Insect juvenile hormone resistance gene homology with the bHLH-PAS family of transcriptional regulators
AUTOR(ES)
Ashok, Mudgapalli
FONTE
The National Academy of Sciences
RESUMO
Juvenile hormone analog (JHA) insecticides are relatively nontoxic to vertebrates and offer effective control of certain insect pests. Recent reports of resistance in whiteflies and mosquitoes demonstrate the need to identify and understand genes for resistance to this class of insect growth regulators. Mutants of the Methoprene-tolerant (Met) gene in Drosophila melanogaster show resistance to both JHAs and JH, and previous biochemical studies have demonstrated a mechanism of resistance involving an intracellular JH binding-protein that has reduced ligand affinity in Met flies. We cloned the Met+ gene by transposable P-element tagging and found reduced transcript level in several mutant alleles, showing that underproduction of the normal gene product can lead to insecticide resistance. Transformation of Met flies with a Met+ cDNA resulted in susceptibility to methoprene, indicating that the cDNA encodes a functional Met+ protein. MET shows homology to the basic helix-loop-helix (bHLH)-PAS family of transcriptional regulators, implicating MET in the action of JH at the gene level in insects. This family also includes the vertebrate dioxin receptor, a transcriptional regulator known to bind a variety of environmental toxicants. Because JHAs include a diverse array of chemicals with JH activity, a mechanism whereby they can exert effects in insects through a common pathway is suggested.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=19642Documentos Relacionados
- The Drosophila dysfusion Basic Helix-Loop-Helix (bHLH)-PAS Gene Controls Tracheal Fusion and Levels of the Trachealess bHLH-PAS Protein
- Development of neuroendocrine lineages requires the bHLH–PAS transcription factor SIM1
- Altered DNA binding specificity of Arnt by selection of partner bHLH–PAS proteins
- The Caenorhabditis elegans hif-1 gene encodes a bHLH-PAS protein that is required for adaptation to hypoxia
- Molecular characterization of two mammalian bHLH-PAS domain proteins selectively expressed in the central nervous system