1
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Zhang C, Chen Z, Zhang D, Wang X, Qiu M, Tan Z. Role of Gltp in Maturation of Oligodendrocytes Under the Regulation of Nkx2.2. Mol Neurobiol 2023; 60:4897-4908. [PMID: 37191854 DOI: 10.1007/s12035-023-03383-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 05/08/2023] [Indexed: 05/17/2023]
Abstract
Myelin, a lipid-enriched multi-layer membrane structure, allows for rapid long-distance saltatory conduction of neuronal impulses. Although glycolipids are the predominant types of lipids in the myelin bilayer, the role of glycolipid transfer protein (GLTP), which selectively mediates the transfer of various glycolipids between phospholipid bilayer, in myelin development and maintenance remains unknown at present. In this study, we identified Gltp as the key lipid metabolism gene in myelin-forming oligodendrocytes (OLs) through integrated omics analysis across independent transcriptomic and single-cell sequencing studies. Gene expression analysis revealed that Gltp is selectively expressed in the differentiated OLs. Functional study demonstrated that its expression is essential for the differentiation of OLs, and promotes the outgrowth of OL membrane. Moreover, we found that the expression of Gltp is regulated by OL-lineage transcriptional factors, such as NKX2.2, OLIG2, SOX10, and MYRF. These findings provide important insights into the unrecognized functions of Gltp in OL differentiation and maturation.
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Affiliation(s)
- Chengfu Zhang
- Department of Psychiatry, National Clinical Research Center for Mental Disorders, and National Center for Mental Disorders, The Second Xiangya Hospital of Central South University, Changsha, China
- Center for Cognition and Brain Disorders, The Affiliated Hospital of Hangzhou Normal University, Hangzhou, China
| | - Zhen Chen
- Division of Cardiology, The Affiliated Hospital of Hangzhou Normal University, Hangzhou, China
| | - Dai Zhang
- Institute of Mental Health, Peking University Sixth Hospital, Beijing, China
| | - Xiaoping Wang
- Department of Psychiatry, National Clinical Research Center for Mental Disorders, and National Center for Mental Disorders, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Mengsheng Qiu
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environment Sciences, Hangzhou Normal University, Hangzhou, China
| | - Zhou Tan
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environment Sciences, Hangzhou Normal University, Hangzhou, China.
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2
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Mishra SK, Gao YG, Zou X, Stephenson DJ, Malinina L, Hinchcliffe EH, Chalfant CE, Brown RE. Emerging roles for human glycolipid transfer protein superfamily members in the regulation of autophagy, inflammation, and cell death. Prog Lipid Res 2020; 78:101031. [PMID: 32339554 DOI: 10.1016/j.plipres.2020.101031] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 02/27/2020] [Accepted: 02/27/2020] [Indexed: 12/14/2022]
Abstract
Glycolipid transfer proteins (GLTPs) were first identified over three decades ago as ~24kDa, soluble, amphitropic proteins that specifically accelerate the intermembrane transfer of glycolipids. Upon discovery that GLTPs use a unique, all-α-helical, two-layer 'sandwich' architecture (GLTP-fold) to bind glycosphingolipids (GSLs), a new protein superfamily was born. Structure/function studies have provided exquisite insights defining features responsible for lipid headgroup selectivity and hydrophobic 'pocket' adaptability for accommodating hydrocarbon chains of differing length and unsaturation. In humans, evolutionarily-modified GLTP-folds have been identified with altered sphingolipid specificity, e. g. ceramide-1-phosphate transfer protein (CPTP), phosphatidylinositol 4-phosphate adaptor protein-2 (FAPP2) which harbors a GLTP-domain and GLTPD2. Despite the wealth of structural data (>40 Protein Data Bank deposits), insights into the in vivo functional roles of GLTP superfamily members have emerged slowly. In this review, recent advances are presented and discussed implicating human GLTP superfamily members as important regulators of: i) pro-inflammatory eicosanoid production associated with Group-IV cytoplasmic phospholipase A2; ii) autophagy and inflammasome assembly that drive surveillance cell release of interleukin-1β and interleukin-18 inflammatory cytokines; iii) cell cycle arrest and necroptosis induction in certain colon cancer cell lines. The effects exerted by GLTP superfamily members appear linked to their ability to regulate sphingolipid homeostasis by acting in either transporter and/or sensor capacities. These timely findings are opening new avenues for future cross-disciplinary, translational medical research involving GLTP-fold proteins in human health and disease. Such avenues include targeted regulation of specific GLTP superfamily members to alter sphingolipid levels as a therapeutic means for combating viral infection, neurodegenerative conditions and circumventing chemo-resistance during cancer treatment.
