FIG 3.

OGT/HCF-1 complex is required for activation of proteasome subunit genes in response to proteasome inhibition. (A to C) Relative mRNA levels of proteasome subunit genes. HeLa cells were transfected with control siRNA, NRF1 siRNAs (A), OGT siRNAs (B), or HCF-1 siRNAs (C). After 72 h, the cells were treated with DMSO or 1 μM MG132 for 10 h. Values were normalized to HPRT values. Normalized values of control cells that were treated with DMSO were set to 1. Averages and SD were calculated from triplicate samples. *, P < 0.05; **, P < 0.01. (D) Relative mRNA levels of proteasome subunit genes. 293F cells were stably transduced with empty vector, 3×FLAG-NRF1-WT, or 3×FLAG-NRF1-M1 expression vector and treated with high-glucose medium for 24 h before harvest. Values were normalized to HPRT values. The normalized values of mock-transduced cells were set to 1. Averages and SD were calculated from triplicate samples. *, P < 0.01. n.s., not significant.