1
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Dingjan T, Futerman AH. Fine-tuned protein-lipid interactions in biological membranes: exploration and implications of the ORMDL-ceramide negative feedback loop in the endoplasmic reticulum. Front Cell Dev Biol 2024; 12:1457209. [PMID: 39170919 PMCID: PMC11335536 DOI: 10.3389/fcell.2024.1457209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2024] [Accepted: 07/26/2024] [Indexed: 08/23/2024] Open
Abstract
Biological membranes consist of a lipid bilayer in which integral membrane proteins are embedded. Based on the compositional complexity of the lipid species found in membranes, and on their specific and selective interactions with membrane proteins, we recently suggested that membrane bilayers can be best described as "finely-tuned molecular machines." We now discuss one such set of lipid-protein interactions by describing a negative feedback mechanism operating in the de novo sphingolipid biosynthetic pathway, which occurs in the membrane of the endoplasmic reticulum, and describe the atomic interactions between the first enzyme in the pathway, namely serine palmitoyl transferase, and the product of the fourth enzyme in the pathway, ceramide. We explore how hydrogen-bonding and hydrophobic interactions formed between Asn13 and Phe63 in the serine palmitoyl transferase complex and ceramide can influence the ceramide content of the endoplasmic reticulum. This example of finely-tuned biochemical interactions raises intriguing mechanistic questions about how sphingolipids and their biosynthetic enzymes could have evolved, particularly in light of their metabolic co-dependence.
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Affiliation(s)
- Tamir Dingjan
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
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2
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Ali O, Szabó A. Fumonisin distorts the cellular membrane lipid profile: A mechanistic insight. Toxicology 2024; 506:153860. [PMID: 38871209 DOI: 10.1016/j.tox.2024.153860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Revised: 06/04/2024] [Accepted: 06/06/2024] [Indexed: 06/15/2024]
Abstract
Monitoring modifications in membrane lipids in association with external stimuli/agents, including fumonisins (FUMs), is a widely employed approach to assess cellular metabolic response/status. FUMs are prevalent fusariotoxins worldwide that have diverse structures with varying toxicity across species; nevertheless, they can induce metabolic disturbances and disease, including cancer. The capacity of FUMs to disrupt membrane lipids, demonstrated across numerous species and organs/tissues, is ascribed to a multitude of factors/events, which range from direct to indirect effects. Certain events are well established, whereas the potential consequences of others remain speculative. The most notable effect is their resemblance to sphingoid bases, which impacts the synthesis of ceramides leading to numerous changes in lipids' composition that are not limited to sphingolipids' composition of the membranes. The next plausible scenario involves the induction of oxidative stress, which is considered an indirect/secondary effect of FUMs. Additional modes of action include modifications of enzyme activities and nuclear signals related to lipid metabolism, although these are likely not yet fully comprehended. This review provides in-depth insight into the current state of these events and their potential mechanistic actions in modifying membrane lipids, with a focus on long-chain fatty acids. This paper also presents a detailed description of the reported modifications to membrane lipids by FUMs.
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Affiliation(s)
- Omeralfaroug Ali
- Agribiotechnology and Precision Breeding for Food Security National Laboratory, Institute of Physiology and Animal Nutrition, Department of Animal Physiology and Health, Hungarian University of Agriculture and Life Sciences, Guba Sándor Str. 40, Kaposvár 7400, Hungary.
