scholarly journals An essential vesicular-trafficking phospholipase mediates neutral lipid synthesis and contributes to hemozoin formation in Plasmodium falciparum

BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Mohd Asad ◽  
Yoshiki Yamaryo-Botté ◽  
Mohammad E. Hossain ◽  
Vandana Thakur ◽  
Shaifali Jain ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Neutral Lipid ◽  
Neutral Lipids ◽  
Lipid Synthesis ◽  
Large Family ◽  
Degradation Pathway ◽  
Food Vacuole ◽  
Parasite Growth ◽  
Lipid Homeostasis ◽  
Parasite Development

Abstract Background Plasmodium falciparum is the pathogen responsible for the most devastating form of human malaria. As it replicates asexually in the erythrocytes of its human host, the parasite feeds on haemoglobin uptaken from these cells. Heme, a toxic by-product of haemoglobin utilization by the parasite, is neutralized into inert hemozoin in the food vacuole of the parasite. Lipid homeostasis and phospholipid metabolism are crucial for this process, as well as for the parasite’s survival and propagation within the host. P. falciparum harbours a uniquely large family of phospholipases, which are suggested to play key roles in lipid metabolism and utilization. Results Here, we show that one of the parasite phospholipase (P. falciparum lysophospholipase, PfLPL1) plays an essential role in lipid homeostasis linked with the haemoglobin degradation and heme conversion pathway. Fluorescence tagging showed that the PfLPL1 in infected blood cells localizes to dynamic vesicular structures that traffic from the host-parasite interface at the parasite periphery, through the cytosol, to get incorporated into a large vesicular lipid rich body next to the food-vacuole. PfLPL1 is shown to harbour enzymatic activity to catabolize phospholipids, and its transient downregulation in the parasite caused a significant reduction of neutral lipids in the food vacuole-associated lipid bodies. This hindered the conversion of heme, originating from host haemoglobin, into the hemozoin, and disrupted the parasite development cycle and parasite growth. Detailed lipidomic analyses of inducible knock-down parasites deciphered the functional role of PfLPL1 in generation of neutral lipid through recycling of phospholipids. Further, exogenous fatty-acids were able to complement downregulation of PfLPL1 to rescue the parasite growth as well as restore hemozoin levels. Conclusions We found that the transient downregulation of PfLPL1 in the parasite disrupted lipid homeostasis and caused a reduction in neutral lipids essentially required for heme to hemozoin conversion. Our study suggests a crucial link between phospholipid catabolism and generation of neutral lipids (TAGs) with the host haemoglobin degradation pathway.

scholarly journals GlmS mediated knock-down of a phospholipase expedite alternate pathway to generate phosphocholine required for phosphatidylcholine synthesis in Plasmodium falciparum

2021 ◽  
Author(s):  
Pradeep K Sheokand ◽  
Monika Narwal ◽  
Vandana Thakur ◽  
Asif Mohmmed
Keyword(s):  
Plasmodium Falciparum ◽  
Phospholipid Metabolism ◽  
Food Vacuole ◽  
Lipid Homeostasis ◽  
Parasite Development ◽  
Therapeutic Approaches ◽  
Knock Down ◽  
Alternate Pathway ◽  
Kennedy Pathway ◽  
Phosphatidylcholine Synthesis

