M current mystery messenger revealed?
The identity of signaling elements that couple muscarinic acetylcholine receptor (mAChR) activation to M current (KCNQ K(+) channels) modulation has remained unknown despite decades of study. Suh and Hille (in this issue of Neuron) demonstrate that activation of phospholipase C (PLC) initiates M current modulation and that recovery requires ATP and phosphoinositide 4-kinase (PI 4-K). These data suggest that breakdown of phosphotidylinositol 4,5-bisphosphate (PIP(2)) is a crucial determinant of M channel modulation.
Ikeda
Stephen R
SR
Laboratory of Molecular Physiology, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, USA.
Kammermeier
Paul J
PJ
D019870:1-Phosphatidylinositol 4-Kinase / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D006801:Humans; D051656:KCNQ Potassium Channels; D051657:KCNQ1 Potassium Channel; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000378:metabolism*; D015221:Potassium Channels / Q000378:metabolism*; D024642:Potassium Channels, Voltage-Gated; D011976:Receptors, Muscarinic / Q000378:metabolism*; D013569:Synapses / Q000378:metabolism*; D009435:Synaptic Transmission / Q000502:physiology*; D010738:Type C Phospholipases / Q000378:metabolism*
D051656:KCNQ Potassium Channels; D051657:KCNQ1 Potassium Channel; C496909:KCNQ1 protein, human; D019269:Phosphatidylinositol 4,5-Diphosphate; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated; D011976:Receptors, Muscarinic; D000255:Adenosine Triphosphate; D019870:1-Phosphatidylinositol 4-Kinase; D010738:Type C Phospholipases