Transcriptional activation of the cloned Heliothis virescens (Lepidoptera) ecdysone receptor (HvEcR) by muristeroneA.
Ecdysteroids play an important role during insect development. We report here the isolation and characterisation of an Ecdysone receptor (EcR) homologue from Heliothis virescens (HvEcR) and present evidence supporting the HvEcR active role as an active component of the native insect receptor. Alignment of the deduced amino acid sequence of HvEcR with those of EcRs from other species confirmed its membership of this family and showed that it is closely related to the B1 isoform of Drosophila melanogaster. Northern blot analysis showed that two transcripts (6.0 and 6.5 kb) were recognised by a probe spanning the DNA and ligand binding domains of the HvEcR. Genomic Southern blots showed that the HvEcR is encoded by a single copy gene. Two lines of evidence towards the functional activity of the HvEcR are presented. In vitro transcribed and translated HvEcR showed specific binding to hsp27 and pall response elements in the presence of CfUSP. Stable expression of HvEcR in 293 cells induced reporter gene activity in the presence of muristeroneA in a dose dependant manner while dexamethasone failed to activate.
Martinez
A
A
ZENECA Agrochemicals, Jealott's Hill Research Station, Bracknell, Berkshire, UK. alberto.martinez@aguk.zeneca.com
Scanlon
D
D
Gross
B
B
Perara
S C
SC
Palli
S R
SR
Greenland
A J
AJ
Windass
J
J
Pongs
O
O
Broad
P
P
Jepson
I
I
D018528:ATP-Binding Cassette Transporters / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D018076:DNA, Complementary; D004441:Ecdysterone / Q000031:analogs & derivatives* / Q000378:metabolism; D005656:Fungal Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D009036:Moths; D009363:Neoplasm Proteins / Q000378:metabolism; D011987:Receptors, Steroid / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D015533:Transcriptional Activation
D018528:ATP-Binding Cassette Transporters; D018076:DNA, Complementary; D005656:Fungal Proteins; D009363:Neoplasm Proteins; C098338:PXA1 protein, S cerevisiae; D011987:Receptors, Steroid; D029701:Saccharomyces cerevisiae Proteins; C055469:ecdysone receptor; C055348:muristerone A; D004441:Ecdysterone