1
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Doyle CP, Timple L, Hammond GRV. OSBP is a major determinant of Golgi phosphatidylinositol 4-phosphate homeostasis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.12.21.572879. [PMID: 38187665 PMCID: PMC10769437 DOI: 10.1101/2023.12.21.572879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
The lipid phosphatidylinositol 4-phosphate (PI4P) plays a master regulatory role at Golgi membranes, orchestrating membrane budding, non-vesicular lipid transport and membrane organization. It follows that harmonious Golgi function requires strictly maintained PI4P homeostasis. One of the most abundant PI4P effector proteins is the oxysterol binding protein (OSBP), a lipid transfer protein that exchanges trans Golgi PI4P for ER cholesterol. Although this protein consumes PI4P as part of its lipid anti-porter function, whether it actively contributes to Golgi PI4P homeostasis has been questioned. Here, we employed a series of acute and chronic genetic manipulations, together with orthogonal targeting of OSBP, to interrogate its control over Golgi PI4P abundance. Modulating OSBP levels at ER:Golgi membrane contact sites produces reciprocal changes in PI4P levels. Additionally, we observe that OSBP has a high capacity for PI4P turnover, even at orthogonal organelle membranes. However, despite also visiting the plasma membrane, endogenous OSBP makes no impact on PI4P levels in this compartment. We conclude that OSBP is a major determinant of Golgi PI4P homeostasis.
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Affiliation(s)
- Colleen P Doyle
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261
| | - Liz Timple
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261
| | - Gerald R V Hammond
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261
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2
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Doyle CP, Timple L, Hammond GRV. OSBP is a Major Determinant of Golgi Phosphatidylinositol 4-Phosphate Homeostasis. CONTACT (THOUSAND OAKS (VENTURA COUNTY, CALIF.)) 2024; 7:25152564241232196. [PMID: 38405037 PMCID: PMC10893830 DOI: 10.1177/25152564241232196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 01/25/2024] [Accepted: 01/26/2024] [Indexed: 02/27/2024]
Abstract
The lipid phosphatidylinositol 4-phosphate (PI4P) plays a master regulatory role at Golgi membranes, orchestrating membrane budding, non-vesicular lipid transport and membrane organization. It follows that harmonious Golgi function requires strictly maintained PI4P homeostasis. One of the most abundant PI4P effector proteins is the oxysterol binding protein (OSBP), a lipid transfer protein that exchanges trans-Golgi PI4P for ER cholesterol. Although this protein consumes PI4P as part of its lipid anti-porter function, whether it actively contributes to Golgi PI4P homeostasis has been questioned. Here, we employed a series of acute and chronic genetic manipulations, together with orthogonal targeting of OSBP, to interrogate its control over Golgi PI4P abundance. Modulating OSBP levels at ER:Golgi membrane contact sites produces reciprocal changes in PI4P levels. Additionally, we observe that OSBP has a high capacity for PI4P turnover, even at orthogonal organelle membranes. However, despite also visiting the plasma membrane, endogenous OSBP makes no impact on PI4P levels in this compartment. We conclude that OSBP is a major determinant of Golgi PI4P homeostasis.
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Affiliation(s)
- Colleen P. Doyle
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Liz Timple
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Gerald R. V. Hammond
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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3
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Khine MN, Sakurai K. Golgi-Targeting Anticancer Natural Products. Cancers (Basel) 2023; 15:cancers15072086. [PMID: 37046746 PMCID: PMC10093635 DOI: 10.3390/cancers15072086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 02/12/2023] [Accepted: 02/15/2023] [Indexed: 04/03/2023] Open
Abstract
The Golgi apparatus plays an important role in maintaining cell homeostasis by serving as a biosynthetic center for glycans, lipids and post-translationally modified proteins and as a sorting center for vesicular transport of proteins to specific destinations. Moreover, it provides a signaling hub that facilitates not only membrane trafficking processes but also cellular response pathways to various types of stresses. Altered signaling at the Golgi apparatus has emerged as a key regulator of tumor growth and survival. Among the small molecules that can specifically perturb or modulate Golgi proteins and organization, natural products with anticancer property have been identified as powerful chemical probes in deciphering Golgi-related pathways and, in particular, recently described Golgi stress response pathways. In this review, we highlight a set of Golgi-targeting natural products that enabled the characterization of the Golgi-mediated signaling events leading to cancer cell death and discuss the potential for selectively exploiting these pathways for the development of novel chemotherapeutic agents.
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4
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Fang R, Jiang Q, Jia X, Jiang Z. ARMH3-mediated recruitment of PI4KB directs Golgi-to-endosome trafficking and activation of the antiviral effector STING. Immunity 2023; 56:500-515.e6. [PMID: 36921576 DOI: 10.1016/j.immuni.2023.02.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 11/30/2022] [Accepted: 01/26/2023] [Indexed: 03/15/2023]
Abstract
The cGAS-STING pathway mediates cytoplasmic DNA-triggered innate immunity. STING activation is initiated by cyclic-GMP-AMP (cGAMP)-induced translocation from the endoplasmic reticulum and sulfated glycosaminoglycans-induced polymerization at the Golgi. Here, we examine the mechanisms underlying STING transport and activation beyond the Golgi. A genome-wide CRISPR-Cas9 screen identified Armadillo-like helical domain-containing protein 3 (ARMH3) as critical for STING activation. Upon cGAMP-triggered translocation, ARMH3 interacted with STING at the Golgi and recruited phosphatidylinositol 4-kinase beta (PI4KB) to synthesize PI4P, which directed STING Golgi-to-endosome trafficking via PI4P-binding proteins AP-1 and GGA2. Disrupting PI4P-dependent lipid transport through RNAi of other PI4P-binding proteins impaired STING activation. Consistently, disturbed lipid composition inhibited STING activation, whereas aberrantly elevated cellular PI4P led to cGAS-independent STING activation. Armh3fl/fllLyzCre/Cre mice were susceptible to DNA virus challenge in vivo. Thus, ARMH3 bridges STING and PIK4B to generate PI4P for STING transportation and activation, an interaction conserved in all eukaryotes.
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Affiliation(s)
- Run Fang
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking University, Beijing 100871, China; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Qifei Jiang
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking University, Beijing 100871, China; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Xinying Jia
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking University, Beijing 100871, China; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Zhengfan Jiang
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking University, Beijing 100871, China; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China.
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5
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Chung LH, Liu D, Liu XT, Qi Y. Ceramide Transfer Protein (CERT): An Overlooked Molecular Player in Cancer. Int J Mol Sci 2021; 22:13184. [PMID: 34947980 PMCID: PMC8705978 DOI: 10.3390/ijms222413184] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 12/02/2021] [Accepted: 12/05/2021] [Indexed: 12/26/2022] Open
Abstract
Sphingolipids are a class of essential lipids implicated in constructing cellular membranes and regulating nearly all cellular functions. Sphingolipid metabolic network is centered with the ceramide-sphingomyelin axis. Ceramide is well-recognized as a pro-apoptotic signal; while sphingomyelin, as the most abundant type of sphingolipids, is required for cell growth. Therefore, the balance between these two sphingolipids can be critical for cancer cell survival and functioning. Ceramide transfer protein (CERT) dictates the ratio of ceramide to sphingomyelin within the cell. It is the only lipid transfer protein that specifically delivers ceramide from the endoplasmic reticulum to the Golgi apparatus, where ceramide serves as the substrate for sphingomyelin synthesis. In the past two decades, an increasing body of evidence has suggested a critical role of CERT in cancer, but much more intensive efforts are required to draw a definite conclusion. Herein, we review all research findings of CERT, focusing on its molecular structure, cellular functions and implications in cancer. This comprehensive review of CERT will help to better understand the molecular mechanism of cancer and inspire to identify novel druggable targets.
