A eukaryotic initiation factor 5C is upregulated during metamorphosis in the cotton bollworm, Helicoverpa armigera

BACKGROUND: The orthologs of eukaryotic initiation factor 5C (eIF5C) are essential to the initiation of protein translation, and their regulation during development is not well known. RESULTS: A cDNA encoding a polypeptide of 419 amino acids containing an N-terminal leucine zipper motif and a C-terminal eIF5C domain was cloned from metamorphic larvae of Helicoverpa armigera. It was subsequently named Ha-eIF5C. Quantitative real-time PCR (QRT-PCR) revealed a high expression of the mRNA of Ha-eIF5C in the head-thorax, integument, midgut, and fat body during metamorphosis. Immunohistochemistry suggested that Ha-eIF5C was distributed into both the cytoplasm and the nucleus in the midgut, fat body and integument. Ha-eIF5C expression was upregulated by 20-hydroxyecdysone (20E). Furthermore, the transcription of Ha-eIF5C was down regulated after silencing of ecdysteroid receptor (EcR) or Ultraspiracle protein (USP) by RNAi. CONCLUSION: These results suggested that during metamorphosis of the cotton bollworm, Ha-eIF5C was upregulated by 20E through the EcR and USP transcription factors.