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Affiliation(s)
- Shrawan K Mishra
- Hormel Institute, University of Minnesota, Austin, MN 55912, USA
| | - Yong-Guang Gao
- Hormel Institute, University of Minnesota, Austin, MN 55912, USA
| | - Xianqiong Zou
- Hormel Institute, University of Minnesota, Austin, MN 55912, USA
| | - Daniel J Stephenson
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University Medical Center, Richmond, VA 23298-0614, USA; Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL 33620, USA
| | - Lucy Malinina
- Hormel Institute, University of Minnesota, Austin, MN 55912, USA
| | | | - Charles E Chalfant
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL 33620, USA; Research Service, James A. Haley Veterans Hospital, Tampa, FL 33612, USA; The Moffitt Cancer Center, Tampa, FL 33620, USA
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3
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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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4
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Malinina L, Patel DJ, Brown RE. How α-Helical Motifs Form Functionally Diverse Lipid-Binding Compartments. Annu Rev Biochem 2017; 86:609-636. [PMID: 28375742 DOI: 10.1146/annurev-biochem-061516-044445] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Lipids are produced site-specifically in cells and then distributed nonrandomly among membranes via vesicular and nonvesicular trafficking mechanisms. The latter involves soluble amphitropic proteins extracting specific lipids from source membranes to function as molecular solubilizers that envelope their insoluble cargo before transporting it to destination sites. Lipid-binding and lipid transfer structural motifs range from multi-β-strand barrels, to β-sheet cups and baskets covered by α-helical lids, to multi-α-helical bundles and layers. Here, we focus on how α-helical proteins use amphipathic helical layering and bundling to form modular lipid-binding compartments and discuss the functional consequences. Preformed compartments generally rely on intramolecular disulfide bridging to maintain conformation (e.g., albumins, nonspecific lipid transfer proteins, saposins, nematode polyprotein allergens/antigens). Insights into nonpreformed hydrophobic compartments that expand and adapt to accommodate a lipid occupant are few and provided mostly by the three-layer, α-helical ligand-binding domain of nuclear receptors. The simple but elegant and nearly ubiquitous two-layer, α-helical glycolipid transfer protein (GLTP)-fold now further advances understanding.
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Affiliation(s)
- Lucy Malinina
- The Hormel Institute, University of Minnesota, Austin, Minnesota 55912; ,
| | - Dinshaw J Patel
- Structural Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065;
| | - Rhoderick E Brown
- The Hormel Institute, University of Minnesota, Austin, Minnesota 55912; ,
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5
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Tian Y, Yang Y, Zhang X, Nakajima T, Tanaka N, Sugiyama E, Kamijo Y, Lu Y, Moriya K, Koike K, Gonzalez FJ, Aoyama T. Age-dependent PPARα activation induces hepatic sulfatide accumulation in transgenic mice carrying the hepatitis C virus core gene. Glycoconj J 2016; 33:927-936. [PMID: 27318478 DOI: 10.1007/s10719-016-9703-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 06/07/2016] [Accepted: 06/08/2016] [Indexed: 01/01/2023]
Abstract
Sulfatides, a type of glycosphingolipid, are associated with carcinogenesis. Peroxisome proliferator-activated receptor α (PPARα) is involved in the regulation of sulfatide metabolism as well as in cancer development. We previously reported that transgenic (Tg) mice expressing hepatitis C virus core protein (HCVcp) exhibited age-dependent PPARα activation and carcinogenesis in liver. However, the metabolism of sulfatides in hepatocellular carcinoma is unknown. To examine the relationship between sulfatide metabolism, carcinogenesis, HCVcp, and PPARα, age-dependent changes of these factors were examined in HCVcpTg, PPARα inhibitor-treated HCVcpTg, and non-Tg mice. The sulfatide content in liver, the hepatic expression of two key enzymes catalyzing the initial and last reactions in sulfatide synthesis, the hepatic expression of known sulfatide-transferring protein, oxidative stress, and hepatic PPARα expression and its activation were age-dependently increased in HCVcpTg mice. The increased synthesis and accumulation of sulfatides and PPARα activation were significantly enhanced in liver cancer lesions. These changes were attenuated by PPARα inhibitor treatment and not observed in non-Tg mice. These results suggest that HCVcp-induced age-dependent PPARα activation increases synthesis of sulfatides and the resulting sulfatide accumulation affects HCV-related liver cancer. The monitoring of hepatic sulfatide content and the modulation of sulfatide generation by intervention using a PPARα inhibitor might be useful for the prediction and prevention of HCV-related hepatocarcinogenesis, respectively.
