Biology subjects

Yamaryo-Botte, Y.

Publications and source records attributed to Yamaryo-Botte, Y..

11 recordsLinked to original sources

bioRxiv2026

Toxoplasma gondii Fatty Acid Elongases are Important for Virulence and Persistence

Toxoplasma gondii is an apicomplexan parasite which can infect a diverse range of warm-blooded host species. This promiscuous lifestyle requires metabolic flexibility yet our understanding of the metabolic pathways in this parasite remains incomplete. This gap includes the endoplasmic reticulum localised fatty acid elongation (FAE) pathway, which is responsible for synthesis of long (LCFA) and very long chain fatty acids (VLCFA), thus contributing to critical functions such as lipid storage and membrane biogenesis. Analyses of FAE in the commonly studied type I T. gondii strain revealed its contribution to the production of LCFA and VLCFA in vitro. However, the cystogenic type II T. gondii, which is responsible for most toxoplasmosis cases worldwide, was not studied. These type II parasites can readily differentiate between virulent and immune-evasive stages whereas type I cannot. This ability to readily transition between life stages, which are metabolically fundamentally different, prompts the question of whether the FAE pathway may play different roles in their distinct phenotype. Here we address this question, first confirming the role of the FAE enzymes, TgELO-A & B, in the production of LCFA and VLCFA in a type II T. gondii strain. Next, we demonstrated that their deletion leads to defects in replication and invasion when grown under lipid-restricted conditions. The mutants were further shown to be attenuated in mice as demonstrated by extended survival. Importantly, FAE enzyme deletion caused reduced brain cyst burdens. These findings highlight the importance of FAE for parasite survival under metabolic stress and in vivo. ImportanceToxoplasma gondii infects a wide range of hosts and persists for life in multiple tissues, making metabolic flexibility essential for its success. Fatty acid elongation (FAE), mediated by elongase (ELO) enzymes, enables the parasite to modify both de novo synthesised and host-scavenged fatty acids to support membrane biogenesis, lipid storage, and adaptation to changing nutrient environments. Previous studies in the type I strain established the importance of FAE for parasite metabolism, but its role in the clinically relevant, cystogenic type II lineage--which causes most cases of human toxoplasmosis and forms long-lived, immune-evasive bradyzoite cysts-- remained unknown. Here, we address this gap by characterising type II ELO mutants and show that disruption of FAE remodels the parasite lipidome, impairs fitness under fatty acid-limiting conditions, and reduces virulence and chronic persistence in mice. These findings identify FAE as a key metabolic pathway underpinning adaptation and persistence during chronic infection.

microbiology↗

bioRxiv2026

Nuclear acetyl-CoA production by acetyl-CoA synthetase enables dynamic histone acetylation and gene expression in Plasmodium falciparum

A complex transcriptional cascade drives the two-day intraerythrocytic developmental cycle of the most virulent human malaria parasite, Plasmodium falciparum, in the human host. Genes are rapidly activated at specific times, then silenced as quickly. Transcriptional activity correlates with histone acetylation, which is modulated by acetyltransferases that use acetyl-CoA and deacetylases that produce acetate. Acetyl-CoA synthetase (ACAS) uses acetate to produce acetyl-CoA and has been implicated in histone acetylation, providing an interesting link between parasite metabolism and transcription. Here, we show that ACAS becomes enriched in the nucleus at a time during the life cycle when the parasite undergoes rapid growth and increased levels of transcription. We use mass spectrometry to show that ACAS inhibition results in a rapid and global depletion of histone acetylation, which leads to a general decrease in chromatin accessibility at gene promoters. These widespread alterations in chromatin composition disrupted the transcriptional cascade, resulting in cell cycle arrest. Our study provides evidence that ACAS plays an important nuclear role in the histone acetylation cycle and insight into the dynamic nature and essentiality of histone acetylation in the parasites complex transcriptional program driving infection of the human host.

molecular biology↗

bioRxiv2026

A lipid droplet triacylglycerol lipase governs neutral lipids mobilization and differentiation of Trypanosoma brucei

