Fig. 2
From: Proteolysis targeting chimeras (PROTACs) are emerging therapeutics for hematologic malignancies
Design and mechanism of homo-PROTACs and light-controllable PROTACs. a Design and mechanism of homo-PROTACs. A homo-PROTAC is consisted of two E3 ligase ligand molecules connected via a linker. Homo-PROTAC recruits an E3 ligase molecule to another E3 ligase molecule followed by bidirectional polyubiquitination of E3 ligase molecules and subsequent degradation of the E3 ligase by the proteasome. b Design and mechanism of light-controllable PROTACs. In a light-controllable PROTAC, a photo-removable group is attached to the POI ligand or E3 ligand or linker. Upon light irradiation, the photo-removable group is detached from the light-controllable PROTAC converting it to an active PROTAC for the proteasomal degradation of POI