Fig. 7

CircDIDO1 promotes PRDX2 ubiquitination and degradation by RBX1. a) Protein degradation was blocked with MG-132 (40 μM) for 8 h. PRDX2 protein levels in GC cells with or without circDIDO1 overexpression were detected by Western blot. Data are shown as means ± SD (n = 3, **P < 0.01). b) Protein biosynthesis in GC cells was blocked with 20 μg/mL of cycloheximide (CHX). PRDX2 protein levels in GC cells with or without circDIDO1 overexpression at different time points were examined by Western blot. c) Prediction of ubiquitination sites in PRDX2 protein by PhosphoSitePlus software. d) Venn plot for the potential interacting proteins of PRDX2 as identified by Co-IP and LC–MS/MS. e) GC cells were transfected with ubiquitin (Ub) and circDIDO1 and treated with MG-132. Whole cell lysates were immunoprecipitated with PRDX2 antibody followed by detection with ubiquitin antibody. f) Validation of the interaction between PRDX2 and RBX1 in GC cells by Co-IP. g) The interaction between PRDX2 and RBX1 in control and circDIDO1 overexpressing GC cells was examined by Co-IP and Western blot