TBBz but not TBBt discriminates between two molecular forms of CK2 in vivo and its implications.
Two ATP-competitive inhibitors-4,5,6,7-tetrabromo-benzotriazole (TBBt) and 4,5,6,7-tetrabromo-benzimidazole (TBBz) have been shown to decrease activity of CK2 holoenzyme. Surprisingly it occurs that TBBz contrary to TBBt does not inhibit free catalytic subunit CK2 [Formula: see text]. Both inhibitors are virtually inactive against RAP protein kinase. The above-mentioned protein kinases phosphorylate in vitro a set of acidic ribosomal P-proteins of the 60S ribosomal subunit. Such a modification is one of the mechanisms regulating translational activity of ribosomes in vivo. Application of these two very selective inhibitors allows us to define the role of free catalytic [Formula: see text] subunit of CK2 in phosphorylation of ribosomal proteins. It occurs that CK2 [Formula: see text] but not CK2 holoenzyme is responsible for phosphorylation of P-proteins in vivo. Moreover, elimination of both forms of protein kinase CK2 (hCK2 and CK2 [Formula: see text] ) activity in living cells led to dramatic loss of the translational activity of the ribosome.
Zień
Piotr
P
Department of Molecular Biology, Environmental Protection Institute, Catholic University of Lublin, Kraśnicka Av.102, 20-718 Lublin, Poland.
Abramczyk
Olga
O
Domańska
Katarzyna
K
Bretner
Maria
M
Szyszka
Ryszard
R
D001562:Benzimidazoles / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity; D001667:Binding, Competitive; D047390:Casein Kinase II; D002455:Cell Division / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D014176:Protein Biosynthesis / Q000187:drug effects / Q000502:physiology; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism*; D015800:Protozoan Proteins; D012269:Ribosomal Proteins / Q000737:chemistry / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology*; D013329:Structure-Activity Relationship; D014230:Triazoles / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity
C475924:4,5,6,7-tetrabromobenzimidazole; C405354:4,5,6,7-tetrabromobenzotriazole; D001562:Benzimidazoles; C064601:L12E protein, Trypanosoma cruzi; D015800:Protozoan Proteins; D012269:Ribosomal Proteins; D014230:Triazoles; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases