Increased amount of a 25-kilodalton phosphoprotein after v-mos transfection of CHO cells

1988 ◽  
Vol 8 (11) ◽  
pp. 4685-4691
Author(s):  
J K Mayo ◽  
K E Sampson ◽  
L D Adams ◽  
E R Crumm ◽  
S L Kelly ◽  
...  
Keyword(s):  
Growth Rate ◽  
Cho Cells ◽  
Kinase Activity ◽  
Chinese Hamster ◽  
Temperature Sensitive ◽  
Serine Threonine Kinase ◽  
Dependent Protein Kinase ◽  
Threonine Kinase ◽  
Dependent Protein ◽  
A Cell

We transfected Chinese hamster ovary (CHO) cells with a cloned v-mos gene (pHT25). The mos family of oncogenes has previously been shown to have serine-threonine kinase activity. This kinase activity may be required for oncogenic transformation, although its exact biological role is unknown. We found that the transfected cells had an altered morphology, a slower doubling time, and an apparent increase in the amount of a 25-kilodalton (kDa) phosphoprotein that appeared to be of low abundance. Transfection of CHO cells with a cloned temperature-sensitive mos gene (ts159) led to isolation of a cell line that showed the presence of the 25-kDa phosphoprotein at the permissive but not at the nonpermissive temperature, suggesting a direct relationship between mos activity and the presence of this phosphoprotein. The characteristics of altered morphology and depressed growth rate were reminiscent of changes seen after the activation of the cyclic AMP-dependent protein kinase (PKA) in CHO cells. However, PKA activation did not stimulate phosphorylation of this 25-kDa protein, nor was there a change in total PKA activity in these cells. We suggest that the increased presence of the 25-kDa phosphoprotein is a consequence of the v-mos transfection and that it may be involved in the change of morphology and growth rate seen in the CHO cells. Phosphorylation of this protein may be a useful marker of mos and have some functional importance in the transformation of cells by the v-mos oncogene.

scholarly journals Increased amount of a 25-kilodalton phosphoprotein after v-mos transfection of CHO cells.

1988 ◽  
Vol 8 (11) ◽  
pp. 4685-4691 ◽  
Author(s):  
J K Mayo ◽  
K E Sampson ◽  
L D Adams ◽  
E R Crumm ◽  
S L Kelly ◽  
...  
Keyword(s):  
Growth Rate ◽  
Cho Cells ◽  
Kinase Activity ◽  
Chinese Hamster ◽  
Temperature Sensitive ◽  
Serine Threonine Kinase ◽  
Dependent Protein Kinase ◽  
Threonine Kinase ◽  
Dependent Protein ◽  
A Cell

We transfected Chinese hamster ovary (CHO) cells with a cloned v-mos gene (pHT25). The mos family of oncogenes has previously been shown to have serine-threonine kinase activity. This kinase activity may be required for oncogenic transformation, although its exact biological role is unknown. We found that the transfected cells had an altered morphology, a slower doubling time, and an apparent increase in the amount of a 25-kilodalton (kDa) phosphoprotein that appeared to be of low abundance. Transfection of CHO cells with a cloned temperature-sensitive mos gene (ts159) led to isolation of a cell line that showed the presence of the 25-kDa phosphoprotein at the permissive but not at the nonpermissive temperature, suggesting a direct relationship between mos activity and the presence of this phosphoprotein. The characteristics of altered morphology and depressed growth rate were reminiscent of changes seen after the activation of the cyclic AMP-dependent protein kinase (PKA) in CHO cells. However, PKA activation did not stimulate phosphorylation of this 25-kDa protein, nor was there a change in total PKA activity in these cells. We suggest that the increased presence of the 25-kDa phosphoprotein is a consequence of the v-mos transfection and that it may be involved in the change of morphology and growth rate seen in the CHO cells. Phosphorylation of this protein may be a useful marker of mos and have some functional importance in the transformation of cells by the v-mos oncogene.

Ca2+/calmodulin-dependent protein kinase II activation and regulation of adrenal glomerulosa Ca2+ signaling

1995 ◽  
Vol 269 (6) ◽  
pp. F751-F760 ◽  
Author(s):  
R. J. Fern ◽  
M. S. Hahm ◽  
H. K. Lu ◽  
L. P. Liu ◽  
F. S. Gorelick ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Kinase Activity ◽  
Low Voltage ◽  
Extracellular Potassium ◽  
Dependent Protein Kinase ◽  
Calmodulin Antagonist ◽  
Cell Extracts ◽  
Protein Kinase Ii ◽  
Dependent Protein ◽  
A Cell

