Expanding the zinc-finger proteins accessible to drug-induced degradation by CRBN.

ABSTRACT: Glutarimide analogs, including thalidomide, redirect the E3 ubiquitin ligase CRL4CRBN to induce the ubiquitylation and proteasomal degradation of specific zinc finger (ZF) proteins. While the core structural motif recognized by CRBN is known, it alone does not account for the full specificity of substrate recognition. To understand the impact of residues adjacent to the core motif, we constructed a comprehensive ZF reporter library including all single ZFs and tandem ZF pairs in the human proteome totaling 9,097 reporters from 1,655 ZF-containing proteins. We performed a library-on-library screen of 29 glutarimide analogs against this ZF library identifying compounds that collectively degrade 38 ZF reporters. Cryo-electron microscopy and crystal structures of wild-type and mutant ZFs in complex with CRBN highlighted the significance of contacts outside the core ZF degron. We conducted systematic mutagenesis of both the ZFs and CRBN to investigate the role of individual amino acids and discovered that residues adjacent to the core ZF degron affect degradability, with single amino acid changes dictating drug specificity. The studies reveal subtle chemical differences between glutarimide analogs that significantly broaden the target scope and redefine target selectivity. This study catalogs the scope of degradable ZF targets, including disease-driving transcription factors, and defines modes of neosubstrate recruitment enabling the rational design of glutarimide analogs.

INSTRUMENT(S):

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Cell Culture

SUBMITTER: Eric Fischer  

LAB HEAD: Eric Fischer

PROVIDER: PXD056913 | Pride | 2025-08-08

REPOSITORIES: Pride