Phospholipid synthesis is crucial for membrane proliferation in malaria parasites during the entire cycle in the host cell. The major phospholipid of parasite membranes, phosphatidylcholine (PC), is mainly synthesized through the Kennedy pathway. The phosphocholine required for this synthetic pathway is generated by phosphorylation of choline derived from catabolism of the lyso-phosphatidylcholine (LPC) scavenged from the host milieu. Here we have characterized a Plasmodium falciparum lysophospholipase (PfLPL20) which showed enzymatic activity on LPC substrate to generate choline. Using GFP- targeting approach, PfLPL20 was localized in vesicular structures associated with the neutral lipid storage bodies present juxtaposed to the food-vacuole. The C-terminal tagged glmS mediated inducible knock-down of PfLPL20 caused transient hindrance in the parasite development, however, the parasites were able to multiply efficiently, suggesting that PfLPL20 is not essential for the parasite. However, in PfLPL20 depleted parasites, transcript levels of enzyme of SDPM pathway (Serine Decarboxylase-Phosphoethanolamine Methyltransferase) were altered along with upregulation of phosphocholine and SAM levels; these results show upregulation of alternate pathway to generate the phosphocholine required for PC synthesis through the Kennedy pathway. Our study highlights presence of alternate pathways for lipid homeostasis/membrane-biogenesis in the parasite; these data could be useful to design future therapeutic approaches targeting phospholipid metabolism in the parasite.

scholarly journals A lysophospholipase plays role in generation of neutral-lipids required for hemozoin formation in malaria parasite

2019 ◽  
Author(s):  
Mohd Asad ◽  
Yoshiki Yamaryo-Botté ◽  
Mohammad E. Hossain ◽  
Vandana Thakur ◽  
Shaifali Jain ◽  
...  
Keyword(s):  
Neutral Lipid ◽  
Malaria Parasite ◽  
Neutral Lipids ◽  
Phospholipid Metabolism ◽  
Food Vacuole ◽  
Specific Role ◽  
Lipid Homeostasis ◽  
Knock Down ◽  
Parasite Survival

AbstractPhospholipid metabolism is crucial for membrane dynamics in malaria parasites during entire cycle in the host cell. Plasmodium falciparum harbours several members of phospholipase family, which play key role in phospholipid metabolism. Here we have functionally characterized a parasite lysophospholipase (PfLPL1) with a view to understand its role in lipid homeostasis. We used a regulated fluorescence affinity tagging, which allowed endogenous localization and transient knock-down of the protein. PffLPL1localizes to dynamic vesicular structures that traffic from parasite periphery, through the cytosol to get associated as a multi-vesicular neutral lipid rich body next to the food-vacuole during blood stages. Down-regulation of the PfLPL1 disrupted parasite lipid-homeostasis leading to significant reduction of neutral lipids in lipid-bodies. This hindered conversion of heme to hemozoin, leading to food-vacuole abnormalities, which in turn disrupted parasite development cycle and significantly inhibited parasite growth. Detailed lipidomic analyses of inducible knock-down parasites confirmed role of PfLPL1 in generation of neutral lipid through recycling of phospholipids. Our study thus suggests a specific role of PfLPL1 to generate neutral lipids in the parasite, which are essential for parasite survival.ImportancePresent study was undertaken with a view to understand the functional role of a unique lipase (lysophopholipase, PfLPL1) of the human malaria parasite. We utilized genetic approaches for GFP tagging as well as to knock-down the target protein in the parasite. Our studies showed that PfLPL1 associates closely with the lysosome like organelle in the parasite, the food-vacuole. During the blood stage parasite cycle, the food-vacuole is involved in degradation of host haemoglobin and conversion of heme to hemozoin. Genetic knock-down approaches and detailed lipidomic studies confirmed that PfLPL1 protein plays key role in generation of neutral lipid stores in the parasite; neutral lipids are essentially required for hemozoin formation in the parasite, a vital function of the food-vacuole. Overall, this study identified specific role of PfLPL1 in the parasite which is essential for parasite survival.

scholarly journals The genetics of neutral lipid biosynthesis: an evolutionary perspective

2009 ◽  
Vol 297 (1) ◽  
pp. E19-E27 ◽  
Author(s):  
Aaron R. Turkish ◽  
Stephen L. Sturley
Keyword(s):  
Neutral Lipid ◽  
Metabolic Pathways ◽  
Fatty Liver Disease ◽  
Molecular Mechanisms ◽  
Neutral Lipids ◽  
Lipid Synthesis ◽  
Therapeutic Interventions ◽  
Wax Ester ◽  
Evolutionary Perspective ◽  
Nonalcoholic Fatty Liver

