The N-terminus of ecdysteroid receptor isoforms and ultraspiracle interacts with different ecdysteroid response elements in a sequence specific manner to modulate transcriptional activity

Influence of hormone response elements (HREs) on ecdysteroid receptor concentration

“…In this study, we used CHO cells because transcriptional activity of EcR isoforms has been extensively studied using this cell line (Henrich et al ., 2003; Beatty et al ., 2006; Ruff et al ., 2009; Schauer et al ., 2011). The rationale for using heterologous cell cultures to test EcR and USP function has been outlined previously (Henrich et al ., 2009).…”

“…In addition to the influence of the N‐terminus of USP as outlined above, heterodimerization reduces EcR stability by interaction with DNA. The considerably improved affinity of the receptor complex with DNA (Braun et al ., 2009) subsequently reduces the concentration of all EcR isoforms, but can stimulate basal transcriptional activity (Ruff et al ., 2009; Schauer et al ., 2011). DNA binding facilitates the formation of an active conformation of the unstructured N‐terminus of nuclear receptors (Kumar & Thompson, 2003; Lavery & McEwan, 2005).…”

“…The construct (SK represents the orientation of the MCS in which lacZ transcription proceeds from SacI to KpnI) was kindly digested with Not I and Kpn I and the dUSP‐ΔDBD fragment was ligated into the multiple cloning site of the vector pEYFP‐N1 (Clontech) and further modified, resulting in the expression of dUSP‐ΔDBD (Dr S. Braun, University of Ulm, Ulm, Germany). For further information see Schauer et al . (2011).…”

“…Therefore the question arises whether interaction with different ecdysteroid response elements (EcREs) alters receptor protein degradation. EcR can interact with a variety of different hormone response elements altering the three‐dimensional structure of the receptor complex and the mode of dimerization (Perera et al ., 2005), which may subsequently not only regulate transcriptional activity in an isoform‐specific manner (Schauer et al ., 2011), but also influence receptor protein stability. In this paper, we studied the impact of receptor‐DNA interaction on the concentration of EcR isoforms.…”

Phospholipase Cγ1 Connects the Cell Membrane Pathway to the Nuclear Receptor Pathway in Insect Steroid Hormone Signaling

“…In the nuclear receptor genomic pathway, 20E binds to the ecdysone receptor (EcR) and forms a heterodimeric transcription complex with ultraspiracle (USP) to bind to the ecdysoneresponse element (EcRE) for gene transcription. Drosophila USP can also directly bind to EcRE (8). The 20E-induced genes, including hormone receptor 3 (HR3), and the metamorphosis initiation factor Broad (Br) subsequently mediate insect molting and metamorphosis (9,10).…”