Comparative metabolism of acetate in the taeniid tapeworms Echinococcus granulosus, E. multilocularis and Taenia hydatigena

Frayha, George J.

doi:10.1016/0305-0491(71)90264-1

Cited by 14 publications

(13 citation statements)

References 10 publications

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“…The fact that E. multilocularis and E. granulosus, like other parasitic flatworms, cannot de novo synthesize cholesterol and the majority of other lipid components, has already been firmly established by previous studies (19,20,35). This is supported by our own analyses of the first draft version of the E. multilocularis genome, which showed that genes for the majority of enzymes that are involved in cholesterol synthesis in other organisms (51) are absent in the cestode (data not shown).…”

Section: Discussionmentioning

confidence: 69%

“…This is supported by our own analyses of the first draft version of the E. multilocularis genome, which showed that genes for the majority of enzymes that are involved in cholesterol synthesis in other organisms (51) are absent in the cestode (data not shown). In the case of the E. granulosus metacestode, an uptake of radioactively labeled, host-derived cholesterol during an infection of laboratory animals has already been demonstrated (20), and it is reasonable to assume that E. multilocularis employs cholesterol uptake mechanisms similar to those of the closely related dog tapeworm. Hence, in addition, or as an alternative, to interfering with lipid/cholesterol transport of the host, EmABP might be actively involved in cholesterol and lipid uptake by the parasite.…”

Section: Discussionmentioning

confidence: 99%

“…As a consequence, they have to take up host-derived lipids during an infection. Particularly in the case of cholesterol, Frayha (19,20) already demonstrated that this compound cannot be synthesized by both E. multilocularis and E. granulosus and that at least E. granulosus incorporates radioactively labeled, hostderived cholesterol during experimental infection of mice. Although several Echinococcus proteins with fatty acid and hydrophobic ligand binding properties have been reported (12,25), none of these displayed cholesterol binding activities nor has, as yet, any cestode molecule been identified that interacts with components of the host's cholesterol transport machinery.…”

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confidence: 99%

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Molecular Characterization of EmABP, an Apolipoprotein A-I Binding Protein Secreted by the Echinococcus multilocularis Metacestode

Bernthaler

Epping

Schmitz³

et al. 2009

Infect Immun

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Cestodes are unable to synthesize de novo most of their own membrane lipids, including cholesterol, and have to take them up from the host during an infection. The underlying molecular mechanisms are so far unknown. Here we report the identification and characterization of a novel gene, Emabp, which is expressed by larval stages and adults of the fox tapeworm Echinococcus multilocularis. The encoded protein, EmABP, displays significant homologies to apolipoprotein A-I binding protein (AI-BP) of mammalian origin and to metazoan YjeF_N domain proteins. Like mammalian AI-BP, EmABP carries an export-directing signal sequence which is absent in predicted AI-BP orthologs from the related flatworms Schistosoma japonicum and Schmidtea mediterranea. Using a specific antibody and immunoprecipitation techniques, we demonstrate that EmABP is secreted into the extraparasitic environment and into the hydatid fluid of in vitro-cultivated metacestode vesicles. Furthermore, we show that apolipoprotein A-I (apoA-I), a major constituent of cholesterol-transporting high-density lipoproteins, is present in hydatid fluid. By pulldown experiments, we demonstrate that recombinantly expressed, purified EmABP interacts with purified human apoA-I and is able to precipitate apoA-I from human serum. On the basis of these features and the suggested function of AI-BP in cholesterol transport in higher eukaryotes, we propose a role for EmABP in cholesterol and lipid uptake mechanisms of larval E. multilocularis.

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Section: Discussionmentioning

confidence: 69%

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

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Molecular Characterization of EmABP, an Apolipoprotein A-I Binding Protein Secreted by the Echinococcus multilocularis Metacestode

Bernthaler

Epping

Schmitz³

et al. 2009

Infect Immun

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“…Tapeworms, like flukes, lack the ability to synthesise fatty acids and cholesterol de novo 17,18 . Instead, they scavenge essential fats from the host using fatty acid transporters and lipid elongation enzymes (Supplementary Table S9.2), along with several tapeworm-specific gene families (Supplementary Information S8) Uptake of fatty acids seems to be crucial in Echinococcus spp.…”

Section: Reduced Metabolic Versatility and Specialised Detoxificationmentioning

confidence: 99%

The genomes of four tapeworm species reveal adaptations to parasitism

Tsai

Zarowiecki

Holroyd

et al. 2013

Nature

640

970

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Summary Tapeworms cause debilitating neglected diseases that can be deadly and often require surgery due to ineffective drugs. Here we present the first analysis of tapeworm genome sequences using the human-infective species Echinococcus multilocularis, E. granulosus, Taenia solium and the laboratory model Hymenolepis microstoma as examples. The 115-141 megabase genomes offer insights into the evolution of parasitism. Synteny is maintained with distantly related blood flukes but we find extreme losses of genes and pathways ubiquitous in other animals, including 34 homeobox families and several determinants of stem cell fate. Tapeworms have species-specific expansions of non-canonical heat shock proteins and families of known antigens; specialised detoxification pathways, and metabolism finely tuned to rely on nutrients scavenged from their hosts. We identify new potential drug targets, including those on which existing pharmaceuticals may act. The genomes provide a rich resource to underpin the development of urgently needed treatments and control.

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“…HACL1, HAO1 and SCP2) disappeared from most metazoan parasites. Previous studies noted that tapeworms, like flukes, lacked the ability to synthesize fatty acids and cholesterol, and instead scavenged essential fats from their hosts [48][49][50] .…”

Section: Trait Lossmentioning

confidence: 99%

Conservation motifs - a novel evolutionary-based classification of proteins

Beer

Sherill-Rofe

Unterman

et al. 2020

Preprint

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Cross-species protein conservation patterns, as directed by natural selection, are indicative of the interplay between protein function, protein-protein interaction and evolution. Since the beginning of the genomic era, proteins were characterized as either conserved or not conserved. This simple classification became archaic and cursory once data on protein orthologs became available for thousands of species.To enrich the language used to describe protein conservation patterns, and to understand their biological significance, we classified 20,294 human proteins against 1096 species. Analyses of the conservation patterns of human proteins in different eukaryotic clades yielded extremely variable and rich patterns that had never been characterized or studied before. Using mathematical classifications, we defined seven conservation motifs: Steps, Critical, Lately Developed, Plateau, Clade Loss, Trait Loss and Gain, which describe the evolution of human proteins.One type of motif, which we termed Gain, describes the human proteins that are highly conserved in a small number of organisms but are not found in most other species.Interestingly, this pattern predicts 73 possible instances of horizontal gene transfer in eukaryotes.Overall, our work offers novel terms for conservation patterns and defines a new language intended to classify proteins based on evolution, reveal aspects of protein evolution, and improve the understanding of protein functions.

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Comparative metabolism of acetate in the taeniid tapeworms Echinococcus granulosus, E. multilocularis and Taenia hydatigena

Cited by 14 publications

References 10 publications

Molecular Characterization of EmABP, an Apolipoprotein A-I Binding Protein Secreted by the Echinococcus multilocularis Metacestode

Molecular Characterization of EmABP, an Apolipoprotein A-I Binding Protein Secreted by the Echinococcus multilocularis Metacestode

The genomes of four tapeworm species reveal adaptations to parasitism

Conservation motifs - a novel evolutionary-based classification of proteins

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