Regulation of the Ca-Channel by Phosphorylation-Dephosphorylation
Similar as other second messengers, Ca++ ions can trigger many intracellular enzymatic reactions (e.g. activation of the contractile filaments, 3, 4). One of the strategic points for regulation of the intracellular Ca concentration are Ca channels, transmembrane proteins, which have -under physiological conditions- a high selectivity for conducting Ca ions. Beside their voltage dependency, it was found that the Ca channels are also substrates for different enzymatic reactions (13, 14). Here we report that cAMP-dependent protein kinase (cAMP-PK) can increase the Ca current (ICa) amplitude by phosphorylation of a channel related protein. The phosphorylation is antagonized by several phosphatases.
KeywordsCatalytic Subunit Pipette Solution Protein Kinase Inhibitor Microscopic Picture Strategic Point
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