title: The 20S proteasome of Schistosoma mansoni: a proteomic analysis.
abstract: Proteasomes are molecular machines found in virtually all cells that provide one of the mechanisms for protein turnover. We have analysed the 20S proteasome of Schistosoma mansoni, the first multimeric complex isolated from this helminth parasite. Three chromatographic steps were employed to yield a highly homogeneous preparation. 2-DE of the purified complex revealed 58 spots, of which 46 could be assigned either an alpha or a beta proteasome signature by MS. Most of the 14 transcripts (7alpha and 7beta) encoded by the parasite genome were represented by multiple spots and we suggest that this diversity is due to PTMs of subunits. For most of the isoforms, variations in pI predominated although alterations in mass were also observed. 2-DE separations of extracts from infective cercariae and blood-dwelling adult worms probed by Western blotting, using a human anti-alpha subunit antibody, revealed different patterns of reactivity, most probably in alpha3 and alpha6 subunits, on the basis of sequence conservation. This difference was rapidly lost following transformation of the cercaria to the skin schistosomulum stage, suggesting that changes in the proteasome structure, likely caused by the introduction of a new set of PTMs, precede remodelling of the parasite body prior to intravascular migration.
authors: Department of Biology, University of York, Heslington, York, UK. wb5@york.ac.uk
authors: William
authors: W
authors: Castro-Borges
authors: Jared
authors: J
authors: Cartwright
authors: Peter D
authors: PD
authors: Ashton
authors: Simon
authors: S
authors: Braschi
authors: Renata
authors: R
authors: Guerra Sa
authors: Vanderlei
authors: V
authors: Rodrigues
authors: R Alan
authors: RA
authors: Wilson
authors: Rachel S
authors: RS
authors: Curwen
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D015180:Electrophoresis, Gel, Two-Dimensional; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D046988:Proteasome Endopeptidase Complex / Q000737:chemistry* / Q000302:isolation & purification; D012550:Schistosoma mansoni / Q000201:enzymology* / Q000254:growth & development; D016415:Sequence Alignment; D012908:Snails
chemical_list: D046988:Proteasome Endopeptidase Complex