title: Identification of a novel family of non-lysosomal aspartic proteases in nematodes.
abstract: A protein encoded by cDNAs from the human parasite Onchocerca volvulus and its homologs from Caenorhabditis elegans and Ancyclostoma caninum define a family of aspartic proteases that are most closely related to cathepsins D, but differ from them in lacking the N-glycosylation site known to be required for lysosomal targeting. The nematode proteins have a potential N-glycosylation site at the same position as mammalian cathepsins E and in common with these have atypically long N-terminal extensions. The literature implies that cathepsins E may be secreted, and adult female O. volvulus are known to secrete a specific inhibitor of aspartic proteases; we therefore predict that the protease is secreted as an enzyme-inhibitor complex.
authors.affiliation: Department of Biochemistry and Molecular Biology, James Cook University of North Queensland, Townsville, Australia.
authors.forename: A
authors.initials: A
authors.lastname: Jolodar
authors.forename: D J
authors.initials: DJ
authors.lastname: Miller
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016282:Aspartic Acid Endopeptidases / Q000737:chemistry* / Q000235:genetics; D017173:Caenorhabditis elegans / Q000201:enzymology; D020059:Cathepsin E; D002403:Cathepsins / Q000737:chemistry; D018076:DNA, Complementary; D005260:Female; D006031:Glycosylation; D006801:Humans; D008322:Mammals; D008969:Molecular Sequence Data; D009348:Nematoda / Q000201:enzymology* / Q000235:genetics; D017181:Onchocerca volvulus / Q000201:enzymology; D010802:Phylogeny; D016415:Sequence Alignment
chemical_list: D018076:DNA, Complementary; D002403:Cathepsins; D016282:Aspartic Acid Endopeptidases; D020059:Cathepsin E