title: SUMOylation pathway in Trypanosoma cruzi: functional characterization and proteomic analysis of target proteins.
abstract: SUMOylation is a relevant protein post-translational modification in eukaryotes. The C terminus of proteolytically activated small ubiquitin-like modifier (SUMO) is covalently linked to a lysine residue of the target protein by an isopeptide bond, through a mechanism that includes an E1-activating enzyme, an E2-conjugating enzyme, and transfer to the target, sometimes with the assistance of a ligase. The modification is reversed by a protease, also responsible for SUMO maturation. A number of proteins have been identified as SUMO targets, participating in the regulation of cell cycle progression, transcription, translation, ubiquitination, and DNA repair. In this study, we report that orthologous genes corresponding to the SUMOylation pathway are present in the etiological agent of Chagas disease, Trypanosoma cruzi. Furthermore, the SUMOylation system is functionally active in this protozoan parasite, having the requirements for SUMO maturation and conjugation. Immunofluorescence analysis showed that T. cruzi SUMO (TcSUMO) is predominantly found in the nucleus. To identify SUMOylation targets and get an insight into their physiological roles we generated transfectant T. cruzi epimastigote lines expressing a double-tagged T. cruzi SUMO, and SUMOylated proteins were enriched by tandem affinity chromatography. By two-dimensional liquid chromatography-mass spectrometry a total of 236 proteins with diverse biological functions were identified as potential T. cruzi SUMO targets. Of these, metacaspase-3 was biochemically validated as a bona fide SUMOylation substrate. Proteomic studies in other organisms have reported that orthologs of putative T. cruzi SUMOylated proteins are similarly modified, indicating conserved functions for protein SUMOylation in this early divergent eukaryote.
authors.affiliation: IIB-INTECH, Buenos Aires, Argentina.
authors.forename: Julio C
authors.initials: JC
authors.lastname: Bayona
authors.forename: Ernesto S
authors.initials: ES
authors.lastname: Nakayasu
authors.forename: Marc
authors.initials: M
authors.lastname: Laverrière
authors.forename: Clemente
authors.initials: C
authors.lastname: Aguilar
authors.forename: Tiago J P
authors.initials: TJ
authors.lastname: Sobreira
authors.forename: Hyungwon
authors.initials: H
authors.lastname: Choi
authors.forename: Alexey I
authors.initials: AI
authors.lastname: Nesvizhskii
authors.forename: Igor C
authors.initials: IC
authors.lastname: Almeida
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Cazzulo
authors.forename: Vanina E
authors.initials: VE
authors.lastname: Alvarez
mesh_terms: D000595:Amino Acid Sequence; D002846:Chromatography, Affinity; D017124:Conserved Sequence; D008969:Molecular Sequence Data; D011499:Protein Processing, Post-Translational; D020543:Proteome / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D040901:Proteomics; D015800:Protozoan Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D016415:Sequence Alignment; D025841:Small Ubiquitin-Related Modifier Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D058207:Sumoylation; D053719:Tandem Mass Spectrometry; D014349:Trypanosoma cruzi / Q000201:enzymology / Q000378:metabolism* / Q000502:physiology
chemical_list: D020543:Proteome; D015800:Protozoan Proteins; D025841:Small Ubiquitin-Related Modifier Proteins