Immunologically defined subclasses of the protein kinase CK2 beta-subunit in prostate carcinoma cell lines.
Both, the activity as well as the expression of protein kinase CK2 is enhanced in various cancer types and in established tumour cell lines. This phenomenon is not due to an increase in the CK2 message but rather to posttranscriptional and posttranslational mechanisms. In order to get an insight into these posttranslational modifications we analyzed CK2 in prostate cancer cell lines, which differ by their hormone-sensitivity. We found that the CK2 activity is significantly higher in hormone-refractory than in hormone-sensitive cells although the amount of the catalytic alpha- and alpha'- subunits is comparable. In contrast, we detected seemingly lower amounts of the regulatory beta-subunit in the hormone-refractory cell lines, which later turned out to be an immunologically defined subclass. This subclass is realized by a phosphate group, which is attached to serine 209. The phosphorylation occurs in vivo during mitosis and is executed by the p34(cdc2)/cyclin B kinase. As this phosphorylation enhances the CK2 activity this change might well account for the higher activity of CK2 in prostate cancer cells.
Götz
Claudia
C
Universität des Saarlandes, Medizinische Biochemie und Molekularbiologie, Gebäude 44, D-66421 Homburg, Germany.
Kartarius
Sabine
S
Schetting
Sarah
S
Montenarh
Mathias
M
D015153:Blotting, Western; D016203:CDC2 Protein Kinase / Q000378:metabolism*; D047390:Casein Kinase II / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D019926:Cyclin B / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D008297:Male; D008938:Mitosis; D009154:Mutation; D009376:Neoplasms, Hormone-Dependent; D010766:Phosphorylation; D011471:Prostatic Neoplasms; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012694:Serine / Q000378:metabolism
D019926:Cyclin B; D021122:Protein Subunits; D012694:Serine; D047390:Casein Kinase II; D016203:CDC2 Protein Kinase