Proteasome inhibition induces expression of the CHOP10 gene, and represses expression of the GLUT4 and C/EBPα genes in 3T3-L1 adipocytes. (A) Total RNA was isolated from 3T3-L1 adipocytes treated with 10 µM MG132 or vehicle (control) for 6 hours. Quantitative real-time RT-PCR was used to quantitate CHOP10, GLUT4, and C/EBPα mRNA levels. mRNA levels are expressed relative to levels in vehicle-treated cells, after controlling for 18S RNA expression level. (B) Nuclei were isolated from 3T3-L1 adipocytes treated with 10 µM MG132 or vehicle (control) for 3 hours. Run-on transcription was performed in the presence of biotin-16-UTP, and newly formed transcripts were purified using streptavidin-coupled Dynabeads M-280. Quantitative real-time RT-PCR was used to quantitate CHOP10, GLUT4, and C/EBPα transcript levels, which are expressed relative to levels in vehicle-treated cells, after controlling for 18S RNA expression level. Results represent the mean of 5 (A) or 3 (B) independent experiments; error bars indicate one standard deviation. * P < 0.05 vs. control.