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Basu S, Pawlowic MC, Hsu FF, Thomas G, Zhang K. Ethanolaminephosphate cytidylyltransferase is essential for survival, lipid homeostasis and stress tolerance in Leishmania major. PLoS Pathog 2023; 19:e1011112. [PMID: 37506172 PMCID: PMC10411802 DOI: 10.1371/journal.ppat.1011112] [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: 01/10/2023] [Revised: 08/09/2023] [Accepted: 07/12/2023] [Indexed: 07/30/2023] Open
Abstract
Glycerophospholipids including phosphatidylethanolamine (PE) and phosphatidylcholine (PC) are vital components of biological membranes. Trypanosomatid parasites of the genus Leishmania can acquire PE and PC via de novo synthesis and the uptake/remodeling of host lipids. In this study, we investigated the ethanolaminephosphate cytidylyltransferase (EPCT) in Leishmania major, which is the causative agent for cutaneous leishmaniasis. EPCT is a key enzyme in the ethanolamine branch of the Kennedy pathway which is responsible for the de novo synthesis of PE. Our results demonstrate that L. major EPCT is a cytosolic protein capable of catalyzing the formation of CDP-ethanolamine from ethanolamine-phosphate and cytidine triphosphate. Genetic manipulation experiments indicate that EPCT is essential in both the promastigote and amastigote stages of L. major as the chromosomal null mutants cannot survive without the episomal expression of EPCT. This differs from our previous findings on the choline branch of the Kennedy pathway (responsible for PC synthesis) which is required only in promastigotes but not amastigotes. While episomal EPCT expression does not affect promastigote proliferation under normal conditions, it leads to reduced production of ethanolamine plasmalogen or plasmenylethanolamine, the dominant PE subtype in Leishmania. In addition, parasites with episomal EPCT exhibit heightened sensitivity to acidic pH and starvation stress, and significant reduction in virulence. In summary, our investigation demonstrates that proper regulation of EPCT expression is crucial for PE synthesis, stress response, and survival of Leishmania parasites throughout their life cycle.
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Affiliation(s)
- Somrita Basu
- Department of Biological Sciences, Texas Tech University, Lubbock, Texas, United States of America
| | - Mattie C. Pawlowic
- Department of Biological Sciences, Texas Tech University, Lubbock, Texas, United States of America
- Wellcome Centre for Anti-Infectives Research (WCAIR), Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Fong-Fu Hsu
- Mass Spectrometry Resource, Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | - Geoff Thomas
- Department of Biological Sciences, Texas Tech University, Lubbock, Texas, United States of America
| | - Kai Zhang
- Department of Biological Sciences, Texas Tech University, Lubbock, Texas, United States of America
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2
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Haram CS, Moitra S, Keane R, Kuhlmann FM, Frankfater C, Hsu FF, Beverley SM, Zhang K, Keyel PA. The sphingolipids ceramide and inositol phosphorylceramide protect the Leishmania major membrane from sterol-specific toxins. J Biol Chem 2023; 299:104745. [PMID: 37094699 PMCID: PMC10209034 DOI: 10.1016/j.jbc.2023.104745] [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: 01/16/2023] [Revised: 04/19/2023] [Accepted: 04/21/2023] [Indexed: 04/26/2023] Open
Abstract
The accessibility of sterols in mammalian cells to exogenous sterol-binding agents has been well-described previously, but sterol accessibility in distantly related protozoa is unclear. The human pathogen Leishmania major uses sterols and sphingolipids distinct from those used in mammals. Sterols in mammalian cells can be sheltered from sterol-binding agents by membrane components, including sphingolipids, but the surface exposure of ergosterol in Leishmania remains unknown. Here, we used flow cytometry to test the ability of the Leishmania major sphingolipids inositol phosphorylceramide (IPC), and ceramide to shelter ergosterol by preventing binding of the sterol-specific toxins streptolysin O and perfringolysin O and subsequent cytotoxicity. In contrast to mammalian systems, we found that Leishmania sphingolipids did not preclude toxin binding to sterols in the membrane. However, we show that IPC reduced cytotoxicity, and that ceramide reduced perfringolysin O-, but not streptolysin O-, mediated cytotoxicity in cells. Furthermore, we demonstrate ceramide sensing was controlled by the toxin L3 loop, and that ceramide was sufficient to protect L. major promastigotes from the anti-leishmaniasis drug amphotericin B. Based on these results, we propose a mechanism whereby pore-forming toxins engage additional lipids like ceramide to determine the optimal environment to sustain pore formation. Thus, L. major could serve as a genetically tractable protozoan model organism for understanding toxin-membrane interactions.
