Fig. 6.

GRIP1 binding and catalytic activities are required for Suv4-20h1-mediated regulation of GR target genes. (A) Suv4-20h1 long and short isoforms, the mutant proteins deficient in GRIP1 binding (N409) or catalysis (H264I), and the SET domain core with 4 conserved motifs (I-IV) are shown on the Left. We replaced a conserved histidine in motif III (H264, Right), involved in AdoMet binding with isoleucine. (B) U2OS-GR cells were transfected with an empty vector, wt Suv4-20h1, or its N409 or H264I mutants, as indicated. Twenty hours later, cells were treated with Dex for 2 h as shown, and the expression of indicated GR target genes were assessed as in Fig. 4C. Ectopic expression of Suv4-20h1.1 derivatives was assessed by anti-Flag immunoblotting (Inset).