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Affiliation(s)
- Yangyang Tian
- Department of Metabolic Regulation, Shinshu University Graduate School of Medicine, Matsumoto, 390-8621, Japan
| | - Yang Yang
- Department of Metabolic Regulation, Shinshu University Graduate School of Medicine, Matsumoto, 390-8621, Japan
| | - Xiaowei Zhang
- Department of Neurosurgery, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, 050000, China
| | - Takero Nakajima
- Department of Metabolic Regulation, Shinshu University Graduate School of Medicine, Matsumoto, 390-8621, Japan
| | - Naoki Tanaka
- Department of Metabolic Regulation, Shinshu University Graduate School of Medicine, Matsumoto, 390-8621, Japan
| | - Eiko Sugiyama
- Department of Nutritional Science, Prefectural College, Nagano, Nagano, 380-8525, Japan
| | - Yuji Kamijo
- Department of Nephrology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, 390-8621, Japan.
| | - Yu Lu
- Department of Metabolic Regulation, Shinshu University Graduate School of Medicine, Matsumoto, 390-8621, Japan
| | - Kyoji Moriya
- Department of Infection Control and Prevention, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Kazuhiko Koike
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Frank J Gonzalez
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Toshifumi Aoyama
- Department of Metabolic Regulation, Shinshu University Graduate School of Medicine, Matsumoto, 390-8621, Japan
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6
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Mattjus P. Specificity of the mammalian glycolipid transfer proteins. Chem Phys Lipids 2016; 194:72-8. [DOI: 10.1016/j.chemphyslip.2015.07.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Revised: 07/08/2015] [Accepted: 07/27/2015] [Indexed: 12/31/2022]
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7
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Abstract
Maintenance of cellular homeostasis requires tight and coordinated control of numerous metabolic pathways, which are governed by interconnected networks of signaling pathways and energy-sensing regulators. Autophagy, a lysosomal degradation pathway by which the cell self-digests its own components, has over the past decade been recognized as an essential part of metabolism. Autophagy not only rids the cell of excessive or damaged organelles, misfolded proteins, and invading microorganisms, it also provides nutrients to maintain crucial cellular functions. Besides serving as essential structural moieties of biomembranes, lipids including sphingolipids are increasingly being recognized as central regulators of a number of important cellular processes, including autophagy. In the present review we describe how sphingolipids, with special emphasis on ceramides and sphingosine-1-phosphate, can act as physiological regulators of autophagy in relation to cellular and organismal growth, survival, and aging.
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Affiliation(s)
- Eva Bang Harvald
- Villum Center for Bioanalytical Sciences, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, 5230, Odense M, Denmark
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8
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Tuuf J, Mattjus P. Membranes and mammalian glycolipid transferring proteins. Chem Phys Lipids 2013; 178:27-37. [PMID: 24220498 DOI: 10.1016/j.chemphyslip.2013.10.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Revised: 10/29/2013] [Accepted: 10/30/2013] [Indexed: 01/04/2023]
Abstract
Glycolipids are synthesized in and on various organelles throughout the cell. Their trafficking inside the cell is complex and involves both vesicular and protein-mediated machineries. Most important for the bulk lipid transport is the vesicular system, however, lipids moved by transfer proteins are also becoming more characterized. Here we review the latest advances in the glycolipid transfer protein (GLTP) and the phosphoinositol 4-phosphate adaptor protein-2 (FAPP2) field, from a membrane point of view.
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Affiliation(s)
- Jessica Tuuf
- Biochemistry, Department of Biosciences, Åbo Akademi University, Turku, Finland
| | - Peter Mattjus
- Biochemistry, Department of Biosciences, Åbo Akademi University, Turku, Finland.
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9
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Riboni L, Giussani P, Viani P. Sphingolipid transport. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010; 688:24-45. [PMID: 20919644 DOI: 10.1007/978-1-4419-6741-1_2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Sphingolipids are a family of ubiquitous membrane components that exhibit multiple functional properties fundamental to cell properties. Sphingolipid transport represents a crucial aspect in the metabolism, signaling and biological role of sphingolipids. Different mechanisms of sphingolipid movements contribute to their selective localization in different membranes but also in different portions and sides of the same membrane, thus ensuring and regulating their interaction with different enzymes and target molecules. In this chapter we will describe the knowledge of the different mechanisms ofsphingolipid movements within and between membranes, focusing on the recent advances in this field and considering the role played by selective sphingolipid molecules in the regulation of these mechanisms.
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Affiliation(s)
- Laura Riboni
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, USA.
