Development of Photolenalidomide for Cellular Target Identification.
Zhi LinYuka AmakoFarah KabirHope A FlaxmanBogdan BudnikChristina M WooPublished in: Journal of the American Chemical Society (2022)
The thalidomide analogue lenalidomide (Len) is a clinical therapeutic that alters the substrate engagement of cereblon (CRBN), a substrate receptor for the CRL4 E3 ubiquitin ligase. Here, we report the development of photolenalidomide (pLen), a Len probe with a photoaffinity label and enrichment handle, designed for target identification by chemical proteomics. pLen preserves the substrate degradation profile, phenotypic antiproliferative and immunomodulatory properties of Len, and enhances interactions with the thalidomide-binding domain of CRBN, as revealed by binding site mapping and molecular modeling. Using pLen, we captured the known targets IKZF1 and CRBN from multiple myeloma MM.1S cells and further identified a new target, eukaryotic translation initiation factor 3 subunit i (eIF3i), from HEK293T cells. eIF3i is directly labeled by pLen and forms a ternary complex with CRBN in the presence of Len across several epithelial cell lines but is itself not ubiquitylated or degraded. These data point to the existence of a broader array of targets induced by ligands to CRBN that may or may not be degraded, which can be identified by the highly translatable application of pLen to additional biological systems.
Keyphrases
- multiple myeloma
- high resolution
- induced apoptosis
- acute lymphoblastic leukemia
- mass spectrometry
- amino acid
- social media
- cell cycle arrest
- high density
- high throughput
- electronic health record
- binding protein
- bioinformatics analysis
- living cells
- big data
- low dose
- cell death
- quantum dots
- cell proliferation
- computed tomography
- pet imaging
- oxidative stress
- transcription factor
- dna binding
- pi k akt
- chronic lymphocytic leukemia