Fig. 7

TXN1 regulates P53 at both post transcriptional and transcriptional levels. A TXN1 deletion prevented p53 and MDM2 from degradation. EML/TXN1KO and EML control cells were incubated with 50uM cycloheximide (CHX). At various time-points (2, 4, 6, 8, 10, 12, 14 and 24 h), the cells were harvested and p53, MDM2 and β-actin were measured by Western Blot analysis. B Expression levels of p53 and MDM2 were determined by image J software of the immunoblots in A (errors bars indicate mean ± sd; n = 3). C EML cells were transfected with flag-tag plasmid encoding TXN1 as indicated. Then the binding of TXN1 to the P53 promotor was analyzed by chromatin immunoprecipitation (CHIP-qPCR). D CHIP-qPCR representing the significant enrichment of the total input of the TP53 promotor region in a CHIP experiment using the TXN1 flag-tag antibody relative to the enrichment by nonspecific IgG. E) Tp53 promoter region (− 1600 to − 100) was cloned into pGL3 firefly/renilla luciferase reporter system. The p53 promoter-pGL3 reporter was transduced into EML cells and the EML cells were then treated with PX12 (thioredoxin inhibitor, recombinant TXN1 or NAC). Relative luciferase activity Luc (fold change) was calculated from the ratio of P53PGL3 Luc activity after normalization to the pRenilla