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Affiliation(s)
- Long Hoa Chung
- Centenary Institute of Cancer Medicine and Cell Biology, University of Sydney, Camperdown, NSW 2050, Australia; (D.L.); (X.T.L.)
| | | | | | - Yanfei Qi
- Centenary Institute of Cancer Medicine and Cell Biology, University of Sydney, Camperdown, NSW 2050, Australia; (D.L.); (X.T.L.)
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6
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Tu YXI, Sydor AM, Coyaud E, Laurent EMN, Dyer D, Mellouk N, St-Germain J, Vernon RM, Forman-Kay JD, Li T, Hua R, Zhao K, Ridgway ND, Kim PK, Raught B, Brumell JH. Global Proximity Interactome of the Human Macroautophagy Pathway. Autophagy 2021; 18:1174-1186. [PMID: 34524948 PMCID: PMC9196747 DOI: 10.1080/15548627.2021.1965711] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Macroautophagy is a highly conserved eukaryotic cellular pathway involving the engulfment of macromolecules, organelles, and invading microbes by a double-membrane compartment and subsequent lysosomal degradation. The mechanisms that regulate macroautophagy, and the interaction of its components with other cellular pathways, have remained unclear. Here, we performed proximity-dependent biotin identification (BioID) on 39 core human macroautophagy proteins, identifying over 700 unique high confidence proximity interactors with new putative connections between macroautophagic and essential cellular processes. Of note, we identify members of the OSBPL (oxysterol binding protein like) family as Atg8-family protein interactors. We subsequently conducted comprehensive screens of the OSBPL family for LC3B-binding and roles in xenophagy and aggrephagy. OSBPL7 and OSBPL11 emerged as novel lipid transfer proteins required for macroautophagy of selective cargo. Altogether, our proximity interaction map provides a valuable resource for the study of autophagy and highlights the critical role of membrane contact site proteins in the pathway.
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Affiliation(s)
- Yi Xin Iris Tu
- Cell Biology Program, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Andrew M Sydor
- Cell Biology Program, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Etienne Coyaud
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - Estelle M N Laurent
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - Diana Dyer
- Cell Biology Program, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Nora Mellouk
- Cell Biology Program, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Jonathan St-Germain
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - Robert M Vernon
- Molecular Medicine Program, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Julie D Forman-Kay
- Molecular Medicine Program, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Taoyingnan Li
- Cell Biology Program, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Rong Hua
- Cell Biology Program, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Kexin Zhao
- Departments of Pediatrics and Biochemistry and Molecular Biology, Atlantic Research Centre, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Neale D Ridgway
- Departments of Pediatrics and Biochemistry and Molecular Biology, Atlantic Research Centre, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Peter K Kim
- Cell Biology Program, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Brian Raught
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - John H Brumell
- Cell Biology Program, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada.,Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada.,SickKids IBD Centre, Hospital for Sick Children, Toronto, Ontario, Canada
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7
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Boutry M, Kim PK. ORP1L mediated PI(4)P signaling at ER-lysosome-mitochondrion three-way contact contributes to mitochondrial division. Nat Commun 2021; 12:5354. [PMID: 34504082 PMCID: PMC8429648 DOI: 10.1038/s41467-021-25621-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 08/16/2021] [Indexed: 12/15/2022] Open
Abstract
Mitochondrial division is not an autonomous event but involves multiple organelles, including the endoplasmic reticulum (ER) and lysosomes. Whereas the ER drives the constriction of mitochondrial membranes, the role of lysosomes in mitochondrial division is not known. Here, using super-resolution live-cell imaging, we investigate the recruitment of lysosomes to the site of mitochondrial division. We find that the ER recruits lysosomes to the site of division through the interaction of VAMP-associated proteins (VAPs) with the lysosomal lipid transfer protein ORP1L to induce a three-way contact between the ER, lysosome, and the mitochondrion. We also show that ORP1L might transport phosphatidylinositol-4-phosphate (PI(4)P) from lysosomes to mitochondria, as inhibiting its transfer or depleting PI(4)P at the mitochondrial division site impairs fission, demonstrating a direct role for PI(4)P in the division process. Our findings support a model where the ER recruits lysosomes to act in concert at the fission site for the efficient division of mitochondria.
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Affiliation(s)
- Maxime Boutry
- Cell Biology Program, Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, Toronto, ON, Canada
| | - Peter K Kim
- Cell Biology Program, Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, Toronto, ON, Canada. .,Department of Biochemistry, University of Toronto, Toronto, ON, Canada.
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8
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Nakatsu F, Kawasaki A. Functions of Oxysterol-Binding Proteins at Membrane Contact Sites and Their Control by Phosphoinositide Metabolism. Front Cell Dev Biol 2021; 9:664788. [PMID: 34249917 PMCID: PMC8264513 DOI: 10.3389/fcell.2021.664788] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Accepted: 05/06/2021] [Indexed: 01/10/2023] Open
Abstract
Lipids must be correctly transported within the cell to the right place at the right time in order to be fully functional. Non-vesicular lipid transport is mediated by so-called lipid transfer proteins (LTPs), which contain a hydrophobic cavity that sequesters lipid molecules. Oxysterol-binding protein (OSBP)-related proteins (ORPs) are a family of LTPs known to harbor lipid ligands, such as cholesterol and phospholipids. ORPs act as a sensor or transporter of those lipid ligands at membrane contact sites (MCSs) where two different cellular membranes are closely apposed. In particular, a characteristic functional property of ORPs is their role as a lipid exchanger. ORPs mediate counter-directional transport of two different lipid ligands at MCSs. Several, but not all, ORPs transport their lipid ligand from the endoplasmic reticulum (ER) in exchange for phosphatidylinositol 4-phosphate (PI4P), the other ligand, on apposed membranes. This ORP-mediated lipid “countertransport” is driven by the concentration gradient of PI4P between membranes, which is generated by its kinases and phosphatases. In this review, we will discuss how ORP function is tightly coupled to metabolism of phosphoinositides such as PI4P. Recent progress on the role of ORP-mediated lipid transport/countertransport at multiple MCSs in cellular functions will be also discussed.