Lipid droplets (LD) are dynamic organelles largely distributed in all living cells that are essential notably for membrane biogenesis and cell proliferation. In Trypanosoma brucei, a protozoan parasite responsible for major lethal infectious diseases in humans and cattle, lipid acquisition and mobilization are essential for its survival and adaptation to its different hosts, but the roles of LD in these processes remain largely unknown. To address this gap, we identified and characterized a unique functional orthologue of the human adipose triacylglycerol lipase (ATGL), responsible for the initiation of neutral lipid mobilization, in T. brucei. In this study, we present TbPatatin-like (TbPat), the first ATGL ortholog in protozoan parasites. By combining reverse genetics, microscopy and -omics analysis, we deciphered the role of TbPat in lipolysis and neutral lipid maintenance in both insect and mammalian stages of African trypanosomes and imaged its distribution on the LD surface at an unprecedented resolution by using Cryo-Expansion microscopy. We found that inactivation of TbPat in mammalian form T. brucei led to a global upregulation of the mitochondrial metabolic proteome; furthermore, these cells appeared remarkably unable to differentiate into the procyclic insect stage. Through its expression and localization, TbPat appears to be at an essential checkpoint linking lipid environment and metabolism to more complex cell programs involving proteome, compartment remodeling and lifecycle completion.

microbiology↗

bioRxiv2026

Cardiolipin constrains lipid unsaturation during anaerobic adaptation in Escherichia coli

Membrane lipids play a crucial role in cellular adaptation; though their specific functions in bacterial adaptation to oxygen limitation are not yet fully elucidated. Cardiolipin (CL), a signature phospholipid in energy-transducing membranes and a key organizer of mitochondrial respiration, has an unclear role in bacterial anaerobic physiology. Here, genetics, quantitative lipidomics and proteomics, enzymology, and fluorescence imaging were combined to explore how CL facilitates hypoxia adaptation in Escherichia coli. ClsA emerged as the predominant CL synthase under anaerobic conditions, and CL deficiency selectively impaired nitrate-dependent growth, while fermentation and fumarate respiration remained largely unaffected. CL depletion triggered extensive lipidome rewiring during the aerobic-to-anaerobic transition, including increased levels of phosphatidylglycerol, phosphatidic acid, and diacylglycerol, along with a broad enrichment of more unsaturated lipid species. In parallel, proteome remodeling linked CL loss to reduced abundance of proteins involved in anoxic respiration and nitrosative stress management, alongside the induction of membrane stress responses. Interestingly, CL deficiency did not markedly affect cell morphology, nor the spatial distribution or stability of respiratory complexes. This suggests a specialized role in optimizing membrane protein function rather than providing generic structural support. Wild-type lipidome profiling further showed that anaerobiosis induces a shift of lipid species toward higher unsaturation, with only modest class-level changes. Collectively, these results connect lipid remodeling to functional outcomes in vivo, offering mechanistic insights into how bacteria adapt their membranes to maintain energy conservation in fluctuating environments.

microbiology↗

bioRxiv2026

MMV687794 blocks Plasmodium falciparum invasion of red blood cells by targeting a Surface-associated Lipid-Interacting Rhoptry Protein, PfSLIRP

Invasion of red blood cells (RBCs) by the human malaria parasite, Plasmodium falciparum, drives disease. During invasion, the parasite pushes its way into the RBC while wrapping the RBC membrane around itself to establish the parasitophorous vacuole, a stable niche within the RBC where the parasite grows. To better understand invasion, we investigated the mechanism of action of an invasion-inhibitory compound, MMV687794 (MMV794). Lattice light-sheet microscopy revealed that MMV794 blocks parasite entry by preventing parasitophorous vacuole formation. In vitro drug resistance selection of parasites with MMV794 found mutations to the /{beta} hydrolase, PF3D7_0403800, and engineering one of these mutations (C36W) into parasites by CRISPR/Cas9 recapitulated the resistance phenotype. Expansion microscopy demonstrated that this protein is expressed in schizonts, localising to the surface of rhoptries, which are specialised apical secretory organelles that function during invasion. Lipidomics and proteomics analyses of C36W parasites uncovered widespread changes to lipid composition/homeostasis and altered abundance of proteins involved in invasion, indicating a role for PF3D7_0403800 in invasion-associated lipid metabolism. Finally, we used solvent-induced proteome profiling and reactivity assays to confirm drug-target engagement. Together, our findings identify a novel Surface-associated Lipid-Interacting Rhoptry Protein (PfSLIRP) that coordinates lipid metabolism at the rhoptries to enable RBC invasion.

