Kinetic Flux Profiling Elucidates Two Independent Acetyl-CoA Biosynthetic Pathways in Plasmodium falciparum

Cobbold, Simon A.; Vaughan, Ashley M.; Lewis, Ian A.; Painter, Heather J.; Camargo, Nelly; Perlman, David H.; Fishbaugher, Matthew; Healer, Julie; Cowman, Alan F.; Kappe, Stefan H. I.; Llinás, Manuel

doi:10.1074/jbc.m113.503557

Cited by 80 publications

(163 citation statements)

References 54 publications

(112 reference statements)

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“…Apicomplexans have repurposed another member of this family -the branched-chain ketoacid dehydrogenase (BCKDH) complex, usually responsible for branched-chain amino acid (BCAA) degradationfor mitochondrial conversion of pyruvate to acetyl-CoA [46]. BCKDH had been hypothesized to have PDH activity in Apicomplexa because (i) BCKDH has some PDH activity in other organisms [48][49][50],[ 1 6 _ T D $ D I F F ] and (ii) other enzymes of the BCAA degradation pathway and associated detoxification steps by the methyl-citrate cycle are lacking in Plasmodium spp., resulting in the apparent 'orphan' status of this enzyme [4,6,9,47]. Genetic ablation of the functional subunit of BCKDH (E1/) in P. berghei leads to abrogation of gametocyte maturation and ookinete production, and an almost complete halt in oocyst development, consistent with increased TCA function during this differentiation ( Figure 1) [46].…”

Section: Apicomplexan Mitochondrial Enzymes: Old Dogs New Tricksmentioning

confidence: 92%

“…In Apicomplexa, however, PDH is restricted to the apicoplast and has no apparent function in providing acetylCoA for TCA activity [47]. With the TCA cycle implicated in maintenance of the ETC, the In asexual blood stages, most glucose is processed through glycolysis to produce lactate, with only a low proportion of pyruvate being converted to acetyl-CoA by BCKDH to feed the TCA cycle.…”

Section: Apicomplexan Mitochondrial Enzymes: Old Dogs New Tricksmentioning

confidence: 99%

“…A Role for Glutaminolysis Advances in metabolomics techniques have revealed that glucose and glutamine fuel a canonical TCA cycle in P. falciparum [26,36,47,62] and P. berghei [46], with carbon source usage being both stage-specific and flexible. In Plasmodium asexual blood stages there is minimal flux from glycolysis into the TCA, which is instead predominantly driven by glutaminolysis [26,46,47] and has been thought to have a role in maintenance of ubiquinone levels for pyrimidine biosynthesis.…”

Section: Mitochondrial Metabolism Across the Alveolatamentioning

confidence: 99%

“…In Plasmodium asexual blood stages there is minimal flux from glycolysis into the TCA, which is instead predominantly driven by glutaminolysis [26,46,47] and has been thought to have a role in maintenance of ubiquinone levels for pyrimidine biosynthesis. Essential to this is production of the reducing equivalents FADH 2 and NAD(P)H, which in most eukaryotes are primarily supplied by the TCA cycle through the activity of succinate dehydrogenase (SDH) for FADH 2 , and IDH, /-ketoglutarate dehydrogenase (KGDH), and malate dehydrogenase (MDH) for NAD(P)H, although the latter is replaced by MQO in Plasmodium (Figure 2).…”

Section: Mitochondrial Metabolism Across the Alveolatamentioning

confidence: 99%

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Apicomplexan Energy Metabolism: Carbon Source Promiscuity and the Quiescence Hyperbole

Jacot

Waller

Soldati‐Favre

et al. 2016

Trends in Parasitology

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Pages 15apicomplexan mitochondrion in energy generation has remained unclear, given the glucosereplete intracellular nature of the environmental niches of these parasites and the apparent reduction of mitochondrial metabolic pathways [4][5][6][7]. For example, apicomplexan mitochondria lack 'type I' NADH dehydrogenase (NDH, complex I of the ETC) and many apparently lack the enzymes and transporters required for fatty acid b-oxidation [8,9]. Furthermore, the pyruvate dehydrogenase complex (PDH) responsible for conversion of pyruvate into acetyl-CoA -an obligate fuel for the TCA cycle -is only present in the apicoplast [10]. Consequently, there was no obvious entry point to allow catalysis of glycolytic pyruvate by the TCA cycle [10][11][12][13][14]. Despite this, there is overwhelming evidence that apicomplexans rely on a functional and canonical TCA cycle (as reviewed [4,5,15]), and apicomplexan genome annotations indicate the presence of all enzymes of the TCA cycle. Only one clade of apicomplexans, Cryptosporidium spp., show evidence of outright loss of the TCA cycle, but these taxa retain only a highly reduced mitochondrion, the mitosome, and have also lost their apicoplast [5,8,16].This review highlights how metabolomics technologies coupled to genetic manipulation have helped in unraveling apicomplexan parasite plasticity in carbon source utilization through different life stages, revealing a complex and sometimes counter-intuitive pattern of metabolic gains, losses, and reassignments. These changes have presumably been tailored to allow these parasites to thrive within their various host niches, but may constitute some much-needed Achilles' heels in the fight against these devastating diseases. Plasmodium falciparum and the Glycolytic DeceitGlycolysis has long appeared to be the main source of ATP and NAD(P)H in the erythrocytic stages of the malaria parasites, [5,[17][18][19][20][21]. Indeed, glucose uptake in P. falciparum-infected red blood cells (RBCs) has been observed to increase 75-100-fold compared to uninfected RBC [22][23][24][25]. Up to 93% of glucose is converted directly to lactate in asexual stages [26][ 4 _ T D $ D I F F ] and is ultimately excreted into the surrounding host cell. Perturbation of glucose uptake is detrimental to parasite growth [27,28], suggesting that glycolysis is an important part of the parasite's strategy for rapid proliferation. In a manner analogous to the Warburg effect observed in highly-proliferative cancer lines and other rapidly-growing cells (e.g., yeast and bloodstream Trypanosoma spp.), Plasmodium (in erythrocytic stages) has opted for fast generation of ATP through substrate-level phosphorylation and secretion of lactate as an end-product (aerobic fermentative glycolysis), as opposed to the 'slow but efficient' mitochondrial oxidative phosphorylation and complete oxidation [29]. Reasons for this dependence on glycolytic fermentation remain unclear -after all, blood stages of Plasmodium certainly have access to oxygen -but it may be a way of avoiding excessiv...

