title: Role of UPR pathway in defense response of Aedes aegypti against Cry11Aa toxin from Bacillus thuringiensis.
abstract: The insecticidal Cry toxins are pore-forming toxins produced by the bacteria Bacillus thuringiensis that disrupt insect-midgut cells. Cells can trigger different survival mechanisms to counteract the effects of sub-lytic doses of pore forming toxins. Particularly, two signaling pathways have been demonstrated to play a role in the defense mechanism to other toxins in Caenorhabditis elegans and in mammalian cells. These are the unfolded protein response (UPR) and the sterol regulatory element binding proteins (SREBP) pathways, which are proposed to facilitate membrane repair responses. In this work we analyzed the role of these pathways in Aedes aegypti response to intoxication with Cry11Aa toxin. We show that UPR is activated upon toxin ingestion. The role of these two pathways was analyzed in vivo by using RNA interference. We silenced the expression of specific proteins in A. aegypti larvae. Gene silencing of Ire-1 and Xbp-1 proteins from UPR system, resulted in hypersensitive to Cry11Aa toxin action. In contrast, silencing of Cas-1, Scap and S2P from SREBP pathway had no affect on Cry11Aa toxicity in A. aegypti larvae. However, the role of SREBP pathway requires further studies to be conclusive. Our data indicate that the UPR pathway is involved in the insect defense against Cry toxins.
authors.affiliation: Instituto de Biotecnología, Universidad Nacional Autónoma de México. AP 510-3, Cuernavaca 62250, Morelos, Mexico. bravo@ibt.unam.mx.
authors.forename: Leidy P
authors.initials: LP
authors.lastname: Bedoya-Pérez
authors.forename: Angeles
authors.initials: A
authors.lastname: Cancino-Rodezno
authors.forename: Biviana
authors.initials: B
authors.lastname: Flores-Escobar
authors.forename: Mario
authors.initials: M
authors.lastname: Soberón
authors.forename: Alejandra
authors.initials: A
authors.lastname: Bravo
mesh_terms: D000330:Aedes / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology*; D000818:Animals; D001413:Bacillus thuringiensis / Q000472:pathogenicity*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000633:toxicity*; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D004731:Endotoxins / Q000633:toxicity*; D017344:Genes, Insect; D006460:Hemolysin Proteins / Q000633:toxicity*; D019476:Insect Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D007814:Larva / Q000235:genetics / Q000378:metabolism / Q000382:microbiology; D010802:Phylogeny; D034622:RNA Interference; D000071701:Regulatory Factor X Transcription Factors; D015398:Signal Transduction; D051779:Sterol Regulatory Element Binding Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D013312:Stress, Physiological; D014157:Transcription Factors / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D056811:Unfolded Protein Response
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D004731:Endotoxins; D006460:Hemolysin Proteins; D019476:Insect Proteins; D000071701:Regulatory Factor X Transcription Factors; D051779:Sterol Regulatory Element Binding Proteins; D014157:Transcription Factors; C030956:insecticidal crystal protein, Bacillus Thuringiensis