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Affiliation(s)
- Chaitanya S Haram
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409
| | - Samrat Moitra
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409
| | - Rilee Keane
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409
| | - F Matthew Kuhlmann
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110
| | - Cheryl Frankfater
- Mass Spectrometry Resource, Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110
| | - Fong-Fu Hsu
- Mass Spectrometry Resource, Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110
| | - Stephen M Beverley
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110
| | - Kai Zhang
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409
| | - Peter A Keyel
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409.
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3
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Basu S, Pawlowic M, Hsu FF, Thomas G, Zhang K. Ethanolaminephosphate cytidyltransferase is essential for survival, lipid homeostasis and stress tolerance in Leishmania major. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.10.523530. [PMID: 36712124 PMCID: PMC9882048 DOI: 10.1101/2023.01.10.523530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Glycerophospholipids including phosphatidylethanolamine (PE) and phosphatidylcholine (PC) are vital components of biological membranes. Trypanosomatid parasites of the genus Leishmania can acquire PE and PC via de novo synthesis and the uptake/remodeling of host lipids. In this study, we investigated the ethanolaminephosphate cytidyltransferase (EPCT) in Leishmania major , which is the causative agent for cutaneous leishmaniasis. EPCT is a key enzyme in the ethanolamine branch of the Kennedy pathway which is responsible for the de novo synthesis of PE. Our results demonstrate that L. major EPCT is a cytosolic protein capable of catalyzing the formation of CDP-ethanolamine from ethanolamine-phosphate and cytidine triphosphate. Genetic manipulation experiments indicate that EPCT is essential in both the promastigote and amastigote stages of L. major as the chromosomal null mutants cannot survive without the episomal expression of EPCT. This differs from our previous findings on the choline branch of the Kennedy pathway (responsible for PC synthesis) which is required only in promastigotes but not amastigotes. While episomal EPCT expression does not affect promastigote proliferation under normal conditions, it leads to reduced production of ethanolamine plasmalogen or plasmenylethanolamine, the dominant PE subtype in Leishmania . In addition, parasites with epsiomal EPCT exhibit heightened sensitivity to acidic pH and starvation stress, and significant reduction in virulence. In summary, our investigation demonstrates that proper regulation of EPCT expression is crucial for PE synthesis, stress response, and survival of Leishmania parasites throughout their life cycle. AUTHOR SUMMARY In nature, Leishmania parasites alternate between fast replicating, extracellular promastigotes in sand fly gut and slow growing, intracellular amastigotes in macrophages. Previous studies suggest that promastigotes acquire most of their lipids via de novo synthesis whereas amastigotes rely on the uptake and remodeling of host lipids. Here we investigated the function of ethanolaminephosphate cytidyltransferase (EPCT) which catalyzes a key step in the de novo synthesis of phosphatidylethanolamine (PE) in Leishmania major . Results showed that EPCT is indispensable for both promastigotes and amastigotes, indicating that de novo PE synthesis is still needed at certain capacity for the intracellular form of Leishmania parasites. In addition, elevated EPCT expression alters overall PE synthesis and compromises parasite’s tolerance to adverse conditions and is deleterious to the growth of intracellular amastigotes. These findings provide new insight into how Leishmania acquire essential phospholipids and how disturbance of lipid metabolism can impact parasite fitness.