| | - András Szabó
- Agribiotechnology and Precision Breeding for Food Security National Laboratory, Institute of Physiology and Animal Nutrition, Department of Animal Physiology and Health, Hungarian University of Agriculture and Life Sciences, Guba Sándor Str. 40, Kaposvár 7400, Hungary; HUN-REN-MATE Mycotoxins in the Food Chain Research Group, Hungarian University of Agriculture and Life Sciences, Guba Sándor Str. 40, Kaposvár 7400, Hungary
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3
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Zhang Z, Fang Q, Xie T, Gong X. Mechanism of ceramide synthase inhibition by fumonisin B 1. Structure 2024:S0969-2126(24)00220-X. [PMID: 38964337 DOI: 10.1016/j.str.2024.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 05/20/2024] [Accepted: 06/07/2024] [Indexed: 07/06/2024]
Abstract
Ceramide synthases (CerSs) play crucial roles in sphingolipid metabolism and have emerged as promising drug targets for metabolic diseases, cancers, and antifungal therapy. However, the therapeutic targeting of CerSs has been hindered by a limited understanding of their inhibition mechanisms by small molecules. Fumonisin B1 (FB1) has been extensively studied as a potent inhibitor of eukaryotic CerSs. In this study, we characterize the inhibition mechanism of FB1 on yeast CerS (yCerS) and determine the structures of both FB1-bound and N-acyl-FB1-bound yCerS. Through our structural analysis and the observation of N-acylation of FB1 by yCerS, we propose a potential ping-pong catalytic mechanism for FB1 N-acylation by yCerS. Lastly, we demonstrate that FB1 exhibits lower binding affinity for yCerS compared to the C26- coenzyme A (CoA) substrate, suggesting that the potent inhibitory effect of FB1 on yCerS may primarily result from the N-acyl-FB1 catalyzed by yCerS, rather than through direct binding of FB1.
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Affiliation(s)
- Zike Zhang
- Shenzhen Key Laboratory of Plant Genetic Engineering and Molecular Design, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China; Department of Chemical Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Qi Fang
- Shenzhen Key Laboratory of Plant Genetic Engineering and Molecular Design, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China; Department of Chemical Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Tian Xie
- Shenzhen Key Laboratory of Plant Genetic Engineering and Molecular Design, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China; Department of Chemical Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China.
| | - Xin Gong
- Shenzhen Key Laboratory of Plant Genetic Engineering and Molecular Design, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China; Department of Chemical Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China; Institute for Biological Electron Microscopy, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China.
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4
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Brown RDR, Mahawar U, Wattenberg BW, Spiegel S. ORMDL mislocalization by impaired autophagy in Niemann-Pick type C disease leads to increased de novo sphingolipid biosynthesis. J Lipid Res 2024; 65:100556. [PMID: 38719150 PMCID: PMC11170278 DOI: 10.1016/j.jlr.2024.100556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 04/21/2024] [Accepted: 04/23/2024] [Indexed: 06/04/2024] Open
Abstract
Niemann-Pick type C1 (NPC1) disease is a rare neurodegenerative cholesterol and sphingolipid storage disorder primarily due to mutations in the cholesterol-trafficking protein NPC1. In addition to catabolic-derived sphingolipids, NPC1 dysfunction also leads to an increase in de novo sphingolipid biosynthesis, yet little is known about the cellular mechanism involved. Although deletion of NPC1 or inhibition of the NPC1 sterol binding domain enhanced de novo sphingolipid biosynthesis, surprisingly levels of the ORMDLs, the regulatory subunits of serine palmitoyltransferase (SPT), the rate-limiting step in sphingolipid biosynthesis, were also greatly increased. Nevertheless, less ORMDL was bound in the SPT-ORMDL complex despite elevated ceramide levels. Instead, ORMDL colocalized with p62, the selective autophagy receptor, and accumulated in stalled autophagosomes due to defective autophagy in NPC1 disease cells. Restoration of autophagic flux with N-acetyl-L-leucine in NPC1 deleted cells decreased ORMDL accumulation in autophagosomes and reduced de novo sphingolipid biosynthesis and their accumulation. This study revealed a previously unknown link between de novo sphingolipid biosynthesis, ORMDL, and autophagic defects present in NCP1 disease. In addition, we provide further evidence and mechanistic insight for the beneficial role of N-acetyl-L-leucine treatment for NPC1 disease which is presently awaiting approval from the Food and Drug Administration and the European Medicines Agency.
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Affiliation(s)
- Ryan D R Brown
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
| | - Usha Mahawar
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
| | - Binks W Wattenberg
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
| | - Sarah Spiegel
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA.
