title: Entamoeba mitosomes play an important role in encystation by association with cholesteryl sulfate synthesis.
abstract: Hydrogenosomes and mitosomes are mitochondrion-related organelles (MROs) that have highly reduced and divergent functions in anaerobic/microaerophilic eukaryotes. Entamoeba histolytica, a microaerophilic, parasitic amoebozoan species, which causes intestinal and extraintestinal amoebiasis in humans, possesses mitosomes, the existence and biological functions of which have been a longstanding enigma in the evolution of mitochondria. We previously demonstrated that sulfate activation, which is not generally compartmentalized to mitochondria, is a major function of E. histolytica mitosomes. However, because the final metabolites of sulfate activation remain unknown, the overall scheme of this metabolism and the role of mitosomes in Entamoeba have not been elucidated. In this study we purified and identified cholesteryl sulfate (CS) as a final metabolite of sulfate activation. We then identified the gene encoding the cholesteryl sulfotransferase responsible for synthesizing CS. Addition of CS to culture media increased the number of cysts, the dormant form that differentiates from proliferative trophozoites. Conversely, chlorate, a selective inhibitor of the first enzyme in the sulfate-activation pathway, inhibited cyst formation in a dose-dependent manner. These results indicate that CS plays an important role in differentiation, an essential process for the transmission of Entamoeba between hosts. Furthermore, we show that Mastigamoeba balamuthi, an anaerobic, free-living amoebozoan species, which is a close relative of E. histolytica, also has the sulfate-activation pathway in MROs but does not possess the capacity for CS production. Hence, we propose that a unique function of MROs in Entamoeba contributes to its adaptation to its parasitic life cycle.
authors.affiliation: Division of Molecular and Cellular Immunoscience, Department of Biomolecular Sciences, Faculty of Medicine, Saga University, Saga, Saga 849-8501, Japan; fumika@cc.saga-u.ac.jp nozaki@nih.go.jp.
authors.forename: Fumika
authors.initials: F
authors.lastname: Mi-ichi
authors.affiliation: Department of Natural Products Chemistry, Graduate School of Pharmaceutical Sciences, Kyushu University, Higashi-ku, Fukuoka 812-8582, Japan;
authors.forename: Tomofumi
authors.initials: T
authors.lastname: Miyamoto
authors.affiliation: Division of Molecular and Cellular Immunoscience, Department of Biomolecular Sciences, Faculty of Medicine, Saga University, Saga, Saga 849-8501, Japan;
authors.forename: Shouko
authors.initials: S
authors.lastname: Takao
authors.affiliation: Department of Parasitology, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo 162-8640, Japan;
authors.forename: Ghulam
authors.initials: G
authors.lastname: Jeelani
authors.affiliation: Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan; Centre for Computational Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Hashimoto
authors.affiliation: Division of Molecular and Cellular Immunoscience, Department of Biomolecular Sciences, Faculty of Medicine, Saga University, Saga, Saga 849-8501, Japan;
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Hara
authors.affiliation: Department of Parasitology, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo 162-8640, Japan; Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan; fumika@cc.saga-u.ac.jp nozaki@nih.go.jp.
authors.forename: Tomoyoshi
authors.initials: T
authors.lastname: Nozaki
authors.affiliation: Division of Molecular and Cellular Immunoscience, Department of Biomolecular Sciences, Faculty of Medicine, Saga University, Saga, Saga 849-8501, Japan;
authors.forename: Hiroki
authors.initials: H
authors.lastname: Yoshida
mesh_terms: D000220:Adaptation, Biological / Q000502:physiology*; D056896:Archamoebae / Q000502:physiology*; D005075:Biological Evolution; D053898:Biosynthetic Pathways / Q000502:physiology*; D002704:Chlorates / Q000494:pharmacology; D002788:Cholesterol Esters / Q000096:biosynthesis* / Q000302:isolation & purification; D019295:Computational Biology; D004305:Dose-Response Relationship, Drug; D004747:Entamoeba / Q000502:physiology*; D019084:Fluorescent Antibody Technique, Indirect; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008928:Mitochondria / Q000378:metabolism / Q000502:physiology*; D010802:Phylogeny; D060888:Real-Time Polymerase Chain Reaction; D013045:Species Specificity; D015238:Sulfotransferases / Q000235:genetics
chemical_list: D002704:Chlorates; D002788:Cholesterol Esters; D015238:Sulfotransferases; C007045:cholesteryl sulfate
keywords: differentiation; mitochondrion-related organelles; protist; sulfolipids