Proteins that bind to Drosophila chorion cis-regulatory elements: a new C2H2 zinc finger protein and a C2C2 steroid receptor-like component.

Abstract

Gel mobility-shift assays have been used to identify proteins that bind specifically to the promoter region of the Drosophila s15 chorion gene. These proteins are present in nuclear extracts of ovarian follicles, the tissue where s15 is expressed during development, and bind to specific elements of the promoter that have been shown by transformation analysis to be important for in vivo expression. The DNA binding specificity has been used for molecular cloning of two components from expression cDNA libraries and for their tentative identification with specific DNA-binding proteins of the nuclear extracts. The mRNAs for both of these components, CF1 and CF2, are differentially enriched in the follicles. DNA sequence analysis suggests that both CF1 and CF2 are novel Drosophila transcription factors. CF2 is a member of the C2H2 family of zinc finger proteins, whereas CF1 is a member of the family of steroid hormone receptors. The putative DNA-binding domain of CF1 is highly similar to the corresponding domains of certain vertebrate hormone receptors and recognizes a region of DNA with similar, hyphenated palindromic sequences. The nature of CF1 raises the possibility of hormonal control of choriogenesis in Drosophila.

Interaction of proteins involved in ecdysone and juvenile hormone signal transduction

“…Ecdysone is a prohormone; it is converted to the active hormone 20E in target tissues (Gilbert et al, 2002). Ecdysteroids activate the target genes through a heterodimeric receptor complex comprising the ecdysone receptor (EcR) (Koelle et al, 1991) and ultraspiracle (USP) (Henrich et al, 1990;Oro et al, 1990;Shea et al, 1990) proteins; both of them are members of the nuclear steroid/thyroid/retinoid receptor superfamily.…”

Identification of ecdysone response elements by analysis of the Drosophila Eip28/29 gene.

“…There is precedent in the literature for competitive interactions between steroid receptors and other proteins for binding to HREs (Briiggemeier et al 1990;Crawford and Chapman 1990). It is intriguing to note that the steroid receptor-like proteins encoded by the Diosophila genes E75 (Segraves and Hogness 1990), CPl (Shea et al 1990), tU (Pignoni et al 1990), svp (Mlodzik et al 1990), kni (Nauber et al 1988), kml (Oro et al 1988), and egon (Rothe et al 1989) all have sequences suggesting binding to TGACCT-related half-sites (for a summary, see Pignoni et al 1990). The CFl product has been shown experimentally to bind to such a sequence (Shea et al 1990).…”

Autophagic programmed cell death in Drosophila

“…The ecdysone receptor is encoded by the nuclear receptor genes EcR and usp. [45][46][47][48][49][50] The ecdysone receptor complex, and the nuclear receptor competence factor bFTZ-F1, activate transcription of the early genes BR-C, E74A, and E93. 51,52 Salivary glands are not destroyed in animals with mutations in bFTZ-F1, BR-C, E74A, and E93.…”