Figure 4

Ionizing Radiation inhibits GSK3β kinase activity. SAOS-2 cells were immunoprecipitated with anti-GSK3 antibody and incubated with CREB phosphopeptide substrate. Total CPM incorporated into the substrate peptide are shown. Pep: Assays carried out with or without peptide. Ab: Immunoprecipitation carried out with either IgG or anti-GSK3 antibody (+). Cell: Cells were either growing asynchronously (+) or preincubated for 24 h in 0.5% Serum to induce quiescence (Go). IR: Cells were exposed to 5 or 10Gy of Ionizing Radiation and allowed to recover for 60 min.