Tankyrase Inhibitors Stimulate the Ability of Tankyrases to Bind Axin and Drive Assembly of β-Catenin Degradation-Competent Axin Puncta
Fig 6
Proteasome inhibitor induces PARylation of TNKSs and TNKSi reduces basal PARylation levels.
A. SW480 and HEK293 cells were exposed to combinations of TNKSi (G007-LK) and MG132 treatments similar to that shown in legend to Fig 3. The cells were then lysed and extracts analysed by IP assay using a specific antibody against PAR. PARylated forms of TNKS1/2 were then detected by western blot. The IgG control was negative. Pull-down of PARylated proteins revealed an increase in PARylation of TNKS1 by MG132 treatment, and a decrease of PARylation induced by TNKSi. When combined, the MG132 dominated and caused some induction of PARylated TNKS1 in both SW480 and HEK293 cells. Levels of PARylated TNKS2 (and also axin, not shown) were too low for detection. Quantification of band intensities (mean ± SD) was from two separate experiments. B. Total extract western blot shows similar TNKS levels after different treatments.