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Affiliation(s)
- Fubito Nakatsu
- Department of Neurochemistry and Molecular Cell Biology, Niigata University School of Medicine and Graduate School of Medical/Dental Sciences, Niigata, Japan
| | - Asami Kawasaki
- Department of Neurochemistry and Molecular Cell Biology, Niigata University School of Medicine and Graduate School of Medical/Dental Sciences, Niigata, Japan
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9
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Meng Y, Heybrock S, Neculai D, Saftig P. Cholesterol Handling in Lysosomes and Beyond. Trends Cell Biol 2020; 30:452-466. [PMID: 32413315 DOI: 10.1016/j.tcb.2020.02.007] [Citation(s) in RCA: 90] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 02/14/2020] [Accepted: 02/21/2020] [Indexed: 01/06/2023]
Abstract
Lysosomes are of major importance for the regulation of cellular cholesterol homeostasis. Food-derived cholesterol and cholesterol esters contained within lipoproteins are delivered to lysosomes by endocytosis. From the lysosomal lumen, cholesterol is transported to the inner surface of the lysosomal membrane through the glycocalyx; this shuttling requires Niemann-Pick C (NPC) 1 and NPC2 proteins. The lysosomal membrane proteins lysosomal-associated membrane protein (LAMP)-2 and lysosomal integral membrane protein (LIMP)-2/SCARB2 also bind cholesterol. LAMP-2 may serve as a cholesterol reservoir, whereas LIMP-2, like NPC1, is able to transport cholesterol through a transglycocalyx tunnel. Contact sites and fusion events between lysosomes and other organelles mediate the distribution of cholesterol. Lysosomal cholesterol content is sensed thereby regulating mammalian target of rapamycin complex (mTORC)-dependent signaling. This review summarizes our understanding of the major steps in cholesterol handling from the moment it enters the lysosome until it leaves this compartment.
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Affiliation(s)
- Ying Meng
- Department of Cell Biology, School of Basic Medical Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Saskia Heybrock
- Biochemisches Institut, Christian-Albrechts-Universität Kiel, Kiel, Germany
| | - Dante Neculai
- Department of Cell Biology, School of Basic Medical Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Paul Saftig
- Biochemisches Institut, Christian-Albrechts-Universität Kiel, Kiel, Germany.
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10
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ER-lysosome contacts enable cholesterol sensing by mTORC1 and drive aberrant growth signalling in Niemann-Pick type C. Nat Cell Biol 2019; 21:1206-1218. [PMID: 31548609 PMCID: PMC6936960 DOI: 10.1038/s41556-019-0391-5] [Citation(s) in RCA: 177] [Impact Index Per Article: 35.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 08/15/2019] [Indexed: 12/24/2022]
Abstract
Cholesterol activates the master growth regulator, mTORC1 kinase, by promoting its recruitment to the surface of lysosomes via the Rag guanosine triphosphatases (GTPases). The mechanisms that regulate lysosomal cholesterol content to enable mTORC1 signaling are unknown. We show that Oxysterol Binding Protein (OSBP) and its anchors at the endoplasmic reticulum (ER), VAPA/B, deliver cholesterol across ER-lysosome contacts to activate mTORC1. In cells lacking OSBP, but not other VAP-interacting cholesterol carriers, mTORC1 recruitment by the Rag GTPases is inhibited due to impaired cholesterol transport to lysosomes. Conversely, OSBP-mediated cholesterol trafficking drives constitutive mTORC1 activation in a disease model caused by loss of the lysosomal cholesterol transporter, Niemann-Pick C1 (NPC1). Chemical and genetic inactivation of OSBP suppresses aberrant mTORC1 signaling and restores autophagic function in cellular models of NPC. Thus, ER-lysosome contacts are signaling hubs that enable cholesterol sensing by mTORC1, and targeting their sterol-transfer activity could be beneficial in NPC.
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11
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von Blume J, Hausser A. Lipid-dependent coupling of secretory cargo sorting and trafficking at the trans-Golgi network. FEBS Lett 2019; 593:2412-2427. [PMID: 31344259 PMCID: PMC8048779 DOI: 10.1002/1873-3468.13552] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 07/10/2019] [Accepted: 07/22/2019] [Indexed: 12/17/2022]
Abstract
In eukaryotic cells, the trans-Golgi network (TGN) serves as a platform for secretory cargo sorting and trafficking. In recent years, it has become evident that a complex network of lipid–lipid and lipid–protein interactions contributes to these key functions. This review addresses the role of lipids at the TGN with a particular emphasis on sphingolipids and diacylglycerol. We further highlight how these lipids couple secretory cargo sorting and trafficking for spatiotemporal coordination of protein transport to the plasma membrane.
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Affiliation(s)
- Julia von Blume
- Department of Cell Biology, Yale School of Medicine, New Haven, CT, USA.,Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Angelika Hausser
- Institute of Cell Biology and Immunology, University of Stuttgart, Germany.,Stuttgart Research Center Systems Biology, University of Stuttgart, Germany
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12
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Kumagai K, Hanada K. Structure, functions and regulation of CERT, a lipid-transfer protein for the delivery of ceramide at the ER-Golgi membrane contact sites. FEBS Lett 2019; 593:2366-2377. [PMID: 31254361 DOI: 10.1002/1873-3468.13511] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 06/26/2019] [Accepted: 06/26/2019] [Indexed: 12/17/2022]
Abstract
The inter-organelle transport of lipids must be regulated to ensure appropriate lipid composition of each organelle. In mammalian cells, ceramide synthesised in the endoplasmic reticulum (ER) is transported to the trans-Golgi regions, where ceramide is converted to sphingomyelin (SM) with the concomitant production of diacylglycerol. Ceramide transport protein (CERT) transports ceramide from the ER to the trans-Golgi regions at the ER-Golgi membrane contact sites (MCS). The function of CERT is down-regulated by multisite phosphorylation of a serine-repeat motif (SRM) and up-regulated by phosphorylation of serine 315 in CERT. Multisite phosphorylation of the SRM is primed by protein kinase D, which is activated by diacylglycerol. The function of CERT is regulated by a phosphorylation-dependent feedback mechanism in response to cellular requirements of SM. CERT-dependent ceramide transport is also affected by the pool of phosphatidylinositol (PtdIns)-4-phosphate (PtdIns(4)P) in the trans-Golgi regions, while the PtdIns(4)P pool is regulated by PtdIns-4-kinases and oxysterol-binding protein. The ER-Golgi MCS may serve as inter-organelle communication zones, in which many factors work in concert to serve as an extensive rheostat of SM, diacylglycerol, cholesterol and PtdIns(4)P.
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Affiliation(s)
- Keigo Kumagai
- Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Kentaro Hanada
- Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, Tokyo, Japan
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13
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Funato K, Riezman H, Muñiz M. Vesicular and non-vesicular lipid export from the ER to the secretory pathway. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1865:158453. [PMID: 31054928 DOI: 10.1016/j.bbalip.2019.04.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 12/20/2018] [Accepted: 01/06/2019] [Indexed: 11/26/2022]
Abstract
The endoplasmic reticulum is the site of synthesis of most glycerophospholipids, neutral lipids and the initial steps of sphingolipid biosynthesis of the secretory pathway. After synthesis, these lipids are distributed within the cells to create and maintain the specific compositions of the other secretory organelles. This represents a formidable challenge, particularly while there is a simultaneous and quantitatively important flux of membrane components stemming from the vesicular traffic of proteins through the pathway, which can also vary depending on the cell type and status. To meet this challenge cells have developed an intricate system of interorganellar contacts and lipid transport proteins, functioning in non-vesicular lipid transport, which are able to ensure membrane lipid homeostasis even in the absence of membrane trafficking. Nevertheless, under normal conditions, lipids are transported in cells by both vesicular and non-vesicular mechanisms. In this review we will discuss the mechanism and roles of vesicular and non-vesicular transport of lipids from the ER to other organelles of the secretory pathway.
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Affiliation(s)
- Kouichi Funato
- Department of Bioresource Science and Technology, Hiroshima University, Japan.
| | - Howard Riezman
- NCCR Chemical Biology and Department of Biochemistry, Sciences II, University of Geneva, Switzerland.
| | - Manuel Muñiz
- Department of Cell Biology, University of Seville, 41012 Seville, Spain; Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Spain.