microbiology↗

bioRxiv2025

Plasmodium falciparum aquaglyceroporin (PfAQP) orchestrates glycerol-dependent lipid metabolism, membrane biogenesis, metabolomic flux, parasite growth and stress adaptation

Aquaglyceroporins (AQPs) are integral membrane channel proteins that facilitate transport of water and other solutes such as glycerol, thereby playing vital roles in cellular homeostasis. Here, we functionally characterized Plasmodium falciparum aquaglyceroporin (PfAQP) through localization, inducible knockdown, and comprehensive metabolomic analyses revealing its key role in lipid homeostasis and metabolomic flux. PfAQP localizes to the parasite plasma membrane and food vacuole membrane, at critical interfaces for nutrient and metabolite exchange. A glmS-ribozyme mediated inducible knock-down of PfAQP severely impairs parasite development from trophozoite to schizont, leading to marked suppression in parasite growth. Ultra-Expansion Microscopy (UExM) analyses show profound defects in membrane biogenesis, along with disruption in cytokinesis under PfAQP knock-down conditions. Detailed lipidomic analyses suggests that PfAQP disruption cause altered lipid homeostasis, characterized by reduced membrane phospholipid biosynthesis, impaired lipid scavenging, and accumulation of storage lipids. Metabolomic analyses further indicate metabolic dysregulation characterized by reduction in amino acid levels and dysregulated mitochondrial metabolism, including impaired tricarboxylic acid (TCA) cycle. Strikingly, PfAQP expression gets transiently upregulated under nutrient starvation condition, and its ablation drastically compromise parasite recovery, highlighting its role in adaptive responses. Overall, these results establish PfAQP as a critical regulator of glycerol-dependent metabolic pathways, orchestrating membrane biogenesis, energy metabolism, and stress resilience--functions indispensable for parasite growth and survival.

microbiology↗

bioRxiv2023

Nucleoside Diphosphate Kinases 1 and 2 regulate a protective liver response to a high-fat diet

De novo lipogenesis (DNL), the process whereby cells synthesize fatty acids from acetyl-coenzyme A (acetyl-CoA), is deregulated in diverse pathologies, including cancer. Here we report that DNL is negatively regulated by Nucleoside Diphosphate Kinases 1 and 2 (NME1/2), housekeeping enzymes involved in nucleotide homeostasis that were recently discovered to bind co-enzyme A (CoA). We show that NME1 additionally binds acetyl-CoA and that ligand recognition involves a unique binding mode dependent on the CoA/acetyl-CoA 3 phosphate. We report that Nme2 knockout mice fed a high-fat diet (HFD) exhibit excessive triglyceride synthesis and liver steatosis. In liver cells NME2 mediates a gene transcriptional response to HFD leading to DNL repression and activation of a protective gene expression program via targeted histone acetylation. Our findings implicate NME1/2 in the epigenetic regulation of a protective liver response to HFD and suggest a potential role in controlling acetyl-CoA usage between the competing paths of histone acetylation and DNL.

molecular biology↗

bioRxiv2022

Disruption of the plastid-hosted iron-sulfur cluster biogenesis pathway in Toxoplasma gondii has pleiotropic effects irreversibly impacting parasite viability