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10
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Mattjus P. Glycolipid transfer proteins and membrane interaction. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2008; 1788:267-72. [PMID: 19007748 DOI: 10.1016/j.bbamem.2008.10.003] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2008] [Revised: 10/07/2008] [Accepted: 10/07/2008] [Indexed: 12/17/2022]
Abstract
The glycolipid transfer protein is found from animals and fungi to plants and red micro-alga. Some eukaryotes that do not encode the glucosylceramide synthase like the yeast Schizosaccharomyces pombe and Saccharomyces cerevisiae do neither produce glycolipid transfer like proteins. On the other hand yeast like Eremothecium gossypii that do synthesize glucosylceramide also express glycolipid transfer protein. Based on this novel genetic relationship it is not far fetched to assume that there must be a strong correlation between the synthesis of the glycolipid precursor and the glycolipid transfer protein. Because the glycolipid transfer protein is localized in the cytosol it is unlikely that it would participate in events associated with lipid rafts or caveolar structures, since they are found on the outer leaflet of the plasma membrane. Rather, GLTP is likely to be involved in events at the cytosolic side of the plasma membrane or the endoplasmic reticulum, maybe function as a reporter or sensor of glycolipid levels. A similar function has been proposed for other proteins with affinity for lipids like the oxysterol binding proteins and phosphatidylinositol transfer proteins that are thought to be able act as lipid sensors. Recent discoveries in the glycolipid transfer protein field are discussed.
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Affiliation(s)
- Peter Mattjus
- Department of Biochemistry and Pharmacy, Abo Akademi University, Turku, Finland.
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11
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Yamaji T, Kumagai K, Tomishige N, Hanada K. Two sphingolipid transfer proteins, CERT and FAPP2: Their roles in sphingolipid metabolism. IUBMB Life 2008; 60:511-8. [DOI: 10.1002/iub.83] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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12
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West G, Viitanen L, Alm C, Mattjus P, Salminen TA, Edqvist J. Identification of a glycosphingolipid transfer protein GLTP1 in Arabidopsis thaliana. FEBS J 2008; 275:3421-37. [DOI: 10.1111/j.1742-4658.2008.06498.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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13
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Glycolipid transfer protein: Clear structure and activity, but enigmatic function. ACTA ACUST UNITED AC 2008; 48:137-51. [DOI: 10.1016/j.advenzreg.2007.11.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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14
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Tuuf J, Mattjus P. Human glycolipid transfer protein—Intracellular localization and effects on the sphingolipid synthesis. Biochim Biophys Acta Mol Cell Biol Lipids 2007; 1771:1353-63. [DOI: 10.1016/j.bbalip.2007.09.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2007] [Revised: 08/30/2007] [Accepted: 09/11/2007] [Indexed: 12/20/2022]
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15
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Brown RE, Mattjus P. Glycolipid transfer proteins. Biochim Biophys Acta Mol Cell Biol Lipids 2007; 1771:746-60. [PMID: 17320476 PMCID: PMC1986823 DOI: 10.1016/j.bbalip.2007.01.011] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2006] [Revised: 01/08/2007] [Accepted: 01/13/2007] [Indexed: 10/23/2022]
Abstract
Glycolipid transfer proteins (GLTPs) are small (24 kDa), soluble, ubiquitous proteins characterized by their ability to accelerate the intermembrane transfer of glycolipids in vitro. GLTP specificity encompasses both sphingoid- and glycerol-based glycolipids, but with a strict requirement that the initial sugar residue be beta-linked to the hydrophobic lipid backbone. The 3D architecture of GLTP reveals liganded structures with unique lipid-binding modes. The biochemical properties of GLTP action at the membrane surface have been studied rather comprehensively, but the biological role of GLTP remains enigmatic. What is clear is that GLTP differs distinctly from other known glycolipid-binding proteins, such as nonspecific lipid transfer proteins, lysosomal sphingolipid activator proteins, lectins, lung surfactant proteins as well as other lipid-binding/transfer proteins. Based on the unique conformational architecture that targets GLTP to membranes and enables glycolipid binding, GLTP is now considered the prototypical and founding member of a new protein superfamily in eukaryotes.
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Affiliation(s)
- Rhoderick E Brown
- The Hormel Institute, University of Minnesota-Hormel Institute, 801 16th Ave NE, Austin, MN 55912, USA.
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16
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Radin NS. Preventing the binding of pathogens to the host by controlling sphingolipid metabolism. Microbes Infect 2006; 8:938-45. [PMID: 16460984 DOI: 10.1016/j.micinf.2005.09.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2005] [Revised: 09/05/2005] [Accepted: 09/06/2005] [Indexed: 11/16/2022]
Abstract
The binding of many pathogens and toxins to human cells can be inhibited by (1) depleting host cells of their surface glycosphingolipids; (2) coating the binding sites on pathogens (adhesins) with glycosphingolipid-like substances (decoys); (3) coating the host's glycosphingolipids with substances that compete with the pathogen for binding. Details of using these methods are described.