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14
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Genevini P, Colombo MN, Venditti R, Marcuzzo S, Colombo SF, Bernasconi P, De Matteis MA, Borgese N, Navone F. VAPB depletion alters neuritogenesis and phosphoinositide balance in motoneuron-like cells: relevance to VAPB-linked amyotrophic lateral sclerosis. J Cell Sci 2019; 132:jcs.220061. [PMID: 30745341 DOI: 10.1242/jcs.220061] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 02/01/2019] [Indexed: 12/12/2022] Open
Abstract
VAPB and VAPA are ubiquitously expressed endoplasmic reticulum membrane proteins that play key roles in lipid exchange at membrane contact sites. A mutant, aggregation-prone, form of VAPB (P56S) is linked to a dominantly inherited form of amyotrophic lateral sclerosis; however, it has been unclear whether its pathogenicity is due to toxic gain of function, to negative dominance, or simply to insufficient levels of the wild-type protein produced from a single allele (haploinsufficiency). To investigate whether reduced levels of functional VAPB, independently from the presence of the mutant form, affect the physiology of mammalian motoneuron-like cells, we generated NSC34 clones, from which VAPB was partially or nearly completely depleted. VAPA levels, determined to be over fourfold higher than those of VAPB in untransfected cells, were unaffected. Nonetheless, cells with even partially depleted VAPB showed an increase in Golgi- and acidic vesicle-localized phosphatidylinositol-4-phosphate (PI4P) and reduced neurite extension when induced to differentiate. Conversely, the PI4 kinase inhibitors PIK93 and IN-10 increased neurite elongation. Thus, for long-term survival, motoneurons might require the full dose of functional VAPB, which may have unique function(s) that VAPA cannot perform.
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Affiliation(s)
- Paola Genevini
- Consiglio Nazionale delle Ricerche Neuroscience Institute and BIOMETRA Department, Università degli Studi di Milano, Milan 20129, Italy
| | - Maria Nicol Colombo
- Consiglio Nazionale delle Ricerche Neuroscience Institute and BIOMETRA Department, Università degli Studi di Milano, Milan 20129, Italy
| | | | - Stefania Marcuzzo
- Neurology IV - Neuroimmunology and Neuromuscular Diseases Unit, Fondazione Istituto Neurologico 'Carlo Besta', Milan 20133, Italy
| | - Sara Francesca Colombo
- Consiglio Nazionale delle Ricerche Neuroscience Institute and BIOMETRA Department, Università degli Studi di Milano, Milan 20129, Italy
| | - Pia Bernasconi
- Neurology IV - Neuroimmunology and Neuromuscular Diseases Unit, Fondazione Istituto Neurologico 'Carlo Besta', Milan 20133, Italy
| | - Maria Antonietta De Matteis
- Telethon Institute of Genetics and Medicine, Pozzuoli 80078, Italy.,Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Naples 80133, Italy
| | - Nica Borgese
- Consiglio Nazionale delle Ricerche Neuroscience Institute and BIOMETRA Department, Università degli Studi di Milano, Milan 20129, Italy
| | - Francesca Navone
- Consiglio Nazionale delle Ricerche Neuroscience Institute and BIOMETRA Department, Università degli Studi di Milano, Milan 20129, Italy
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15
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Definition of phosphoinositide distribution in the nanoscale. Curr Opin Cell Biol 2019; 57:33-39. [DOI: 10.1016/j.ceb.2018.10.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 10/18/2018] [Accepted: 10/30/2018] [Indexed: 11/20/2022]
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16
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Nakao N, Ueno M, Sakai S, Egawa D, Hanzawa H, Kawasaki S, Kumagai K, Suzuki M, Kobayashi S, Hanada K. Natural ligand-nonmimetic inhibitors of the lipid-transfer protein CERT. Commun Chem 2019. [DOI: 10.1038/s42004-019-0118-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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17
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Roberts BL, Severance ZC, Bensen RC, Le AT, Kothapalli NR, Nuñez JI, Ma H, Wu S, Standke SJ, Yang Z, Reddig WJ, Blewett EL, Burgett AWG. Transient Compound Treatment Induces a Multigenerational Reduction of Oxysterol-Binding Protein (OSBP) Levels and Prophylactic Antiviral Activity. ACS Chem Biol 2019; 14:276-287. [PMID: 30576108 PMCID: PMC6379863 DOI: 10.1021/acschembio.8b00984] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
![]()
Oxysterol-binding
protein (OSBP) is a lipid transport and regulatory
protein required for the replication of Enterovirus genus viruses, which includes many significant human pathogens.
Short-term exposure (i.e., 1–6 h) to a low dose (i.e., 1 nM)
of the natural product compound OSW-1 induces a reduction of cellular
OSBP levels by ∼90% in multiple different cell lines with no
measurable cytotoxicity, defect in cellular proliferation, or global
proteome reduction. Interestingly, the reduction of OSBP levels persists
multiple days after the low-dose, transient OSW-1 compound treatment
is ended and the intracellular OSW-1 compound levels drop to undetectable
levels. The reduction in OSBP levels is inherited in multiple generations
of cells that are propagated after the OSW-1 compound treatment is
stopped. The enduring multiday, multigenerational reduction of OSBP
levels triggered by the OSW-1 compound is not due to proteasome degradation
of OSBP or due to a reduction in OSBP mRNA levels. OSW-1 compound
treatment induces transient autophagy in cells, but blocking autophagy
does not rescue OSBP levels. Although the specific cellular mechanism
of long-term OSBP repression is not yet identified, these results
clearly show the existence of an OSBP specific cellular regulation
process that is triggered upon treatment with an OSBP-binding compound.
The stable reduction of OSBP levels upon short-term, transient OSW-1
compound treatment will be a powerful tool to understand OSBP regulation
and cellular function. Additionally, the persistent reduction in OSBP
levels triggered by the transient OSW-1 compound treatment substantially
reduces viral replication in treated cells. Therefore, the long-term,
compound-induced reduction of OSBP in cells presents a new route to
broad spectrum anti-Enterovirus activity, including
as a novel route to antiviral prophylactic treatment through small
molecule targeting a human host protein.
