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Analysis of transcriptional activity mediated by Drosophila melanogaster ecdysone receptor isoforms in a heterologous cell culture system
Author(s) -
Beatty J.,
Fauth T.,
Callender J. L.,
SpindlerBarth M.,
Henrich V. C.
Publication year - 2006
Publication title -
insect molecular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.955
H-Index - 93
eISSN - 1365-2583
pISSN - 0962-1075
DOI - 10.1111/j.1365-2583.2006.00683.x
Subject(s) - ecdysone receptor , ecdysone , biology , drosophila melanogaster , gene isoform , ecdysteroid , microbiology and biotechnology , transcription factor , mutagenesis , juvenile hormone , heterologous , nuclear receptor , gene , genetics , biochemistry , mutation , hormone
Ecdysteroid regulation of gene transcription in Drosophila melanogaster and other insects is mediated by a heterodimer comprised of Ultraspiracle (USP) and one of three ecdysone receptor (EcR) isoforms (A, B1 and B2). This study revealed that the EcR/USP heterodimer displays isoform‐specific capabilities. EcRB1 is normally induced with a form of USP that is missing its DNA‐binding domain (DBD), although potentiation by juvenile hormone (JH) III is reduced. The EcRA and B2 isoforms, however, display almost no response to ecdysteroids with the DBD − USP. A mutation, K497E, in the shared ligand‐binding domain of the EcR isoforms caused elevated EcRB2‐specific affinity for a canonical ecdysone response element. The effects of directed modification and mutagenesis offer a strategy for developing hypotheses and considerations for studying in vivo function.