Figure 1.

p21 interacts with the PSMA3 Trapper. (A) Schematic presentation of the proposed model whereby IDP/IDR interacts with the PSMA3 (A3) trapper as a prerequisite step for degradation by the 20S proteasome particle. (B) Illustration of the luciferase complementation assay system demonstrating the direct interaction between the PSMA3 Trapper and the p21 protein, both fused to luciferase split fragments. Upon interaction, a bioluminescent signal is detected. (C) The boxplot represents the obtained bioluminescent signals, calculated as the fold increase over the signal of the control plasmids (number of repeats N = 10). (D) SDS–PAGE and immunoblot analysis of the overexpressed proteins tested in panel (C). Ponceau staining was used as a loading control.