LanthaScreen® fluorescent nuclear receptor coregulator peptides contain known interaction motifs and are labeled with fluorescein. These peptides are matched and validated to complement the LanthaScreen® TR-FRET Nuclear Receptor Coregulator Assays. Assays developed using these reagents enable primary or secondary screening of nuclear receptor agonists and/or antagonists.
How they work Ligand binding to nuclear receptors causes conformational changes in the receptor, resulting in a cascade of events, including dissociation of repressor proteins, association of coactivator proteins, and assembly of pol II and other transcriptional factors for activation of target genes. TR-FRET based assays can be developed using the LanthaScreen® panel of fluorescein-labeled coregulator peptides to investigate conformational changes of nuclear receptors upon ligand binding, either by determining the affinity of ligand-bound receptor for different coregulator peptides, or by identifying additional agonists or antagonists via displacement or recruitment of a specific coregulator peptide. In the LanthaScreen® TR-FRET RXR beta Coactivator Assay, a terbium (Tb)-labeled anti-GST antibody is used to indirectly label GSTtagged RXR beta protein. An agonist (9-cis Retinoic Acid) added to the receptor which, upon ligand binding, causes a conformational change resulting in recruitment of the Fl-D22 coactivator peptide (Figure 1). The binding of the fluorescent coregulator peptide to RXR beta causes an increase in the TR-FRET emission ratio (Figure 2). Contents and Storage: LanthaScreen® fluorescent nuclear receptor coregulator peptides are supplied as 100 µM solutions in peptide-appropriate buffers. Store peptides at -20°C.
For Research Use Only. Not for use in diagnostic procedures.
Contents & Storage
Store in freezer (-5 to -30°C).
Table 1 - LanthaScreen™ fluorescent nuclear receptor coregulator peptides currently available from Invitrogen
Figure 2 - Representative data measuring recruitment of fluorescein-D22 coactivator peptide to RXR beta