We recently reported that elevations in the intracellular Ca2+ concentration ([Ca2+]i) enhance low-voltage-activated, T-type, Ca2+ channel activity via Ca2+/calmodulin-dependent protein kinase II (CaMKII). Here, we document CaMKII activity in bovine adrenal glomerulosa (AG) cells and assess the importance of CaMKII in depolarization-induced Ca2+ signaling. AG cell extracts exhibited kinase activity toward a CaMKII-selective peptide substrate that was dependent on both Ca2+ [half-maximal concentration for Ca2+ activation (K0.5) = 1.5 microM] and calmodulin (K0.5 = 46 nM) and was sensitive to a calmodulin antagonist and a CaMKII peptide inhibitor. On cell treatment with elevated extracellular potassium (10-60 mM) or angiotensin II, Ca(2+)-independent CaMKII activity increased to 133-205% of basal activity. Ca(2+)-independent kinase activity in agonist-stimulated extracts was inhibited by the CaMKII inhibitor peptide, 1(-)[N,O-bis(1,5- isoquinolinesulfonyl)-N-methyl-L-tyrosyl]-4-phenylpiperazine (KN-62), a cell-permeable inhibitor of CaMKII, reduced the agonist-induced stimulation of Ca(2+)-independent CaMKII activity. KN-62 also diminished depolarization-induced increases in [Ca2+]i without affecting the membrane potential. These observations suggest that CaMKII is activated in situ by aldosterone secretagogues and augments Ca2+ signaling through voltage-gated Ca2+ channels.

scholarly journals Fyn Regulates Binding Partners of Cyclic-AMP Dependent Protein Kinase A

Proteomes ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 37
Author(s):  
Anna Schmoker ◽  
Samuel Barritt ◽  
Marion Weir ◽  
Jacqueline Mann ◽  
Tyler Hogan ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Quantitative Mass Spectrometry ◽  
Serine Threonine Kinase ◽  
Dependent Protein Kinase ◽  
Threonine Kinase ◽  
Cellular Processes ◽  
Binding Partners ◽  
Dependent Protein ◽  
Kinase A

The cAMP-dependent protein kinase A (PKA) is a serine/threonine kinase involved in many fundamental cellular processes, including migration and proliferation. Recently, we found that the Src family kinase Fyn phosphorylates the catalytic subunit of PKA (PKA-C) at Y69, thereby increasing PKA kinase activity. We also showed that Fyn induced the phosphorylation of cellular proteins within the PKA preferred target motif. This led to the hypothesis that Fyn could affect proteins in complex with PKA. To test this, we employed a quantitative mass spectrometry approach to identify Fyn-dependent binding partners in complex with PKA-C. We found Fyn enhanced the binding of PKA-C to several cytoskeletal regulators that localize to the centrosome and Golgi apparatus. Three of these Fyn-induced PKA interactors, AKAP9, PDE4DIP, and CDK5RAP2, were validated biochemically and were shown to exist in complex with Fyn and PKA in a glioblastoma cell line. Intriguingly, the complexes formed between PKA-C and these known AKAPs were dependent upon Fyn catalytic activity and expression levels. In addition, we identified Fyn-regulated phosphorylation sites on proteins in complex with PKA-C. We also identified and biochemically validated a novel PKA-C interactor, LARP4, which complexed with PKA in the absence of Fyn. These results demonstrate the ability of Fyn to influence the docking of PKA to specific cellular scaffolds and suggest that Fyn may affect the downstream substrates targeted by PKA.

scholarly journals CPG16, a Novel Protein Serine/Threonine Kinase Downstream of cAMP-dependent Protein Kinase

1999 ◽  
Vol 274 (5) ◽  
pp. 2631-2636 ◽  
Author(s):  
Michael A. Silverman ◽  
Outhiriaradjou Benard ◽  
Hanna Jaaro ◽  
Amir Rattner ◽  
Yoav Citri ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Serine Threonine Kinase ◽  
Dependent Protein Kinase ◽  
Threonine Kinase ◽  
Camp Dependent Protein Kinase ◽  
Dependent Protein ◽  
Novel Protein

scholarly journals CaMKII in the Cardiovascular System: Sensing Redox States

2011 ◽  
Vol 91 (3) ◽  
pp. 889-915 ◽  
Author(s):  
Jeffrey R. Erickson ◽  
B. Julie He ◽  
Isabella M. Grumbach ◽  
Mark E. Anderson
Keyword(s):  
Cardiovascular Disease ◽  
Cardiovascular System ◽  
Regulatory Domain ◽  
Serine Threonine Kinase ◽  
Dependent Protein Kinase ◽  
Redox States ◽  
Threonine Kinase ◽  
Parallel Processes ◽  
Dependent Protein ◽  
Transduction Signal

The multifunctional Ca2+- and calmodulin-dependent protein kinase II (CaMKII) is now recognized to play a central role in pathological events in the cardiovascular system. CaMKII has diverse downstream targets that promote vascular disease, heart failure, and arrhythmias, so improved understanding of CaMKII signaling has the potential to lead to new therapies for cardiovascular disease. CaMKII is a multimeric serine-threonine kinase that is initially activated by binding calcified calmodulin (Ca2+/CaM). Under conditions of sustained exposure to elevated Ca2+/CaM, CaMKII transitions into a Ca2+/CaM-autonomous enzyme by two distinct but parallel processes. Autophosphorylation of threonine-287 in the CaMKII regulatory domain “traps” CaMKII into an open configuration even after Ca2+/CaM unbinding. More recently, our group identified a pair of methionines (281/282) in the CaMKII regulatory domain that undergo a partially reversible oxidation which, like autophosphorylation, prevents CaMKII from inactivating after Ca2+/CaM unbinding. Here we review roles of CaMKII in cardiovascular disease with an eye to understanding how CaMKII may act as a transduction signal to connect pro-oxidant conditions into specific downstream pathological effects that are relevant to rare and common forms of cardiovascular disease.

Sign in / Sign up

Export Citation Format

Share Document