Ion channel regulation by calmodulin binding.
While many ion channels are modulated by phosphorylation, there is growing evidence that they can also be regulated by Ca(2+)-calmodulin, apparently through direct binding. In some cases, this binding activates channels; in others, it modulates channel activities. These phenomena have been documented in Paramecium, in Drosophila, in vertebrate photoreceptors and olfactory receptors, as well as in ryanodine receptor Ca(2+)-release channels. Furthermore, studies on calmodulin mutants in Paramecium have shown a clear bipartite distribution of two groups of mutations in the calmodulin gene that lead to opposite behavioral and electrophysiological phenotypes. These results indicate that the N-lobe of calmodulin specifically interacts with one class of ion-channel proteins and the C-lobe with another.
Saimi
Y
Y
Laboratory of Molecular Biology, University of Wisconsin, Madison.
Kung
C
C
D000595:Amino Acid Sequence; D000818:Animals; D015220:Calcium Channels / Q000502:physiology; D002147:Calmodulin / Q000502:physiology*; D004331:Drosophila melanogaster / Q000502:physiology; D015640:Ion Channel Gating; D008969:Molecular Sequence Data; D009124:Muscle Proteins / Q000502:physiology; D009132:Muscles / Q000502:physiology; D010247:Paramecium / Q000502:physiology; D015221:Potassium Channels / Q000502:physiology; D019837:Ryanodine Receptor Calcium Release Channel; D011984:Sensory Receptor Cells / Q000502:physiology; D012903:Smell / Q000502:physiology; D015222:Sodium Channels / Q000502:physiology
D015220:Calcium Channels; D002147:Calmodulin; D009124:Muscle Proteins; D015221:Potassium Channels; D019837:Ryanodine Receptor Calcium Release Channel; D015222:Sodium Channels