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5
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Demkova L, Bugajev V, Adamcova MK, Kuchar L, Grusanovic S, Alberich-Jorda M, Draber P, Halova I. Simultaneous deletion of ORMDL1 and ORMDL3 proteins disrupts immune cell homeostasis. Front Immunol 2024; 15:1376629. [PMID: 38715613 PMCID: PMC11074395 DOI: 10.3389/fimmu.2024.1376629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Accepted: 04/08/2024] [Indexed: 06/04/2024] Open
Abstract
ORMDL3 is a prominent member of a family of highly conserved endoplasmic reticulum resident proteins, ORMs (ORM1 and ORM2) in yeast, dORMDL in Drosophila and ORMDLs (ORMDL1, ORMDL2, and ORMDL3) in mammals. ORMDL3 mediates feedback inhibition of de novo sphingolipid synthesis. Expression levels of ORMDL3 are associated with the development of inflammatory and autoimmune diseases including asthma, systemic lupus erythematosus, type 1 diabetes mellitus and others. It has been shown that simultaneous deletions of other ORMDL family members could potentiate ORMDL3-induced phenotypes. To understand the complex function of ORMDL proteins in immunity in vivo, we analyzed mice with single or double deletions of Ormdl genes. In contrast to other single and double knockouts, simultaneous deletion of ORMDL1 and ORMDL3 proteins disrupted blood homeostasis and reduced immune cell content in peripheral blood and spleens of mice. The reduced number of splenocytes was not caused by aberrant immune cell homing. A competitive bone marrow transplantation assay showed that the development of Ormdl1-/-/Ormdl3-/- B cells was dependent on lymphocyte intrinsic factors. Highly increased sphingolipid production was observed in the spleens and bone marrow of Ormdl1-/-/Ormdl3-/- mice. Slight, yet significant, increase in some sphingolipid species was also observed in the spleens of Ormdl3-/- mice and in the bone marrow of both, Ormdl1-/- and Ormdl3-/- single knockout mice. Taken together, our results demonstrate that the physiological expression of ORMDL proteins is critical for the proper development and circulation of lymphocytes. We also show cell-type specific roles of individual ORMDL family members in the production of different sphingolipid species.
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Affiliation(s)
- Livia Demkova
- Laboratory of Signal Transduction, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Viktor Bugajev
- Laboratory of Signal Transduction, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Miroslava K. Adamcova
- Laboratory of Hemato-Oncology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Ladislav Kuchar
- Research Unit for Rare Diseases, Department of Pediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czechia
| | - Srdjan Grusanovic
- Laboratory of Hemato-Oncology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Meritxell Alberich-Jorda
- Laboratory of Hemato-Oncology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Petr Draber
- Laboratory of Signal Transduction, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Ivana Halova
- Laboratory of Signal Transduction, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
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6
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Xie T, Dong F, Han G, Wu X, Liu P, Zhang Z, Zhong J, Niranjanakumari S, Gable K, Gupta SD, Liu W, Harrison PJ, Campopiano DJ, Dunn TM, Gong X. Collaborative regulation of yeast SPT-Orm2 complex by phosphorylation and ceramide. Cell Rep 2024; 43:113717. [PMID: 38285738 DOI: 10.1016/j.celrep.2024.113717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 12/14/2023] [Accepted: 01/12/2024] [Indexed: 01/31/2024] Open
Abstract
The homeostatic regulation of serine palmitoyltransferase (SPT) activity in yeast involves N-terminal phosphorylation of Orm proteins, while higher eukaryotes lack these phosphorylation sites. Although recent studies have indicated a conserved ceramide-mediated feedback inhibition of the SPT-ORM/ORMDL complex in higher eukaryotes, its conservation and relationship with phosphorylation regulation in yeast remain unclear. Here, we determine the structure of the yeast SPT-Orm2 complex in a dephosphomimetic state and identify an evolutionarily conserved ceramide-sensing site. Ceramide stabilizes the dephosphomimetic Orm2 in an inhibitory conformation, facilitated by an intramolecular β-sheet between the N- and C-terminal segments of Orm2. Moreover, we find that a phosphomimetic mutant of Orm2, positioned adjacent to its intramolecular β-sheet, destabilizes the inhibitory conformation of Orm2. Taken together, our findings suggest that both Orm dephosphorylation and ceramide binding are crucial for suppressing SPT activity in yeast. This highlights a distinctive regulatory mechanism in yeast involving the collaborative actions of phosphorylation and ceramide.