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Affiliation(s)
- Somrita Basu
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA
| | - Mattie Pawlowic
- Wellcome Centre for Anti-Infectives Research (WCAIR), Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Fong-Fu Hsu
- Mass Spectrometry Resource, Division of Endocrinology, Diabetes, Metabolism, and Lipid Research, Department of Internal Medicine, Washington University School of Medicine, 660S. Euclid Ave., Saint Louis, MO 63110, USA
| | - Geoff Thomas
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA
| | - Kai Zhang
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA
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Cerone M, Roberts M, Smith TK. The lipidome of Crithidia fasiculataand its plasticity. Front Cell Infect Microbiol 2022; 12:945750. [DOI: 10.3389/fcimb.2022.945750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 09/13/2022] [Indexed: 11/13/2022] Open
Abstract
Crithidia fasiculata belongs to the trypanosomatidae order of protozoan parasites, bearing close relation to other kinetoplastid parasites such as Trypanosoma brucei and Leishmania spp. As an early diverging lineage of eukaryotes, the study of kinetoplastid parasites has provided unique insights into alternative mechanisms to traditional eukaryotic metabolic pathways. Crithidia are a monogenetic parasite for mosquito species and have two distinct lifecycle stages both taking place in the mosquito gut. These consist of a motile choanomastigote form and an immotile amastigote form morphologically similar to amastigotes in Leishmania. Owing to their close relation to Leishmania, Crithidia are a growing research tool, with continuing interest in its use as a model organism for kinetoplastid research with the added benefit that they are non-pathogenic to humans and can be grown with no special equipment or requirements for biological containment. Although comparatively little research has taken place on Crithidia, similarities to other kinetoplast species has been shown in terms of energy metabolism and genetics. Crithidia also show similarities to kinetoplastids in their production of the monosaccharide D-arabinopyranose similar to Leishmania, which is incorporated into a lipoarabinogalactan a major cell surface GPI-anchored molecule. Additionally, Crithidia have been used as a eukaryotic expression system to express proteins from other kinetoplastids and potentially other eukaryotes including human proteins allowing various co- and post-translational protein modifications to the recombinant proteins. Despite the obvious usefulness and potential of this organism very little is known about its lipid metabolism. Here we describe a detailed lipidomic analyses and demonstrate the possible placidity of Crithidia’s lipid metabolis. This could have important implications for biotechnology approaches and how other kinetoplastids interact with, and scavenge nutrients from their hosts.
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Okundaye B, Biyani N, Moitra S, Zhang K. The Golgi-localized sphingosine-1-phosphate phosphatase is indispensable for Leishmania major. Sci Rep 2022; 12:16064. [PMID: 36163400 PMCID: PMC9513092 DOI: 10.1038/s41598-022-20249-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Accepted: 09/12/2022] [Indexed: 11/09/2022] Open
Abstract
Sphingosine-1-phosphate phosphatase (SPP) catalyzes the dephosphorylation of sphingosine-1-phosphate (S1P) into sphingosine, the reverse reaction of sphingosine kinase. In mammals, S1P acts as a potent bioactive molecule regulating cell proliferation, migration, and immunity. In Leishmania, S1P production is crucial for the synthesis of ethanolamine and choline phospholipids, and cell survival under stress conditions. To better understand the roles of S1P, we characterized a SPP ortholog in Leishmania major which displays activity towards S1P but not structurally related lipids such as ceramide-1-phosphate or lysophosphatidic acid. While this enzyme is found in the endoplasmic reticulum in mammalian cells, L. major SPP is localized at the Golgi apparatus. Importantly, chromosomal SPP alleles cannot be deleted from L. major even with the addition of a complementing episome, suggesting that endogenously expressed SPP is essential. Finally, SPP overexpression in L. major leads to a slower growth rate and heightened sensitivity to brefeldin A and sodium orthovanadate. Together, these results suggest that the equilibrium between S1P and sphingosine is vital for the function of Golgi apparatus in Leishmania.
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Affiliation(s)
- Brian Okundaye
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, 79409, USA
- The Institute of Environmental and Human Health, Texas Tech University, Lubbock, TX, 79409, USA
| | - Neha Biyani
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, 79409, USA
- Lantern Pharma Inc., 1920 McKinney Ave., Dallas, TX, 75201, USA
| | - Samrat Moitra
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, 79409, USA
| | - Kai Zhang
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, 79409, USA.
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6
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Zhang K. Balancing de novo synthesis and salvage of lipids by Leishmania amastigotes. Curr Opin Microbiol 2021; 63:98-103. [PMID: 34311265 PMCID: PMC8463422 DOI: 10.1016/j.mib.2021.07.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 06/30/2021] [Accepted: 07/05/2021] [Indexed: 11/24/2022]
Abstract
Leishmania parasites replicate as flagellated, extracellular promastigotes in the sand fly vector and then differentiate into non-flagellated, intracellular amastigotes in the vertebrate host. Promastigotes rely on de novo synthesis to produce the majority of their lipids including glycerophospholipids, sterols and sphingolipids. In contrast, amastigotes acquire most of their lipids from the host although they retain some capacity for de novo synthesis. The switch from de novo synthesis to salvage reflects the transition of Leishmania from fast-replicating promastigotes to slow-growing, metabolically quiescent amastigotes. Future studies will reveal the uptake and remodeling of host lipids by amastigotes at the cellular and molecular levels. Blocking the lipid transfer from host to parasites may present a novel strategy to control Leishmania growth.
