title: Proteomic Identification of Oxidized Proteins in Entamoeba histolytica by Resin-Assisted Capture: Insights into the Role of Arginase in Resistance to Oxidative Stress.
abstract: Entamoeba histolytica is an obligate protozoan parasite of humans, and amebiasis, an infectious disease which targets the intestine and/or liver, is the second most common cause of human death due to a protozoan after malaria. Although amebiasis is usually asymptomatic, E. histolytica has potent pathogenic potential. During host infection, the parasite is exposed to reactive oxygen species that are produced and released by cells of the innate immune system at the site of infection. The ability of the parasite to survive oxidative stress (OS) is essential for a successful invasion of the host. Although the effects of OS on the regulation of gene expression in E. histolytica and the characterization of some proteins whose function in the parasite's defense against OS have been previously studied, our knowledge of oxidized proteins in E. histolytica is lacking. In order to fill this knowledge gap, we performed a large-scale identification and quantification of the oxidized proteins in oxidatively stressed E. histolytica trophozoites using resin-assisted capture coupled to mass spectrometry. We detected 154 oxidized proteins (OXs) and the functions of some of these proteins were associated with antioxidant activity, maintaining the parasite's cytoskeleton, translation, catalysis, and transport. We also found that oxidation of the Gal/GalNAc impairs its function and contributes to the inhibition of E. histolytica adherence to host cells. We also provide evidence that arginase, an enzyme which converts L-arginine into L-ornithine and urea, is involved in the protection of the parasite against OS. Collectively, these results emphasize the importance of OS as a critical regulator of E. histolytica's functions and indicate a new role for arginase in E. histolytica's resistance to OS.
authors.affiliation: Department of Molecular Microbiology, Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.
authors.forename: Preeti
authors.initials: P
authors.lastname: Shahi
authors.affiliation: Department of Molecular Microbiology, Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.
authors.forename: Meirav
authors.initials: M
authors.lastname: Trebicz-Geffen
authors.affiliation: Department of Molecular Microbiology, Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.
authors.forename: Shruti
authors.initials: S
authors.lastname: Nagaraja
authors.affiliation: Department of Molecular Microbiology, Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.
authors.forename: Sharon
authors.initials: S
authors.lastname: Alterzon-Baumel
authors.affiliation: Department of Molecular Microbiology, Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.
authors.forename: Rivka
authors.initials: R
authors.lastname: Hertz
authors.affiliation: University of Greifswald, Institute of Biochemistry, Greifswald, Germany.
authors.forename: Karen
authors.initials: K
authors.lastname: Methling
authors.affiliation: University of Greifswald, Institute of Biochemistry, Greifswald, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Lalk
authors.affiliation: Department of Molecular Microbiology, Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.
authors.forename: Serge
authors.initials: S
authors.lastname: Ankri
mesh_terms: D001119:Arginase / Q000378:metabolism*; D002448:Cell Adhesion; D004748:Entamoeba histolytica / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D037102:Lectins / Q000378:metabolism; D018384:Oxidative Stress / Q000502:physiology*; D040901:Proteomics / Q000379:methods*; D012117:Resins, Synthetic; D053058:Trophozoites / Q000502:physiology
chemical_list: D037102:Lectins; D012117:Resins, Synthetic; D001119:Arginase