Molecular cloning and characterization of a transferrin cDNA from the white-spotted flower chafer, Protaetia brevitarsis.

A full-length cDNA clone with high homology to insect transferrin genes was cloned by screening a Protaetia brevitarsis cDNA library. This gene (PbTf) had a total length of 2338 bp with an open reading frame (ORF) of 2163 bp, and encoded a predicted peptide of 721 amino acid residues. Like known cockroach, termite, and beetle transferrins, PbTf appears to have residues comprising iron-binding sites in both N- and C-terminal lobes. The deduced amino acid sequence of the PbTf cDNA was closest in structure to the beetle Apriona germari transferrin (68% protein sequence identity). Northern blot analysis revealed that PbTf exhibited fat body-specific expression and was upregulated by wounding, bacterial or fungal infection and iron overload, suggesting a functional role for PbTf in defense and stress responses.