JAK3 physically interacts with EZH2 and negatively regulates H3K27 trimethylation. (A-B) Coimmunoprecipitation experiments to examine the interaction between endogenous EZH2 and JAK3 in NKYS or KHYG cell lines. Ab1 and Ab2 are 2 different JAK3 antibodies (Santa Cruz SC-513 and Cell Signaling 3775s for Ab1 and Ab2, respectively). (C) Immunoblot analysis of indicated proteins from NKYS cells treated with or without 0.5 μM CP-690550 (CP). (D) Immunoblot analysis of indicated proteins from NKYS cells treated with or without 1 μM PF956980 (PF). (E) Immunoblot analysis of H3 K27 trimethylation and EZH2 in NKYS cells transfected with control siRNA or 2 different individual JAK3 siRNAs for 24 hours. (F) Immunoblot analysis of H3 K27 trimethylation and EZH2 in 293T cells transfected with control vector or JAK3 expression plasmid for 48 hours.