Molecular cloning and characterization of a cDNA encoding a novel antibacterial peptide, defensin, from the mulberry longicorn beetle, Apriona germari

Abstract

A full-length cDNA clone with high homology (62% mature peptide sequence identity) to an Acalolepta luxuriosa antibacterial gene, possessing a conserved cysteine-stabilized αβ motif, was cloned by screening an Apriona germari cDNA library. This gene (AgCRP) had a total length of 360 bp with an open reading frame of 207 bp, and encoded a predicted peptide of 69 amino acid residues. The mature AgCRP peptide was 27 amino acid residues long and had a cysteine-stabilized αβ motif of C…CXXXC…C…CXC consensus sequence, similar to insect defensins. Northern blot analysis revealed that the AgCRP exhibited fat body-specific expression and was up-regulated by wounding, bacterial or fungal challenge.

• Antibacterial peptide
• Apriona germari
• cDNA
• cysteine-rich peptide
• defensin
• mulberry longicorn beetle

• AY771360

Acknowledgements

This work was funded by the Dong-A University Research Fund in 2006.