Cbz-B3A is a potent and selective inhibitor of mTORC1 signaling that appear to bind to ubiquilins 1, 2, and 4, and Cbz-B3A inhibits the phosphorylation of eIF4E-binding protein 1 (4EBP1).
Cbz-B3A slows cellular growth of some human leukemia cell lines, but is not cytotoxic.Cbz-B3A has a larger effect on the phosphorylation of 4EBP1 than p70S6k compared to repamycin. Cbz-B3A inhibits mTOR through Ubiquilins. Cbz-B3A decreases the incorporation of [35S]methionine/cysteine into protein in a dose-dependent manner, with maximal inhibition of 68% observed at 10 μM, and an EC50 of ~3 μM.
[1]. Coffey RT, et al. Ubiquilin-mediated Small Molecule Inhibition of Mammalian Target of Rapamycin Complex 1 (mTORC1) Signaling. J Biol Chem. 2016 Mar 4;291(10):5221-33.