Cloning and expression pattern of eukaryotic translation initiation factor 4A of the diamondback moth, Plutella xylostella

Eukaryotic translation initiation factor 4A (eIF4A) is required for a cap-binding complex to recognize the 5' end of mRNA. A eIF4A gene (Px-eIF4A) was identified from Plutella xylostella. Its full cDNA (1,700 bp) encoded 422 amino acids and showed high sequence similarity (59.6-96.2%) with other insect and human eIF4As. Three dimensional analysis of Px-eIF4A indicated two globular domains, both of which were predicted to participate in RNA binding and helicase activity. Both RT-PCR and Western blotting indicated that the expression of Px-eIF4A showed a constitutive pattern regardless of developmental stage or tissue. An indirect immunofluorescence assay indicated that Px-eIF4A was localized in the cytoplasm. An immunoprecipitation with Px-eIF4A against a protein extract of P. xylostella indicated that Px-eIF4A could bind eIF4G, presumably to form a functional cap-binding complex. These results suggest that Px-eIF4A is constitutively expressed in all tissues and plays a role in the formation of the translation initiation complex in P. xylostella. (C) Korean Society of Applied Entomology, Taiwan Entomological Society and Malaysian Plant Protection Society, 2010 Published by Elsevier B.V. All rights reserved.