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Affiliation(s)
- Norman S Radin
- Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, MI, USA.
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17
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Lauc G, Heffer-Lauc M. Shedding and uptake of gangliosides and glycosylphosphatidylinositol-anchored proteins. Biochim Biophys Acta Gen Subj 2005; 1760:584-602. [PMID: 16388904 DOI: 10.1016/j.bbagen.2005.11.014] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2005] [Revised: 11/22/2005] [Accepted: 11/23/2005] [Indexed: 10/25/2022]
Abstract
Gangliosides and glycosylphosphatidylinositol (GPI)-anchored proteins have very different biosynthetic origin, but they have one thing in common: they are both comprised of a relatively large hydrophilic moiety tethered to a membrane by a relatively small lipid tail. Both gangliosides and GPI-anchored proteins can be actively shed from the membrane of one cell and taken up by other cells by insertion of their lipid anchors into the cell membrane. The process of shedding and uptake of gangliosides and GPI-anchored proteins has been independently discovered in several disciplines during the last few decades, but these discoveries were largely ignored by people working in other areas of science. By bringing together results from these, sometimes very distant disciplines, in this review, we give an overview of current knowledge about shedding and uptake of gangliosides and GPI-anchored proteins. Tumor cells and some pathogens apparently misuse this process for their own advantage, but its real physiological functions remain to be discovered.
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Affiliation(s)
- Gordan Lauc
- Department of Chemistry and Biochemistry, University of Osijek School of Medicine, Croatia.
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18
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Malakhova ML, Malinina L, Pike HM, Kanack AT, Patel DJ, Brown RE. Point mutational analysis of the liganding site in human glycolipid transfer protein. Functionality of the complex. J Biol Chem 2005; 280:26312-20. [PMID: 15901739 PMCID: PMC1393170 DOI: 10.1074/jbc.m500481200] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mammalian glycolipid transfer proteins (GLTPs) facilitate the selective transfer of glycolipids between lipid vesicles in vitro. Recent structural determinations of the apo- and glycolipid-liganded forms of human GLTP have provided the first insights into the molecular architecture of the protein and its glycolipid binding site (Malinina, L., Malakhova, M. L., Brown, R. E., and Patel, D. J. (2004) Nature 430, 1048-1053). In the present study, we have evaluated the functional consequences of point mutation of the glycolipid liganding site of human GLTP within the context of a carrier-based mechanism of glycolipid intermembrane transfer. Different approaches were developed to rapidly and efficiently assess the uptake and release of glycolipid by GLTP. They included the use of glass-immobilized, glycolipid films to load GLTP with glycolipid and separation of GLTP/glycolipid complexes from vesicles containing glycolipid (galactosylceramide or lactosylceramide) or from monosialoganglioside dispersions by employing nickel-nitrilotriacetic acid-based affinity or gel filtration strategies. Point mutants of the sugar headgroup recognition center (Trp-96, Asp-48, Asn-52) and of the ceramide-accommodating hydrophobic tunnel (Phe-148, Phe-183, Leu-136) were analyzed for their ability to acquire and release glycolipid ligand. Two manifestations of point mutation within the liganding site were apparent: (i) impaired formation of the GLTP/glycolipid complex; (ii) impaired acquisition and release of bound glycolipid by GLTP. The results are consistent with a carrier-based mode of GLTP action to accomplish the intermembrane transfer of glycolipid. Also noteworthy was the inefficient release of glycolipid by wtGLTP into phosphatidylcholine acceptor vesicles, raising the possibility of a function other than intermembrane glycolipid transfer in vivo.
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19
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Malinina L, Malakhova ML, Teplov A, Brown RE, Patel DJ. Structural basis for glycosphingolipid transfer specificity. Nature 2004; 430:1048-53. [PMID: 15329726 PMCID: PMC2640488 DOI: 10.1038/nature02856] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2004] [Accepted: 07/13/2004] [Indexed: 11/08/2022]
Abstract
Lipid transfer proteins are important in membrane vesicle biogenesis and trafficking, signal transduction and immunological presentation processes. The conserved and ubiquitous mammalian glycolipid transfer proteins (GLTPs) serve as potential regulators of cell processes mediated by glycosphingolipids, ranging from differentiation and proliferation to invasive adhesion, neurodegeneration and apoptosis. Here we report crystal structures of apo-GLTP (1.65 A resolution) and lactosylceramide-bound (1.95 A) GLTP, in which the bound glycosphingolipid is sandwiched, after adaptive recognition, within a previously unknown two-layer all-alpha-helical topology. Glycosphingolipid binding specificity is achieved through recognition and anchoring of the sugar-amide headgroup to the GLTP recognition centre by hydrogen bond networks and hydrophobic contacts, and encapsulation of both lipid chains, in a precisely oriented manner within a 'moulded-to-fit' hydrophobic tunnel. A cleft-like conformational gating mechanism, involving two interhelical loops and one alpha-helix of GLTP, could enable the glycolipid chains to enter and leave the tunnel in the membrane-associated state. Mutation and functional analyses of residues in the glycolipid recognition centre and within the hydrophobic tunnel support a framework for understanding how GLTPs acquire and release glycosphingolipids during lipid intermembrane transfer and presentation processes.
