title: Specific sorting and post-Golgi trafficking of dendritic potassium channels in living neurons.
abstract: 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.
authors.affiliation: Department of Biomedical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark; Department of Neural and Pain Sciences, University of Maryland, Baltimore, Maryland 21201.
authors.forename: Camilla Stampe
authors.initials: CS
authors.lastname: Jensen
authors.affiliation: Unit for Brain Pathology, Graduate School of Brain Science, Doshisha University, Kyoto 619-02225, Japan.
authors.forename: Shoji
authors.initials: S
authors.lastname: Watanabe
authors.affiliation: Department of Biomedical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark.
authors.forename: Hanne Borger
authors.initials: HB
authors.lastname: Rasmussen
authors.affiliation: Department of Biomedical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark.
authors.forename: Nicole
authors.initials: N
authors.lastname: Schmitt
authors.affiliation: Department of Biomedical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark.
authors.forename: Søren-Peter
authors.initials: SP
authors.lastname: Olesen
authors.affiliation: Department of Physiology, University of Maryland, Baltimore, Maryland 21201.
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Frost
authors.affiliation: Department of Physiology, University of Maryland, Baltimore, Maryland 21201.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Blanpied
authors.affiliation: Department of Neural and Pain Sciences, University of Maryland, Baltimore, Maryland 21201; Unit for Brain Pathology, Graduate School of Brain Science, Doshisha University, Kyoto 619-02225, Japan. Electronic address: h_misonou@mac.com.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Misonou
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D003599:Cytoskeleton / Q000378:metabolism; D003712:Dendrites / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D057809:HEK293 Cells; D006624:Hippocampus / Q000378:metabolism; D006801:Humans; D009218:Myosins / Q000378:metabolism; D009474:Neurons / Q000378:metabolism*; D021381:Protein Transport; D051381:Rats; D017208:Rats, Wistar; D051669:Shab Potassium Channels / Q000378:metabolism*; D051672:Shal Potassium Channels / Q000378:metabolism; D015398:Signal Transduction; D013696:Temperature
chemical_list: C496991:Kcnb1 protein, rat; D051669:Shab Potassium Channels; D051672:Shal Potassium Channels; D049452:Green Fluorescent Proteins; D009218:Myosins
keywords: Actin; Golgi; Intracellular Trafficking; Ion Channels; Myosin; Protein Sorting