Chromatin association of CTR9 requires kinase activity inhibited by AG490.

<p><i>A</i>, Cells were transfected with control siRNA or CTR9 siRNA for 48 hrs and treated with DMSO (mock) or AG490 (100 uM) for 4 hrs prior to IL-6 plus IL-6sR (20 ng/ml each) stimulation for 30 min. The c-Fos mRNA induction level was measured by RT-qPCR. <i>B</i>, Cells were treated as in A and a ChIP assay was performed with an anti-CTR9 antibody. Bound DNAs were analyzed by quantitative PCR using primers specific to c-Fos genomic loci. <i>C</i>, Cells were treated with DMSO (mock), 100 uM or 200 uM of AG490 for 12 hrs prior to IL-6 plus IL-6sR (20 ng/ml each) stimulation for 30 min. Cells were fractionated into chromatin -unbound and -bound fractions and blotted with anti-CTR9, anti-STAT3, anti-TBP, and anti-GAPDH antibodies. <i>D</i>, Negative function of PAFc in IL-6-responsive gene regulation. At TSS of IEG loci in basal condition, PAFc is associated with NELF. Upon IL-6 stimulation, PAFc along with NELF dissociates from the elongation block to allow transcriptional elongation to occur. SIE: Serum Inducible Element (STAT3 binding site). n.s. = not significant, **p<0.01 by Student's t test. Error bars represents SD (n = 3).