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Affiliation(s)
- Lucy Malinina
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA
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Rogers DP, Bankaitis VA. Phospholipid transfer proteins and physiological functions. INTERNATIONAL REVIEW OF CYTOLOGY 2000; 197:35-81. [PMID: 10761115 DOI: 10.1016/s0074-7696(00)97002-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Issues of how cells generate and maintain unique lipid compositions in distinct intracellular membrane systems remain the subject of much study. A ubiquitous class of soluble proteins capable of transporting phospholipid monomers from membrane to membrane across an aqueous milieu has been thought to define part of the mechanism by which lipids are sorted in cells. Progress in the study of these phospholipid transfer proteins (PLTPs) raises questions regarding their physiological functions in cells and the mechanisms by which these proteins execute them. It is now clear that across the eukaryotic kingdom, members of this protein family exert essential roles in the regulation of phospholipid metabolism and central aspects of phospholipid-mediated signaling. Indeed, it is now known that dysfunction of specific PLTPs defines the basis of inherited diseases in mammals, and this list is expected to grow. Phospholipid transfer proteins, their biochemical properties, and the emerging clues regarding their physiological functions are reviewed.
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Affiliation(s)
- D P Rogers
- Department of Cell Biology, University of Alabama at Birmingham 35294, USA
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Lin X, Mattjus P, Pike HM, Windebank AJ, Brown RE. Cloning and expression of glycolipid transfer protein from bovine and porcine brain. J Biol Chem 2000; 275:5104-10. [PMID: 10671554 PMCID: PMC2621014 DOI: 10.1074/jbc.275.7.5104] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Glycolipid transfer protein (GLTP) is a small (23-24 kDa), basic protein (pI congruent with 9.0) that accelerates the intermembrane transfer of various glycolipids. Here, we report the first cloning of cDNAs that encode the bovine and porcine GLTPs. The cDNA open reading frame for bovine GLTP was constructed by bridge-overlapping extension polymerase chain reaction (PCR) after obtaining partial coding cDNA clones by hot start, seminested, and rapid amplification of cDNA ends-PCR. The cDNA open reading frame for porcine GLTP was constructed by reverse transcriptase-PCR. The encoded amino acid sequences in the full-length bovine and porcine cDNAs were identical, consisting of 209 amino acid residues, and were nearly the same as the published sequence determined by Edman degradation. The cDNA encoded one additional amino acid at the N terminus (methionine), arginine at positions 10 and 200 instead of lysine, and threonine at position 65 instead of alanine. Expression of GLTP-cDNA in Escherichia coli using pGEX-6P-1 vector resulted in glutathione S-transferase (GST)-GLTP fusion protein. Regulation of growth and induction conditions led to approximately 50% of expressed fusion protein being soluble and active. Proteolytic cleavage of GST-GLTP fusion protein (bound to GST-Sepharose) and affinity purification resulted in fully active GLTP. Northern blot analyses of bovine tissues showed a single transcript of approximately 2.2 kilobases and the following hierarchy of mRNA levels: cerebrum > kidney > spleen congruent with lung congruent with cerebellum > liver > heart muscle. Reverse transcriptase-PCR analyses of mRNA levels supported the Northern blot results.
