[Participation of calmodulin in the regulation of plasma membrane electric potential by intracellular calcium].
The effect of Ca2+ on the electric potential and permeability of human erythrocyte membranes for K+ was investigated. An increase of K+ concentration in a medium containing a Ca-ionophore A 23187 causes hyperpolarization of the erythrocyte membrane (by 50-60 mV) due to a 70-fold increase of its permeability for K+ (K0.5 for Ca2+ in both cases is equal to 2-3 microM). Using calmodulin-deficient inside-out erythrocyte membrane vesicles, it was demonstrated that regulation of the transmembrane potentials by Ca2+ is mediated by its interaction with calmodulin (K0.5 for Ca2+ and calmodulin is equal to 2-3 microM and 100-150 nM, respectively). It was assumed that the Ca2+-calmodulin complex is involved in the functioning of the plasma membrane K+-channel.
D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000097:blood* / Q000494:pharmacology; D002147:Calmodulin / Q000494:pharmacology*; D002463:Cell Membrane Permeability / Q000187:drug effects*; D004910:Erythrocyte Membrane / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D007700:Kinetics; D008564:Membrane Potentials / Q000187:drug effects; D011188:Potassium / Q000494:pharmacology
D002147:Calmodulin; D000001:Calcimycin; D011188:Potassium; D002118:Calcium
Uchastie kal'modulina v reguliatsii élektricheskogo potentsiala plazmaticheskoĭ membrany vnutrikletochnym kal'tsiem.