The costa of trichomonads: A complex macromolecular cytoskeleton structure made of uncommon proteins

ABSTRACT: Background Information The costa is a prominent striated fiber that is found in protozoa of the Trichomonadidae family that present an undulating membrane. It is composed primarily of proteins that have not yet been explored. In this study, we used cell fractionation to obtain a highly enriched costa fraction whose structure and composition was further analyzed by electron microscopy and mass spectrometry. Results Electron microscopy of negatively stained samples revealed that the costa, which is a periodic structure with alternating electron-dense and electron-lucent bands, displays three distinct regions, named the head, neck and body. Fourier transform analysis showed that the electron-lucent bands present sub-bands with a regular pattern. An analysis of the costa fraction via one- and two-dimensional electrophoresis and liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) allowed the identification of 54 hypothetical proteins. Fourteen of those proteins were considered to be major components of the fraction. Conclusions The costa of T. foetus is a complex and organized cytoskeleton structure made of a large number of proteins which is assembled into filamentous structures. Some of these proteins exhibit uncharacterized domains and no function related according to gene ontology, suggesting that the costa structure may be formed by a new class of proteins that differ from those previously described in other organisms. Seven of these proteins contain prefoldin domains displaying coiled-coil regions. This propriety is shared with proteins of the striated fibers of other protozoan as well as in intermediate filaments. Significance Our observations suggest the presence of a new class of the cytoskeleton filaments in T. foetus. We believe that our data could auxiliate in determine the specific locations of these proteins in the distinct regions that compose the costa, as well as to define the functional roles of each component. Therefore, our study will help in the better understanding of the organization and function of this structure in unicellular organisms.

INSTRUMENT(S): Synapt MS

ORGANISM(S): Tritrichomonas Foetus

SUBMITTER: Eidy Santos  

LAB HEAD: Marlene Benchimol

PROVIDER: PXD005915 | Pride | 2017-04-04

REPOSITORIES: Pride