Involvement of cAMP-Dependent protein kinase and intracellular free calcium ions in regulation of ovulation of the follicle-enclosed oocytes ofRana temporaria by gonadotropic hormones

2000 ◽  
Vol 31 (5) ◽  
pp. 320-325
Author(s):  
M. N. Skoblina
Keyword(s):  
Protein Kinase ◽  
Calcium Ions ◽  
Intracellular Free Calcium ◽  
Free Calcium ◽  
Dependent Protein Kinase ◽  
Camp Dependent Protein Kinase ◽  
Dependent Protein ◽  
Ofrana Temporaria ◽  
Gonadotropic Hormones

scholarly journals Anti-immunoglobulin M activates nuclear calcium/calmodulin-dependent protein kinase II in human B lymphocytes.

1995 ◽  
Vol 182 (6) ◽  
pp. 1943-1949 ◽  
Author(s):  
M A Valentine ◽  
A J Czernik ◽  
N Rachie ◽  
H Hidaka ◽  
C L Fisher ◽  
...  
Keyword(s):  
Protein Kinase ◽  
B Lymphocytes ◽  
Intracellular Free Calcium ◽  
Free Calcium ◽  
Cam Kinase Ii ◽  
Dependent Manner ◽  
Cam Kinase ◽  
Dependent Protein Kinase ◽  
Calcium Calmodulin Dependent ◽  
Dependent Protein

We and others have previously shown that the nuclear protein, Ets-1, is phosphorylated in a calcium-dependent manner after ligation of immunoglobulin (Ig) M on B lymphocytes. As this phosphorylation was independent of protein kinase C activity, we tested whether a calcium/calmodulin-dependent protein kinase (CaM kinase) might phosphorylate the Ets-1 protein after elevation of intracellular free calcium concentrations. The dephosphorylated form of Ets-1 has been shown to bind to chromatin, suggesting that the operative kinase should be detectable in the nucleus. We prepared nuclear extracts from two human B cell lines in which increased intracellular free calcium levels correlated with increased phosphorylation of the Ets-1 protein. Activity of the CaM kinases was determined using a synthetic peptide substrate both in the absence and presence of an inhibitor specific for the CaM kinase family, KN-62. Stimulation of cells with anti-IgM led to increased activity of a nuclear kinase that could phosphorylate the peptide, and this activity was reduced by 10 microM KN-62. Kinase activity was reduced in lysates preadsorbed using an antibody specific for CaM kinase II. Two-dimensional phosphopeptide maps of the Ets-1 protein from cells incubated with ionomycin or anti-IgM contained two unique phosphopeptides that were absent in untreated cells. Incubation of isolated Ets-1 protein with purified CaM kinase II produced phosphorylation of peptides that migrated identically to those found in cells incubated with either anti-IgM or ionomycin. These data suggest a model of signal transduction by the antigen receptor on B lymphocytes in which increased intracellular free calcium can rapidly activate nuclear CaM kinase II, potentially resulting in phosphorylation and regulation of DNA-binding proteins.

Sign in / Sign up

Export Citation Format

Share Document