Isoform-Selective ATAD2 Chemical Probe with Novel Chemical Structure and Unusual Mode of Action.

Amaury E Fernández-Montalván,John W Cuozzo,Benno Kuropka,Seong Joo Koo,Paolo A Centrella,Eric A Sigel,Anthony D Keefe,Hilmar Weinmann,Ingo V Hartung,Holly H Soutter,Christoph E Dumelin,Antonius Ter Laak,Detlef Stöckigt,Vera Puetter,Mátyás Gorjánácz,Jan Hübner,Oleg Fedorov,Simon J Holton,Markus Berger,James M Bennett,Volker Badock,Didier Roche,Vincent Rodeschini,Ying Zhang,Joerg Weiske,Dawn M Troast,L Diaz-Saez ,Matthew Clark ,Kilian Huber ,A Chaikuad

doi:10.1021/acschembio.7b00708

Abstract

ATAD2 (ANCCA) is an epigenetic regulator and transcriptional cofactor, whose overexpression has been linked to the progress of various cancer types. Here, we report a DNA-encoded library screen leading to the discovery of BAY-850, a potent and isoform selective inhibitor that specifically induces ATAD2 bromodomain dimerization and prevents interactions with acetylated histones in vitro, as well as with chromatin in cells. These features qualify BAY-850 as a chemical probe to explore ATAD2 biology.

Highlights

A TPase family AAA-domain containing protein 2 (ATAD2, or ANCCA) is an epigenetic regulator that associates with chromatin via its bromodomain (BD); a conserved structural motif specialized in acetyl-lysine recognition.[1]
We have recently reported a novel role for ATAD2 during DNA
We embarked on a screening program to identify an isoform-selective ATAD2 inhibitor from a differentiated chemical class with enhanced cellular activity to further support the functional exploration of ATAD2

Summary

ACS Chemical Biology

The selectivity profile of BAY-850 and BAY-460 was initially investigated in the BROMOscan panel, where the first compound exclusively hit ATAD2 but -surprisingly- not the closely related ATAD2B, while the latter did not show significant effects at the same concentrations (Figure 2D and Supporting Information Figure 5A). That ATAD2 melting curves transitioned from a monophasic to a biphasic shape with increasing concentrations of the compound, suggesting the appearance of a new protein species with a differentiated melting profile upon saturation with BAY850 (Figure 2C) These observations prompted us to conduct an in-depth investigation of the BAY-850 binding mode using nondenaturing or native mass spectrometry (MS), a wellestablished method to investigate protein−ligand interactions,[10] which delivers information about the multimeric character and the conformation of a protein by its charge-state distribution in the mass spectrum. Our work lays the foundation for further compound development, e.g., toward PROTAC “warheads” with higher potency and improved PK properties, which may lead to in vivo probes and novel therapeutic agents

■ METHODS

■ ACKNOWLEDGMENTS

■ REFERENCES