Figure 5.
USP36 regulates K29-linked polyubiquitination of PrimPol. (A) Knock-down of USP36 promotes K29-linked polyubiquitination of PrimPol. HEK293T cells stably expressing control (Ctrl) or USP36 shRNAs were transiently transfected with HA-tagged Ub-K29 and Myc-tagged PrimPol. After 48 h, cells were treated with MG132 (50 μM) for 3 h before collecting. Cell lysates were subjected to immunoprecipitation with anti-Myc agarose beads, and then blotted with the indicated antibodies. (B) USP36 stably knock-down HEK293T cells were transiently transfected with indicated constructs. After 48 h, cells were treated with MG132 (50 μM) for 3 h before collecting. Cell lysates were subjected to immunoprecipitation with anti-Myc agarose beads, and then blotted with the indicated antibodies. (C) Ctrl or USP36 stably knock-down HEK293T cells were transiently transfected with indicated HA-K29 lysine-specific mutant constructs and Myc-tagged PrimPol. After 48 h, cells were treated with MG132 (50 μM) for 3 h before collecting. Cell lysates were subjected to immunoprecipitation with anti-Myc agarose beads, and then blotted with the indicated antibodies.