Specific sorting and post-Golgi trafficking of dendritic potassium channels in living neurons.
Proper membrane localization of ion channels is essential for the function of neuronal cells. Particularly, the computational ability of dendrites depends on the localization of different ion channels in specific subcompartments. However, the molecular mechanisms that control ion channel localization in distinct dendritic subcompartments are largely unknown. Here, we developed a quantitative live cell imaging method to analyze protein sorting and post-Golgi vesicular trafficking. We focused on two dendritic voltage-gated potassium channels that exhibit distinct localizations: Kv2.1 in proximal dendrites and Kv4.2 in distal dendrites. Our results show that Kv2.1 and Kv4.2 channels are sorted into two distinct populations of vesicles at the Golgi apparatus. The targeting of Kv2.1 and Kv4.2 vesicles occurred by distinct mechanisms as evidenced by their requirement for specific peptide motifs, cytoskeletal elements, and motor proteins. By live cell and super-resolution imaging, we identified a novel trafficking machinery important for the localization of Kv2.1 channels. Particularly, we identified non-muscle myosin II as an important factor in Kv2.1 trafficking. These findings reveal that the sorting of ion channels at the Golgi apparatus and their subsequent trafficking by unique molecular mechanisms are crucial for their specific localizations within dendrites.
['Jensen|Camilla Stampe|CS|', 'Watanabe|Shoji|S|', 'Rasmussen|Hanne Borger|HB|', 'Schmitt|Nicole|N|', 'Olesen|Søren-Peter|SP|', 'Frost|Nicholas A|NA|', 'Blanpied|Thomas A|TA|', 'Misonou|Hiroaki|H|']
D020816:Amino Acid Motifs D000818:Animals D003599:Cytoskeleton D003712:Dendrites D006056:Golgi Apparatus D049452:Green Fluorescent Proteins D057809:HEK293 Cells D006624:Hippocampus D006801:Humans D009218:Myosins D009474:Neurons D021381:Protein Transport D051381:Rats D017208:Rats, Wistar D051669:Shab Potassium Channels D051672:Shal Potassium Channels D015398:Signal Transduction D013696:Temperature
Ion Channels Protein Sorting Golgi Myosin Actin Intracellular Trafficking