Discovery of HyT-Based Degraders of CDK9-Cyclin T1 Complex

Direct modulation of the non-kinase functions of cyclin and CDK-cyclin complexes poses challenges. We utilize hydrophobic tag (HyT) based small-molecule degraders induced degradation of cyclin T1 and its corresponding kinase partner CDK9. LL-CDK9-12 demonstrated the most potent and selective degradation ability, with DC50 values of 0.362 & mu;M against CDK9 and 0.680 & mu;M against cyclin T1. In prostate cancer cells, LL-CDK9-12 showed enhanced anti-proliferative activity than its parental molecule SNS032 and LL-K9-3, the previous reported CDK9-cyclin T1 degrader. Moreover, LL-CDK9-12 suppressed the downstream signaling of CDK9 and AR efficiently. Altogether, LL-CDK9-12 was an effective dual degrader of CDK9-cyclin T1 and helped study the unknown function of CDK9-cyclin T1. These results suggest that HyT-based degraders could be used as a strategy to induce the degradation of protein complexes, providing insights for the design of protein complexes & PRIME; degraders.