KB02-SLF is a PROTAC-based nuclear FKBP12 degrader (molecular glue). KB02-SLF promotes nuclear FKBP12 degradation by covalently modifying DCAF16 (E3 ligase) and can improve the durability of protein degradation in biological systems. SLF binds ubiquitin E3 ligase ligand KB02 via a linker to form KB02-SLF[1].

KB02-SLF (2 µM; 4-72 hours; HEK293T cells) treatment promotes a substantial reduction in nuclear FKBP12 that is sustained across a 4-72 h time frame[1].Cell imaging studies confirms the selective loss of nuclear-localized FKBP12 in KB02-SLF-treated cells. KB02-SLF promotes the loss of FKBP12_NLS across a concentration of ~0.5-5µM, but shows varied reductions in activity at higher concentrations. The degradation of FKBP12_NLS induced by KB02-SLF is mediated by DCAF16[1].

[1]. Zhang X, et al. Electrophilic PROTACs that degrade nuclear proteins by engaging DCAF16. Nat Chem Biol. 2019 Jul;15(7):737-746.