title: The Onchocerca volvulus homologue of the multifunctional polypeptide protein disulfide isomerase.
abstract: Protein disulfide isomerase (PDI) functions to catalyze the formation of correct disulfide bonds in nascent proteins, and also acts as one of the subunits of prolyl-4 hydroxylase, the enzyme responsible for the oxidative maturation of procollagen. Since the cuticle of parasitic nematodes consists primarily of a network of collagen molecules which are connected through intermolecular disulfide bonds, PDI might be expected to be involved in the process of cuticle biosynthesis. The isolation and characterization of a cDNA encoding the PDI homologue of Onchocerca volvulus is described. This cDNA contains a single, long open reading frame that encodes sequence motifs identical to the two known active sites of PDI for isomerase activity. The O. volvulus PDI appears to be encoded by a single copy gene. Both in situ hybridization and immunolocalization data suggest that PDI is both spatially and temporally regulated in O. volvulus. The pattern of spatial and temporal regulation is consistent with the involvement of PDI in the biosynthesis of the parasite cuticle. The parasite protein appears to be an antigen recognized by a minority of individuals exposed to O. volvulus.
authors.affiliation: Division of Geographic Medicine, University of Alabama at Birmingham 35294.
authors.forename: W R
authors.initials: WR
authors.lastname: Wilson
authors.forename: R S
authors.initials: RS
authors.lastname: Tuan
authors.forename: K J
authors.initials: KJ
authors.lastname: Shepley
authors.forename: D O
authors.initials: DO
authors.lastname: Freedman
authors.forename: B M
authors.initials: BM
authors.lastname: Greene
authors.forename: K
authors.initials: K
authors.lastname: Awadzi
authors.forename: T R
authors.initials: TR
authors.lastname: Unnasch
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000947:Antigens, Helminth / Q000235:genetics; D001483:Base Sequence; D018076:DNA, Complementary / Q000235:genetics; D018509:DNA, Helminth / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007535:Isomerases / Q000235:genetics* / Q000276:immunology; D008969:Molecular Sequence Data; D017181:Onchocerca volvulus / Q000201:enzymology* / Q000235:genetics* / Q000276:immunology; D016366:Open Reading Frames; D019704:Protein Disulfide-Isomerases; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity
chemical_list: D000947:Antigens, Helminth; D018076:DNA, Complementary; D018509:DNA, Helminth; D011993:Recombinant Fusion Proteins; D007535:Isomerases; D019704:Protein Disulfide-Isomerases