Fig. 3

Targeting protein for degradation by Proteolysis-targeting chimeras (PROTACs). a PROTACs contain an E3 ligase binding moiety (purple rhombus), attached to another small molecule (blue oval) binding to the target protein through a linker. PROTACs can bring target protein to the E3 ligase for ubiquitination and subsequent degradation. b Chemical structure of thalidomide, JQ1(S) and one published PROTAC, dBET1. (adapted from Winter, GE, et al., Science 2015)