| Autor: |
Bond AG; Centre for Targeted Protein Degradation, School of Life Sciences, University of Dundee, 1 James Lindsay Place, Dundee DD1 5JJ, U.K., Muñoz I Ordoño M; CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences Vienna 1090, Austria., Bisbach CM; Promega Corporation, 2800 Woods Hollow Road, Madison, Wisconsin 53711, United States., Craigon C; Centre for Targeted Protein Degradation, School of Life Sciences, University of Dundee, 1 James Lindsay Place, Dundee DD1 5JJ, U.K., Makukhin N; Centre for Targeted Protein Degradation, School of Life Sciences, University of Dundee, 1 James Lindsay Place, Dundee DD1 5JJ, U.K., Caine EA; Promega Corporation, 2800 Woods Hollow Road, Madison, Wisconsin 53711, United States., Nagala M; Centre for Targeted Protein Degradation, School of Life Sciences, University of Dundee, 1 James Lindsay Place, Dundee DD1 5JJ, U.K., Urh M; Promega Corporation, 2800 Woods Hollow Road, Madison, Wisconsin 53711, United States., Winter GE; CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences Vienna 1090, Austria., Riching KM; Promega Corporation, 2800 Woods Hollow Road, Madison, Wisconsin 53711, United States., Ciulli A; Centre for Targeted Protein Degradation, School of Life Sciences, University of Dundee, 1 James Lindsay Place, Dundee DD1 5JJ, U.K. |
| Abstrakt: |
Proteolysis targeting chimera (PROTAC) degraders are typically bifunctional with one E3 ligase ligand connected to one target protein ligand via a linker. While augmented valency has been shown with trivalent PROTACs targeting two binding sites within a given target protein, or used to recruit two different targets, the possibility of recruiting two different E3 ligases within the same compound has not been demonstrated. Here we present dual-ligase recruitment as a strategy to enhance targeted protein degradation. We designed heterotrivalent PROTACs composed of CRBN, VHL and BET targeting ligands, separately tethered via a branched trifunctional linker. Structure-activity relationships of 12 analogues qualifies AB3067 as the most potent and fastest degrader of BET proteins, with minimal E3 ligase cross-degradation. Comparative kinetic analyses in wild-type and ligase single and double knockout cell lines revealed that protein ubiquitination and degradation induced by AB3067 was contributed to by both CRBN and VHL in an additive fashion. We further expand the scope of the dual-ligase approach by developing a heterotrivalent CRBN/VHL-based BromoTag degrader and a tetravalent PROTAC comprising of two BET ligand moieties. In summary, we provide proof-of-concept for dual-E3 ligase recruitment as a strategy to boost degradation fitness by recruiting two E3 ligases with a single degrader molecule. This approach could potentially delay the outset of resistance mechanisms involving loss of E3 ligase functionality. |