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Affiliation(s)
- Brett L. Roberts
- Department of Chemistry and Biochemistry, The University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Zachary C. Severance
- Department of Chemistry and Biochemistry, The University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Ryan C. Bensen
- Department of Chemistry and Biochemistry, The University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Anh T. Le
- Department of Chemistry and Biochemistry, The University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Naga Rama Kothapalli
- Department of Chemistry and Biochemistry, The University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Juan I. Nuñez
- Department of Chemistry and Biochemistry, The University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Hongyan Ma
- Department of Chemistry and Biochemistry, The University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Si Wu
- Department of Chemistry and Biochemistry, The University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Shawna J. Standke
- Department of Chemistry and Biochemistry, The University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Zhibo Yang
- Department of Chemistry and Biochemistry, The University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - William J. Reddig
- Department of Biochemistry and Microbiology, Oklahoma State University Center for Health Sciences, 1111 West 17th Street, Tulsa, Oklahoma 74107, United States
| | - Earl L. Blewett
- Department of Biochemistry and Microbiology, Oklahoma State University Center for Health Sciences, 1111 West 17th Street, Tulsa, Oklahoma 74107, United States
| | - Anthony W. G. Burgett
- Department of Chemistry and Biochemistry, The University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
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18
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Goto A, Charman M, Ridgway ND. Protein kinase D1 and oxysterol-binding protein form a regulatory complex independent of phosphorylation. Traffic 2018; 19:854-866. [DOI: 10.1111/tra.12609] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 08/08/2018] [Accepted: 08/08/2018] [Indexed: 12/25/2022]
Affiliation(s)
- Asako Goto
- Department of Pediatrics; Atlantic Research Centre, Dalhousie University; Halifax Nova Scotia Canada
- Department of Molecular Biology and Molecular Biology; Atlantic Research Centre, Dalhousie University; Halifax Nova Scotia Canada
| | - Mark Charman
- Department of Pediatrics; Atlantic Research Centre, Dalhousie University; Halifax Nova Scotia Canada
- Department of Molecular Biology and Molecular Biology; Atlantic Research Centre, Dalhousie University; Halifax Nova Scotia Canada
| | - Neale D. Ridgway
- Department of Pediatrics; Atlantic Research Centre, Dalhousie University; Halifax Nova Scotia Canada
- Department of Molecular Biology and Molecular Biology; Atlantic Research Centre, Dalhousie University; Halifax Nova Scotia Canada
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19
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Hanada K. Lipid transfer proteins rectify inter-organelle flux and accurately deliver lipids at membrane contact sites. J Lipid Res 2018; 59:1341-1366. [PMID: 29884707 PMCID: PMC6071762 DOI: 10.1194/jlr.r085324] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 05/24/2018] [Indexed: 12/22/2022] Open
Abstract
The endoplasmic reticulum (ER) is the main center for the synthesis of various lipid types in cells, and newly synthesized lipids are delivered from the ER to other organelles. In the past decade, various lipid transfer proteins (LTPs) have been recognized as mediators of lipid transport from the ER to other organelles; inter-organelle transport occurs at membrane contact sites (MCSs) and in a nonvesicular manner. Although the intermembrane transfer reaction catalyzed by LTPs is an equilibrium reaction, various types of newly synthesized lipids are transported unidirectionally in cells. This review provides a brief history of the inter-organelle trafficking of lipids and summarizes the structural and biochemical characteristics of the ceramide transport protein (CERT) as a typical LTP acting at MCSs. In addition, this review compares several LTP-mediated inter-organelle lipid trafficking systems and proposes that LTPs generate unidirectional fluxes of specific lipids between different organelles by indirect coupling with the metabolic reactions that occur in specific organelles. Moreover, the available data also suggest that the major advantage of LTP-mediated lipid transport at MCSs may be the accuracy of delivery. Finally, how cholesterol is enriched in the plasma membrane is discussed from a thermodynamic perspective.
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Affiliation(s)
- Kentaro Hanada
- Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo 162-8640, Japan
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20
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Pietrangelo A, Ridgway ND. Golgi localization of oxysterol binding protein-related protein 4L (ORP4L) is regulated by ligand binding. J Cell Sci 2018; 131:jcs.215335. [PMID: 29930082 DOI: 10.1242/jcs.215335] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 06/06/2018] [Indexed: 12/18/2022] Open
Abstract
Oxysterol binding protein (OSBP)-related protein 4L (ORP4L, also known as OSBPL2), a closely related paralogue and interacting partner of OSBP, binds sterols and phosphatidylinositol 4-phosphate [PI(4)P] and regulates cell proliferative signalling at the plasma membrane (PM). Here, we report that ORP4L also interacts with the trans-Golgi network (TGN) in an OSBP-, sterol- and PI(4)P-dependent manner. Characterization of ORP4L lipid and VAP binding mutants indicated an indirect mechanism for translocation to ER-Golgi contact sites in response to 25-hydroxycholesterol that was dependent on OSBP and PI(4)P. shRNA silencing revealed that ORP4L was required to maintain the organization and PI(4)P content of the Golgi and TGN. In contrast, the interaction of ORP4L with the PM was not dependent on its sterol, PI(4)P or VAP binding activities. At the PM, ORP4L partially localized with a genetically encoded probe for PI(4)P but not with a probe for phosphatidylinositol 4,5-bisphosphate. We conclude that ORP4L is differentially localized to the PM and ER-Golgi contacts sites. OSBP-, lipid- and VAP-regulated interactions of ORP4L with ER-Golgi contact sites are involved in the maintenance of Golgi and TGN structure.
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Affiliation(s)
- Antonietta Pietrangelo
- Atlantic Research Center, Departments of Pediatrics and Biochemistry & Molecular Biology, Dalhousie University, Halifax, NS, Canada, B3H 4R2
| | - Neale D Ridgway
- Atlantic Research Center, Departments of Pediatrics and Biochemistry & Molecular Biology, Dalhousie University, Halifax, NS, Canada, B3H 4R2
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21
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Mukherjee P, Madarati H, Ridgway ND, Atkinson J. Lipid and membrane recognition by the oxysterol binding protein and its phosphomimetic mutant using dual polarization interferometry. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:2356-2365. [PMID: 29879417 DOI: 10.1016/j.bbamem.2018.05.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Revised: 05/22/2018] [Accepted: 05/31/2018] [Indexed: 10/14/2022]
Abstract
OSBP binds, extracts and transfers sterols and phosphatidylinositol-4-phosphate (PI(4)P between liposomes, but the sequence of steps at the membrane surface leading to ligand removal is poorly characterized. In this study, we used dual polarization interferometry (DPI), a label-free surface analytical technique, to characterize the interaction of recombinant, purified OSBP as it flows over immobilized dioleoyl-phosphatidylcholine (DOPC) bilayers containing PI(4)P, cholesterol or 25-hydroxycholesterol. Kinetics of membrane interaction were analyzed for PI(4)P-binding and phosphorylation mutants of OSBP. Wild-type OSBP demonstrated a distinctive association with immobilized DOPC bilayers containing 1-8 mol% PI(4)P that was characterized by initial saturable binding followed by desorption, indicative of PI(4)P extraction. In support of this conclusion, an OSBP mutant with impaired binding and extraction of PI(4)P was stably absorbed to PI(4)P-containing membranes, while a pleckstrin homology domain mutant did not associate with PI(4)P-containing membranes. The inclusion of >2 mol% cholesterol, but not 25-hydroxycholesterol, in membranes, enhanced the absorption of the wild-type OSBP. A phosphomimetic of OSBP with enhanced in vitro sterol binding activity displayed membrane interaction properties similar to wild-type. These real-time flow studies allow us to dissect the association of OSBP with PI(4)P into discrete components; initial recruitment to PI(4)P membranes by the PH domain, detection and extraction of PI(4)P, and desorption due to ligand depletion.
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Affiliation(s)
- Parthajit Mukherjee
- Department of Chemistry and Centre for Biotechnology, Brock University, St. Catharines, Ontario L2A 3S1, Canada
| | - Hasam Madarati
- Department of Chemistry and Centre for Biotechnology, Brock University, St. Catharines, Ontario L2A 3S1, Canada
| | - Neale D Ridgway
- Department of Pediatrics and Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Jeffrey Atkinson
- Department of Chemistry and Centre for Biotechnology, Brock University, St. Catharines, Ontario L2A 3S1, Canada.
