Improved correction of F508del-CFTR biogenesis with a folding facilitator and an inhibitor of protein ubiquitination
- Bioorg Med Chem Lett. 2021 Sep 15:48:128243. doi: 10.1016/j.bmcl.2021.128243.
- 1. Department of Biological Science, University of Pittsburgh, Pittsburgh, PA 15260, USA.
- 2. Department of Inflammation & Immunology, Pfizer Inc., Cambridge, MA 02139, USA.
- 3. Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322 USA.
- 4. Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, USA.
- 5. Department of Pediatrics, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, USA.
- 6. Department of Biological Science, University of Pittsburgh, Pittsburgh, PA 15260, USA. Electronic address: [email protected].
A growing number of diseases are linked to the misfolding of integral membrane proteins, and many of these proteins are targeted for ubiquitin-proteasome-dependent degradation. One such substrate is a mutant form of the Cystic Fibrosis Transmembrane Conductance Regulator (F508del-CFTR). Protein folding "correctors" that repair the F508del-CFTR folding defect have entered the clinic, but they are unlikely to protect the entire protein from degradation. To increase the pool of F508del-CFTR protein that is available for correction by existing treatments, we determined a structure-activity relationship to improve the efficacy and reduce the toxicity of an inhibitor of the E1 ubiquitin activating enzyme that facilitates F508del-CFTR maturation. A resulting lead compound lacked measurable toxicity and improved the ability of an FDA-approved corrector to augment F508del-CFTR folding, transport the protein to the plasma membrane, and maintain its activity. These data support a proof-of-concept that modest inhibition of substrate ubiquitination improves the activity of small molecule correctors to treat CF and potentially Other protein conformational disorders.