Fig. 6

SERPINH1 binds to c-Myc and inhibits its ubiquitination-degradation. A Co-IP assay was shown the interaction between SERPINH1 and c-Myc in three NPC cell lines. B Co-localization of SERPINH1 and c-Myc protein in NPC cells was determined by immunofluorescence. Scale bars = 20 μm. C Western blotting analysis of c-Myc expression in CNE2 cells after overexpression of circCAMSAP1 and knockdown of SERPINH1 or circCAMSAP1 or overexpression of SERPINH1. D Western blotting analysis of the c-Myc protein stability in NPC cells after treatment with cycloheximide (CHX). E Western blotting analysis of the ubiquitination of c-Myc protein after overexpression of circCAMSAP1 in NPC cells. F The phosphorylation level of c-Myc T58 and S62 phosphorylation sites was measured by western blotting in CNE2 cells after overexpression of circCAMSAP1 and knockdown of SERPINH1, or knockdown of circCAMSAP1 and overexpression of SERPINH1. G The nuclear c-Myc expression was examined in NPC cells after overexpression of circCAMSAP1 in CNE2 cells by western blotting. H The transcript activity of c-Myc was measured in NPC cells after overexpression of circCAMSAP1 and knockdown of SERPINH1, or knockdown of circCAMSAP1 and overexpression of SERPINH1. ***, p < 0.001; ****, p < 0.0001