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Affiliation(s)
- Kai Zhang
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA.
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Unexpected Role of Sterol Synthesis in RNA Stability and Translation in Leishmania. Biomedicines 2021; 9:biomedicines9060696. [PMID: 34205466 PMCID: PMC8235615 DOI: 10.3390/biomedicines9060696] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/09/2021] [Accepted: 06/15/2021] [Indexed: 01/16/2023] Open
Abstract
Leishmania parasites are trypanosomatid protozoans that cause leishmaniasis affecting millions of people worldwide. Sterols are important components of the plasma and organellar membranes. They also serve as precursors for the synthesis of signaling molecules. Unlike animals, Leishmania does not synthesize cholesterol but makes ergostane-based sterols instead. C-14-demethylase is a key enzyme involved in the biosynthesis of sterols and an important drug target. In Leishmania parasites, the inactivation of C-14-demethylase leads to multiple defects, including increased plasma membrane fluidity, mitochondrion dysfunction, hypersensitivity to stress and reduced virulence. In this study, we revealed a novel role for sterol synthesis in the maintenance of RNA stability and translation. Sterol alteration in C-14-demethylase knockout mutant leads to increased RNA degradation, reduced translation and impaired heat shock response. Thus, sterol biosynthesis in Leishmania plays an unexpected role in global gene regulation.
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8
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Moitra S, Basu S, Pawlowic M, Hsu FF, Zhang K. De Novo Synthesis of Phosphatidylcholine Is Essential for the Promastigote But Not Amastigote Stage in Leishmania major. Front Cell Infect Microbiol 2021; 11:647870. [PMID: 33777852 PMCID: PMC7996062 DOI: 10.3389/fcimb.2021.647870] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 02/09/2021] [Indexed: 12/18/2022] Open
Abstract
Phosphatidylcholine (PC) is the most abundant type of phospholipids in eukaryotes constituting ~30% of total lipids in Leishmania. PC synthesis mainly occurs via the choline branch of the Kennedy pathway (choline ⇒ choline-phosphate ⇒ CDP-choline ⇒ PC) and the N-methylation of phosphatidylethanolamine (PE). In addition, Leishmania parasites can acquire PC and other lipids from the host or culture medium. In this study, we assessed the function and essentiality of choline ethanolamine phosphotransferase (CEPT) in Leishmania major which is responsible for the final step of the de novo synthesis of PC and PE. Our data indicate that CEPT is localized in the endoplasmic reticulum and possesses the activity to generate PC from CDP-choline and diacylglycerol. Targeted deletion of CEPT is only possible in the presence of an episomal CEPT gene in the promastigote stage of L. major. These chromosomal null parasites require the episomal expression of CEPT to survive in culture, confirming its essentiality during the promastigote stage. In contrast, during in vivo infection of BALB/c mice, these chromosomal null parasites appeared to lose the episomal copy of CEPT while maintaining normal levels of virulence, replication and cellular PC. Therefore, while the de novo synthesis of PC/PE is indispensable for the proliferation of promastigotes, intracellular amastigotes appear to acquire most of their lipids through salvage and remodeling.
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Affiliation(s)
- Samrat Moitra
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, United States
| | - Somrita Basu
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, United States
| | - Mattie Pawlowic
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, United States
| | - Fong-Fu Hsu
- Mass Spectrometry Resource, Division of Endocrinology, Diabetes, Metabolism, and Lipid research, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO, United States
| | - Kai Zhang
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, United States
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Abstract
To understand the interplay of lipids between Leishmania promastigotes, amastigotes, and vertebrate host cells, a robust method for cultivating Leishmania parasites, lipid extraction, and shotgun lipidomic analysis with loop injection is described. This book chapter provides the step-by-step workflow to guide readers from sample preparation to the global lipid analysis by multiple stage mass spectrometry with high resolution and tandem quadrupole mass spectrometric approaches toward studying the metabolomic roles that lipids may play in Leishmania parasite infections.
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Affiliation(s)
- Kai Zhang
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, USA
| | - Fong-Fu Hsu
- Mass Spectrometry Resource, Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA.
