Identification of a trafficking determinant localized to the Kv1 potassium channel pore.
The repertoire of Kv1 potassium channels expressed in presynaptic terminals of mammalian central neurons is shaped by intrinsic trafficking signals that determine surface-expression efficiencies of homomeric and heteromeric Kv1 channel complexes. Here, we show that a determinant controlling surface expression of Kv1 channels is localized to the highly conserved pore region. Point-mutation analysis revealed two residues as critical for channel trafficking, one in the extracellular "turret" domain and one in the region distal to the selectivity filter. Interestingly, these same residues also form the binding sites for polypeptide neurotoxins. Our findings demonstrate a previously uncharacterized function for the channel-pore domain as a regulator of channel trafficking.
Manganas
L N
LN
Department of Biochemistry and Cell Biology, State University of New York, Stony Brook, NY 11794, USA.
Wang
Q
Q
Scannevin
R H
RH
Antonucci
D E
DE
Rhodes
K J
KJ
Trimmer
J S
JS
D000595:Amino Acid Sequence; D000818:Animals; D001692:Biological Transport; D019556:COS Cells; D002460:Cell Line; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism; D006624:Hippocampus / Q000166:cytology; D051662:Kv1.1 Potassium Channel; D051665:Kv1.4 Potassium Channel; D008969:Molecular Sequence Data; D015221:Potassium Channels / Q000235:genetics / Q000378:metabolism*; D024642:Potassium Channels, Voltage-Gated; D051381:Rats
C496979:Kcna4 protein, rat; D051665:Kv1.4 Potassium Channel; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D051662:Kv1.1 Potassium Channel