Fig. 5.

CHIP-induced OCT4 polyubiquitination at K284 regulates cell viability and side population. a Transcriptional activation in MCF7 cells was measured by performing the reporter assay. The cells were transfected with OCT4 reporter vector alone or were cotransfected with CHIP siRNA or FLAG–CHIP-expressing vector for 48 h. b, c The cells were transfected with the indicated siRNAs alone or in combination for 48 h, and cell viability was detected by performing WST assay, and side population was analyzed, as described in Materials and methods. d, e The cells were transfected with the indicated expression vectors alone or in combination for 48 h and cell viability was detected by performing WST assay, and side population was analyzed, as described in Materials and methods. OCT4 and CHIP levels were detected by performing western blotting, with GAPDH as a loading control. Significant differences are indicated by an asterisk (*p < 0.05, **p < 0.01); p values were calculated using Student’s ttest