Fig. 4: PKD1 prolongs the half-life of KAT7 protein and reduces KAT7 protein ubiquitination.

a PKD1 overexpression increases the half-life of KAT7 protein. HEK293T cells were transfected with empty vector or HA-PKD1-CA plasmids for 36 h. Then 100 μg/ml cycloheximide (CHX) was added for the indicated time. The indicated proteins were detected by Western blot. b Data from a were quantified and graphed. c PKD1 knockdown decreases the half-life of KAT7 protein. HEK293T cells were transfected with PKD1 siRNA or control siRNA for 60 h. Then 100 ug/ml CHX was added for the indicated time. The indicated proteins were detected by Western blot. d Data from c were quantified and graphed. e, f PKD1 knockdown-induced KAT7 protein reduction is inhibited by proteasome inhibitor MG132. HEK293T and H1299 cells were transfected with PKD1 siRNA or control siRNA for 66 h, then cells were incubated with or without MG132 for another 6 h. The indicated proteins were detected by western blot. g PKD1 overexpression reduces KAT7 ubiquitination. HEK293T cells were co-transfected with Flag-KAT7, HA-Ub with or without Myc-PKD1-CA for 42 h and then treated with MG132 for another 6 h. Then IP assay was performed with Flag antibody and immunoblotted with HA antibody and other antibodies. h PKD1 knockdown enhances KAT7 ubiquitination. HEK293T cells were co-transfected with Flag-KAT7, HA-Ub, PKD1 siRNA or control siRNA for 42 h and then treated with MG132 for another 6 h. Then IP assay was performed with Flag antibody and immunoblotted with HA antibody and other antibodies. i 293 T cells were co-transfected with Flag-KAT7, HA-Ub for 42 h and treated with or without Gö6976, and then treated with MG132 for another 6 h. Then IP assay was performed with Flag antibody and immunoblotted with HA antibody and other antibodies.