Targeted protein degradation is a new therapeutic modality based on drugs that destabilize proteins by inducing their proximity to E3 ubiquitin ligases. Of particular interest are molecular glues that can degrade otherwise unligandable proteins by orchestrating direct interactions between target and ligase. However, their discovery has so far been serendipitous, thus hampering broad translational efforts. Here, we describe a scalable strategy toward glue degrader discovery that is based on chemical screening in hyponeddylated cells coupled to a multi-omics target deconvolution campaign. This approach led us to identify compounds that induce ubiquitination and degradation of cyclin K by prompting an interaction of CDK12–cyclin K with a CRL4B ligase complex. Notably, this interaction is independent of a dedicated substrate receptor, thus functionally segregating this mechanism from all described degraders. Collectively, our data outline a versatile and broadly applicable strategy to identify degraders with nonobvious mechanisms and thus empower future drug discovery efforts.

靶向蛋白质降解是一种新的治疗方式，其基础是通过诱导蛋白质接近 E3 泛素连接酶来破坏蛋白质的稳定性。特别令人感兴趣的是分子胶，它可以通过协调靶标和连接酶之间的直接相互作用来降解原本不可配位的蛋白质。然而，迄今为止，他们的发现都是偶然的，因此阻碍了广泛的转化努力。在这里，我们描述了一种发现胶水降解剂的可扩展策略，该策略基于对hypoddylated细胞进行化学筛选，并结合多组学目标反卷积活动。这种方法使我们发现了通过促进 CDK12-细胞周期蛋白 K 与 CRL4B 连接酶复合物相互作用来诱导细胞周期蛋白 K 泛素化和降解的化合物。值得注意的是，这种相互作用独立于专用底物受体，因此在功能上将该机制与所有描述的降解剂分开。总的来说，我们的数据概述了一种通用且广泛适用的策略，用于识别具有非明显机制的降解剂，从而为未来的药物发现工作提供支持。