title: The Cytoskeleton of Parabasalian Parasites Comprises Proteins that Share Properties Common to Intermediate Filament Proteins.
abstract: Certain protist lineages bear cytoskeletal structures that are germane to them and define their individual group. Trichomonadida are excavate parasites united by a unique cytoskeletal framework, which includes tubulin-based structures such as the pelta and axostyle, but also other filaments such as the striated costa whose protein composition remains unknown. We determined the proteome of the detergent-resistant cytoskeleton of Tetratrichomonas gallinarum. 203 proteins with homology to Trichomonas vaginalis were identified, which contain significantly more long coiled-coil regions than control protein sets. Five candidates were shown to associate with previously described cytoskeletal structures including the costa and the expression of a single T. vaginalis protein in T. gallinarum induced the formation of accumulated, striated filaments. Our data suggests that filament-forming proteins of protists other than actin and tubulin share common structural properties with metazoan intermediate filament proteins, while not being homologous. These filament-forming proteins might have evolved many times independently in eukaryotes, or simultaneously in a common ancestor but with different evolutionary trajectories downstream in different phyla. The broad variety of filament-forming proteins uncovered, and with no homologs outside of the Trichomonadida, once more highlights the diverse nature of eukaryotic proteins with the ability to form unique cytoskeletal filaments.
authors.affiliation: Institute for Molecular Evolution, Heinrich-Heine-University, Düsseldorf, Germany.
authors.forename: Harald
authors.initials: H
authors.lastname: Preisner
authors.affiliation: Department of Cell Research and Immunology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel.
authors.forename: Eli Levy
authors.initials: EL
authors.lastname: Karin
authors.affiliation: Molecular Proteomics Laboratory (MPL), BMFZ, Heinrich-Heine-University, Düsseldorf, Germany.
authors.forename: Gereon
authors.initials: G
authors.lastname: Poschmann
authors.affiliation: Molecular Proteomics Laboratory (MPL), BMFZ, Heinrich-Heine-University, Düsseldorf, Germany.
authors.forename: Kai
authors.initials: K
authors.lastname: Stühler
authors.affiliation: Department of Cell Research and Immunology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel.
authors.forename: Tal
authors.initials: T
authors.lastname: Pupko
authors.affiliation: Institute for Molecular Evolution, Heinrich-Heine-University, Düsseldorf, Germany. Electronic address: gould@hhu.de.
authors.forename: Sven B
authors.initials: SB
authors.lastname: Gould
mesh_terms: D000818:Animals; D003599:Cytoskeleton / Q000378:metabolism / Q000648:ultrastructure; D007381:Intermediate Filament Proteins / Q000378:metabolism; D046529:Microscopy, Electron, Transmission; D010271:Parasites / Q000378:metabolism / Q000648:ultrastructure; D020543:Proteome; D015800:Protozoan Proteins / Q000378:metabolism*; D016834:Trichomonadida / Q000378:metabolism / Q000648:ultrastructure*
chemical_list: D007381:Intermediate Filament Proteins; D020543:Proteome; D015800:Protozoan Proteins
keywords: Cytoskeleton; Trichomonadida; Trichomonas vaginalis.; coiled-coils; convergent evolution; intermediate filament proteins