Protein Kinase Activity in Lymphocytes; Effects of Concanavalin A and a Phorbol Ester

1984 ◽  
pp. 151-158
Author(s):  
Anand P. Iyer ◽  
Sharon A. Pishak ◽  
Marion J. Sniezek ◽  
Andrea M. Mastro
Keyword(s):  
Protein Kinase ◽  
Phorbol Ester ◽  
Concanavalin A ◽  
Kinase Activity ◽  
Protein Kinase Activity

Staurosporine advances interblastomeric flattening of the mouse embryo

Zygote ◽  
1993 ◽  
Vol 1 (2) ◽  
pp. 103-112 ◽  
Author(s):  
D. Michael O'Sullivan ◽  
Martin H. Johnson ◽  
Josie M.L. McConnell
Keyword(s):  
Protein Kinase ◽  
Phorbol Ester ◽  
Mouse Embryo ◽  
Kinase Activity ◽  
Protein Kinase Activity ◽  
Calcium Dependent

Staurosporine, an inhibitor of protein kinase activity, causes premature intercellular flattening of blastomeres but does not induce their premature polarisation. The flattening induced is calcium dependent, is reversed transiently at mitosis and requires the continuing presence of the drug. Staurosporine also blocks the decompacting effect of phorbol ester on 8-cell embryos.

Unphosphorylated α-PKC exhibits phorbol ester binding but lacks protein kinase activity in vitro

1993 ◽  
Vol 52 (1) ◽  
pp. 78-83 ◽  
Author(s):  
Ireos Filipuzzi ◽  
Doriano Fabbro ◽  
Roland Imber
Keyword(s):  
Protein Kinase ◽  
Phorbol Ester ◽  
Kinase Activity ◽  
Protein Kinase Activity

Effect of Thrombin on Phosphorylation of Platelet Membrane Proteins

1976 ◽  
Vol 35 (03) ◽  
pp. 635-642 ◽  
Author(s):  
M Steiner
Keyword(s):  
Protein Kinase ◽  
Kinase Activity ◽  
Qualitative Change ◽  
Protein Kinase Activity ◽  
Protein Substrates ◽  
Phosphoprotein Phosphatase ◽  
Progressive Loss ◽  
Platelet Membranes ◽  
Endogenous Protein ◽  
Considerable Loss

SummaryThe effect of thrombin on the phosphorylating activity of platelet membranes was compared to that of trypsin. Preincubation of non-32P phosphorylated platelet membranes with or without either of these two enzymes resulted in a considerable loss of membrane protein kinase activity which was most severe when trypsin was used. Protein kinase activity and endogenous protein acceptors decreased in parallel. 32P-phosphorylated membranes showed a slow but progressive loss of label which was accelerated by trypsin. Thrombin under these conditions prevented the loss of 32P-phosphate. These results are interpreted to indicate a thrombin-induced destruction of a phosphoprotein phosphatase. The protein kinase activity of phosphorylated platelet membranes using endogenous or exogenous protein substrates showed a significant reduction compared to non-phosphorylated membranes suggesting a deactivation of protein kinase by phosphorylation of platelet membranes. Neither thrombin nor trypsin caused a qualitative change in the membrane polypeptides accepting 32P-phosphate but resulted in quantitative alterations of their ability to become phosphorylated.

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