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22
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Sugiki T, Egawa D, Kumagai K, Kojima C, Fujiwara T, Takeuchi K, Shimada I, Hanada K, Takahashi H. Phosphoinositide binding by the PH domain in ceramide transfer protein (CERT) is inhibited by hyperphosphorylation of an adjacent serine-repeat motif. J Biol Chem 2018; 293:11206-11217. [PMID: 29848549 DOI: 10.1074/jbc.ra118.002465] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 05/24/2018] [Indexed: 12/13/2022] Open
Abstract
Sphingolipids such as ceramide are important constituents of cell membranes. The ceramide transfer protein (CERT) moves ceramide from the endoplasmic reticulum to the Golgi apparatus in a nonvesicular manner. Hyperphosphorylation of the serine-repeat motif (SRM) adjacent to the pleckstrin homology (PH) domain of CERT down-regulates the inter-organelle ceramide transport function of CERT. However, the mechanistic details of this down-regulation remain elusive. Using solution NMR and binding assays, we herein show that a hyperphosphorylation-mimetic CERT variant in which 10 serine/threonine residues of SRM had been replaced with glutamate residues (the 10E variant) displays an intramolecular interaction between SRM and positively charged regions of the PH domain, which are involved in the binding of this domain to phosphatidylinositol 4-monophosphate (PI4P). Of note, the binding of the PH domain to PI4P-embedded membranes was attenuated by the SRM 10E substitutions in cell-free assays. Moreover, the 10E substitutions reduced the Golgi-targeting activity of the PH-SRM construct in living cells. These results indicate that hyperphosphorylated SRM directly interacts with the surface of the PH domain in an intramolecular manner, thereby decreasing the PI4P-binding activity of the PH domain. In light of these findings, we propose that the hyperphosphorylation of SRM may trigger the dissociation of CERT from the Golgi apparatus, resulting in a functionally less active conformation of CERT.
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Affiliation(s)
- Toshihiko Sugiki
- From the Graduate School of Pharmaceutical Sciences, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.,the Japan Biological Informatics Consortium (JBiC), Aomi, Koto-ku, Tokyo 135-8073, Japan.,the Biomedicinal Information Research Center (BIRC), National Institute of Advanced Industrial Science and Technology (AIST), Aomi, Koto-ku, Tokyo 135-0064, Japan.,the Institute for Protein Research, Osaka University, Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Daichi Egawa
- the Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Keigo Kumagai
- the Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Chojiro Kojima
- the Institute for Protein Research, Osaka University, Yamadaoka, Suita, Osaka 565-0871, Japan.,the Graduate School and Faculty of Engineering, Yokohama National University, Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan, and
| | - Toshimichi Fujiwara
- the Institute for Protein Research, Osaka University, Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Koh Takeuchi
- the Biomedicinal Information Research Center (BIRC), National Institute of Advanced Industrial Science and Technology (AIST), Aomi, Koto-ku, Tokyo 135-0064, Japan
| | - Ichio Shimada
- From the Graduate School of Pharmaceutical Sciences, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.,the Biomedicinal Information Research Center (BIRC), National Institute of Advanced Industrial Science and Technology (AIST), Aomi, Koto-ku, Tokyo 135-0064, Japan
| | - Kentaro Hanada
- the Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, Toyama, Shinjuku-ku, Tokyo 162-8640, Japan,
| | - Hideo Takahashi
- the Biomedicinal Information Research Center (BIRC), National Institute of Advanced Industrial Science and Technology (AIST), Aomi, Koto-ku, Tokyo 135-0064, Japan, .,the Graduate School of Medical Life Science, Yokohama City University, Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
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23
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Vance JE. Historical perspective: phosphatidylserine and phosphatidylethanolamine from the 1800s to the present. J Lipid Res 2018; 59:923-944. [PMID: 29661786 DOI: 10.1194/jlr.r084004] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 04/12/2018] [Indexed: 12/17/2022] Open
Abstract
This article provides a historical account of the discovery, chemistry, and biochemistry of two ubiquitous phosphoglycerolipids, phosphatidylserine (PS) and phosphatidylethanolamine (PE), including the ether lipids. In addition, the article describes the biosynthetic pathways for these phospholipids and how these pathways were elucidated. Several unique functions of PS and PE in mammalian cells in addition to their ability to define physical properties of membranes are discussed. For example, the translocation of PS from the inner to the outer leaflet of the plasma membrane of cells occurs during apoptosis and during some other specific physiological processes, and this translocation is responsible for profound life-or-death events. Moreover, mitochondrial function is severely impaired when the PE content of mitochondria is reduced below a threshold level. The discovery and implications of the existence of membrane contact sites between the endoplasmic reticulum and mitochondria and their relevance for PS and PE metabolism, as well as for mitochondrial function, are also discussed. Many of the recent advances in these fields are due to the use of isotope labeling for tracing biochemical pathways. In addition, techniques for disruption of specific genes in mice are now widely used and have provided major breakthroughs in understanding the roles and metabolism of PS and PE in vivo.
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Affiliation(s)
- Jean E Vance
- Department of Medicine and Group on the Molecular and Cell Biology of Lipids, University of Alberta, Edmonton, Alberta T6G 2S2, Canada.
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24
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Antonny B, Bigay J, Mesmin B. The Oxysterol-Binding Protein Cycle: Burning Off PI(4)P to Transport Cholesterol. Annu Rev Biochem 2018; 87:809-837. [PMID: 29596003 DOI: 10.1146/annurev-biochem-061516-044924] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
To maintain an asymmetric distribution of ions across membranes, protein pumps displace ions against their concentration gradient by using chemical energy. Here, we describe a functionally analogous but topologically opposite process that applies to the lipid transfer protein (LTP) oxysterol-binding protein (OSBP). This multidomain protein exchanges cholesterol for the phosphoinositide phosphatidylinositol 4-phosphate [PI(4)P] between two apposed membranes. Because of the subsequent hydrolysis of PI(4)P, this counterexchange is irreversible and contributes to the establishment of a cholesterol gradient along organelles of the secretory pathway. The facts that some natural anti-cancer molecules block OSBP and that many viruses hijack the OSBP cycle for the formation of intracellular replication organelles highlight the importance and potency of OSBP-mediated lipid exchange. The architecture of some LTPs is similar to that of OSBP, suggesting that the principles of the OSBP cycle-burning PI(4)P for the vectorial transfer of another lipid-might be general.
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Affiliation(s)
- Bruno Antonny
- Institut de Pharmacologie Moléculaire et Cellulaire, CNRS UMR 7275, Université Côte d'Azur, 06560 Valbonne, France;
| | - Joëlle Bigay
- Institut de Pharmacologie Moléculaire et Cellulaire, CNRS UMR 7275, Université Côte d'Azur, 06560 Valbonne, France;
| | - Bruno Mesmin
- Institut de Pharmacologie Moléculaire et Cellulaire, CNRS UMR 7275, Université Côte d'Azur, 06560 Valbonne, France;
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25
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Zewe JP, Wills RC, Sangappa S, Goulden BD, Hammond GR. SAC1 degrades its lipid substrate PtdIns4 P in the endoplasmic reticulum to maintain a steep chemical gradient with donor membranes. eLife 2018; 7:35588. [PMID: 29461204 PMCID: PMC5829913 DOI: 10.7554/elife.35588] [Citation(s) in RCA: 101] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 02/13/2018] [Indexed: 12/22/2022] Open
Abstract
Gradients of PtdIns4P between organelle membranes and the endoplasmic reticulum (ER) are thought to drive counter-transport of other lipids via non-vesicular traffic. This novel pathway requires the SAC1 phosphatase to degrade PtdIns4P in a 'cis' configuration at the ER to maintain the gradient. However, SAC1 has also been proposed to act in 'trans' at membrane contact sites, which could oppose lipid traffic. It is therefore crucial to determine which mode SAC1 uses in living cells. We report that acute inhibition of SAC1 causes accumulation of PtdIns4P in the ER, that SAC1 does not enrich at membrane contact sites, and that SAC1 has little activity in 'trans', unless a linker is added between its ER-anchored and catalytic domains. The data reveal an obligate 'cis' activity of SAC1, supporting its role in non-vesicular lipid traffic and implicating lipid traffic more broadly in inositol lipid homeostasis and function.
