dTAG-13 is a degradation tag (dTAG) system heterobifunctional degrader composed of an E3 ubiquitin ligase cereblon (CRBN)-binding thalidomide moiety and an FKBP12(F36V) mutant-specific ligand AP1867 void of affinity for endogenous (wild-type) FKBP12, allowing selective degradation of target proteins of interest when expressed as an FKBP12(F36V) in-frame fusion (by transgene expression or locus-specific knock-in) by bridging them with CRBN for ubiquitination. dTAG-13 is shown to potently degrade FKBP12F36V-MELK(sg3R) in MDA-MB-468 cells (100 nM for 4 hrs) as well as ENL-FKBP12F36V-HA, but not endogenous ENL, in MV4;1 cells (500 nM for 0.5-1 hrs).
