Molecular cloning, expression, and characterization of a cDNA encoding the arylphorin-like hexameric storage protein from the mulberry longicorn beetle, Apriona germari.

We describe here the cloning, expression, and characterization of a cDNA encoding the arylphorin-like hexameric storage protein from the mulberry longicorn beetle, Apriona germari (Coleoptera, Cerambycidae). The complete cDNA sequence of A. germari hexamerin (AgeHex) is comprised of 2,160 bp with 720 amino acid residues. The deduced protein sequence of AgeHex is most similar to Tenebrio molitor hexamerin2 (65.3%). Phylogenetic analysis further confirmed the AgeHex is more closely related to T. molitor hexmerin2 and T. molitor early-staged encapsulation inducing protein than to the other insect storage proteins. Southern blot analysis suggested the presence of A. germari hexamerin gene as a single copy and Northern blot analysis confirmed fat body-specific expression at the transcriptional level. The cDNA encoding AgeHex was expressed as a 80-kDa protein in the baculovirus-infected insect cells. Western blot analysis using the polyclonal antiserum against recombinant AgeHex indicated that the AgeHex corresponds to storage protein 2 (SP2) present in the A. germari larval hemolymph. Copyright 2003 Wiley-Liss, Inc.