Fig. 1: Schematic representation of the Logic-gated AdPROM deploying SrtA mediated Element Recombination (LASER) bioPROTAC platform.
From: Synthetic protein degradation circuits using programmable cleavage and ligation by Sortase A
Programmable targeted protein degradation outcomes with integrated target selection and safety modes can be achieved using different input combinations. LASER is comprised of the Von Hippel Lindel (VHL) E3 ligase recruitment protein fused to a designer binding protein (DBP1) that recruits a target protein (T1) for degradation. These proteins are genetically fused together using a Sortase A (SrtA) recognition motif linker. Concurrently, a DPB2 capable of binding a different target protein (T2) is expressed with an N-terminal tobacco etch virus protease (TEVp) responsive motif as a protective cap and a triglycine sequence for Sortase ligation. The default LASER state (1) redirects the native ubiquitin proteasome system to degrade T1 with no impact on T2. Expression of TEVp (2) removes the protective cap from DPB2 but no switching occurs without SrtA. However, LASER can be deactivated via addition of SrtA alone (3), resulting in rescue of T1. When both inputs are introduced (4), the LASER targeting is switched – T1 is rescued and the orthogonal T2 is now degraded.
