Fig. 2.

Phosphorylation on Ser-269 by HIPK2 in vitro and in vivo. (A) 2 μg of recombinant PDX1-c-myc wild-type or S269A was mixed with (pmol, picomoles) of HIPK2 and [γ-³²P] ATP for 30 min. Autoradiography shows the radiolabeled PDX1 and HIPK2. Coomassie staining shows the PDX1 protein level. (B) Parallel experiment with cold ATP, analyzed by Western blot using indicated antibodies. MIN6 β-cells were cultured in the presence of 1 nM HIPK2 or scrambled siRNA for 72 h prior to analysis by real-time PCR using primers against mouse HIPK2 (C) or Western blotting with anti-phospho-Ser-269 PDX1 antibody (D). ∗p < 0.05, ∗∗p < 0.01. Data shown are from a minimum of three independent experiments.