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Affiliation(s)
- Tian Xie
- Department of Chemical Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Feitong Dong
- Department of Chemical Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Gongshe Han
- Department of Biochemistry and Molecular Biology, Uniformed Services University of Health Sciences, Bethesda, MD 20814, USA
| | - Xinyue Wu
- Department of Chemical Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Peng Liu
- Department of Chemical Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Zike Zhang
- Department of Chemical Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Jianlong Zhong
- Department of Chemical Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Somashekarappa Niranjanakumari
- Department of Biochemistry and Molecular Biology, Uniformed Services University of Health Sciences, Bethesda, MD 20814, USA
| | - Kenneth Gable
- Department of Biochemistry and Molecular Biology, Uniformed Services University of Health Sciences, Bethesda, MD 20814, USA
| | - Sita D Gupta
- Department of Biochemistry and Molecular Biology, Uniformed Services University of Health Sciences, Bethesda, MD 20814, USA
| | - Wenchen Liu
- Department of Chemical Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Peter J Harrison
- School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, UK
| | | | - Teresa M Dunn
- Department of Biochemistry and Molecular Biology, Uniformed Services University of Health Sciences, Bethesda, MD 20814, USA.
| | - Xin Gong
- Department of Chemical Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China; Institute for Biological Electron Microscopy, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China.
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7
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Mohassel P, Abdullah M, Eichler FS, Dunn TM. Serine Palmitoyltransferase (SPT)-related Neurodegenerative and Neurodevelopmental Disorders. J Neuromuscul Dis 2024; 11:735-747. [PMID: 38788085 PMCID: PMC11307022 DOI: 10.3233/jnd-240014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/22/2024] [Indexed: 05/26/2024]
Abstract
Motor neuron diseases and peripheral neuropathies are heterogeneous groups of neurodegenerative disorders that manifest with distinct symptoms due to progressive dysfunction or loss of specific neuronal subpopulations during different stages of development. A few monogenic, neurodegenerative diseases associated with primary metabolic disruptions of sphingolipid biosynthesis have been recently discovered. Sphingolipids are a subclass of lipids that form critical building blocks of all cellular and subcellular organelle membranes including the membrane components of the nervous system cells. They are especially abundant within the lipid portion of myelin. In this review, we will focus on our current understanding of disease phenotypes in three monogenic, neuromuscular diseases associated with pathogenic variants in components of serine palmitoyltransferase, the first step in sphingolipid biosynthesis. These include hereditary sensory and autonomic neuropathy type 1 (HSAN1), a sensory predominant peripheral neuropathy, and two neurodegenerative disorders: juvenile amyotrophic lateral sclerosis affecting the upper and lower motor neurons with sparing of sensory neurons, and a complicated form of hereditary spastic paraplegia with selective involvement of the upper motor neurons and more broad CNS neurodegeneration. We will also review our current understanding of disease pathomechanisms, therapeutic approaches, and the unanswered questions to explore in future studies.
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Affiliation(s)
- Payam Mohassel
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Meher Abdullah
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Florian S. Eichler
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Teresa M. Dunn
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
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8
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Mughram MHA, Kellogg GE, Wattenberg BW. Three kingdoms and one ceramide to rule them all. A comparison of the structural basis of ceramide-dependent regulation of sphingolipid biosynthesis in animals, plants, and fungi. Adv Biol Regul 2024; 91:101010. [PMID: 38135565 PMCID: PMC10922298 DOI: 10.1016/j.jbior.2023.101010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 12/11/2023] [Indexed: 12/24/2023]
Abstract
Sphingolipids are a diverse class of lipids with essential functions as determinants of membrane physical properties and as intra- and intercellular signaling agents. Disruption of the normal biochemical processes that establish the levels of individual sphingolipids is associated with a variety of human diseases including cancer, cardiovascular disease, metabolic disease, skin diseases, and lysosomal storage diseases. A unique aspect of this metabolic network is that there is a single enzymatic step that initiates the biosynthetic pathway for all sphingolipids. This step is catalyzed by the enzyme serine palmitoyltranserase (SPT). Under most circumstances SPT condenses serine and the 16-carbon acyl-CoA, palmitoyl-CoA to produce the precursor of all sphingolipids. SPT, a four-subunit protein complex, is subject to classic feedback regulation: when cellular sphingolipids are elevated, SPT activity is inhibited. Ceramide is the sphingolipid sensed by this system and it regulates SPT by directly binding to the complex. The ceramide binding site in the SPT complex, and how ceramide binding results in SPT inhibition, has now been determined in vertebrates, plants, and yeast using molecular modeling and cryo-electron microscopy. Here we discuss the similarities and differences revealed by these resolved structures and the surprising result that ceramide binds at almost identical positions in the SPT complex of these divergent organisms, but accomplishes SPT regulation in very different ways.
