title: Ancylostoma secreted protein 2: cloning and characterization of a second member of a family of nematode secreted proteins from Ancylostoma caninum.
abstract: Invading infective third-stage larvae (L3) of parasitic nematodes execute a series of programmed developmental events in response to a host-specific signal encountered during infection. One of these early events is the release of excretory/secretory products. Using an in vitro feeding assay that mimics these early events of infection, a protein released by in vitro activated larvae of the hookworm Ancylostoma caninum was identified. This protein, Ac-ASP-2, was partially sequenced, and the cDNA encoding it isolated by PCR and screening of an A. caninum L3 cDNA library. The Ac-asp-2 cDNA encodes a protein of 219 amino acids that is related to a previously identified protein, Ac-ASP-1, from hookworms. Both molecules are members of an evolutionarily diverse family of molecules that include the venom allergens of the Hymenoptera, and the testes specific proteins/sperm-coating glycoproteins of mammals. Homologues are present in nearly all nematodes tested, as demonstrated by PCR-hybridization and database searching. The Ac-asp-2 mRNA is synthesized in all life history stages, but the gene product is released only by L3 activated to feed in vitro. The wide distribution of the Ac-asp-2 in nematodes and its release in response to host specific signals suggests that Ac-ASP-2 serves an important function in nematode physiology and development, and possibly in the infective process of parasitic species.
authors.affiliation: Medical Helminthology Laboratory, Yale University School of Medicine, New Haven, CT 06520, USA. john.hawdon@yale.edu
authors.forename: J M
authors.initials: JM
authors.lastname: Hawdon
authors.forename: S
authors.initials: S
authors.lastname: Narasimhan
authors.forename: P J
authors.initials: PJ
authors.lastname: Hotez
mesh_terms: D000595:Amino Acid Sequence; D000722:Ancylostoma / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D000723:Ancylostomatoidea / Q000145:classification / Q000235:genetics; D000818:Animals; D000909:Antibodies, Helminth; D000918:Antibody Specificity; D016282:Aspartic Acid Endopeptidases / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D001483:Base Sequence; D015139:Blotting, Southern; D015153:Blotting, Western; D003001:Cloning, Molecular; D018509:DNA, Helminth / Q000032:analysis; D004285:Dogs; D017238:Genes, Helminth; D015801:Helminth Proteins / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D007814:Larva / Q000737:chemistry / Q000502:physiology; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000096:biosynthesis; D016415:Sequence Alignment
chemical_list: D000909:Antibodies, Helminth; D018509:DNA, Helminth; D015801:Helminth Proteins; D011994:Recombinant Proteins; C101887:Acasp1 protein, Ancylostoma caninum; D016282:Aspartic Acid Endopeptidases