title: Identification of membrane-bound and secreted proteins from Echinococcus granulosus by signal sequence trap.
abstract: The signal sequence trap technique was applied to identify genes coding for secreted and membrane bound proteins from Echinococcus granulosus, the etiologic agent of cystic hydatid disease. An E. granulosus protoscolex cDNA library was constructed in the AP-PST vector such that randomly primed cDNAs were fused with a placental alkaline phosphatase reporter gene lacking its endogenous signal peptide. E. granulosus cDNAs encoding a functional signal peptide were selected by their ability to rescue secretion of alkaline phosphatase by COS-7 cells that had been transfected with the cDNA library. Eighteen positive clones were identified and sequenced. Their deduced amino acid sequences showed significant similarity with amino acid transporters, Krebs cycle intermediates transporters, presenilins and vacuolar protein sorter proteins. Other cDNAs encoded secreted proteins without homologues. Three sequences were transcribed antisense to E. granulosus expressed sequence tags. All the mRNAs were expressed in protoscoleces and adult worms, but some of them were not found in oncospheres. The putative E. granulosus secreted and membrane bound proteins identified are likely to play important roles in the metabolism, development and survival in the host and represent potential targets for diagnosis, drugs and vaccines against E. granulosus.
authors.affiliation: Queensland Institute of Medical Research, 300 Herston Road, Herston, Brisbane, Qld 4029, Australia. marar@anlis.gov.ar
authors.forename: Mara C
authors.initials: MC
authors.lastname: Rosenzvit
authors.forename: Wenbao
authors.initials: W
authors.lastname: Zhang
authors.forename: Hossein
authors.initials: H
authors.lastname: Motazedian
authors.forename: Danielle
authors.initials: D
authors.lastname: Smyth
authors.forename: Mark
authors.initials: M
authors.lastname: Pearson
authors.forename: Alex
authors.initials: A
authors.lastname: Loukas
authors.forename: Malcolm K
authors.initials: MK
authors.lastname: Jones
authors.forename: Donald P
authors.initials: DP
authors.lastname: McManus
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular / Q000379:methods; D004270:DNA, Circular / Q000235:genetics; D018509:DNA, Helminth / Q000235:genetics; D048209:Echinococcus granulosus / Q000737:chemistry*; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D017238:Genes, Helminth / Q000235:genetics; D015801:Helminth Proteins / Q000032:analysis* / Q000235:genetics; D008565:Membrane Proteins / Q000032:analysis* / Q000235:genetics; D008969:Molecular Sequence Data; D021382:Protein Sorting Signals / Q000235:genetics; D018510:RNA, Helminth / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D020539:Sequence Analysis, Protein / Q000379:methods
chemical_list: D004270:DNA, Circular; D018509:DNA, Helminth; D015801:Helminth Proteins; D008565:Membrane Proteins; D021382:Protein Sorting Signals; D018510:RNA, Helminth; D012333:RNA, Messenger; D000469:Alkaline Phosphatase