title: Schistosoma mansoni encodes SMT3B and SMT3C molecules responsible for post-translational modification of cellular proteins.
abstract: The sumoylation pathway is a post-translational modification of nuclear proteins widespread among several organisms. SMT3C is the main protein involved in this process and it is covalently conjugated to a diverse assortment of nuclear protein targets. To date, 3 SUMO paralogues (SMT3C, A/B) have been characterized in mammals and plants. In this work we characterized two SUMO related genes, named SMT3B and SMT3C throughout Schistosoma mansoni life cycle. The SmSMTB/C encodes for proteins sharing significant amino acid homology with SMT3. Phylogenetical analyses revealed that both SmSMT3B/C are distinct proteins. Additionally, SmSMT3B and C are expressed in cercariae, adult worms, eggs and schistosomula however SmSMT3C gene showed an expression level 7 to 9 fold higher than SmSMT3B in eggs, schistosomula and adult worms. The comparison between the SmSMT3C genomic and cDNA sequences established that the encoding sequence is interrupted by 3 introns of 70, 37 and 36 bp. Western Blot has shown SMT3 conjugates are present in nuclear and total protein fractions of adults and cercariae. Therefore our results suggest a functional sumoylation pathway, and the presence of two paralogues also suggests the specificity of substrates for SMT3 in S. mansoni.
authors.affiliation: Department of Biochemistry and Immunology, School of Medicine, University of São Paulo, Av Bandeirantes, 3900, Monte Alegre, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Fernanda J
authors.initials: FJ
authors.lastname: Cabral
authors.forename: Olavo S
authors.initials: OS
authors.lastname: Pereira
authors.forename: Camila S
authors.initials: CS
authors.lastname: Silva
authors.forename: Renata
authors.initials: R
authors.lastname: Guerra-Sá
authors.forename: Vanderlei
authors.initials: V
authors.lastname: Rodrigues
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015801:Helminth Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008018:Life Cycle Stages; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D011499:Protein Processing, Post-Translational; D012550:Schistosoma mansoni / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D017422:Sequence Analysis, DNA; D025841:Small Ubiquitin-Related Modifier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D015801:Helminth Proteins; D025841:Small Ubiquitin-Related Modifier Proteins