of discoveries regarding contact site biology in general and mitochondrial contacts specifically. The number and types of characterized contacts increased dramatically, new molecular mechanisms enabling contact formation were discovered, additional unexpected functions for contacts were shown, and their roles in cellular and organismal physiology were emphasized. Here, we focus on mitochondria as we highlight the most recent developments, future goals and unresolved questions in the field.
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Affiliation(s)
- Naama Zung
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Maya Schuldiner
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, 7610001, Israel
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54
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Abstract
Many critical biological events, including biochemical signaling, membrane traffic, and cell motility, originate at membrane surfaces. Each such event requires that members of a specific group of proteins and lipids rapidly assemble together at a specific site on the membrane surface. Understanding the biophysical mechanisms that stabilize these assemblies is critical to decoding and controlling cellular functions. In this article, we review progress toward a quantitative biophysical understanding of the mechanisms that drive membrane heterogeneity and organization. We begin from a physical perspective, reviewing the fundamental principles and key experimental evidence behind each proposed mechanism. We then shift to a biological perspective, presenting key examples of the role of heterogeneity in biology and asking which physical mechanisms may be responsible. We close with an applied perspective, noting that membrane heterogeneity provides a novel therapeutic target that is being exploited by a growing number of studies at the interface of biology, physics, and engineering.
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Affiliation(s)
- Wade F Zeno
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA;
| | - Kasey J Day
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA;
| | - Vernita D Gordon
- Department of Physics, The University of Texas at Austin, Austin, Texas 78712, USA
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas 78712, USA
- Center for Nonlinear Dynamics, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Jeanne C Stachowiak
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA;
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas 78712, USA
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55
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Bradley MC, Yang K, Fernández-Del-Río L, Ngo J, Ayer A, Tsui HS, Novales NA, Stocker R, Shirihai OS, Barros MH, Clarke CF. COQ11 deletion mitigates respiratory deficiency caused by mutations in the gene encoding the coenzyme Q chaperone protein Coq10. J Biol Chem 2020; 295:6023-6042. [PMID: 32205446 DOI: 10.1074/jbc.ra119.012420] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 03/17/2020] [Indexed: 12/17/2022] Open
Abstract
Coenzyme Q (Q n ) is a vital lipid component of the electron transport chain that functions in cellular energy metabolism and as a membrane antioxidant. In the yeast Saccharomyces cerevisiae, coq1-coq9 deletion mutants are respiratory-incompetent, sensitive to lipid peroxidation stress, and unable to synthesize Q6 The yeast coq10 deletion mutant is also respiratory-deficient and sensitive to lipid peroxidation, yet it continues to produce Q6 at an impaired rate. Thus, Coq10 is required for the function of Q6 in respiration and as an antioxidant and is believed to chaperone Q6 from its site of synthesis to the respiratory complexes. In several fungi, Coq10 is encoded as a fusion polypeptide with Coq11, a recently identified protein of unknown function required for efficient Q6 biosynthesis. Because "fused" proteins are often involved in similar biochemical pathways, here we examined the putative functional relationship between Coq10 and Coq11 in yeast. We used plate growth and Seahorse assays and LC-MS/MS analysis to show that COQ11 deletion rescues respiratory deficiency, sensitivity to lipid peroxidation, and decreased Q6 biosynthesis of the coq10Δ mutant. Additionally, immunoblotting indicated that yeast coq11Δ mutants accumulate increased amounts of certain Coq polypeptides and display a stabilized CoQ synthome. These effects suggest that Coq11 modulates Q6 biosynthesis and that its absence increases mitochondrial Q6 content in the coq10Δcoq11Δ double mutant. This augmented mitochondrial Q6 content counteracts the respiratory deficiency and lipid peroxidation sensitivity phenotypes of the coq10Δ mutant. This study further clarifies the intricate connection between Q6 biosynthesis, trafficking, and function in mitochondrial metabolism.
