title: The cell surface proteome of Entamoeba histolytica.
abstract: Surface molecules are of major importance for host-parasite interactions. During Entamoeba histolytica infections, these interactions are predicted to be of prime importance for tissue invasion, induction of colitis and liver abscess formation. To date, however, little is known about the molecules involved in these processes, with only about 20 proteins or protein families found exposed on the E. histolytica surface. We have therefore analyzed the complete surface proteome of E. histolytica. Using cell surface biotinylation and mass spectrometry, 693 putative surface-associated proteins were identified. In silico analysis predicted that ∼26% of these proteins are membrane-associated, as they contain transmembrane domains and/or signal sequences, as well as sites of palmitoylation, myristoylation, or prenylation. An additional 25% of the identified proteins likely represent nonclassical secreted proteins. Surprisingly, no membrane-association sites could be predicted for the remaining 49% of the identified proteins. To verify surface localization, 23 proteins were randomly selected and analyzed by immunofluorescence microscopy. Of these 23 proteins, 20 (87%) showed definite surface localization. These findings indicate that a far greater number of E. histolytica proteins than previously supposed are surface-associated, a phenomenon that may be based on the high membrane turnover of E. histolytica.
authors.affiliation: Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-Str. 74, 20359 Hamburg, Germany;
authors.forename: Laura
authors.initials: L
authors.lastname: Biller
authors.forename: Jenny
authors.initials: J
authors.lastname: Matthiesen
authors.forename: Vera
authors.initials: V
authors.lastname: Kühne
authors.forename: Hannelore
authors.initials: H
authors.lastname: Lotter
authors.forename: Ghassan
authors.initials: G
authors.lastname: Handal
authors.forename: Tomoyoshi
authors.initials: T
authors.lastname: Nozaki
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Saito-Nakano
authors.forename: Michael
authors.initials: M
authors.lastname: Schümann
authors.forename: Thomas
authors.initials: T
authors.lastname: Roeder
authors.forename: Egbert
authors.initials: E
authors.lastname: Tannich
authors.forename: Eberhard
authors.initials: E
authors.lastname: Krause
authors.forename: Iris
authors.initials: I
authors.lastname: Bruchhaus
mesh_terms: D003092:Colitis / Q000235:genetics / Q000469:parasitology / Q000473:pathology; D004748:Entamoeba histolytica / Q000235:genetics* / Q000472:pathogenicity; D006790:Host-Parasite Interactions / Q000235:genetics; D006801:Humans; D054878:Lipoylation / Q000235:genetics; D013058:Mass Spectrometry; D008565:Membrane Proteins / Q000096:biosynthesis*; D054876:Prenylation / Q000235:genetics; D020543:Proteome
chemical_list: D008565:Membrane Proteins; D020543:Proteome