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Section: Apicomplexan Mitochondrial Enzymes: Old Dogs New Tricksmentioning

confidence: 92%

Section: Apicomplexan Mitochondrial Enzymes: Old Dogs New Tricksmentioning

confidence: 99%

Section: Mitochondrial Metabolism Across the Alveolatamentioning

confidence: 99%

Section: Mitochondrial Metabolism Across the Alveolatamentioning

confidence: 99%

See 2 more Smart Citations

Apicomplexan Energy Metabolism: Carbon Source Promiscuity and the Quiescence Hyperbole

Jacot

Waller

Soldati‐Favre

et al. 2016

Trends in Parasitology

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“…Parasite enrichment was performed using a custom-made magnetic apparatus (38) and LD columns (Miltenyi Biotec, Bergisch Gladbach, Germany) to obtain Ͼ95% purity of mid-trophozoite stage- (23). LC-MS data were processed using MAVEN (39).…”

Section: Cell Culture and Drug Incubations For Lc-ms Metabolomics Anamentioning

confidence: 99%

Metabolomics-Based Screening of the Malaria Box Reveals both Novel and Established Mechanisms of Action

Creek

Chua

Cobbold

et al. 2016

Antimicrob Agents Chemother

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130

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e High-throughput phenotypic screening of chemical libraries has resulted in the identification of thousands of compounds with potent antimalarial activity, although in most cases, the mechanism(s) of action of these compounds remains unknown. Here we have investigated the mode of action of 90 antimalarial compounds derived from the Malaria Box collection using high-coverage, untargeted metabolomics analysis. Approximately half of the tested compounds induced significant metabolic perturbations in in vitro cultures of Plasmodium falciparum. In most cases, the metabolic profiles were highly correlated with known antimalarials, in particular artemisinin, the 4-aminoquinolines, or atovaquone. Select Malaria Box compounds also induced changes in intermediates in essential metabolic pathways, such as isoprenoid biosynthesis (i.e., 2-C-methyl-D-erythritol 2,4-cyclodiphosphate) and linolenic acid metabolism (i.e., traumatic acid). This study provides a comprehensive database of the metabolic perturbations induced by chemically diverse inhibitors and highlights the utility of metabolomics for triaging new lead compounds and defining specific modes of action, which will assist with the development and optimization of new antimalarial drugs. Malaria remains a major global health problem, and there is a pressing need to discover and develop new antimalarials. Traditional antimalarial drugs have been severely undermined by the emergence of drug-resistant strains and current treatments rely heavily on artemisinin-based combination therapies. Alarmingly, artemisinin resistance has arisen in Southeast Asia during the last decade, highlighting the urgent need for new antimalarials (1). Extensive efforts to produce a malaria vaccine have met limited success and a pipeline of new antimalarial drugs will be required to mitigate extensive morbidity and mortality from malaria for the foreseeable future (2).High-throughput phenotypic screening of chemical libraries against the malaria parasite, Plasmodium falciparum, has provided a major step forward in the discovery of novel antimalarial compounds. Almost 30,000 compounds that selectively inhibit growth of cultured P. falciparum asexual red blood cell (RBC) stages have been identified in these screens, providing excellent starting points for the discovery of new antimalarial drugs (3-5). A prioritized collection of these "hit" compounds, known as the Malaria Box, has been assembled by the Medicines for Malaria Venture (MMV) and provided free to the research community to facilitate this drug development pipeline (6).A key limitation to the further optimization of many of these compounds is the lack of information on their mode of action. While not essential for registration, information on the mode of action of inhibitors discovered in phenotypic screens will significantly accelerate drug development by allowing structure-based drug design, monitoring of activity, toxicity and resistance, and facilitation of rational clinical usage in combination with other medicines. Furthermore, in...

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The biochemistry of Plasmodium falciparum

Ginsburg

2016

Advances in Malaria Research

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Kinetic Flux Profiling Elucidates Two Independent Acetyl-CoA Biosynthetic Pathways in Plasmodium falciparum

Cited by 80 publications

References 54 publications

Apicomplexan Energy Metabolism: Carbon Source Promiscuity and the Quiescence Hyperbole

Apicomplexan Energy Metabolism: Carbon Source Promiscuity and the Quiescence Hyperbole

Metabolomics-Based Screening of the Malaria Box Reveals both Novel and Established Mechanisms of Action

The biochemistry of Plasmodium falciparum

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