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

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.

1988 ◽  
Vol 8 (11) ◽  
pp. 4685-4691
Author(s):  
J K Mayo ◽  
K E Sampson ◽  
L D Adams ◽  
E R Crumm ◽  
S L Kelly ◽  
...  

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.


Proteomes ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 37
Author(s):  
Anna Schmoker ◽  
Samuel Barritt ◽  
Marion Weir ◽  
Jacqueline Mann ◽  
Tyler Hogan ◽  
...  

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.


1999 ◽  
Vol 274 (5) ◽  
pp. 2631-2636 ◽  
Author(s):  
Michael A. Silverman ◽  
Outhiriaradjou Benard ◽  
Hanna Jaaro ◽  
Amir Rattner ◽  
Yoav Citri ◽  
...  

1988 ◽  
Vol 8 (11) ◽  
pp. 4685-4691 ◽  
Author(s):  
J K Mayo ◽  
K E Sampson ◽  
L D Adams ◽  
E R Crumm ◽  
S L Kelly ◽  
...  

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.


1997 ◽  
Vol 321 (2) ◽  
pp. 333-339 ◽  
Author(s):  
Scott PLUSKEY ◽  
Mohammad MAHROOF-TAHIR ◽  
Debbie C. CRANS ◽  
David S. LAWRENCE

Vanadium oxoions have been shown to elicit a wide range of effects in biological systems, including an increase in the quantity of phosphorylated proteins. This response has been attributed to the inhibition of protein phosphatases, the indirect activation of protein kinases via stimulation of enzymes at early steps in signal transduction pathways and/or the direct activation of protein kinases. We have evaluated the latter possibility by exploring the effects of vanadate, decavanadate and vanadyl cation species on the activity of the cAMP-dependent protein kinase (PKA), a serine/threonine kinase. Vanadate, in the form of monomer, dimer, tetramer and pentamer species, neither inhibits nor activates PKA. In marked contrast, decavanadate is a competitive inhibitor (Ki = 1.8ŷ0.1 mM) of kemptide (Leu-Arg-Arg-Ala-Ser-Leu-Gly), a peptide-based substrate. This inhibition pattern is especially surprising, since the negatively charged decavanadate would not be predicted to bind to the region of the active site of the enzyme that accommodates the positively charged kemptide substrate. Our studies suggest that decavanadate can associate with kemptide in solution, which would prevent kemptide from interacting with the enzyme. Vanadium(IV) also inhibits the PKA-catalysed phosphorylation of kemptide, but with an IC50 of 366ŷ10 ƁM. However, in this case V4+ appears to bind to the Mg2+-binding site, since it can substitute for Mg2+. In the absence of Mg2+, the optimal concentration of vanadium(IV) for the PKA-catalysed phosphorylation of kemptide is 100 ƁM, with concentrations above 100 ƁM being markedly inhibitory. However, even at the optimal 100 ƁM V4+ concentration, the Vmax and Km values (for kemptide) are significantly less favourable than those obtained in the presence of 100 ƁM Mg2+. In summary, we have found that oxovanadium ions can directly alter the activity of the serine/threonine-specific PKA.


Science ◽  
1991 ◽  
Vol 252 (5008) ◽  
pp. 951-954 ◽  
Author(s):  
J. Harper ◽  
M. Sussman ◽  
G. Schaller ◽  
C Putnam-Evans ◽  
H Charbonneau ◽  
...  

1989 ◽  
Vol 264 (9) ◽  
pp. 4800-4804 ◽  
Author(s):  
R J Colbran ◽  
M K Smith ◽  
C M Schworer ◽  
Y L Fong ◽  
T R Soderling

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