Phosphorylase Kinase from Bovine Stomach Smooth Muscle: A Ca2+-Dependent Protein Kinase Associated with an Actin-Like Molecule

1990 ◽  
pp. 321-329
Author(s):  
V. G. Zevgolis ◽  
T. G. Sotiroudis ◽  
A. E. Evangelopoulos
Keyword(s):  
Smooth Muscle ◽  
Protein Kinase ◽  
Phosphorylase Kinase ◽  
Dependent Protein Kinase ◽  
Dependent Protein

PKC activates BKCa channels in rat pulmonary arterial smooth muscle via cGMP-dependent protein kinase

2004 ◽  
Vol 286 (6) ◽  
pp. L1275-L1281 ◽  
Author(s):  
Scott A. Barman ◽  
Shu Zhu ◽  
Richard E. White
Keyword(s):  
Smooth Muscle ◽  
Protein Kinase ◽  
Channel Activity ◽  
Sprague Dawley ◽  
Dependent Protein Kinase ◽  
Pulmonary Vasoconstriction ◽  
Sprague Dawley Rat ◽  
Dependent Protein ◽  
Pulmonary Arterial ◽  
Pulmonary Arterial Smooth Muscle

Normally, signaling mechanisms that activate large-conductance, calcium- and voltage-activated potassium (BKCa) channels in pulmonary vascular smooth muscle cause pulmonary vasodilatation. BKCa-channel modulation is important in the regulation of pulmonary arterial pressure, and inhibition (decrease in the opening probability) of the BKCa channel has been implicated in the development of pulmonary vasoconstriction. Protein kinase C (PKC) causes pulmonary vasoconstriction, but little is known about the effect of PKC on BKCa-channel activity in pulmonary vascular smooth muscle. Accordingly, studies were done to determine the effect of PKC on BKCa-channel activity using patch-clamp studies in pulmonary arterial smooth muscle cells (PASMCs) of the Sprague-Dawley rat. The PKC activators phorbol myristate acetate (PMA) and thymeleatoxin opened BKCa channels in single Sprague-Dawley rat PASMC. The activator response to both PMA and thymeleatoxin on BKCa-channel activity was blocked by Gö-6983, which selectively blocks PKC-α, -δ, -γ, and -ζ, and by rottlerin, which selectively inhibits PKC-δ. In addition, the specific cyclic GMP-dependent protein kinase antagonist KT-5823 blocked the responses to PMA and thymelatoxin, whereas the specific cyclic AMP-dependent protein kinase blocker KT-5720 had no effect. In isolated pulmonary arterial vessels, both PMA and forskolin caused vasodilatation, which was inhibited by KT-5823, Gö-6983, or the BKCa-channel blocker tetraethylammonium. The results of this study indicate that activation of specific PKC isozymes increases BKCa-channel activity in Sprague-Dawley rat PASMC via cyclic GMP-dependent protein kinase, which suggests a unique signaling mechanism for vasodilatation.

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