Therapeutic potential of allosteric HECT E3 ligase inhibition
Targeting ubiquitin E3 ligases is therapeutically attractive; however, the absence of an active-site pocket impedes computational approaches for identifying inhibitors. In a large, unbiased biochemical screen, we discover inhibitors that bind a cryptic cavity distant from the catalytic cysteine of the homologous to E6-associated protein C terminus domain (HECT) E3 ligase, SMAD ubiquitin regulatory factor 1 (SMURF1). Structural and biochemical analyses and engineered escape mutants revealed that these inhibitors restrict an essential catalytic motion by extending an α helix over a conserved glycine hinge. SMURF1 levels are increased in pulmonary arterial hypertension (PAH), a disease caused by mutation of bone morphogenetic protein receptor-2 (BMPR2). We demonstrated that SMURF1 inhibition prevented BMPR2 ubiquitylation, normalized bone morphogenetic protein (BMP) signaling, restored pulmonary vascular cell homeostasis, and reversed pathology in established experimental PAH. Leveraging this deep mechanistic understanding, we undertook an in silico machine-learning-based screen to identify inhibitors of the prototypic HECT E6AP and confirmed glycine-hinge-dependent allosteric activity in vitro. Inhibiting HECTs and other glycine-hinge proteins opens a new druggable space.
Authors
- Oded Kleifeld (ORCID: https://orcid.org/0000-0003-3091-7154)
- Alexander Rothman (ORCID: https://orcid.org/0000-0002-7847-4500)
- Maulik Thaker
- Sven Weiler
- Olivier Bonneau
- Gábor Járai
- Nichola J. Smith (ORCID: https://orcid.org/0000-0002-3799-0074)
- Tomáš Rejtar
- René Hemmig
- Nicholas W. Morrell (ORCID: https://orcid.org/0000-0001-5700-9792)
- Alina Kordonsky
- Ji-Hu Zhang
- David J. Rowlands (ORCID: https://orcid.org/0000-0002-4742-9272)
- Sabine Guth (ORCID: https://orcid.org/0000-0001-9115-1397)
- Sarah Binmahfooz (ORCID: https://orcid.org/0000-0003-3332-5576)
- Elon Yariv (ORCID: https://orcid.org/0000-0001-7457-2608)
- Shih-Min A. Huang (ORCID: https://orcid.org/0009-0004-9587-3986)
- Amanda Hachey
- Johannes Ottl (ORCID: https://orcid.org/0000-0002-1945-9116)
- Rishi K. Jain (ORCID: https://orcid.org/0009-0002-9890-2143)
- Catherine Quigley (ORCID: https://orcid.org/0000-0003-4696-5329)
- Florence Zink
- Rohan E. J. Beckwith (ORCID: https://orcid.org/0000-0001-6437-1087)
- John A. Tallarico (ORCID: https://orcid.org/0000-0002-8040-8422)
- Duncan Shaw (ORCID: https://orcid.org/0009-0005-2025-9057)
- Nils Ostermann (ORCID: https://orcid.org/0000-0002-3391-1228)
- Reut Avishid
- Gali Prag (ORCID: https://orcid.org/0000-0003-4703-7161)
- Amir Florentin (ORCID: https://orcid.org/0009-0007-8059-2139)
- Jennifer Cobb
- Marc Humbert (ORCID: https://orcid.org/0000-0003-0703-2892)
- Simona Cotesta (ORCID: https://orcid.org/0000-0002-4089-2213)
- Thomas Troxler
- Daniel Sutton (ORCID: https://orcid.org/0000-0002-5224-2912)
- Matthew Thomas (ORCID: https://orcid.org/0000-0002-7819-7988)
- Jan Roger
- Salil Srivastava
- Ritu Rathi
- Oshrit Khvalevsky
Institutions
- Novartis (Switzerland) (CH)
- Inserm (FR)
- Tel Aviv University (IL)
- Technion – Israel Institute of Technology (IL)
- King Abdulaziz University (SA)
- University of Cambridge (GB)
- Université Paris-Saclay (FR)
- Novartis (China) (CN)
- Bicêtre Hospital (FR)
- Novartis Foundation (CH)
- University of Sheffield (GB)
Publication Details
- Journal
- Cell
- Published
- 2025-04-04
- DOI
- https://doi.org/10.1016/j.cell.2025.03.001
- Citations
- 18
- Primary Topic
- Protein Degradation and Inhibitors
- Type
- article
- Field-Weighted Citation Impact
- 14.51