2. Academic Validation
  3. Functional E3 ligase hotspots and resistance mechanisms to small-molecule degraders

Functional E3 ligase hotspots and resistance mechanisms to small-molecule degraders

  • Nat Chem Biol. 2022 Nov 3. doi: 10.1038/s41589-022-01177-2.
Alexander Hanzl 1,  Ryan Casement # 2,  Hana Imrichova # 1,  Scott J Hughes 2 3,  Eleonora Barone 1,  Andrea Testa 2 3,  Sophie Bauer 1 4,  Jane Wright 2,  Matthias Brand 1 4,  Alessio Ciulli 5,  Georg E Winter 6
Affiliations

Affiliations

  • 1 CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria.
  • 2 Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, James Black Centre, Dundee, UK.
  • 3 Amphista Therapeutics Ltd., Newhouse, UK.
  • 4 Proxygen GmbH, Vienna, Austria.
  • 5 Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, James Black Centre, Dundee, UK. a.ciulli@dundee.ac.uk.
  • 6 CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria. gwinter@cemm.oeaw.ac.at.
  • # Contributed equally.
PMID: 36329119 DOI: 10.1038/s41589-022-01177-2
Abstract

Targeted protein degradation is a novel pharmacology established by drugs that recruit target proteins to E3 ubiquitin ligases. Based on the structure of the degrader and the target, different E3 interfaces are critically involved, thus forming defined 'functional hotspots'. Understanding disruptive mutations in functional hotspots informs on the architecture of the assembly, and highlights residues susceptible to acquire resistance phenotypes. Here we employ haploid genetics to show that hotspot mutations cluster in substrate receptors of hijacked ligases, where mutation type and frequency correlate with gene essentiality. Intersection with deep mutational scanning revealed hotspots that are conserved or specific for chemically distinct degraders and targets. Biophysical and structural validation suggests that hotspot mutations frequently converge on altered ternary complex assembly. Moreover, we validated hotspots mutated in patients that relapse from degrader treatment. In sum, we present a fast and widely accessible methodology to characterize small-molecule degraders and associated resistance mechanisms.

Figures
Products