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Affiliation(s)
- James P Zewe
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, United States
| | - Rachel C Wills
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, United States
| | - Sahana Sangappa
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, United States
| | - Brady D Goulden
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, United States
| | - Gerald Rv Hammond
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, United States
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26
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A Lipid Transfer Protein Signaling Axis Exerts Dual Control of Cell-Cycle and Membrane Trafficking Systems. Dev Cell 2018; 44:378-391.e5. [PMID: 29396115 DOI: 10.1016/j.devcel.2017.12.026] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 09/24/2017] [Accepted: 12/28/2017] [Indexed: 11/21/2022]
Abstract
Kes1/Osh4 is a member of the conserved, but functionally enigmatic, oxysterol binding protein-related protein (ORP) superfamily that inhibits phosphatidylinositol transfer protein (Sec14)-dependent membrane trafficking through the trans-Golgi (TGN)/endosomal network. We now report that Kes1, and select other ORPs, execute cell-cycle control activities as functionally non-redundant inhibitors of the G1/S transition when cells confront nutrient-poor environments and promote replicative aging. Kes1-dependent cell-cycle regulation requires the Greatwall/MASTL kinase ortholog Rim15, and is opposed by Sec14 activity in a mechanism independent of Kes1/Sec14 bulk membrane-trafficking functions. Moreover, the data identify Kes1 as a non-histone target for NuA4 through which this lysine acetyltransferase co-modulates membrane-trafficking and cell-cycle activities. We propose the Sec14/Kes1 lipid-exchange protein pair constitutes part of the mechanism for integrating TGN/endosomal lipid signaling with cell-cycle progression and hypothesize that ORPs define a family of stage-specific cell-cycle control factors that execute tumor-suppressor-like functions.
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27
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Arenas F, Garcia-Ruiz C, Fernandez-Checa JC. Intracellular Cholesterol Trafficking and Impact in Neurodegeneration. Front Mol Neurosci 2017; 10:382. [PMID: 29204109 PMCID: PMC5698305 DOI: 10.3389/fnmol.2017.00382] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 11/02/2017] [Indexed: 12/13/2022] Open
Abstract
Cholesterol is a critical component of membrane bilayers where it plays key structural and functional roles by regulating the activity of diverse signaling platforms and pathways. Particularly enriched in brain, cholesterol homeostasis in this organ is singular with respect to other tissues and exhibits a heterogeneous regulation in distinct brain cell populations. Due to the key role of cholesterol in brain physiology and function, alterations in cholesterol homeostasis and levels have been linked to brain diseases and neurodegeneration. In the case of Alzheimer disease (AD), however, this association remains unclear with evidence indicating that either increased or decreased total brain cholesterol levels contribute to this major neurodegenerative disease. Here, rather than analyzing the role of total cholesterol levels in neurodegeneration, we focus on the contribution of intracellular cholesterol pools, particularly in endolysosomes and mitochondria through its trafficking via specialized membrane domains delineated by the contacts between endoplasmic reticulum and mitochondria, in the onset of prevalent neurodegenerative diseases such as AD, Parkinson disease, and Huntington disease as well as in lysosomal disorders like Niemann-Pick type C disease. We dissect molecular events associated with intracellular cholesterol accumulation, especially in mitochondria, an event that results in impaired mitochondrial antioxidant defense and function. A better understanding of the mechanisms involved in the distribution of cholesterol in intracellular compartments may shed light on the role of cholesterol homeostasis disruption in neurodegeneration and may pave the way for specific intervention opportunities.
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Affiliation(s)
- Fabian Arenas
- Department of Cell Death and Proliferation, Instituto de Investigaciones Biomédicas de Barcelona, Consejo Superior de Investigaciones Científicas, Barcelona, Spain
- Liver Unit and Hospital Clinic I Provincial, IDIBAPS, Barcelona, Spain
- Centro de Investigación Biomédica en Red, CIBEREHD, Barcelona, Spain
| | - Carmen Garcia-Ruiz
- Department of Cell Death and Proliferation, Instituto de Investigaciones Biomédicas de Barcelona, Consejo Superior de Investigaciones Científicas, Barcelona, Spain
- Liver Unit and Hospital Clinic I Provincial, IDIBAPS, Barcelona, Spain
- Centro de Investigación Biomédica en Red, CIBEREHD, Barcelona, Spain
- Southern California Research Center for ALDP and Cirrhosis, Los Angeles, CA, United States
| | - Jose C. Fernandez-Checa
- Department of Cell Death and Proliferation, Instituto de Investigaciones Biomédicas de Barcelona, Consejo Superior de Investigaciones Científicas, Barcelona, Spain
- Liver Unit and Hospital Clinic I Provincial, IDIBAPS, Barcelona, Spain
- Centro de Investigación Biomédica en Red, CIBEREHD, Barcelona, Spain
- Southern California Research Center for ALDP and Cirrhosis, Los Angeles, CA, United States
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28
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Mesmin B, Bigay J, Polidori J, Jamecna D, Lacas-Gervais S, Antonny B. Sterol transfer, PI4P consumption, and control of membrane lipid order by endogenous OSBP. EMBO J 2017; 36:3156-3174. [PMID: 28978670 DOI: 10.15252/embj.201796687] [Citation(s) in RCA: 152] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 08/28/2017] [Accepted: 09/04/2017] [Indexed: 11/09/2022] Open
Abstract
The network of proteins that orchestrate the distribution of cholesterol among cellular organelles is not fully characterized. We previously proposed that oxysterol-binding protein (OSBP) drives cholesterol/PI4P exchange at contact sites between the endoplasmic reticulum (ER) and the trans-Golgi network (TGN). Using the inhibitor OSW-1, we report here that the sole activity of endogenous OSBP makes a major contribution to cholesterol distribution, lipid order, and PI4P turnover in living cells. Blocking OSBP causes accumulation of sterols at ER/lipid droplets at the expense of TGN, thereby reducing the gradient of lipid order along the secretory pathway. OSBP consumes about half of the total cellular pool of PI4P, a consumption that depends on the amount of cholesterol to be transported. Inhibiting the spatially restricted PI4-kinase PI4KIIIβ triggers large periodic traveling waves of PI4P across the TGN These waves are cadenced by long-range PI4P production by PI4KIIα and PI4P consumption by OSBP Collectively, these data indicate a massive spatiotemporal coupling between cholesterol transport and PI4P turnover via OSBP and PI4-kinases to control the lipid composition of subcellular membranes.
