Skip to main content
. 2021 Jan 1;11(5):2108–2122. doi: 10.7150/thno.48112

Figure 6.

Figure 6

STK39 interacts with PLK1 and promotes PLK1 phosphorylation. (A) HCCLM3-Flag-STK39 cells were lysed and immunoprecipitated with anti-Flag antibody or control IgG, binding proteins were analyzed by mass spectrometry. (B) HCCLM3-Flag-STK39 cells were lysed and immunoprecipitated with anti-Flag antibody or control IgG, STK39-PLK1 interaction was assessed by immunoprecipitation and immunoblotting. (C) 293T cells were transfected with plasmids encoding STK39-GFP and Dsred-PLK1 for 72 h, co-localization of STK39 and PLK1 was analyzed by confocal microscopy, scale bar, 25 µm. (D) HA-PLK1 was co-transfected with Flag-STK39 or Flag-STK39-truncated mutants into 293T cells for 48 h, cell lysates were immunoprecipitated using anti-Flag antibody and immunoblotted with antibodies to PLK1 or Flag tags. (E) Flag-STK39 was co-transfected with HA-PLK1 or HA-PLK1-truncated mutants into 293T cells for 48 h, cell lysates were immunoprecipitated using anti-HA antibody and immunoblotted with antibodies to STK39 or HA tags. (F) 293T cells were transfected with plasmids encoding Flag-STK39, Flag-STK39 (D210A) and Flag-STK39 (T231A) for 48 h, the levels of p-NKCC1, p-PLK1, p-CRAF and p-ERK1/2 were assessed by immunoblotting. (G) Stable knockdown of STK39 in HuH7 cells by shRNA, the levels of p-ERK1/2, p-MEK1/2, p-CRAF, p-PLK1 and STK39 were examined by immunoblotting. (H) The levels of p-ERK1/2, p-PLK1 and STK39 in STK39-overexpression and control HCCLM3 cells were assessed by immunoblotting. Data are shown as mean ±SEM. *p<0.05; **p<0.01; ***p<0.001.