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Affiliation(s)
- X Lin
- Hormel Institute, University of Minnesota, Austin, Minnesota 55912, USA
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Mattjus P, Molotkovsky JG, Smaby JM, Brown RE. A fluorescence resonance energy transfer approach for monitoring protein-mediated glycolipid transfer between vesicle membranes. Anal Biochem 1999; 268:297-304. [PMID: 10075820 PMCID: PMC4009740 DOI: 10.1006/abio.1998.3065] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
A lipid transfer protein, purified from bovine brain (23.7 kDa, 208 amino acids) and specific for glycolipids, has been used to develop a fluorescence resonance energy transfer assay (anthrylvinyl-labeled lipids; energy donors and perylenoyl-labeled lipids; energy acceptors) for monitoring the transfer of lipids between membranes. Small unilamellar vesicles composed of 1 mol% anthrylvinyl-galactosylceramide, 1.5 mol% perylenoyl-triglyceride, and 97.5% 1-palmitoyl-2-oleoyl phosphatidylcholine (POPC) served as donor membranes. Acceptor membranes were 100% POPC vesicles. Addition of glycolipid transfer protein to mixtures of donor and acceptor vesicles resulted in increasing emission intensity of anthrylvinyl-galactosylceramide and decreasing emission intensity of the nontransferable perylenoyl-triglyceride as a function of time. The behavior was consistent with anthrylvinyl-galactosylceramide being transferred from donor to acceptor vesicles. The anthrylvinyl and perylenoyl energy transfer pair offers advantages over frequently used energy transfer pairs such as NBD and rhodamine. The anthrylvinyl emission overlaps effectively the perylenoyl excitation spectrum and the fluorescence parameters of the anthrylvinyl fluorophore are nearly independent of the medium polarity. The nonpolar fluorophores are localized in the hydrophobic region of the bilayer thus producing minimal disturbance of the bilayer polar region. Our results indicate that this method is suitable for assay of lipid transfer proteins including mechanistic studies of transfer protein function.
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Affiliation(s)
- P Mattjus
- Hormel Institute, University of Minnesota, Austin, Minnesota, 55912, USA
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Kuroki Y, Gasa S, Ogasawara Y, Makita A, Akino T. Binding of pulmonary surfactant protein A to galactosylceramide and asialo-GM2. Arch Biochem Biophys 1992; 299:261-7. [PMID: 1444464 DOI: 10.1016/0003-9861(92)90273-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The binding of pulmonary surfactant protein A (SP-A) to glycolipids was examined in the present study. The direct binding of SP-A on a thin-layer chromatogram was visualized using 125I-SP-A as a probe. 125I-SP-A bound to galactosylceramide and asialo-GM2, but failed to exhibit significant binding to GM1, GM2, asialo-GM1, sulfatide, and Forssman antigen. The study of 125I-SP-A binding to glycolipids coated onto microtiter wells also revealed that SP-A bound to galactosylceramide and asialo-GM2. SP-A bound to galactosylceramides with non-hydroxy or hydroxy fatty acids, but showed no binding to either glucosylceramide or galactosylsphingosine. Excess native SP-A competed with 125I-SP-A for the binding to asialo-GM2 and galactosylceramide. Specific antibody to rat SP-A inhibited 125I-SP-A binding to glycolipids. In spite of chelation of Ca2+ with EDTA or EGTA, SP-A retained a significant binding to glycolipids. Inclusion of excess monosaccharides in the binding buffer reduced the glycolipid binding of SP-A, but failed to achieve complete abolishment. The oligosaccharide isolated from asialo-GM2 is also effective at reducing 125I-SP-A binding to the solid-phase asialo-GM2. From these data, we conclude that SP-A binds to galactosylceramide and asialo-GM2, and that both saccharide and ceramide moieties in the glycolipid molecule are important for the binding of SP-A to glycolipids.
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Affiliation(s)
- Y Kuroki
- Department of Biochemistry, Sapporo Medical College, Japan
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Abstract
Translocations of various lipid species between membranes have been extensively studied. The transport of water-insoluble lipids is thought to require the participation of lipid transfer proteins (LTP). Several LTP, differing in their physiochemical properties and substrate specificities, have been purified to homogeneity from blood plasma, eucaryotic and procaryotic cells. Depending on their site of activity, they can be classified as extracellular and intracellular LTP. Extracellular LTP are found in the blood plasma and intracellular LTP, which were originally characterized as phospholipid exchange proteins, are ubiquitous in nature. Despite the enormous knowledge about their physicochemical properties and their function in vitro their physiological role has not been clearly demonstrated. However, their ubiquitous occurrence indicates an important role in cellular events. This review gives an overview of this interesting category of proteins, which are able to catalyze inter-membrane transfer and exchange of lipids.
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Affiliation(s)
- D G Rueckert
- Department of Surgery, University of Tuebingen, F.R.G
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25
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Sasaki T. Glycolipid transfer protein and intracellular traffic of glucosylceramide. EXPERIENTIA 1990; 46:611-6. [PMID: 2193825 DOI: 10.1007/bf01939700] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Glycolipid transfer protein (GL-TP), a nonglycosylated protein with a molecular weight of 22,000 K, has been purified from pig brain. The protein transfers, by a carrier mechanism, glycolipids with a beta-glucosyl or beta-galactosyl residue directly linked to either ceramide or diacylglycerol. GL-TP appears to be present in most animal cells, and evidence has been obtained which indicates that it is a cytoplasmic protein. Little is known about the function of GL-TP. Current evidence indicates that glycosphingolipid glycosylation occurs at the luminal side of the Golgi apparatus, except for the glucosylation of ceramide, which has been shown to occur at the cytoplasmic side of the Golgi or endoplasmic membrane. It appears most likely that GL-TP participates in the intracellular traffic of glucosylceramide.