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Affiliation(s)
- Mohammed H Al Mughram
- Department of Medicinal Chemistry, Institute for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University School of Pharmacy, Richmond, VA, USA
| | - Glen E Kellogg
- Department of Medicinal Chemistry, Institute for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University School of Pharmacy, Richmond, VA, USA
| | - Binks W Wattenberg
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA.
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9
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Xie T, Fang Q, Zhang Z, Wang Y, Dong F, Gong X. Structure and mechanism of a eukaryotic ceramide synthase complex. EMBO J 2023; 42:e114889. [PMID: 37953642 PMCID: PMC10711658 DOI: 10.15252/embj.2023114889] [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: 06/29/2023] [Revised: 10/20/2023] [Accepted: 10/24/2023] [Indexed: 11/14/2023] Open
Abstract
Ceramide synthases (CerS) catalyze ceramide formation via N-acylation of a sphingoid base with a fatty acyl-CoA and are attractive drug targets for treating numerous metabolic diseases and cancers. Here, we present the cryo-EM structure of a yeast CerS complex, consisting of a catalytic Lac1 subunit and a regulatory Lip1 subunit, in complex with C26-CoA substrate. The CerS holoenzyme exists as a dimer of Lac1-Lip1 heterodimers. Lac1 contains a hydrophilic reaction chamber and a hydrophobic tunnel for binding the CoA moiety and C26-acyl chain of C26-CoA, respectively. Lip1 interacts with both the transmembrane region and the last luminal loop of Lac1 to maintain the proper acyl chain binding tunnel. A lateral opening on Lac1 serves as a potential entrance for the sphingoid base substrate. Our findings provide a template for understanding the working mechanism of eukaryotic ceramide synthases and may facilitate the development of therapeutic CerS modulators.
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Affiliation(s)
- Tian Xie
- Department of Chemical Biology, School of Life SciencesSouthern University of Science and TechnologyShenzhenChina
| | - Qi Fang
- Department of Chemical Biology, School of Life SciencesSouthern University of Science and TechnologyShenzhenChina
| | - Zike Zhang
- Department of Chemical Biology, School of Life SciencesSouthern University of Science and TechnologyShenzhenChina
| | - Yanfei Wang
- Department of Chemical Biology, School of Life SciencesSouthern University of Science and TechnologyShenzhenChina
| | - Feitong Dong
- Department of Chemical Biology, School of Life SciencesSouthern University of Science and TechnologyShenzhenChina
| | - Xin Gong
- Department of Chemical Biology, School of Life SciencesSouthern University of Science and TechnologyShenzhenChina
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10
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Thomas S, Samuel SV, Hoch A, Syphurs C, Diray-Arce J. The Implication of Sphingolipids in Viral Infections. Int J Mol Sci 2023; 24:17303. [PMID: 38139132 PMCID: PMC10743733 DOI: 10.3390/ijms242417303] [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: 10/28/2023] [Revised: 12/03/2023] [Accepted: 12/06/2023] [Indexed: 12/24/2023] Open
Abstract
Sphingolipids are involved in cell signaling and metabolic pathways, and their metabolites play a critical role in host defense against intracellular pathogens. Here, we review the known mechanisms of sphingolipids in viral infections and discuss the potential implication of the study of sphingolipid metabolism in vaccine and therapeutic development.
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Affiliation(s)
- Sanya Thomas
- Precision Vaccines Program, Department of Pediatrics, Boston Children’s Hospital, Boston, MA 02115, USA; (S.T.); (A.H.); (C.S.)
