Figure 1.
Chemical structures of MLN4924, [Rh(ppy)2(dppz)]+ (1) and Rh(III) analogues (2–4).
Figure 2.
Complex 1 inhibits NAE activity in a dose-dependent manner.
Western blots show dose-dependent inhibition of a) Ubc-12-NEDD8 formation in a cell-free system and b) cellular Ubc12-NEDD8 levels by 1. MLN4924 was included for comparison.
Figure 3.
Dose-dependent inhibition of IκBα degradation by 1.
Caco-2 cells were pre-incubated with indicated concentrations of 1 for 16 hours and then stimulated with 5 ng/ml of TNF-α at indicated time intervals. Whole cell lysates were analyzed by Western blot using anti-IκBα antibody. Densitometry estimates of IκBα levels normalized with GAPDH are shown under each lane. b) Caco-2 cells were treated with 1 or MLN4924 for 16 h. The cell lysates were immunoblotted to analyse the level of CRL substrate p27.
Figure 4.
Complex 1 suppresses NAE-regulated NF-κB-dependent luciferase reporter gene expression in a dose-dependent manner.
Caco-2 cells were transfected with the NF-κB-dependent luciferase reporter p3EnhConA-Luc gene, treated with 1 for 16 hours, and then stimulated with 5 ng/ml of TNF-α for 3 hours. Luciferase expression was measured and normalized with β-galactosidase activity. Results are expressed as fold change compared to TNF-α stimulation alone and the errors bar show the standard derivation of triplicate results. MLN4924 was included for comparison.
Figure 5.
Low-energy binding conformations of a) 1, b) MLN4924 and c) both 1 and ATP bound to NAE heterodimer generated by virtual ligand docking.
Proteins APPBP1 (blue), UBA3 (purple) and NEDD8 (yellow) are displayed in ribbon form. Small molecules are depicted as a ball-and-stick model showing showing carbon (yellow), hydrogen (grey), oxygen (red), nitrogen (blue), phosphorus (orange) and sulfur (green). Non-polar hydrogens were not shown.