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Affiliation(s)
- T Sasaki
- Department of Biochemistry, Sapporo Medical College, Japan
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Brown RE, Jarvis KL, Hyland KJ. Purification and characterization of glycolipid transfer protein from bovine brain. BIOCHIMICA ET BIOPHYSICA ACTA 1990; 1044:77-83. [PMID: 2340310 DOI: 10.1016/0005-2760(90)90221-i] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Bovine brain contains a lipid transfer protein that is specific for neutral glycosphingolipids and gangliosides but does not stimulate phospholipid or neutral lipid intermembrane transfer (Brown, R.E., Stephenson, F.A., Markello, T., Barenholz, Y. and Thompson, T.E. (1985) Chem. Phys. Lipids 38, 79-93). This report describes a new procedure for purifying glycolipid transfer protein from bovine brain as well as a characterization of the resulting protein. Chief among the newly introduced approaches are dye-ligand and fast protein cation-exchange liquid chromatography. Other modifications include increasing the overall scale of purification, incorporating a pH precipitation step and adding different proteinase inhibitors. The resulting procedure simplifies and accelerates the purification process while yielding a homogeneous protein. The purified protein has a molecular weight near 23 kDa as estimated by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Chromatofocusing reveals that glycolipid transfer protein activity co-elutes with the 23 kDa protein and has an isoelectric point near pH 9.0. A similar isoelectric point is observed using denaturing isoelectric focusing conditions. The protein's amino acid composition reveals high levels of amino acids with non-polar side chains (48%). Based on the findings reported here and on previously published data, bovine brain glycolipid transfer protein has been compared to other lipid transfer proteins as well as lysosomal sphingolipid activator proteins.
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Affiliation(s)
- R E Brown
- Hormel Institute, University of Minnesota, Austin 55912
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Nichols GE, Shiraishi T, Young WW. Polarity of neutral glycolipids, gangliosides, and sulfated lipids in MDCK epithelial cells. J Lipid Res 1988. [DOI: 10.1016/s0022-2275(20)38458-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Abstract
The production by cancer cells of glycolipids, perhaps derived partly from host glycolipids, may play essential roles in malignancy, tumor growth, immunity from host immunodefense, and metastasis. The glycolipids are derived from the primary glycolipid, glucosylceramide (GlcCer), which is formed enzymatically from ceramide and uridine diphosphoglucose (UDP-glu). Injection of an inhibitor of this enzyme into mice bearing intraperitoneal Ehrlich ascites tumor cells (EATC) resulted in complete cure of about 30% of the mice and marked prolongation of life in the remainder. Almost all of the surviving mice were immune to a second inoculation of EATC. Injection of GlcCer stimulated cancer cell growth about 50% but this was largely reversed by the inhibitor. This type of inhibitor may have wide application to cancer chemotherapy.
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Affiliation(s)
- J Inokuchi
- Mental Health Research Institute, University of Michigan, Ann Arbor 48109
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Bernier I, Jollès P. A survey on cytosolic non-enzymic proteins involved in the metabolism of lipophilic compounds: from organic anion binders to new protein families. Biochimie 1987; 69:1127-52. [PMID: 3129018 DOI: 10.1016/0300-9084(87)90140-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
This review deals with recent advances in the research of cytosolic non-enzymic proteins involved in the metabolism of lipophilic compounds. Emphasis is given to the important contribution of structural data in the understanding of the functional properties of these proteins and in the emergence of new protein families. The possibility that many of the 'cytosolic' proteins might be structure-bound and structure-forming in the living cell is discussed, with references to so far available structural data and to recent investigations on the architecture and biochemical composition of the cytoplasm. The aim of this review is to present in a condensed form (227 references) the evolution in the study of cytosolic proteins binding and transferring lipophilic compounds and to enable interested investigators to become aware of current concepts and perspectives in this active and steadily growing area of research.
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Affiliation(s)
- I Bernier
- Université de Paris V, Laboratoire des Protéines, CNRS UA1188, France
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Glycolipid transfer protein from pig brain transfers glycolipids with β-linked sugars but not with α-linked sugars at the sugar-lipid linkage. ACTA ACUST UNITED AC 1986. [DOI: 10.1016/0005-2760(86)90224-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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