Bedard, Lynn GlowczewskiDronamraju, RaghuvarKerschner, Jenny L.Hunter, Gerald O.Axley, Elizabeth DeVliegerBoyd, Asha K.Strahl, Brian D.Mosley, Amber L.2017-11-282017-11-282016-06-24Bedard, L. G., Dronamraju, R., Kerschner, J. L., Hunter, G. O., Axley, E. D., Boyd, A. K., … Mosley, A. L. (2016). Quantitative Analysis of Dynamic Protein Interactions during Transcription Reveals a Role for Casein Kinase II in Polymerase-associated Factor (PAF) Complex Phosphorylation and Regulation of Histone H2B Monoubiquitylation. The Journal of Biological Chemistry, 291(26), 13410–13420. http://doi.org/10.1074/jbc.M116.727735https://hdl.handle.net/1805/14674Using affinity purification MS approaches, we have identified a novel role for casein kinase II (CKII) in the modification of the polymerase associated factor complex (PAF-C). Our data indicate that the facilitates chromatin transcription complex (FACT) interacts with CKII and may facilitate PAF complex phosphorylation. Posttranslational modification analysis of affinity-isolated PAF-C shows extensive CKII phosphorylation of all five subunits of PAF-C, although CKII subunits were not detected as interacting partners. Consistent with this, recombinant CKII or FACT-associated CKII isolated from cells can phosphorylate PAF-C in vitro, whereas no intrinsic kinase activity was detected in PAF-C samples. Significantly, PAF-C purifications combined with stable isotope labeling in cells (SILAC) quantitation for PAF-C phosphorylation from wild-type and CKII temperature-sensitive strains (cka1Δ cka2–8) showed that PAF-C phosphorylation at consensus CKII sites is significantly reduced in cka1Δ cka2–8 strains. Consistent with a role of CKII in FACT and PAF-C function, we show that decreased CKII function in vivo results in decreased levels of histone H2B lysine 123 monoubiquitylation, a modification dependent on FACT and PAF-C. Taken together, our results define a coordinated role of CKII and FACT in the regulation of RNA polymerase II transcription through chromatin via phosphorylation of PAF-C.en-USPublisher PolicyChromatinHistone modificationPhosphorylationTranscriptionUbiquitylation (ubiquitination)FACTPAF-CSILACCasein kinase IIQuantitative proteomicsArticle