A CRISPR activation screen identifies FBXO22 supporting targeted protein degradation

  • Nat Chem Biol. 2024 Jul 4. doi: 10.1038/s41589-024-01655-9.
Ananya A Basu  1  2 ,  Chenlu Zhang  1 ,  Isabella A Riha  1 ,  Assa Magassa  1  2 ,  Miguel A Campos  1  2 ,  Alana G Caldwell  1  3 ,  Felicia Ko  1 ,  Xiaoyu Zhang  4  5  6  7  8
Affiliations
  • 1. Department of Chemistry, Northwestern University, Evanston, IL, USA.
  • 2. Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, USA.
  • 3. Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL, USA.
  • 4. Department of Chemistry, Northwestern University, Evanston, IL, USA. [email protected].
  • 5. Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, USA. [email protected].
  • 6. Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL, USA. [email protected].
  • 7. Center for Human Immunobiology, Northwestern University, Chicago, IL, USA. [email protected].
  • 8. International Institute for Nanotechnology, Northwestern University, Evanston, IL, USA. [email protected].
PMID: 38965383 DOI: 10.1038/s41589-024-01655-9
Abstract

Targeted protein degradation (TPD) represents a potent chemical biology paradigm that leverages the cellular degradation machinery to pharmacologically eliminate specific proteins of interest. Although multiple E3 Ligases have been discovered to facilitate TPD, there exists a compelling requirement to diversify the pool of E3 Ligases available for such applications. Here we describe a clustered regularly interspaced short palindromic repeats (CRISPR)-based transcriptional activation screen focused on human E3 Ligases, with the goal of identifying E3 Ligases that can facilitate heterobifunctional compound-mediated target degradation. Through this approach, we identified a candidate proteolysis-targeting chimera (PROTAC), 22-SLF, that induces the degradation of FK506-binding protein 12 when the transcription of FBXO22 gene is activated. Subsequent mechanistic investigations revealed that 22-SLF interacts with C227 and/or C228 in F-box protein 22 (FBXO22) to achieve target degradation. Lastly, we demonstrated the versatility of FBXO22-based PROTACs by effectively degrading additional endogenous proteins, including bromodomain-containing protein 4 and the echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase fusion protein.

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