The storage of fatty acids and fatty alcohols in the form of neutral lipids such as triacylglycerol (TAG), cholesteryl ester (CE), and wax ester (WE) serves to provide reservoirs for membrane formation and maintenance, lipoprotein trafficking, lipid detoxification, evaporation barriers, and fuel in times of stress or nutrient deprivation. This ancient process likely originated in actinomycetes and has persisted in eukaryotes, albeit by different molecular mechanisms. A surfeit of neutral lipids is strongly, perhaps causally, related to several human diseases such as diabetes mellitus, obesity, atherosclerosis and nonalcoholic fatty liver disease. Therefore, understanding the metabolic pathways of neutral lipid synthesis and the roles of the enzymes involved may facilitate the development of new therapeutic interventions for these syndromes.

scholarly journals Protein ubiquitylation is essential for the schizont to merozoite transition in Plasmodium falciparum blood-stage development

2019 ◽  
Author(s):  
Yang Wu ◽  
Vesela Encheva ◽  
Judith L. Green ◽  
Edwin Lasonder ◽  
Adchara Prommaban ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Homology Model ◽  
Food Vacuole ◽  
Blood Stage ◽  
Parasite Development ◽  
Parasite Line ◽  
Schizont Stage ◽  
Post Translational Modification ◽  
Asexual Blood Stage ◽  
Erythrocyte Invasion

AbstractUbiquitylation is a common post translational modification of eukaryotic proteins and in the human malaria parasite, Plasmodium falciparum (Pf) overall ubiquitylation increases in the transition from intracellular schizont to extracellular merozoite stages in the asexual blood stage cycle. Here, we identify specific ubiquitylation sites of protein substrates in three intracellular parasite stages and extracellular merozoites; a total of 1464 sites in 546 proteins were identified (data available via ProteomeXchange with identifier PXD014998). 469 ubiquitylated proteins were identified in merozoites compared with only 160 in the preceding intracellular schizont stage, indicating a large increase in protein ubiquitylation associated with merozoite maturation. Following merozoite invasion of erythrocytes, few ubiquitylated proteins were detected in the first intracellular ring stage but as parasites matured through trophozoite to schizont stages the extent of ubiquitylation increased. We identified commonly used ubiquitylation motifs and groups of ubiquitylated proteins in specific areas of cellular function, for example merozoite pellicle proteins involved in erythrocyte invasion, exported proteins, and histones. To investigate the importance of ubiquitylation we screened ubiquitin pathway inhibitors in a parasite growth assay and identified the ubiquitin activating enzyme (UBA1 or E1) inhibitor MLN7243 (TAK-243) to be particularly effective. This small molecule was shown to be a potent inhibitor of recombinant PfUBA1, and a structural homology model of MLN7243 bound to the parasite enzyme highlights avenues for the development of P. falciparum specific inhibitors. We created a genetically modified parasite with a rapamycin-inducible functional deletion of uba1; addition of either MLN7243 or rapamycin to the recombinant parasite line resulted in the same phenotype, with parasite development blocked at the late schizont stage. These results indicate that the intracellular target of MLN7243 is UBA1, and this activity is essential for the final differentiation of schizonts to merozoites. The ubiquitylation of many merozoite proteins and their disappearance in ring stages are consistent with the idea that ubiquitylation leads to their destruction via the proteasome once their function is complete following invasion, which would allow amino acid recycling in the period prior to the parasite’s elaboration of a new food vacuole.

scholarly journals The role of neutral lipid nanospheres in Plasmodium falciparum haem crystallization

2007 ◽  
Vol 402 (1) ◽  
pp. 197-204 ◽  
Author(s):  
John M. Pisciotta ◽  
Isabelle Coppens ◽  
Abhai K. Tripathi ◽  
Peter F. Scholl ◽  
Joel Shuman ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Neutral Lipid ◽  
Membrane Lipids ◽  
Neutral Lipids ◽  
Close Association ◽  
Subcellular Fractionation ◽  
Digestive Vacuole ◽  
Lipid Mixture ◽  
Intracellular Mechanism

