Fig. 5

CUL7 leads to ubiquitin-mediated MST1 protein degradation and promotes activation of the NF-κB pathway. a GSEA highlighting positive association of increased CUL7 expression levels with NF-κB signal pathway. NES = normalized enrichment score; NOM = nominal FDR = false discovery rate. b Western blot for protein levels of NF-κB pathway components in lysates (20 μg) from U87MG, U251 and GSC267 cells transfected with siRNA against CUL7 and controls. GAPDH was used as a loading control. c Western blot for protein levels of MST1 in lysates (20 μg) from U87MG, U251 and GSC267 cells transfected with siRNA against CUL7 and controls. d qRT-PCR analysis of MST1 in U87MG, U251 and GSC267 cells. Expression is normalized to GAPDH mRNA. Data are represented as the mean ± SEM. e Western blot analysis of co-precipitating proteins in IPs performed using anti-CUL7 or -MST1 antibody on lysates prepared from U87MG, U251 and GSC267-NC, si-CUL7 cells. f Western blot analysis of MST1 protein in modified U87MG, U251 and GSC267 cells treated with CHX (25 μg/mL) for the indicated time. g Western blot analysis of MST1 IPs performed on lysates prepared from U87MG, U251 and GSC267 cells treated with MG132 (20 μM) for 8 h to examine endogenous MST1 ubiquitination. NC: non-silencing siRNA; si-CUL7: siRNAs targeting CUL7