Objective

Protein-protein interactions (PPI) are a fundamental mechanism by which cells regulate biological processes. Pharmacological intervention with PPI’s represents an opportunity to antagonise interactions and may result in disease modulation. We have used the Promgea NanoBRET™ technology which relies on Bioluminescence Resonance Energy Transfer (BRET) using NanoLuc® Luciferase as the BRET energy donor and HaloTag® protein labelled with the HaloTag® NanoBRET™ 618 fluorescent ligand as the energy acceptor to measure the interaction of two binding partners in living cells, namely Schnurri-3 (Shn-3) and ERK-2. By identifying compounds that block the Shn-3-ERK-2 PPI we hope to increase bone mass due to augmentation of osteoblast activity in osteoporetic patients. With the assistance of Promega we have developed a 384 well cellular screening assay to identify compounds that inhibit the Shn-3-ERK-2 PPI and successfully screened approximately 20,000 compounds, taking hits through to the dose-response phase.  In addition, these hits were profiledagainst both a selectivity counter screen (Shn-2-ERK) and a technology counterscreen (p53-MDM-2) to identify selective antagonists of the Shn-3-ERK-2 interaction.