The intraerythrocytic malaria parasite constructs an intracellular haem crystal, called haemozoin, within an acidic digestive vacuole where haemoglobin is degraded. Haem crystallization is the target of the widely used antimalarial quinoline drugs. The intracellular mechanism of molecular initiation of haem crystallization, whether by proteins, polar membrane lipids or by neutral lipids, has not been fully substantiated. In the present study, we show neutral lipid predominant nanospheres, which envelop haemozoin inside Plasmodium falciparum digestive vacuoles. Subcellular fractionation of parasite-derived haemozoin through a dense 1.7 M sucrose cushion identifies monoacylglycerol and diacylglycerol neutral lipids as well as some polar lipids in close association with the purified haemozoin. Global MS lipidomics detects monopalmitic glycerol and monostearic glycerol, but not mono-oleic glycerol, closely associated with haemozoin. The complex neutral lipid mixture rapidly initiates haem crystallization, with reversible pH-dependent quinoline inhibition associated with quinoline entry into the neutral lipid microenvironment. Neutral lipid nanospheres both enable haem crystallization in the presence of high globin concentrations and protect haem from H2O2 degradation. Conceptually, the present study shifts the intracellular microenvironment of haem crystallization and quinoline inhibition from a polar aqueous location to a non-polar neutral lipid nanosphere able to exclude water for efficient haem crystallization.

scholarly journals Married at Birth: Regulation of Cellular Fat Metabolism by ER–Lipid Droplet Crosstalk

Contact ◽  
2020 ◽  
Vol 3 ◽  
pp. 251525642093467
Author(s):  
Zhe Cao ◽  
Ho Yi Mak
Keyword(s):  
Neutral Lipid ◽  
Neutral Lipids ◽  
Close Contact ◽  
Low Density Lipoprotein ◽  
Lipid Synthesis ◽  
Density Lipoprotein ◽  
Very Low Density Lipoprotein ◽  
Low Density ◽  
Acid Modification

The endoplasmic reticulum (ER) is a hub that coordinates neutral lipid synthesis, storage, and export. To fulfill this role, the ER maintains close contact with lipid droplets (LDs), which are evolutionarily conserved organelles for the storage of neutral lipids. Decades of biochemical evidence points to fatty acid modification and neutral lipid synthesis in the ER. Conceptually, lipid export into extracellular space or lipid retention intracellularly require the subsequent remodeling of an ER membrane leaflet that faces the lumen or cytoplasm, respectively. This is because LDs and very-low-density lipoprotein particles are all structures surrounded by a phospholipid monolayer. While the export of neutral lipids via very-low-density lipoprotein production is well characterized, there has been increasing interest in the mechanisms that underlie neutral lipid retention in LDs. Structural determination, in vitro reconstitution, and localization of key proteins by advanced microscopy techniques collectively enrich models of ER-LD engagement. In this review, we consider current concepts on how LDs emerge from the ER in a directional manner and how sustained ER-LD contacts support LD expansion.

scholarly journals PfPI3K, a phosphatidylinositol-3 kinase from Plasmodium falciparum, is exported to the host erythrocyte and is involved in hemoglobin trafficking

Blood ◽  
2010 ◽  
Vol 115 (12) ◽  
pp. 2500-2507 ◽  
Author(s):  
Ankush Vaid ◽  
Ravikant Ranjan ◽  
Wynand A. Smythe ◽  
Heinrich C. Hoppe ◽  
Pushkar Sharma
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Parasite ◽  
Second Messengers ◽  
Active Form ◽  
Food Vacuole ◽  
Parasite Growth ◽  
Phosphatidylinositol 3 Kinase ◽  
Pi3k Inhibitors ◽  
Parasite Plasmodium ◽  
Phosphatidylinositol 3