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10
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Moitra S, Pawlowic MC, Hsu FF, Zhang K. Phosphatidylcholine synthesis through cholinephosphate cytidylyltransferase is dispensable in Leishmania major. Sci Rep 2019; 9:7602. [PMID: 31110206 PMCID: PMC6527706 DOI: 10.1038/s41598-019-44086-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 05/09/2019] [Indexed: 11/20/2022] Open
Abstract
Phosphatidylcholine (PC) is a major cell membrane constituent and precursor of important second messengers. In Leishmania parasites, PC synthesis can occur via the choline branch of the Kennedy pathway, the N-methylation of phosphatidylethanolamine (PE), or the remodeling of exogenous phospholipids. To investigate the role of de novo PC synthesis in Leishmania major, we focused on the cholinephosphate cytidylyltransferase (CPCT) which catalyzes the formation of CDP-choline, a key intermediate in the choline branch of the Kennedy pathway. Without CPCT, L. major parasites cannot incorporate choline into PC, yet the CPCT-null mutants contain similar levels of PC and PE as wild type parasites. Loss of CPCT does not affect the growth of parasites in complete medium or their virulence in mice. These results suggest that other mechanisms of PC synthesis can compensate the loss of CPCT. Importantly, CPCT-null parasites exhibited severe growth defects when ethanolamine and exogenous lipids became limited or when they were co-cultured with certain bacteria that are known to be members of sandfly midgut microbiota. These findings suggest that Leishmania employ multiple PC synthesis pathways to utilize a diverse pool of nutrients, which may be crucial for their survival and development in the sandfly.
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Affiliation(s)
- Samrat Moitra
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, 79409, USA
| | - Mattie C Pawlowic
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, 79409, USA.,Wellcome Centre for Anti-Infectives Research (WCAIR), Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Fong-Fu Hsu
- Department of Internal Medicine, Washington University School of Medicine, 660S. Euclid Ave., Saint Louis, MO, 63110, USA
| | - Kai Zhang
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, 79409, USA.
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11
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Mukherjee S, Xu W, Hsu FF, Patel J, Huang J, Zhang K. Sterol methyltransferase is required for optimal mitochondrial function and virulence in Leishmania major. Mol Microbiol 2018; 111:65-81. [PMID: 30260041 DOI: 10.1111/mmi.14139] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/21/2018] [Indexed: 12/24/2022]
Abstract
Limited knowledge on the exact functions of ergostane-based sterols has hampered the application of sterol synthesis inhibitors against trypanosomatid parasites. Sterol methyltransferase (SMT) is directly involved in the synthesis of parasite-specific C24-methylated sterols, including ergosterol and 5-dehydroepisterol. While pharmacological studies hint at its potential as a drug target against trypanosomatids, direct evidence for the cellular function and essentiality of SMT is lacking. Here, we characterized the SMT knockout mutants and their complemented strains in Leishmania major, the causative agent for cutaneous leishmaniasis. Deletion of SMT alleles led to a complete loss of C24-methylated sterols, which were replaced by cholestane-based sterols. SMT-null mutants were fully viable and replicative in culture but showed increased sensitivity to sphingolipid synthesis inhibition. They were not particularly vulnerable to heat, acidic pH, nitrosative or oxidative stress, yet exhibited high mitochondrial membrane potential and increased superoxide generation indicating altered physiology of the mitochondria. Despite possessing high levels of GPI-anchored glycoconjugates, SMT-null mutants showed significantly attenuated virulence in mice. In total, our study reveals that the biosynthesis of ergostane-based sterols is crucial for the proper function of mitochondria and the proliferation of Leishmania parasites in mammals.
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Affiliation(s)
- Sumit Mukherjee
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, 79409, USA
| | - Wei Xu
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, 79409, USA
| | - Fong-Fu Hsu
- Mass Spectrometry Resource, Division of Endocrinology, Diabetes, Metabolism, and Lipid research, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Jigesh Patel
- Department of Physics, Texas Tech University, Lubbock, TX, 79409, USA
| | - Juyang Huang
- Department of Physics, Texas Tech University, Lubbock, TX, 79409, USA
| | - Kai Zhang
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, 79409, USA
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12
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Jardim A, Hardie DB, Boitz J, Borchers CH. Proteomic Profiling of Leishmania donovani Promastigote Subcellular Organelles. J Proteome Res 2018; 17:1194-1215. [PMID: 29332401 DOI: 10.1021/acs.jproteome.7b00817] [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] [Indexed: 11/28/2022]
Abstract
To facilitate a greater understanding of the biological processes in the medically important Leishmania donovani parasite, a combination of differential and density-gradient ultracentrifugation techniques were used to achieve a comprehensive subcellular fractionation of the promastigote stage. An in-depth label-free proteomic LC-MS/MS analysis of the density gradients resulted in the identification of ∼50% of the Leishmania proteome (3883 proteins detected), which included ∼645 integral membrane proteins and 1737 uncharacterized proteins. Clustering and subcellular localization of proteins was based on a subset of training Leishmania proteins with known subcellular localizations that had been determined using biochemical, confocal microscopy, or immunoelectron microscopy approaches. This subcellular map will be a valuable resource that will help dissect the cell biology and metabolic processes associated with specific organelles of Leishmania and related kinetoplastids.
