Protein kinase A phosphorylation enhances sodium channel currents in Xenopus oocytes

1992 ◽  
Vol 263 (3) ◽  
pp. C660-C666 ◽  
Author(s):  
R. D. Smith ◽  
A. L. Goldin
Keyword(s):  
Protein Kinase ◽  
Sodium Channel ◽  
Protein Kinase A ◽  
Rat Brain ◽  
Xenopus Oocytes ◽  
Kinase Inhibitor ◽  
Sodium Current ◽  
Specific Inhibitor ◽  
Channel Currents ◽  
Kinase A

The voltage-sensitive rat brain sodium channel is known to be phosphorylated by adenosine 3',5'-cyclic monophosphate (cAMP)-dependent protein kinase A (PKA), but the functional significance of that phosphorylation is unknown. We have shown that rat brain sodium channel currents expressed in Xenopus oocytes were enhanced by induction of PKA activity. Stimulation of the beta 2-adrenergic receptor or treatment with dibutyryl cAMP resulted in increased sodium current amplitudes without affecting the voltage dependence of channel activation or inactivation. These increases were completely blocked by preinjection of protein kinase inhibitor, a specific inhibitor of PKA. Injection of phosphatase into the oocytes resulted in a significant decrease in sodium current amplitude, indicating that phosphorylation is important for basal levels of sodium channel activity in oocytes. The enhancement was specific for the rat brain IIA sodium channel, because currents expressed from the rat muscle microI sodium channel were not enhanced by the same procedures. These data demonstrate a modulatory role of PKA phosphorylation on brain sodium channel function and suggest a means by which the electrical excitability of cells may be regulated.

Modulation by protein kinase A of a cloned rat brain potassium channel expressed in Xenopus oocytes

1994 ◽  
Vol 428 (2) ◽  
pp. 186-193 ◽  
Author(s):  
G. G. Wilson ◽  
C. A. O'Neill ◽  
A. Sivaprasadarao ◽  
J. B. C. Findlay ◽  
D. Wray
Keyword(s):  
Protein Kinase ◽  
Potassium Channel ◽  
Protein Kinase A ◽  
Rat Brain ◽  
Xenopus Oocytes ◽  
Kinase A

Involvement of protein kinase A and casein kinase II in the in vivo protein kinase activities in prophase arrested Xenopus oocytes

1989 ◽  
Vol 9 (3) ◽  
pp. 351-358 ◽  
Author(s):  
Patrick cormier ◽  
Odile Mulner-Lorillon ◽  
René Ozon ◽  
Robert Bellé
Keyword(s):  
Cell Division ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Xenopus Oocytes ◽  
Kinase Inhibitor ◽  
Casein Kinase Ii ◽  
Casein Kinase ◽  
Meiotic Cell ◽  
Kinase A

In vivo β casein phosphorylation was analysed in Xenopus full-grown oocytes arrested in the prophase of the meiotic cell division. The phosphorylation was inhibited by the protein kinase inhibitor (PKI) and also by heparin (3 μg/ml; final concentration). β casein phosphorylation was increased by spermine (2 mM). Therefore, protein kinase A and casein kinase II are both active in vivo in full-grown oocytes and may be involved in the prophase arrest of meiotic cell division.

scholarly journals Activation of Protein Kinase A Modulates Trafficking of the Human Cardiac Sodium Channel in Xenopus Oocytes

2000 ◽  
Vol 87 (1) ◽  
pp. 33-38 ◽  
Author(s):  
Jingsong Zhou ◽  
Jianxun Yi ◽  
NingNing Hu ◽  
Alfred L. George ◽  
Katherine T. Murray
Keyword(s):  
Protein Kinase ◽  
Sodium Channel ◽  
Protein Kinase A ◽  
Xenopus Oocytes ◽  
Cardiac Sodium Channel ◽  
Kinase A

In vivo andin vitro ethanol exposure in prenatal rat brain: GABAB receptor modulation on dopamine D1 receptor and protein kinase A

Synapse ◽  
2008 ◽  
Vol 62 (7) ◽  
pp. 534-543 ◽  
Author(s):  
H.Y. Lee ◽  
N. Naha ◽  
S.P. Li ◽  
M.J. Jo ◽  
M.L. Naseer ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Rat Brain ◽  
Gabab Receptor ◽  
Ethanol Exposure ◽  
Dopamine D1 Receptor ◽  
D1 Receptor ◽  
Receptor Modulation ◽  
Kinase A

scholarly journals A Stapled Peptide Mimic of the Pseudosubstrate Inhibitor PKI Inhibits Protein Kinase A

Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1567 ◽  
Author(s):  
Jascha T. Manschwetus ◽  
George N. Bendzunas ◽  
Ameya J. Limaye ◽  
Matthias J. Knape ◽  
Friedrich W. Herberg ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Kinase Inhibitor ◽  
Stapled Peptide ◽  
Peptide Mimic ◽  
Cellular Environment ◽  
Ic50 Values ◽  
Dependent Protein ◽  
Peptide Targeting ◽  
Kinase A

Kinases regulate multiple and diverse signaling pathways and misregulation is implicated in a multitude of diseases. Although significant efforts have been put forth to develop kinase-specific inhibitors, specificity remains a challenge. As an alternative to catalytic inhibition, allosteric inhibitors can target areas on the surface of an enzyme, thereby providing additional target diversity. Using cAMP-dependent protein kinase A (PKA) as a model system, we sought to develop a hydrocarbon-stapled peptide targeting the pseudosubstrate domain of the kinase. A library of peptides was designed from a Protein Kinase Inhibitor (PKI), a naturally encoded protein that serves as a pseudosubstrate inhibitor for PKA. The binding properties of these peptide analogs were characterized by fluorescence polarization and surface plasmon resonance, and two compounds were identified with KD values in the 500–600 pM range. In kinase activity assays, both compounds demonstrated inhibition with 25–35 nM IC50 values. They were also found to permeate cells and localize within the cytoplasm and inhibited PKA activity within the cellular environment. To the best of our knowledge, these stapled peptide inhibitors represent some of the highest affinity binders reported to date for hydrocarbon stapled peptides.

scholarly journals Protein kinase A reduces voltage-dependent Na+ current in Xenopus oocytes

1992 ◽  
Vol 12 (10) ◽  
pp. 3743-3752 ◽  
Author(s):  
E Gershon ◽  
L Weigl ◽  
I Lotan ◽  
W Schreibmayer ◽  
N Dascal
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Xenopus Oocytes ◽  
Na Current ◽  
Voltage Dependent ◽  
Kinase A
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