FIGURE 3.

Inhibition of protein arginine methyltransferase 5 (PRMT5) reverses protein kinase B (AKT) activation‐induced mature sterol regulatory element‐binding protein 1 (mSREBP1) activation at the post‐translational level. A, After NCI‐H1299 cells were cultured in medium without FBS for 24 h, SC79 (4 µg/mL) was added for 16 h (DMSO as control), then the cells were treated with or without GSK591 (1 µmol/L; Selleck) for 8 h. Cell lysates were immunoblotted with Abs against SREBP1, ATP citrate lyase (ACLY), fatty acid synthase (FASN), acyl‐CoA desaturase (SCD1), PRMT5, Ser473‐phosphorylated AKT (AKT‐473P), or AKT. β‐Tubulin was used as a loading control. B, NCI‐H1299 cells with or without PRMT5 stable deletion were cultured in medium without FBS for 24 h. SC79 (4 µg/mL) was then added (DMSO as control), and cell lysates were immunoblotted with Abs against SREBP1, ACLY, FASN, SCD1, PRMT5, AKT‐473P, or AKT at 24 h. β‐Tubulin was used as a loading control. C, NCI‐H1299 cells with or without PRMT5 stable deletion were cultured in medium without FBS for 24 h. SC79 (4 µg/mL) was then added (DMSO as control; Sh‐NC) for 24 h. Luciferase activities were then analyzed. D‐H, NCI‐H1299 cells with or without PRMT5 stable deletion were cultured in medium without FBS for 24 h. SC79 (4 µg/mL) was then added (DMSO as control; Sh‐NC) for 24 h. mRNA levels of indicated genes were then analyzed. D, SREBF1. E, ACLY. F, FASN. G, SCD1. H, PRMT5