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Affiliation(s)
- Armando Jardim
- Institute of Parasitology, Macdonald Campus, McGill University , 21111 Lakeshore Road, Saine-Anne-de-Bellevue, Québec H9X 3V9, Canada
| | - Darryl B Hardie
- University of Victoria -Genome British Columbia Proteomics Centre , #3101-4464 Markham Street, Vancouver Island Technology Park, Victoria, British Columbia V8Z7X8, Canada
| | - Jan Boitz
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University , Portland, Oregon 97239, United States
| | - Christoph H Borchers
- University of Victoria -Genome British Columbia Proteomics Centre , #3101-4464 Markham Street, Vancouver Island Technology Park, Victoria, British Columbia V8Z7X8, Canada.,Department of Biochemistry and Biophysics, University of North Carolina , 120 Mason Farm Road, Campus Box 7260 Third Floor, Genetic Medicine Building, Chapel Hill, North Carolina 27599, United States.,Department of Biochemistry and Microbiology, University of Victoria , Petch Building, Room 270d, 3800 Finnerty Road, Victoria, British Columbia V8P 5C2, Canada.,Gerald Bronfman Department of Oncology, Jewish General Hospital, McGill University , 3755 Côte Ste-Catherine Road, Montreal, Quebec H3T 1E2, Canada.,Proteomics Centre, Segal Cancer Centre, Lady Davis Institute, Jewish General Hospital, McGill University , 3755 Côte Ste-Catherine Road, Montreal, Quebec H3T 1E2, Canada
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13
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Xu W, Mukherjee S, Ning Y, Hsu FF, Zhang K. Cyclopropane fatty acid synthesis affects cell shape and acid resistance in Leishmania mexicana. Int J Parasitol 2017; 48:245-256. [PMID: 29180119 DOI: 10.1016/j.ijpara.2017.09.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 09/15/2017] [Indexed: 10/18/2022]
Abstract
Cyclopropane fatty acid synthase (CFAS) catalyzes the transfer of a methylene group from S-adenosyl methionine to an unsaturated fatty acid, generating a cyclopropane fatty acid (CFA). The gene encoding CFAS is present in many bacteria and several Leishmania spp. including Leishmania mexicana, Leishmania infantum and Leishmania braziliensis. In this study, we characterised the CFAS-null and -overexpression mutants in L. mexicana, the causative agent for cutaneous leishmaniasis in Mexico and central America. Our data indicate that L. mexicana CFAS modifies the fatty acid chain of plasmenylethanolamine (PME), the dominant class of ethanolamine glycerophospholipids in Leishmania, generating CFA-PME. While the endogenous level of CFA-PME is extremely low in wild type L. mexicana, overexpression of CFAS results in a significant increase. CFAS-null mutants (cfas-) exhibit altered cell shape, increased sensitivity to acidic pH, and aberrant growth in serum-free media. In addition, the CFAS protein is preferentially expressed during the proliferative stage of L. mexicana and is required for the cell membrane targeting of lipophosphoglycan. Finally, the maturation and localization of CFAS protein are dependent upon the downstream sequence of the CFAS coding region. Without the downstream sequence, the mis-localised CFAS protein cannot fully rescue the defects of cfas-. Our data suggest that CFA modification of phospholipids can significantly affect the parasite's response to certain adverse conditions. These findings are distinct from the roles of CFAS in L. infantum, highlighting the functional divergence in lipid modification among Leishmania spp.
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Affiliation(s)
- Wei Xu
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA
| | - Sumit Mukherjee
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA
| | - Yu Ning
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA
| | - Fong-Fu Hsu
- Mass Spectrometry Resource, Division of Endocrinology, Diabetes, Metabolism, and Lipid research, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Kai Zhang
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA.
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