Related Experiment Video
Updated: Sep 21, 2026

Generation of Plasmid Vectors Expressing FLAG-tagged Proteins Under the Regulation of Human Elongation Factor-1α Promoter Using Gibson Assembly
Published on: February 9, 2015
Promoter of FGF8 reveals a unique regulation by unliganded RARalpha
Vincent Brondani1, Thomas Klimkait, Jean-Marc Egly
1Oncology Research, Novartis Pharma AG, CH-4002 Basel, Switzerland.
Abstract:
We previously reported that retinoids were inducing a complete switch in the expression of two isoforms from the fgf8 gene. In order to gain insight into the transcriptional mechanisms possibly involved in this regulation, we cloned and sequenced a fragment of genomic DNA encompassing 6 kb of the region 5' upstream of the fgf8 coding sequence and investigated its promoter elements. A comprehensive series of biochemical and cellular experiments determined two distinct functional regions cis-responsive to retinoids and/or their receptors: (i) a canonical RARE (type DR2) which is the cis target of a RARalpha-RXRalpha liganded heterodimer; and (ii) a completely novel type of response element composed of two half-binding sites separated by 87 nucleotides, which we demonstrate to be the target of an unliganded RARalpha homodimer phosphorylated on the Ser77 residue. Combined activities of these cis and trans-acting factors support a model of a complex regulation of fgf8 expression: by alternative binding to two distinct promoter elements, phosphorylated-unliganded-RARalpha homodimer or its liganded form have two distinct and mutually exclusive trans-activating activities, explaining the expression of two different isoforms of fgf8.
More Related Videos
Related Concept Videos
RNA Polymerase II Accessory Proteins
Master Transcription Regulators
Rab Proteins
Rab proteins switch between a cytosolic, GDP-bound inactive state and a membrane-anchored, GTP-bound active state. By themselves, Rabs show slow rates of GDP/GTP exchange and GTP hydrolysis. Thus, Rab proteins are considered...
Small GTPases - Ras and Rho
Three regulatory proteins control their activity:
TGF - β Signaling Pathway
Activation and Inactivation of G Proteins

