Characteristics of the takeout protein ce-0330 in the silkworm, Bombyx mori (Lepidoptera: Bombycidae)

Insect juvenile hormone (JH)-binding protein (JHBP) transports JH in the hemolymph. The JHBP gene is a member of the takeout gene superfamily, which has more than 10 genes belonging to each species and that play different physiological roles. To characterize these genes, expression analysis of the takeout genes in silkworms was conducted using real-time quantitative RT-PCR. The expression profiles varied for each gene. For example, some genes, including Bm_ce-0330, were expressed in the adult antennae. The functions of takeout proteins in lepidopterans, except for JHBP, remain unknown. Among the Bombyx takeout proteins, Bm_ce-0330 shares a high sequence homology with Epiphyas postvittana takeout 1, the 3-D structure of which has been known recently. Bm_ce-0330 was predicted to bind to the odorant expressed in the adult antennae, with a low ligand selectivity. We collectively propose a strategy to predict the unknown ligands and physiological role of takeout proteins from gene expression patterns and actual and/or computer-associated modeling of 3-D molecular structures.