Submitted to: Russian Journal of Nematology
Publication Type: Abstract Only
Publication Acceptance Date: June 6, 2001
Publication Date: N/A
Accurate processing of biologically inactive neuropeptide and hormone precursors by subtilisin-like proprotein convertases (PCs) is a general mechanism in all eukaryotic phyla. Evolutionarily related PC2-like enzymes of insects, nematodes and other invertebrates, are known to play important roles during development and are involved in such dramatic processes as vitellogenesis, sex determination, molting, egg-laying and hatching. The screening of a larval cDNA library of the plant parasitic nematode H. glycines resulted in the isolation of a full-length cDNA clone encoding a homolog of the mammalian neuropeptide processing endoprotease PC2. The deduced 671 amino acid preprotein was similar to other PC2s, including D/H/S catalytic triad, other conserved residues, which are characteristic of subtilisin family and PC2-specific substitution of catalytically important N for D, thought to be required for 7B2 polypeptide binding. The structural analysis revealed typical for PC2 subfamily regions: signal peptide, catalytic S8 domain, and P domain. The strongest amino acid homology was found to C.elegans PC2 encoded by kpc-2 gene, known to be involved in egg-laying and coordinated movements, and D. melanogaster amontillado protein, responsible for hatching behavior. Expression of PC2 in adult stages of H. glycines was substantially reduced compared to egg and juvenile stages. The results clearly demonstrate the first PC cloned from cDNA library of plant parasitic nematode Heterodera glycines with organization similar to PC2-like subfamily. The proposed involvement of candidate processing enzyme in early stages of embryogenesis makes it an attractive target for development of new antinematode biological control agents.