Increased activity of the eEF-2 specific, Ca2+ and calmodulin dependent protein kinase III during the S-phase in Ehrlich ascites cells.
The activity of the eukaryotic elongation factor (eEF-2) specific, Ca2+ and calmodulin dependent protein kinase III (CaM PK III) was studied in homogenated Ehrlich ascites tumour cells. The eEF-2 kinase activity was determined in the presence of an excess of the substrate, i.e., non-limiting concentrations of eEF-2. The homogenates showed both kinase and phosphatase activity. The latter activity was inhibited by the protein phosphatase 2A inhibitor okadaic acid. Analysis of the kinase using cells from defined stages of the cell cycle showed that the highest activity was found in cells from the early S-phase, whereas the phosphatase activity was most pronounced during the G2+M phase.
Calberg
U
U
Department of Zoological Cell Biology, Stockholm University, Arrhenius Laboratories E5, Sweden.
Nilsson
A
A
Skog
S
S
Palmquist
K
K
Nygård
O
O
D000818:Animals; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D002286:Carcinoma, Ehrlich Tumor / Q000201:enzymology* / Q000473:pathology; D002453:Cell Cycle; D054736:Elongation Factor 2 Kinase; D007700:Kinetics; D051379:Mice; D008970:Molecular Weight; D020652:Peptide Elongation Factor 2; D010445:Peptide Elongation Factors / Q000302:isolation & purification / Q000378:metabolism; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D016196:S Phase
D020652:Peptide Elongation Factor 2; D010445:Peptide Elongation Factors; D011494:Protein Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; C517690:Eef2k protein, mouse; D054736:Elongation Factor 2 Kinase