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Affiliation(s)
- Bruno Mesmin
- Université Côte d'Azur, Inserm, CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne, France
| | - Joëlle Bigay
- Université Côte d'Azur, Inserm, CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne, France
| | - Joël Polidori
- Université Côte d'Azur, Inserm, CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne, France
| | - Denisa Jamecna
- Université Côte d'Azur, Inserm, CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne, France
| | | | - Bruno Antonny
- Université Côte d'Azur, Inserm, CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne, France
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Mitigating Motor Neuronal Loss in C. elegans Model of ALS8. Sci Rep 2017; 7:11582. [PMID: 28912432 PMCID: PMC5599522 DOI: 10.1038/s41598-017-11798-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 08/30/2017] [Indexed: 12/13/2022] Open
Abstract
ALS8 is a late-onset familial autosomal dominant form of Amyotrophic Lateral Sclerosis (ALS) caused by a point mutation (P56S) in the VAPB gene (VAMP associated protein isoform B). Here, we generated two C. elegans models of the disease: a transgenic model where human VAPB wild-type (WT) or P56S mutant was expressed in a subset of motor neurons, and a second model that targeted inducible knockdown of the worm’s orthologue, vpr-1. Overexpression of human VAPB in DA neurons caused a backward locomotion defect, axonal misguidance, and premature neuronal death. Knockdown of vpr-1 recapitulated the reduction in VAPB expression associated with sporadic cases of human ALS. It also caused backward locomotion defects as well as an uncoordinated phenotype, and age-dependent, progressive motor neuronal death. Furthermore, inhibiting phosphatidylinositol-4 (PtdIns 4)-kinase activity with PIK-93 reduced the incidence of DA motor neuron loss and improved backward locomotion. This supports the loss of VAPB function in ALS8 pathogenesis and suggests that reducing intracellular PtdIns4P might be an effective therapeutic strategy in delaying progressive loss of motor neurons.
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Charman M, Goto A, Ridgway ND. Oxysterol-binding protein recruitment and activity at the endoplasmic reticulum-Golgi interface are independent of Sac1. Traffic 2017; 18:519-529. [DOI: 10.1111/tra.12491] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 05/01/2017] [Accepted: 05/01/2017] [Indexed: 12/26/2022]
Affiliation(s)
- Mark Charman
- The Atlantic Research Centre, Department of Pediatrics, and Biochemistry & Molecular Biology; Dalhousie University; Halifax Canada
| | - Asako Goto
- The Atlantic Research Centre, Department of Pediatrics, and Biochemistry & Molecular Biology; Dalhousie University; Halifax Canada
| | - Neale D. Ridgway
- The Atlantic Research Centre, Department of Pediatrics, and Biochemistry & Molecular Biology; Dalhousie University; Halifax Canada
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Liu LK, Choudhary V, Toulmay A, Prinz WA. An inducible ER-Golgi tether facilitates ceramide transport to alleviate lipotoxicity. J Cell Biol 2016; 216:131-147. [PMID: 28011845 PMCID: PMC5223604 DOI: 10.1083/jcb.201606059] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 10/20/2016] [Accepted: 12/07/2016] [Indexed: 01/27/2023] Open
Abstract
Liu et al. show that ER–Golgi tethering increases during ER stress in yeast. The protein Nvj2p is required for this tethering, which promotes nonvesicular ceramide transport from the ER to the Golgi to alleviate ceramide toxicity. Ceramides are key intermediates in sphingolipid biosynthesis and potent signaling molecules. However, excess ceramide is toxic, causing growth arrest and apoptosis. In this study, we identify a novel mechanism by which cells prevent the toxic accumulation of ceramides; they facilitate nonvesicular ceramide transfer from the endoplasmic reticulum (ER) to the Golgi complex, where ceramides are converted to complex sphingolipids. We find that the yeast protein Nvj2p promotes the nonvesicular transfer of ceramides from the ER to the Golgi complex. The protein is a tether that generates close contacts between these compartments and may directly transport ceramide. Nvj2p normally resides at contacts between the ER and other organelles, but during ER stress, it relocalizes to and increases ER–Golgi contacts. ER–Golgi contacts fail to form during ER stress in cells lacking Nvj2p. Our findings demonstrate that cells regulate ER–Golgi contacts in response to stress and reveal that nonvesicular ceramide transfer out of the ER prevents the buildup of toxic amounts of ceramides.
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Affiliation(s)
- Li-Ka Liu
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Vineet Choudhary
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Alexandre Toulmay
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
| | - William A Prinz
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
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Intracellular cholesterol transport proteins: roles in health and disease. Clin Sci (Lond) 2016; 130:1843-59. [DOI: 10.1042/cs20160339] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 07/12/2016] [Indexed: 12/13/2022]
Abstract
Effective cholesterol homoeostasis is essential in maintaining cellular function, and this is achieved by a network of lipid-responsive nuclear transcription factors, and enzymes, receptors and transporters subject to post-transcriptional and post-translational regulation, whereas loss of these elegant, tightly regulated homoeostatic responses is integral to disease pathologies. Recent data suggest that sterol-binding sensors, exchangers and transporters contribute to regulation of cellular cholesterol homoeostasis and that genetic overexpression or deletion, or mutations, in a number of these proteins are linked with diseases, including atherosclerosis, dyslipidaemia, diabetes, congenital lipoid adrenal hyperplasia, cancer, autosomal dominant hearing loss and male infertility. This review focuses on current evidence exploring the function of members of the ‘START’ (steroidogenic acute regulatory protein-related lipid transfer) and ‘ORP’ (oxysterol-binding protein-related proteins) families of sterol-binding proteins in sterol homoeostasis in eukaryotic cells, and the evidence that they represent valid therapeutic targets to alleviate human disease.
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Elustondo P, Martin LA, Karten B. Mitochondrial cholesterol import. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1862:90-101. [PMID: 27565112 DOI: 10.1016/j.bbalip.2016.08.012] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 08/15/2016] [Accepted: 08/19/2016] [Indexed: 02/06/2023]
Abstract
All animal subcellular membranes require cholesterol, which influences membrane fluidity and permeability, fission and fusion processes, and membrane protein function. The distribution of cholesterol among subcellular membranes is highly heterogeneous and the cholesterol content of each membrane must be carefully regulated. Compared to other subcellular membranes, mitochondrial membranes are cholesterol-poor, particularly the inner mitochondrial membrane (IMM). As a result, steroidogenesis can be controlled through the delivery of cholesterol to the IMM, where it is converted to pregnenolone. The low basal levels of cholesterol also make mitochondria sensitive to changes in cholesterol content, which can have a relatively large impact on the biophysical and functional characteristics of mitochondrial membranes. Increased mitochondrial cholesterol levels have been observed in diverse pathological conditions including cancer, steatohepatitis, Alzheimer disease and Niemann-Pick Type C1-deficiency, and are associated with increased oxidative stress, impaired oxidative phosphorylation, and changes in the susceptibility to apoptosis, among other alterations in mitochondrial function. Mitochondria are not included in the vesicular trafficking network; therefore, cholesterol transport to mitochondria is mostly achieved through the activity of lipid transfer proteins at membrane contact sites or by cytosolic, diffusible lipid transfer proteins. Here we will give an overview of the main mechanisms involved in mitochondrial cholesterol import, focusing on the steroidogenic acute regulatory protein StAR/STARD1 and other members of the StAR-related lipid transfer (START) domain protein family, and we will discuss how changes in mitochondrial cholesterol levels can arise and affect mitochondrial function. This article is part of a Special Issue entitled: Lipids of Mitochondria edited by Guenther Daum.
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Affiliation(s)
- Pia Elustondo
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Laura A Martin
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Barbara Karten
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada.
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