Fig. 4.

Ser-269 phosphorylation and PDX1 subnuclear localization (A) Immunocytochemical analysis of the subcellular distribution of PDX1-c-myc. MIN6 β-cells were transduced with adenoviruses encoding for the indicated PDX1 molecules. Cells were cultured at 3 mM glucose for 16 h and then treated with 3 or 20 mM glucose for 6 h. c-myc-tagged PDX1 was detected using anti-c-myc antibody (Roche) and Alexa-568 (Molecular Proves). Nuclear staining was achieved using DAPI. Confocal images were captured using a Leica SP2 upright laser scanning confocal microscope (x63/1.32 oil-immersion lens) equipped with a krypton/argon laser (488 and 568 nm excitation lines) and UV light. Images were analyzed off-line using Volocity^TM 4.0 software. Each sample was prepared in triplicate. (B) The average number of cells displaying PDX1 localization predominantly at nuclear periphery is expressed as a percentage of the total number of cells analyzed. Mean values from three independent experiments are shown.