Updating In Vivo and In Vitro Phosphorylation and Methylation Sites of Voltage‐Gated Kv7.2 Potassium Channels |
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| Authors: | Fatma Asli Erdem Isabella Salzer Wei‐Qiang Chen Gangsoo Jung Gert Lubec Stefan Boehm Jae‐Won Yang |
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| Affiliation: | 1. Institute of Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria;2. Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria;3. Department of Pediatrics, Medical University of Vienna, Vienna, Austria;4. Neuroproteomics, Paracelsus Medical University of Salzburg, Salzburg, Austria |
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| Abstract: | Voltage‐gated Kv7.2 potassium channels regulate neuronal excitability. The gating of these channels is tightly controlled by various mediators and neurotransmitters acting via G protein‐coupled receptors; the underlying signaling cascades involve phosphatidylinositol‐4,5‐bisphosphate (PIP2), Ca2+/calmodulin, and phosphorylation. Recent studies found that the PIP2 sensitivity of Kv7.2 channels is affected by two posttranslational modifications, phosphorylation and methylation, harboured within putative PIP2‐binding domains. In this study, we updated phosphorylation and methylation sites in Kv7.2 either heterologously expressed in mammalian cells or as GST‐fusion proteins exposed to recombinant protein kinases by using LC–MS/MS. In vitro kinase assays revealed that CDK5, protein kinase C (PKC) alpha, PKA, p38 MAPK, CamKIIα, and GSK3β could mediate phosphorylation. Taken together, we provided a comprehensive map of phosphorylation and methylation in Kv7.2 within protein–protein and protein–lipid interaction domains. This may help to interpret the functional roles of individual PTM sites in Kv7.2 channels. All MS data are available via ProteomeXchange with the identifier PXD005567. |
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| Keywords: | Kv7.2 methylation phosphorylation posttranslational modification |
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