Selectivity of the Ca2+-activated and light-dependent K+ channels for monovalent cations.
The ionic selectivity of the Ca(2+)-activated K(+) channel of Aplysia neurons and of the light-dependent K(+) channel of Pecten photoreceptors to metal and organic cations was studied. The selectivity sequence determined from reversal potential measurements is T1(+) K(+) > Rb(+) > NH(+) (4) > Cs(+) > Na(+), Li(+) and is identical to the sequence determined previously for voltage-dependent K(+) channels in a variety of tissues. Our results suggest that some physical aspect of the K(+) channel is conserved in phyllogenetically different tissues and cells.
D000818:Animals; D001048:Aplysia; D002118:Calcium / Q000494:pharmacology*; D002414:Cations, Monovalent / Q000494:pharmacology*; D004558:Electric Stimulation; D007473:Ion Channels / Q000502:physiology*; D008974:Mollusca; D009474:Neurons / Q000502:physiology; D010775:Photic Stimulation; D010786:Photoreceptor Cells / Q000502:physiology; D011188:Potassium / Q000378:metabolism*
D002414:Cations, Monovalent; D007473:Ion Channels; D011188:Potassium; D002118:Calcium