The interacting domains in cereblon differentially modulate the immunomodulatory drug-mediated ubiquitination and degradation of its binding partners.
Cereblon (CRBN), a substrate receptor of the cullin-4 RING E3 ligase (CRL4), has been utilized for the targeted protein degradation via small molecular weight CRBN modulators. However, it is unclear whether and how proteins that interact with CRBN at different domains are affected by these modulators. Here, we use CRBN and its four binding partners, c-Jun, chloride channel protein CLC-1, transcription factor IKZF1, and MEIS2, as model proteins to investigate the effect of immunomodulatory drugs (IMiDs) including thalidomide, lenalidomide, and pomalidomide, on their stability, ubiquitination, and interaction with CRBN. Together with previous discoveries, domain mapping experiment shows that these four proteins interact with CRBN at three distinct regions. Immunoblotting analyses reveal that the protein level of CRBN-binding partners could be enhanced, attenuated, or not affected by IMiDs. Interaction analyses and ubiquitination assay demonstrate that IMiDs modulate the interaction between CRBN and its binding partners in three distinct ways and thus differentially regulate their ubiquitination. This work suggests that the binding domain in CRBN is a critical factor which influences the regulation of IMiDs on the ubiquitination and stability of these CRBN-interacting partners.
['Tao|Jing|J|', 'Yang|Jing|J|', 'Xu|Guoqiang|G|']
D048868:Adaptor Proteins, Signal Transducing D018118:Chloride Channels D057809:HEK293 Cells D006801:Humans D051740:Ikaros Transcription Factor D007155:Immunologic Factors D010447:Peptide Hydrolases D061988:Proteasome Inhibitors D011485:Protein Binding D000072417:Protein Domains D059748:Proteolysis D013329:Structure-Activity Relationship D013379:Substrate Specificity D044767:Ubiquitin-Protein Ligases D054875:Ubiquitination
Cereblon Ubiquitination Degradation Immunomodulatory drugs Cullin-RING E3 ligase