Fig. 6

DDX39B stability is regulated by SUMO-dependent ubiquitination. a IB in U87 cells stably expressing S-tagged wild-type DDX39B (WT) or E55A-DDX39B (E55A) in the presence of cycloheximide (CHX). Cells were harvested at the indicated time after CHX treatment and IB performed with anti-S-tag or anti-GAPDH antibody. b IB in 293T cells transfected with S-tagged DDX39B (WT or the indicated mutant) and Myc-ubiquitin (Myc-Ub). IP performed with S-agarose and IB with anti-Myc or anti-S-tag. c IB in U87 cells transfected with si-PIASx or si-control. IP was performed with anti-DDX39B and IB with anti-ubiquitin. Input was probed with the indicated antibodies. d IB in 293T cells transfected with empty vector or S-tag DDX39B, Myc-Ub, and Flag-PIAS1 or FLAG-PIASx-β. IP with S-agarose was followed by IB with anti-Myc. Input was probed with the indicated antibodies. e IB in U87 cells expressing S-tagged wild-type DDX39B (WT) in the presence of cycloheximide (CHX) and either vehicle or MG132 (10 μM). Cells were harvested at the indicated time after start of CHX treatment, and IB performed with anti-S-tag or anti-GAPDH antibody. f IB in 293T cells transfected with S-tag DDX39B and treated with vehicle or TMZ (100 μM, 12 h). IP was performed with S-agarose and IB with anti-ubiquitin. Input was probed with the indicated antibodies. g IB in U87 cells treated with vehicle or TMZ (100 μM) for the indicated time in the presence of CHX with anti-DDX39B