CLK3 directly interacted with USP13, and CLK3 expression was up-regulated on EGF or TGFβ1 treatment. (A) Immunofluorescence staining indicated the nuclear colocalization of CLK3 and USP13 in HuCCT1 cells. Bar, 50 µm. (B) Indicated constructs were transfected into HEK293T cells. Co-IP was performed with indicated antibody. (C) HCCC9810 and HuH-28 cells were added with or without EGF (50 ng/ml) or TGFβ1 (10 ng/ml) for indicated time. CLK3 expression was analyzed using immunoblotting. Data are representative of three independent experiments with similar results. IB, immunoblot; TUBA, alpha tubulin.