Fig. 4

The kinase domain of DAPK is required for its regulation on DDX20. A Schematic representation of five HA-fused DAPK constructs containing amino acids 1–364, 1–666, 1–1313 and 1–1430 (full length). B–D Co-immunoprecipitation of DDX20-FLAG and the different DAPK domains in the whole cell lysates of 293T cells expressing the indicated proteins. Anti-HA or FLAG antibody were used for immunoprecipitated and the proteins in the precipitates were quantified using Western blotting. E Effect of overexpression of HA-DAPK or HA-DAPK(K42A), a kinase dead mutant of DAPK, on the ubiquitination of DDX20-FLAG in 293T cells. F, G Effect of DAPK kinase inhibitor (TC-DAPK6, 100 nM) on the expression of DDX20 in HCC cells. The relative DDX20 protein level is illustrated graphically(G). INPUT: The whole lysate, IP: immunoprecipitation, PD: pull down, IB: immunoblot. *p < 0.05, between the indicated groups. Data are shown as the mean ± SD of three independent experiments