- Harvard Medical School, Boston, MA 02115, USA;
| | - Stephen Varghese Samuel
- Harvard Medical School, Boston, MA 02115, USA;
- Department of Emergency Medicine, Christian Medical College and Hospital, Vellore 632004, India
| | - Annmarie Hoch
- Precision Vaccines Program, Department of Pediatrics, Boston Children’s Hospital, Boston, MA 02115, USA; (S.T.); (A.H.); (C.S.)
| | - Caitlin Syphurs
- Precision Vaccines Program, Department of Pediatrics, Boston Children’s Hospital, Boston, MA 02115, USA; (S.T.); (A.H.); (C.S.)
| | - Joann Diray-Arce
- Precision Vaccines Program, Department of Pediatrics, Boston Children’s Hospital, Boston, MA 02115, USA; (S.T.); (A.H.); (C.S.)
- Harvard Medical School, Boston, MA 02115, USA;
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11
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Esch BM, Walter S, Schmidt O, Fröhlich F. Identification of distinct active pools of yeast serine palmitoyltransferase in sub-compartments of the ER. J Cell Sci 2023; 136:jcs261353. [PMID: 37982431 DOI: 10.1242/jcs.261353] [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: 05/22/2023] [Accepted: 11/09/2023] [Indexed: 11/21/2023] Open
Abstract
Sphingolipids (SPs) are one of the three major lipid classes in eukaryotic cells and serve as structural components of the plasma membrane. The rate-limiting step in SP biosynthesis is catalyzed by the serine palmitoyltransferase (SPT). In budding yeast (Saccharomyces cerevisiae), SPT is negatively regulated by the two proteins, Orm1 and Orm2. Regulating SPT activity enables cells to adapt SP metabolism to changing environmental conditions. Therefore, the Orm proteins are phosphorylated by two signaling pathways originating from either the plasma membrane or the lysosome (or vacuole in yeast). Moreover, uptake of exogenous serine is necessary for the regulation of SP biosynthesis, which suggests the existence of differentially regulated SPT pools based on their intracellular localization. However, measuring lipid metabolic enzyme activity in different cellular sub-compartments has been challenging. Combining a nanobody recruitment approach with SP flux analysis, we show that the nuclear endoplasmic reticulum (ER)-localized SPT and the peripheral ER localized SPT pools are differentially active. Thus, our data add another layer to the complex network of SPT regulation. Moreover, combining lipid metabolic enzyme re-localization with flux analysis serves as versatile tool to measure lipid metabolism with subcellular resolution.
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Affiliation(s)
- Bianca M Esch
- Osnabrück University, Department of Biology-Chemistry, Bioanalytical Chemistry Section, Barbarastrasse 13, 49076 Osnabrück, Germany
- Osnabrück University, Center for Cellular Nanoanalytic Osnabrück (CellNanOs), Barbarastrasse 11, 49076 Osnabrück, Germany
| | - Stefan Walter
- Osnabrück University, Center for Cellular Nanoanalytic Osnabrück (CellNanOs), Barbarastrasse 11, 49076 Osnabrück, Germany
| | - Oliver Schmidt
- Institute of Cell Biology, Biocenter Innsbruck, Medical University of Innsbruck, Innrain 80, 6020 Innsbruck, Austria
| | - Florian Fröhlich
- Osnabrück University, Department of Biology-Chemistry, Bioanalytical Chemistry Section, Barbarastrasse 13, 49076 Osnabrück, Germany
- Osnabrück University, Center for Cellular Nanoanalytic Osnabrück (CellNanOs), Barbarastrasse 11, 49076 Osnabrück, Germany
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12
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Schäfer JH, Körner C, Esch BM, Limar S, Parey K, Walter S, Januliene D, Moeller A, Fröhlich F. Structure of the ceramide-bound SPOTS complex. Nat Commun 2023; 14:6196. [PMID: 37794019 PMCID: PMC10550967 DOI: 10.1038/s41467-023-41747-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 09/05/2023] [Indexed: 10/06/2023] Open
Abstract
Sphingolipids are structural membrane components that also function in cellular stress responses. The serine palmitoyltransferase (SPT) catalyzes the rate-limiting step in sphingolipid biogenesis. Its activity is tightly regulated through multiple binding partners, including Tsc3, Orm proteins, ceramides, and the phosphatidylinositol-4-phosphate (PI4P) phosphatase Sac1. The structural organization and regulatory mechanisms of this complex are not yet understood. Here, we report the high-resolution cryo-EM structures of the yeast SPT in complex with Tsc3 and Orm1 (SPOT) as dimers and monomers and a monomeric complex further carrying Sac1 (SPOTS). In all complexes, the tight interaction of the downstream metabolite ceramide and Orm1 reveals the ceramide-dependent inhibition. Additionally, observation of ceramide and ergosterol binding suggests a co-regulation of sphingolipid biogenesis and sterol metabolism within the SPOTS complex.