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Affiliation(s)
- Michelle C Bradley
- Department of Chemistry and Biochemistry, Molecular Biology Institute, UCLA, Los Angeles, California 90095-1569
| | - Krista Yang
- Department of Chemistry and Biochemistry, Molecular Biology Institute, UCLA, Los Angeles, California 90095-1569
| | - Lucía Fernández-Del-Río
- Department of Chemistry and Biochemistry, Molecular Biology Institute, UCLA, Los Angeles, California 90095-1569
| | - Jennifer Ngo
- Department of Chemistry and Biochemistry, Molecular Biology Institute, UCLA, Los Angeles, California 90095-1569; Department of Molecular and Medical Pharmacology and Medicine, David Geffen School of Medicine, UCLA, Los Angeles, California 90095
| | - Anita Ayer
- Vascular Biology Division, Victor Chang Cardiac Research Institute, Sydney, New South Wales 2010, Australia; St. Vincent's Clinical School, University of New South Wales Medicine, Sydney, New South Wales 2050, Australia
| | - Hui S Tsui
- Department of Chemistry and Biochemistry, Molecular Biology Institute, UCLA, Los Angeles, California 90095-1569
| | - Noelle Alexa Novales
- Department of Chemistry and Biochemistry, Molecular Biology Institute, UCLA, Los Angeles, California 90095-1569
| | - Roland Stocker
- Vascular Biology Division, Victor Chang Cardiac Research Institute, Sydney, New South Wales 2010, Australia; St. Vincent's Clinical School, University of New South Wales Medicine, Sydney, New South Wales 2050, Australia
| | - Orian S Shirihai
- Department of Molecular and Medical Pharmacology and Medicine, David Geffen School of Medicine, UCLA, Los Angeles, California 90095
| | - Mario H Barros
- Departamento Microbiologia, Universidade de São Paulo, São Paulo 05508-900, Brazil
| | - Catherine F Clarke
- Department of Chemistry and Biochemistry, Molecular Biology Institute, UCLA, Los Angeles, California 90095-1569.
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56
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Prinz WA, Toulmay A, Balla T. The functional universe of membrane contact sites. Nat Rev Mol Cell Biol 2020; 21:7-24. [PMID: 31732717 PMCID: PMC10619483 DOI: 10.1038/s41580-019-0180-9] [Citation(s) in RCA: 329] [Impact Index Per Article: 82.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/23/2019] [Indexed: 12/13/2022]
Abstract
Organelles compartmentalize eukaryotic cells, enhancing their ability to respond to environmental and developmental changes. One way in which organelles communicate and integrate their activities is by forming close contacts, often called 'membrane contact sites' (MCSs). Interest in MCSs has grown dramatically in the past decade as it is has become clear that they are ubiquitous and have a much broader range of critical roles in cells than was initially thought. Indeed, functions for MCSs in intracellular signalling (particularly calcium signalling, reactive oxygen species signalling and lipid signalling), autophagy, lipid metabolism, membrane dynamics, cellular stress responses and organelle trafficking and biogenesis have now been reported.
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Affiliation(s)
- William A Prinz
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA.
| | - Alexandre Toulmay
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Tamas Balla
- National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
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57
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Wang Y, Hekimi S. The Complexity of Making Ubiquinone. Trends Endocrinol Metab 2019; 30:929-943. [PMID: 31601461 DOI: 10.1016/j.tem.2019.08.009] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 08/19/2019] [Accepted: 08/20/2019] [Indexed: 12/15/2022]
Abstract
Ubiquinone (UQ, coenzyme Q) is an essential electron transfer lipid in the mitochondrial respiratory chain. It is a main source of mitochondrial reactive oxygen species (ROS) but also has antioxidant properties. This mix of characteristics is why ubiquinone supplementation is considered a potential therapy for many diseases involving mitochondrial dysfunction. Mutations in the ubiquinone biosynthetic pathway are increasingly being identified in patients. Furthermore, secondary ubiquinone deficiency is a common finding associated with mitochondrial disorders and might exacerbate these conditions. Recent developments have suggested that ubiquinone biosynthesis occurs in discrete domains of the mitochondrial inner membrane close to ER-mitochondria contact sites. This spatial requirement for ubiquinone biosynthesis could be the link between secondary ubiquinone deficiency and mitochondrial dysfunction, which commonly results in loss of mitochondrial structural integrity.
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Affiliation(s)
- Ying Wang
- Department of Biology, McGill University, Montreal, Canada
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58
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Anderson AJ, Jackson TD, Stroud DA, Stojanovski D. Mitochondria-hubs for regulating cellular biochemistry: emerging concepts and networks. Open Biol 2019; 9:190126. [PMID: 31387448 PMCID: PMC6731593 DOI: 10.1098/rsob.190126] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Mitochondria are iconic structures in biochemistry and cell biology, traditionally referred to as the powerhouse of the cell due to a central role in energy production. However, modern-day mitochondria are recognized as key players in eukaryotic cell biology and are known to regulate crucial cellular processes, including calcium signalling, cell metabolism and cell death, to name a few. In this review, we will discuss foundational knowledge in mitochondrial biology and provide snapshots of recent advances that showcase how mitochondrial function regulates other cellular responses.