Abstract Polyphosphorylated phosphoinositides (PIPs) are potent second messengers, which trigger a wide variety of signaling and trafficking events in most eukaryotic cells. However, the role and metabolism of PIPs in malaria parasite Plasmodium have remained largely unexplored. Our present studies suggest that PfPI3K, a novel phosphatidylinositol-3-kinase (PI3K) in Plasmodium falciparum, is exported to the host erythrocyte by the parasite in an active form. PfPI3K is a versatile enzyme as it can generate various 3′-phosphorylated PIPs. In the parasite, PfPI3K was localized in vesicular compartments near the membrane and in its food vacuole. PI3K inhibitors wortmannin and LY294002 were effective against PfPI3K and were used to study PfPI3K function. We found that PfPI3K is involved in endocytosis from the host and trafficking of hemoglobin in the parasite. The inhibition of PfPI3K resulted in entrapment of hemoglobin in vesicles in the parasite cytoplasm, which prevented its transport to the food vacuole, the site of hemoglobin catabolism. As a result, hemoglobin digestion, which is a source of amino acids necessary for parasite growth, was attenuated and caused the inhibition of parasite growth.

scholarly journals Neutral-Lipid Analysis Reveals Elevation of Acylglycerols and Lack of Cholesterol Esters in Plasmodium falciparum-Infected Erythrocytes

2003 ◽  
Vol 2 (5) ◽  
pp. 1128-1131 ◽  
Author(s):  
Parwez Nawabi ◽  
Athanasios Lykidis ◽  
Darder Ji ◽  
Kasturi Haldar
Keyword(s):  
Plasmodium Falciparum ◽  
Toxoplasma Gondii ◽  
Neutral Lipid ◽  
Lipid Analysis ◽  
Neutral Lipids ◽  
Blood Stage ◽  
High Mass ◽  
Cholesterol Esters ◽  
Lipid Species

ABSTRACT Here we show that blood-stage Plasmodium falciparum organisms accumulate a high mass of triacylglycerol and diacylglycerol. However, we failed to detect cholesterol esters, a second neutral lipid species reported to be important for a related apicomplexan, Toxoplasma gondii. Evidence for P. falciparum and T. gondii homologues of acyl coenzyme A:diacylglycerol acyltransferase suggests that acylglycerols may be the conserved neutral lipids in apicomplexans.

Neutral lipid synthesis and storage in the intraerythrocytic stages of Plasmodium falciparum

2004 ◽  
Vol 135 (2) ◽  
pp. 197-209 ◽  
Author(s):  
Ole Vielemeyer ◽  
Michael T. McIntosh ◽  
Keith A. Joiner ◽  
Isabelle Coppens
Keyword(s):  
Plasmodium Falciparum ◽  
Neutral Lipid ◽  
Lipid Synthesis ◽  
And Storage

Regulation of Triglyceride Metabolism. I. Eukaryotic neutral lipid synthesis: “Many ways to skin ACAT or a DGAT”

2007 ◽  
Vol 292 (4) ◽  
pp. G953-G957 ◽  
Author(s):  
Aaron Turkish ◽  
Stephen L. Sturley
Keyword(s):  
Type 2 Diabetes ◽  
Fatty Acids ◽  
Neutral Lipid ◽  
Fatty Liver Disease ◽  
Neutral Lipids ◽  
Lipid Production ◽  
Lipid Synthesis ◽  
Therapeutic Interventions ◽  
Cellular Functions

Esterification of sterols, fatty acids and other alcohols into biologically inert forms conserves lipid resources for many cellular functions. Paradoxically, the accumulation of neutral lipids such as cholesteryl ester or triglyceride, is linked to several major disease pathologies. In a remarkable example of genetic expansion, there are at least eleven acyltransferase reactions that lead to neutral lipid production. In this review, we speculate that the complexity and apparent redundancy of neutral lipid synthesis may actually hasten rather than impede the development of novel, isoform-specific, therapeutic interventions for acne, type 2 diabetes, obesity, hyperlipidemia, fatty liver disease, and atherosclerosis.

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