EGF stimulates inhibitory phosphorylation of GSK-3α and β in a PI3-kinase and AKT dependent fashion. Phosphorylation of GSK-3α and β at serines 9 and 21 respectively was tested by immunoblotting of (A) UMUC-3 and UMUC-14 cells that had been serum starved for 24 hours and then stimulated with 10 ng/ml EGF. Some cells were also pre-treated with 30 μM LY294002 or 10 μM AKTi-1/2 in order to verify that phosphorylation was dependent on PI3-kinase and AKT activity. (B) Quantitation of relative phospho-GSK-3α and β levels normalized to tubulin is shown for UMUC-3 and UMUC-14 cells. Four replicates were tested. Error bars represent S.E.M.
Yohn et al. BMC Urology 2011 11:19 doi:10.1186/1471-2490-11-19