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Affiliation(s)
- Alexander J Anderson
- Department of Biochemistry and Molecular Biology and The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Thomas D Jackson
- Department of Biochemistry and Molecular Biology and The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - David A Stroud
- Department of Biochemistry and Molecular Biology and The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Diana Stojanovski
- Department of Biochemistry and Molecular Biology and The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, 3010, Australia
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59
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Tsui HS, Pham NVB, Amer BR, Bradley MC, Gosschalk JE, Gallagher-Jones M, Ibarra H, Clubb RT, Blaby-Haas CE, Clarke CF. Human COQ10A and COQ10B are distinct lipid-binding START domain proteins required for coenzyme Q function. J Lipid Res 2019; 60:1293-1310. [PMID: 31048406 DOI: 10.1194/jlr.m093534] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 04/12/2019] [Indexed: 12/18/2022] Open
Abstract
Coenzyme Q (CoQ or ubiquinone) serves as an essential redox-active lipid in respiratory electron and proton transport during cellular energy metabolism. CoQ also functions as a membrane-localized antioxidant protecting cells against lipid peroxidation. CoQ deficiency is associated with multiple human diseases; CoQ10 supplementation in particular has noted cardioprotective benefits. In Saccharomyces cerevisiae, Coq10, a putative START domain protein, is believed to chaperone CoQ to sites where it functions. Yeast coq10 deletion mutants (coq10Δ) synthesize CoQ inefficiently during log phase growth and are respiratory defective and sensitive to oxidative stress. Humans have two orthologs of yeast COQ10, COQ10A and COQ10B Here, we tested the human co-orthologs for their ability to rescue the yeast mutant. We showed that expression of either human ortholog, COQ10A or COQ10B, rescues yeast coq10Δ mutant phenotypes, restoring the function of respiratory-dependent growth on a nonfermentable carbon source and sensitivity to oxidative stress induced by treatment with PUFAs. These effects indicate a strong functional conservation of Coq10 across different organisms. However, neither COQ10A nor COQ10B restored CoQ biosynthesis when expressed in the yeast coq10Δ mutant. The involvement of yeast Coq10 in CoQ biosynthesis may rely on its interactions with another protein, possibly Coq11, which is not found in humans. Coexpression analyses of yeast COQ10 and human COQ10A and COQ10B provide additional insights to functions of these START domain proteins and their potential roles in other biologic pathways.
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Affiliation(s)
- Hui S Tsui
- Department of Chemistry and Biochemistry and Molecular Biology Institute,University of California, Los Angeles, Los Angeles, CA 90095
| | - Nguyen V B Pham
- Department of Chemistry and Biochemistry and Molecular Biology Institute,University of California, Los Angeles, Los Angeles, CA 90095
| | - Brendan R Amer
- Department of Chemistry and Biochemistry and Molecular Biology Institute,University of California, Los Angeles, Los Angeles, CA 90095
| | - Michelle C Bradley
- Department of Chemistry and Biochemistry and Molecular Biology Institute,University of California, Los Angeles, Los Angeles, CA 90095
| | - Jason E Gosschalk
- Department of Chemistry and Biochemistry and Molecular Biology Institute,University of California, Los Angeles, Los Angeles, CA 90095.,UCLA-Department of Energy Institute of Genomics and Proteomics University of California, Los Angeles, Los Angeles, CA 90095
| | - Marcus Gallagher-Jones
- Department of Chemistry and Biochemistry and Molecular Biology Institute,University of California, Los Angeles, Los Angeles, CA 90095
| | - Hope Ibarra
- Department of Chemistry and Biochemistry and Molecular Biology Institute,University of California, Los Angeles, Los Angeles, CA 90095
| | - Robert T Clubb
- Department of Chemistry and Biochemistry and Molecular Biology Institute,University of California, Los Angeles, Los Angeles, CA 90095
| | | | - Catherine F Clarke
- Department of Chemistry and Biochemistry and Molecular Biology Institute,University of California, Los Angeles, Los Angeles, CA 90095
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60
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Nguyen TB, Olzmann JA. Getting a handle on lipid droplets: Insights into ER-lipid droplet tethering. J Cell Biol 2019; 218:1089-1091. [PMID: 30886057 PMCID: PMC6446839 DOI: 10.1083/jcb.201902160] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Nguyen and Olzmann highlight new findings from the Henne laboratory that provide insights into the functions of lipid droplet tethers. Lipid droplets (LDs) are hubs for lipid metabolism that form membrane contact sites with multiple organelles. In this issue, Hariri et al. (2019. J. Cell Biol.https://doi.org/10.1083/jcb.201808119) reveal the functions of Mdm1-mediated endoplasmic reticulum (ER)–LD tethering in yeast and Datta et al. (2019. J. Cell Biol.https://doi.org/10.1083/jcb.201808133) identify a role for the Mdm1 orthologue, Snx14, as an ER–LD tether that regulates lipid metabolism in human cells.
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Affiliation(s)
- Truc B Nguyen
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, Berkeley, CA
| | - James A Olzmann
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, Berkeley, CA .,Chan Zuckerberg Biohub, San Francisco, CA
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