F Co-IP analysis of Ctk1 and histone H2B interaction. WT and ulp2Δ strains expressing the indicated tagged proteins were precipitated with IgG-Sepharose. IP and INPUT proteins were subjected to immunoblotting with PAP (Ctk1-TAP) and anti-Flag (Flag-H2B) antibodies. Protein signals were quantified relative to PGK and then normalized to the WT value. 