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

Bernthaler, Peter and Epping, Kerstin and Schmitz, Gerd and Deplazes, Peter and Brehm, Klaus (2009) Molecular Characterization of EmABP, an Apolipoprotein A-I Binding Protein Secreted by the Echinococcus multilocularis Metacestode. INFECTION AND IMMUNITY, 77 (12). pp. 5564-5571. ISSN 0019-9567, 1098-5522

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Abstract

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.

Item Type: Article
Uncontrolled Keywords: GRANULOSUS ANTIGEN-B; VITRO CULTIVATION; ALVEOLAR ECHINOCOCCOSIS; SCHISTOSOMA-JAPONICUM; SCAVENGER RECEPTOR; POTENTIAL ROLE; APOA-I; CHOLESTEROL; METABOLISM; HDL;
Subjects: 600 Technology > 610 Medical sciences Medicine
Divisions: Medicine > Lehrstuhl für Klinische Chemie und Laboratoriumsmedizin
Depositing User: Dr. Gernot Deinzer
Date Deposited: 31 Aug 2020 06:59
Last Modified: 31 Aug 2020 06:59
URI: https://pred.uni-regensburg.de/id/eprint/28044

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