Induction of stable ER–plasma-membrane junctions by Kv2.1 potassium channels
| Autor: | Philip D. Fox, Peter J. Seel, Elizabeth J. Akin, Christopher J. Haberkorn, Michael M. Tamkun, Diego Krapf |
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| Rok vydání: | 2015 |
| Předmět: |
Glutamic Acid
Biology Endoplasmic Reticulum Hippocampus Cell Line Membrane Potentials Cell membrane Shab Potassium Channels medicine Humans Ion channel Neurons Membrane potential Cortical endoplasmic reticulum Endoplasmic reticulum Cell Membrane HEK 293 cells Membrane Proteins Cell Biology Cell biology Transport protein Protein Transport HEK293 Cells medicine.anatomical_structure Membrane protein Calcium Signal Transduction Research Article |
| Zdroj: | Journal of Cell Science. 128:2096-2105 |
| ISSN: | 1477-9137 0021-9533 |
| DOI: | 10.1242/jcs.166009 |
| Popis: | Junctions between cortical endoplasmic reticulum (cER) and the plasma membrane are a subtle but ubiquitous feature in mammalian cells; however, very little is known about the functions and molecular interactions that are associated with neuronal ER–plasma-membrane junctions. Here, we report that Kv2.1 (also known as KCNB1), the primary delayed-rectifier K+ channel in the mammalian brain, induces the formation of ER–plasma-membrane junctions. Kv2.1 localizes to dense, cell-surface clusters that contain non-conducting channels, indicating that they have a function that is unrelated to membrane-potential regulation. Accordingly, Kv2.1 clusters function as membrane-trafficking hubs, providing platforms for delivery and retrieval of multiple membrane proteins. Using both total internal reflection fluorescence and electron microscopy we demonstrate that the clustered Kv2.1 plays a direct structural role in the induction of stable ER–plasma-membrane junctions in both transfected HEK 293 cells and cultured hippocampal neurons. Glutamate exposure results in a loss of Kv2.1 clusters in neurons and subsequent retraction of the cER from the plasma membrane. We propose Kv2.1-induced ER–plasma-membrane junctions represent a new macromolecular plasma-membrane complex that is sensitive to excitotoxic insult and functions as a scaffolding site for both membrane trafficking and Ca2+ signaling. |
| Databáze: | OpenAIRE |
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