Cloning, structural features, and expression analysis of the gene encoding thioredoxin reductase 1 from Apis cerana cerana.

Previous studies have demonstrated that mammalian thioredoxin reductases 1 (TrxRs; EC 1.6.4.5) play roles in protection against oxidant injury, cell growth and transformation, and the recycling of ascorbate from its oxidized form. However, little is known about the function of TrxRs in insects, especially in Apis cerana cerana. To gain a better understanding of its role in insects, we cloned TrxR1 from A.cerana cerana (AccTrxR1) and investigated its structural features and expression. The full-length cDNA is 1998 bp long and contains an open reading frame (ORF) of 1485 bp. The deduced AccTrxR1 protein has 494 aa, a calculated molecular mass (MW) of 54.24 kDa, and an isoelectric point of pH 7.35. The full-length genomic DNA of AccTrxR1 is 3500 bp and contains eight exons and seven introns. In addition, the sequence and putative transcription factor-binding sites of the 5'-flanking region were examined. We also looked for conserved domains/motifs, generated homologous alignments, conducted phylogenetic analysis, and made secondary and tertiary structure predictions using web software. RT-PCR revealed that the expression of AccTrxR1 could be induced by UV and heat (37 degrees C). These results indicate that AccTrxR1 may play a key role in protection against oxidant stress.