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Affiliation(s)
- Jan-Hannes Schäfer
- Osnabrück University Department of Biology/Chemistry Structural Biology section, 49076, Osnabrück, Germany
| | - Carolin Körner
- Osnabrück University Department of Biology/Chemistry Bioanalytical Chemistry section, 49076, Osnabrück, Germany
| | - Bianca M Esch
- Osnabrück University Department of Biology/Chemistry Bioanalytical Chemistry section, 49076, Osnabrück, Germany
| | - Sergej Limar
- Osnabrück University Department of Biology/Chemistry Bioanalytical Chemistry section, 49076, Osnabrück, Germany
| | - Kristian Parey
- Osnabrück University Department of Biology/Chemistry Structural Biology section, 49076, Osnabrück, Germany
- Osnabrück University Center of Cellular Nanoanalytic Osnabrück (CellNanOs), 49076, Osnabrück, Germany
| | - Stefan Walter
- Osnabrück University Center of Cellular Nanoanalytic Osnabrück (CellNanOs), 49076, Osnabrück, Germany
| | - Dovile Januliene
- Osnabrück University Department of Biology/Chemistry Structural Biology section, 49076, Osnabrück, Germany.
- Osnabrück University Center of Cellular Nanoanalytic Osnabrück (CellNanOs), 49076, Osnabrück, Germany.
| | - Arne Moeller
- Osnabrück University Department of Biology/Chemistry Structural Biology section, 49076, Osnabrück, Germany.
- Osnabrück University Center of Cellular Nanoanalytic Osnabrück (CellNanOs), 49076, Osnabrück, Germany.
| | - Florian Fröhlich
- Osnabrück University Department of Biology/Chemistry Bioanalytical Chemistry section, 49076, Osnabrück, Germany.
- Osnabrück University Center of Cellular Nanoanalytic Osnabrück (CellNanOs), 49076, Osnabrück, Germany.
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Clausmeyer L, Fröhlich F. Mechanisms of Nonvesicular Ceramide Transport. CONTACT (THOUSAND OAKS (VENTURA COUNTY, CALIF.)) 2023; 6:25152564231208250. [PMID: 37859671 PMCID: PMC10583516 DOI: 10.1177/25152564231208250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 09/29/2023] [Accepted: 09/29/2023] [Indexed: 10/21/2023]
Abstract
Ceramides, as key components of cellular membranes, play essential roles in various cellular processes, including apoptosis, cell proliferation, and cell signaling. Ceramides are the precursors of all complex sphingolipids in eukaryotic cells. They are synthesized in the endoplasmic reticulum and are further processed at the Golgi apparatus. Therefore, ceramides have to be transported between these two organelles. In mammalian cells, the ceramide transfer protein forms a contact site between the ER and the trans-Golgi region and transports ceramide utilizing its steroidogenic acute regulatory protein-related lipid transfer domain. In yeast, multiple mechanisms of nonvesicular ceramide transport have been described. This involves the nuclear-vacuolar junction protein Nvj2, the yeast tricalbin proteins, and the lipocalin-like protein Svf1. This review aims to provide a comprehensive overview of nonvesicular ceramide transport mechanisms and their relevance in cellular physiology. We will highlight the physiological and pathological consequences of perturbations in nonvesicular ceramide transport and discuss future challenges in identifying and analyzing ceramide transfer proteins.
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Affiliation(s)
- Lena Clausmeyer
- Department of Biology/Chemistry, Bioanalytical Chemistry Section, Osnabrück University, Osnabrück, Germany
| | - Florian Fröhlich
- Department of Biology/Chemistry, Bioanalytical Chemistry Section, Osnabrück University, Osnabrück, Germany
- Center of Cellular Nanoanalytics Osnabrück (CellNanOs), Osnabrück University, Osnabrück, Germany
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