An endogenous membrane-bound protein inhibits the phosphorylation of the L-type calcium channel by the cAMP-dependent protein kinase.
An endogenous protein inhibits the PKA-phosphorylation of the DHP-binding calcium channel complex in vitro. The inhibitory activity could be reduced by a treatment with detergents or dithiothreitol. Further purification separates the inhibitory activity from the dihydropyridine-binding calcium channel complex. Both activities are localized in the plasma membrane indicating that this protein kinase-inhibitor could interfere with the phosphorylation of the calcium channel by the cAMP-dependent protein kinase. The inhibitory activity may therefore take part in the regulation of the calcium channel current.
Woscholski
R
R
Institute of Molecular Cell Biology, University of Freiburg, Germany.
Marmé
D
D
D000818:Animals; D015220:Calcium Channels / Q000378:metabolism*; D002458:Cell Fractionation; D002501:Centrifugation, Zonal; D004095:Dihydropyridines / Q000378:metabolism; D007425:Intracellular Membranes / Q000378:metabolism / Q000648:ultrastructure; D008562:Membrane Glycoproteins / Q000302:isolation & purification / Q000378:metabolism*; D008861:Microsomes / Q000378:metabolism*; D009132:Muscles / Q000378:metabolism*; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*
D015220:Calcium Channels; D004095:Dihydropyridines; D008562:Membrane Glycoproteins; D011494:Protein Kinases