Abstract
Screening of a carefully selected library of 5,195 small molecules identified 34 hit compounds that interact with the regulatory cyclic nucleotide-binding domain (CNB) of the cAMP sensor, EPAC1. Two of these hits (I942 and I178) were selected for their robust and reproducible inhibitory effects within the primary screening assay. Follow-up characterisation by ligand observed nuclear magnetic resonance (NMR) revealed direct interaction of I942 and I178 with EPAC1 and EPAC2-CNBs in vitro. Moreover, in vitro guanine nucleotide exchange factor (GEF) assays revealed that I942 and, to a lesser extent, I178 had partial agonist properties towards EPAC1, leading to activation of EPAC1, in the absence of cAMP, and inhibition of GEF activity in the presence of cAMP. In contrast, there was very little agonist action of I942 towards EPAC2 or protein kinase A (PKA). To our knowledge, this is the first observation of non-cyclic-nucleotide small molecules with agonist properties towards EPAC1. Furthermore, the isoform selective agonist nature of these compounds highlights the potential for the development of small molecule tools that selectively up-regulate EPAC1 activity.
| Original language | English (US) |
|---|---|
| Article number | 294 |
| Journal | Scientific reports |
| Volume | 7 |
| Issue number | 1 |
| DOIs | |
| State | Published - 2017 |
Funding
This work was funded by a project grant from the British Heart Foundation, awarded to S.J.Y. (grant number PG/15/15/31316). The HTS assay development and screen were funded by the SULSA assay development fund through the Scottish Universities Life Sciences Alliance (SULSA) by a grant award from the Scottish Funding Council (SFC Ref: 240599989). E.P. was supported by a PhD scholarship from a BBSRC Doctoral Training Programme in Biochemistry and Molecular Biology (BB/F016735/1) based at the University of Glasgow.
ASJC Scopus subject areas
- General