Figure 2.

Influence of CK2 inhibitors SGC-CK2-1 and CX-4945 on CK2 expression and CK2 kinase activity. MIN6 cells were treated with 1 or 10 µM CX-4945 (CX) or 1 or 10 µM SGC-CK2-1 (SGC) for 24 h. Control cells were incubated with an equal volume of the vehicle DMSO. Proteins were extracted and equal amounts were either loaded on a 12.5% SDS polyacrylamide gel and blotted onto a PVDF membrane or subjected to an in vitro phosphorylation assay. (a) Representative immunoblot analysis of MIN6 cell extracts for the detection of the catalytic subunit CK2α and the non-catalytic CK2β subunit; the detection of α-tubulin served as loading control. (b) Representative immunoblot analysis for the detection of total Akt and Akt phosphorylated at the CK2 site serine 129 (pAkt). α-tubulin served as loading control. (c) Cell extracts were incubated with [³²Pγ]ATP and the synthetic CK2 substrate peptide RRRDDDSDDD. After the kinase reaction, labelled phosphate incorporated into the peptide was determined by Čerenkov counting. Activity measured in control extracts was set 100% and the activity of treated extracts calculated in reference to it. Statistical analysis was performed as described in “Material and Methods”. * Statistical significance was accepted with a p-value of at least p < 0.05.