Development of Protein and RNA Degraders for Drug Discovery

Targeted protein degradation (TPD) is an emerging approach that selectively eliminates specific proteins using synthetic molecules, such as proteolysis-targeting chimeras (PROTACs). It has attracted increasing attention in medicinal chemistry and chemical biology, with several PROTACs being tested in clinical settings. Unlike traditional small molecules, such as enzyme inhibitors and receptor antagonists, PROTACs exhibit a fundamentally different mechanism. Conventional drugs block enzymatic activities or receptor interactions, whereas PROTACs induce the degradation of target proteins, decreasing their cellular levels and abolishing all associated functions. PROTACs targeting enzymes in protein complexes disrupt both their catalytic activity and involvement in complex formation. In some cases, they also degrade other proteins in complexes, facilitating the elimination of entire assemblies. Our study leverages these unique features of TPD. We are currently developing various PROTACs targeting the enzymes responsible for lysine acetylation or methylation in proteins. Recently, the TPD concept has been extended beyond proteins to include nucleic acids, and ribonuclease-targeting chimeras (RIBOTACs) that selectively degrade RNA have been developed. We are also actively exploring new RNA-targeted degradation strategies. Herein, we highlight our recent work on TPD-inducing small molecules and provide an overview of RIBOTACs, which represent an area of growing research interest.