Fig. 1

CDK9 inhibition remodels OGT activity. A C-terminal domain of RNA polymerase II is phosphorylated by cyclin-dependent kinase 7 (CDK7), CDK9 and CDK12 to promote transcription initiation, elongation and to keep up elongation of longer genes, respectively. Small molecule inhibitors: YKL-5-124, NVP2, THZ531, OSMI-4 and Thiamet G target CDK7, CDK9, CDK12, OGT and OGA, respectively. B To identify doses affecting RNA Pol II phosphorylation, cells were treated with increasing doses of specific inhibitors for 4 h and analyzed using western blot. Densitometry was used to measure the signal intensity. C 22RV1 cells were treated with CDK7, CDK9, CDK12, OGT and OGA inhibitor for four hours, after which samples were subjected to wheat-germ agglutinin-lectin pulldown and analyzed using western blot. D CRPC cell lines were treated with CDK9 inhibitor NVP2 for 4 h and the O-GlcNAcylated proteins were enriched using lectin pulldowns (O-Glc PD); the samples were analyzed using western blot