Article
作者: You, Inchul ; Huang, Hubert T ; Yoon, Hojong ; Du, Guangyan ; Yue, Hong ; Henning, Nathaniel J ; Zhang, Tinghu ; Nabet, Behnam ; Nowak, Radosław P ; Fischer, Eric S ; He, Zhixiang ; Eleuteri, Nicholas A ; Safaee, Nozhat ; Donovan, Katherine A ; Che, Jianwei ; Li, Zhengnian ; Gray, Nathanael S ; Koide, Eriko ; Jiang, Jie
Targeted protein degradation (TPD) uses small molecules to recruit E3 ubiquitin ligases into the proximity of proteins of interest, inducing ubiquitination-dependent degradation. A major bottleneck in the TPD field is the lack of accessible E3 ligase ligands for developing degraders. To expand the E3 ligase toolbox, we sought to convert the Kelch-like ECH-associated protein 1 (KEAP1) inhibitor KI696 into a recruitment handle for several targets. While we were able to generate KEAP1-recruiting degraders of BET family and murine focal adhesion kinase (FAK), we discovered that the target scope of KEAP1 was narrow, as targets easily degraded using a cereblon (CRBN)-recruiting degrader were refractory to KEAP1-mediated degradation. Linking the KEAP1-binding ligand to a CRBN-binding ligand resulted in a molecule that induced degradation of KEAP1 but not CRBN. In sum, we characterize tool compounds to explore KEAP1-mediated ubiquitination and delineate the challenges of exploiting new E3 ligases for generating bivalent degraders.