title: Cloning of the proteinase that facilitates infection by schistosome parasites.
abstract: Four cDNA clones encoding a proteinase which facilitates skin invasion by schistosome parasites were isolated by screening a schistosome sporocyst cDNA library, using an oligonucleotide probe containing sequences complementary to predicted 5'-translated regions of its RNA. The amino acid sequence of the enzyme, as deduced from the DNA sequence of the clones, indicates that the enzyme is a serine protease which in many respects is similar to vertebrate pancreatic elastases, although regions outside of the putative active site, binding pocket, and amino-terminal cysteines differ significantly. Regulation of expression of the enzyme occurs at the level of mRNA transcription as well as posttranslationally, the latter involving the processing of a previously unidentified pre-proenzyme (zymogen) sequence. In situ hybridization of the cDNA clones to tissue sections of developing larvae indicates that the enzyme is synthesized within a discrete time frame in specialized cells of the organism.
authors.affiliation: University of California, School of Public Health, Berkeley 94720.
authors.forename: G R
authors.initials: GR
authors.lastname: Newport
authors.forename: J H
authors.initials: JH
authors.lastname: McKerrow
authors.forename: R
authors.initials: R
authors.lastname: Hedstrom
authors.forename: M
authors.initials: M
authors.lastname: Petitt
authors.forename: L
authors.initials: L
authors.lastname: McGarrigle
authors.forename: P J
authors.initials: PJ
authors.lastname: Barr
authors.forename: N
authors.initials: N
authors.lastname: Agabian
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000032:analysis; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010196:Pancreatic Elastase / Q000032:analysis / Q000235:genetics; D012550:Schistosoma mansoni / Q000201:enzymology*; D012552:Schistosomiasis / Q000201:enzymology / Q000635:transmission*; D012697:Serine Endopeptidases / Q000235:genetics*
chemical_list: D004247:DNA; D012697:Serine Endopeptidases; D010196:Pancreatic Elastase