Fig 5.

SIK2 inactivates AKT by upregulation of protein phosphatases PHLPP2 and PP2A. (A) The immunoprecipitate by anti‐AKT (pan) antibodies was examined for the presence of SIK2 or vice versa in MGC803 cells assessed by Western blot analysis. The input sample (*) served as the positive control and IgG sample was the NC. The actual presence of AKT or SIK2 protein per se in the immunocomplex precipitated by anti‐AKT antibody or anti‐SIK2 antibody is shown in the bottom panels. (B) Western blot analysis of the expression of PI3K subunits, phospho‐PTEN, PTEN, PHLPP2 and PP2A in the SIK2‐overexpressed or ‐knockdown AGS and MGC803 cells. (C,D) Effect of siRNA‐mediated knockdown of PHLPP2 (C) or PP2A (D) in the SIK2‐overexpressed MGC803 cells on the expression of total and phosphorylated AKT, and the cell migratory and invasive abilities. Scale bar = 200 µm. Data are expressed as mean ± SD from at least three independent experiments with triple replicates per experiment. *P < 0.05; **P < 0.01.