Isolation and functional characterization of a new shrimp ovarian peritrophin with antimicrobial activity from Fenneropenaeus merguiensis.
Shrimp ovarian peritrophin (SOP), a major protein in jelly layer (JL) and cortical rods (CRs), is proposed to play a role in the protection of spawned eggs. The full sequence of SOP cDNA from Fenneropenaeus merguiensis (Fm-SOP) shares approximately 50% identity with other SOP sequences and contains several putative chitin-binding or peritrophin-A domains. Interestingly, Fm-SOP contains a putative 61-amino acid propeptide located at the N-terminal end, downstream of a 19-amino acid signal peptide, which is unique among penaeid SOP sequences described so far. This 61-amino-acid sequence constitutes a putative chitin-binding domain with six conserved cysteines, and is cleaved at a dibasic recognition site for a furin (subtilisin-like endoprotease). Expression analyses indicated that Fm-SOP mRNA is abundant in early vitellogenic ovaries and scarce in late-vitellogenic ovaries. Conversely, Fm-SOP protein is the most abundant at the end of vitellogenesis. To investigate its biological function, a recombinant Fm-SOP was expressed to generate a glycosylated protein in Spodoptera frugiperda Sf9 cells (rSOP-Sf9) and a nonglycosylated protein (rSOP-Ec) in Escherichia coli. rSOP-Sf9 and rSOP-Ec were found to bind to chitin, similarly to the native protein extracted from F. merguiensis ovaries. Most interestingly, rSOP-Ec displayed a chitinase activity and efficiently inhibited the growth of Vibrio harveyi and Staphylococcus aureus, with minimum inhibitory concentrations of 2.4 and 15.7 microM, respectively. This first report shows that a major component of CR and JL is biologically active against known pathogens and predicts a significant role of JL in the protection of the spawned eggs against pathogens.
Loongyai
Wiriya
W
Center for Genomics and Bioinformatics Research, Faculty of Science, Prince of Songkla University, Hatyai, Songkla, Thailand.
Avarre
Jean-Christophe
JC
Cerutti
Martine
M
Lubzens
Esther
E
Chotigeat
Wilaiwan
W
D000595:Amino Acid Sequence; D000818:Animals; D000890:Anti-Infective Agents / Q000302:isolation & purification* / Q000494:pharmacology; D060829:Arthropod Proteins; D001419:Bacteria / Q000187:drug effects; D001483:Base Sequence; D002478:Cells, Cultured; D002686:Chitin / Q000378:metabolism; D002688:Chitinases / Q000032:analysis / Q000378:metabolism; D018076:DNA, Complementary / Q000737:chemistry; D004926:Escherichia coli / Q000235:genetics; D005260:Female; D005658:Fungi / Q000187:drug effects; D020869:Gene Expression Profiling / Q000662:veterinary; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D008562:Membrane Glycoproteins / Q000235:genetics / Q000302:isolation & purification / Q000494:pharmacology / Q000502:physiology*; D008969:Molecular Sequence Data; D033561:Penaeidae / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D011994:Recombinant Proteins / Q000032:analysis / Q000096:biosynthesis; D016415:Sequence Alignment / Q000662:veterinary; D014818:Vitellogenesis / Q000502:physiology
D000890:Anti-Infective Agents; D060829:Arthropod Proteins; D018076:DNA, Complementary; D008562:Membrane Glycoproteins; D011994:Recombinant Proteins; D002686:Chitin; D002688:Chitinases