Like many other apicomplexan parasites, Toxoplasma gondii contains a plastid harbouring key metabolic pathways, including the SUF pathway that is involved in the biosynthesis of iron-sulfur clusters. These cofactors are key for a variety of proteins involved in important metabolic reactions, potentially including plastidic pathways for the synthesis of isoprenoid and fatty acids. It was shown previously that impairing the NFS2 cysteine desulfurase, involved in the first step of the SUF pathway, leads to an irreversible killing of intracellular parasites. However, the metabolic impact of disrupting the pathway remained unexplored. We have generated another mutant of the pathway, deficient for the SUFC ATPase, and we have investigated in details the phenotypic consequences of TgNFS2 and TgSUFC depletion on parasite homeostasis. Our analysis confirms that Toxoplasma SUF mutants are severely and irreversibly impacted in growth: cell division and membrane homeostasis are particularly affected. Lipidomic analysis suggests a defect in apicoplast-generated fatty acids, along with a simultaneous increase in scavenging of host-derived lipids. However, addition of exogenous lipids did not allow full restauration of growth, suggesting other more important cellular functions were impacted in addition to fatty acid synthesis. For instance, we have shown that the SUF pathway is also key for generating isoprenoid-derived precursors necessary for the proper targeting of GPI-anchored proteins as well as for the parasite gliding motility. Thus, plastid-generated iron-sulfur clusters support the functions of proteins involved in several vital downstream cellular pathways, which implies the SUF machinery may be explored for discovering new potential anti-Toxoplasma targets.

microbiology↗

bioRxiv2021

A Plasmodium falciparum lysophospholipase regulates fatty acid acquisition for membrane biogenesis to enable schizogonic asexual division

Phospholipid metabolism is crucial for membrane biogenesis and homeostasis during the intracellular life cycle of Plasmodium falciparum. To generate large amounts of phospholipids required during blood stages, the parasite massively scavenge, recycle and reassemble host lipids. P. falciparum possesses an unusual large number of lysophospholipases. However, their functional roles and importance remain to be elucidated. Here, we functionally characterized one of P. falciparum lysophospholipase (PfLPL3) (Gene ID PF3D7_1476800), to reveal its critical role in parasite propagation during asexual blood stages. We generated a transgenic parasite line using GFP-glmS C-terminal tagging approach, for localization as well as inducible knockdown of PfLPL3. PfLPL3 displayed a dynamic localization throughout asexual stages, mainly localizing in the host parasite interface: parasitophorous vacuole space and expanding into the tubulovesicular network within the host cell. Inducible knock-down of PfLPL3 hindered normal intraerythrocytic cycle, specifically causing disruption in parasite development from trophozoites to schizont, as well as reduction in number of merozoites progenies. Thus, down-regulation of PfLPL3 significantly inhibited parasite growth suggesting its critical role for proper parasite propagation during blood stages. Detailed lipidomic analyses showed that PfLPL3 generates fatty-acids for the synthesis of neutral lipids DAG and TAG, whilst controlling the timely synthesis of phospholipids that are crucial for membrane biogenesis required for merozoite development during asexual cycle. Setting up an in vitro activity based screening of Malaria Box allowed identification of specific inhibitors of PfLPL3 having potent parasitical efficacies. These compounds are pertinent both as anti-malarial drug candidates and chemical tools specifically targeting membrane biogenesis during asexual blood stages.

microbiology↗

bioRxiv2019

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

Phospholipid 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.\n\nImportancePresent 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.

microbiology↗

bioRxiv2019

Division and adaptation to host nutritional environment of apicomplexan parasites depend on apicoplast lipid metabolic plasticity and host organelles remodelling

Apicomplexan parasites are unicellular eukaryotes responsible for major human diseases including malaria and toxoplasmosis. Apicomplexan parasites must obtain and combine lipids both from host cell scavenging and de novo synthesis to maintain parasite propagation and survival within their human host. Major questions on the actual role for each lipid source or how these are regulated upon fluctuating host nutritional conditions remain unanswered. Characterization of an apicoplast acyltransferase TgATS2, shows that the apicoplast provides local (lyso)phosphatidic acid balance, which is required for the recruitment of a novel dynamin (TgDrpC) critical during parasite cytokinesis. Disruption of TgATS2 led parasites to shift metabolic lipid acquisition from de novo synthesis towards host scavenging. Importantly, both lipid scavenging and de novo synthesis pathways exhibit major metabolic and cellular plasticity upon sensing host lipid-deprived environments through concomitant (i) up-regulation of de novo fatty acid synthesis capacities in the apicoplast, and (ii) parasite-driven host cell remodelling to generate multi-membrane-bound structures from host organelles that are imported towards the parasite.

microbiology↗