Silencing of midgut aminopeptidase N of Spodoptera litura by double-stranded RNA establishes its role as Bacillus thuringiensis toxin receptor.
Insecticidal crystal proteins of Bacillus thuringiensis bind to receptors in the midgut of susceptible insects leading to pore formation and death of the insect. The identity of the receptor is not clearly established. Recently a direct interaction between a cloned and heterologously expressed aminopeptidase (slapn) from Spodoptera litura and the Cry1C protein was demonstrated by immunofluorescence and in vitro ligand blot interaction. Here we show that administration of slapn double-stranded RNA to S. litura larvae reduces its expression. As a consequence of the reduced expression, a corresponding decrease in the sensitivity of these larvae to Cry1C toxin was observed. The gene silencing was retained during the insect's moulting and development and transmitted to the subsequent generation albeit with a reduced effect. These results directly implicate larval midgut aminopeptidase N as receptor for Bacillus thuringiensis insecticidal proteins.
Rajagopal
R
R
International Centre for Genetic Engineering and Biotechnology (ICGEB), P. O. Box 10504, Aruna Asaf Ali Marg, New Delhi 110 067, India.
Sivakumar
S
S
Agrawal
Neema
N
Malhotra
Pawan
P
Bhatnagar
Raj K
RK
D000818:Animals; D001413:Bacillus thuringiensis / Q000378:metabolism*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000737:chemistry; D001427:Bacterial Toxins; D001681:Biological Assay; D015153:Blotting, Western; D018826:CD13 Antigens / Q000235:genetics*; D004731:Endotoxins / Q000737:chemistry; D020868:Gene Silencing; D006460:Hemolysin Proteins; D008024:Ligands; D008856:Microscopy, Fluorescence; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012313:RNA / Q000378:metabolism; D034622:RNA Interference; D012330:RNA, Double-Stranded / Q000378:metabolism*; D018411:Spodoptera / Q000201:enzymology* / Q000235:genetics*; D013997:Time Factors
D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004731:Endotoxins; D006460:Hemolysin Proteins; D008024:Ligands; D012330:RNA, Double-Stranded; C030956:insecticidal crystal protein, Bacillus Thuringiensis; D012313:RNA; D018826:CD13 Antigens