CHARACTERIZATION OF PROTEIN-KINASE CK2 PROTEIN SUBUNITS AND P53 IN F9TERATOCARCINOMA CELLS IN THE ABSENCE AND PRESENCE OF CISPLATIN

The effect of cis-diaminedichloroplatinum(II) (cisplatin) on the induc tion of p53 and protein kinase CK2 activity was studied in the mouse t eratocarcinoma cell line F9. Treatment of the cells with the chemother apeutic agent cisplatin led to the detection of p53 3 h after addition of the drug. F9 cell extracts treated with and without cisplatin were analyzed by ion exchange chromatography for protein kinase CK2 alpha/ beta subunits and p53 distribution. The following results were obtaine d: (a) in crude extracts of cisplatin-treated cells, CK2 activity was sometimes reduced by as much as 50%; (b) after separation by anionic e xchange chromatography (MA7Q, BioRad) of the crude cellular extracts f rom cisplatin-treated cells, lower CK2 activity was found in the peak fractions confirming the results obtained with crude cellular extracts ; (c) besides the detection of CK2 alpha subunit by immunostaining, we have detected, at a concentration of similar to 200 mM NaCl, a protei n of approximately 46 kDa which reacted with the CK2 alpha-specific an tibody. This fraction was devoid of CK2 activity; and (d) cisplatin-tr eated cells exhibited p53 protein, which was mostly eluting ahead but also partly together with CK2 holoenzyme.