Pyr41 (418805-02-4) inhibits ubiquitin activating enzyme E1 (>60% inhibition at 10 μM) with little or no activity against E2 or E3. Cell permeable
PYR 41 is an irreversible and cell-permeable UBE1 inhibitor.
ChEBI: PYR-41 is an ethyl ester resulting from the formal condensation of the carboxy group of 4-{4-[(5-nitrofuran-2-yl)methylidene]-3,5-dioxopyrazolidin-1-yl}benzoic acid with ethanol. It is an irreversible and cell-permeable inhibitor of ubiquitin-activating enzyme E1. It has a role as an EC 6.2.1.45 (E1 ubiquitin-activating enzyme) inhibitor and an antineoplastic agent. It is an ethyl ester, a member of furans, a C-nitro compound, a member of pyrazolidines and a benzoate ester.
PYR-41 is a cell permeable inhibitor of Ubiquitin activating enzyme (E1) with little or no activity against E3, E2, or caspase enzymatic activity.
in addition to blocking ubiquitylation, pyr-41 was found to increase total sumoylation in cells. pyr-41 could attenuate cytokine-mediated nuclear factor-kbactivation. this correlated with inhibition of nonproteasomal ubiquitylation of traf6, which is important to ikbkinase activation. pyr-41 also prevented the downstream ubiquitylation and proteasomal degradation of ikba. moreover, pyr-41 has demonstrated effective uae e1 inhibition as well as some off-target inhibition of the other ubiquitin regulatory enzymes and signal-transducing proteins, suggesting it is a nonspecific inhibitor [1].
1) Yang et al. (2007), Inhibitors of Ubiquitin-Activating Enzyme (E1), a New Class of Potential Cancer Therapeutics; Cancer Res., 67 9472
2) Mi et al. (2009), Cancer Preventive isothiocyanates induce selective degradation of cellular alpha- and beta-tubulins by proteasomes; J. Biol. Chem., 284 17039
3) Maehama et al. (2014), Nucleolar Stress Induces Ubiquitination-independent Proteasomal Degradation of PICT1 Protein PYR41; J. Biol. Chem., 289 20802 [Focus Citation]
