Fig. 1.

Phosphorylation on Ser-269 is regulated by glucose concentrations in pancreatic islets and MIN6 β-cells. (A) Mouse pancreatic islets of Langerhans or (B) MIN6 β-cells cultured in medium containing 3 mM glucose for 1 and 16 h, respectively. Mouse islets were further cultured for 1 h at three or 16.7 mM glucose. MIN6 β-cells were further cultured at the indicated glucose concentrations for the indicated time. Nuclear lysates were separated on SDS–PAGE gels and analyzed by Western blot using anti-phospho-Ser-269 PDX1 and anti-PDX1 antibodies. The blots shown are representative of 3 independent experiments. The ratio of phospho-Ser-269 PDX1 to total PDX1 level are shown graphically (A, B lower panels). ∗p < 0.05, ∗∗p < 0.01, ns: non-significant; samples were prepared in triplicate. Mean values from three independent experiments are shown.