title: Strongyloides stercoralis daf-2 encodes a divergent ortholog of Caenorhabditis elegans DAF-2.
abstract: We hypothesise that developmental arrest in infectious larvae of parasitic nematodes is regulated by signalling pathways homologous to Caenorhabditis elegans DAF (dauer formation) pathways. Alignment of Strongyloides stercoralis (Ss) DAF-2 with DAF-2 of C. elegans and homologs of other species shows that most structural motifs in these insulin-like receptors are conserved. However, the catalytic domain of Ss-DAF-2 contains two substitutions (Q1242 and Q1256), that would result in constitutive dauer formation in C. elegans or diabetes in vertebrate animals. Ss-daf-2 also shows two alternately spliced isoforms, the constitutively expressed Ss-daf-2a, and Ss-daf-2b, which is only expressed in stages leading to parasitism.
authors.affiliation: Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA. hmassey@vet.upenn.edu
authors.forename: Holman C
authors.initials: HC
authors.lastname: Massey
authors.forename: Najju
authors.initials: N
authors.lastname: Ranjit
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Stoltzfus
authors.forename: James B
authors.initials: JB
authors.lastname: Lok
mesh_terms: D020816:Amino Acid Motifs; D019943:Amino Acid Substitution; D000818:Animals; D029742:Caenorhabditis elegans Proteins / Q000235:genetics; D020134:Catalytic Domain; D017124:Conserved Sequence; D018509:DNA, Helminth / Q000737:chemistry / Q000235:genetics; D015801:Helminth Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D020033:Protein Isoforms; D012326:RNA Splicing; D011972:Receptor, Insulin / Q000235:genetics*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D017171:Strongyloides stercoralis / Q000235:genetics*
chemical_list: D029742:Caenorhabditis elegans Proteins; D018509:DNA, Helminth; D015801:Helminth Proteins; D020033:Protein Isoforms; C107483:DAF-2 protein, C elegans; D011972:Receptor, Insulin