Figure 9: Cocaine promotes RNAP II pause-release by phosphorylating TRIM28 at S824.

Jurkat cells were exposed to increasing concentrations of cocaine, and both cytoplasmic and nuclear extracts were subjected to immunoblotting using specific antibodies against pTRIM28 (S824), total TRIM28, DSIF (SPT-5), NELF-E, and HDAC1. Densitometric analysis of protein bands (normalized to actin) confirmed a significant increase in nuclear pTRIM28 (S824) levels following cocaine exposure compared to untreated cells (Ctrl) (A, B & C). Immunoblots are representative of at least three independent experiments. The results are expressed as mean ± SD for three independent experiments, analyzed by two-way ANOVA followed by Tukey’s multiple comparisons test. Asterisks over the bars indicate significant differences. Statistical significance is set as p < 0.05 (∗) compared to untreated cells (Ctrl).