Charles S. Park

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Charybdotoxin (CTX) blocks high conductance Ca(2+)-activated K+ channels by binding to a receptor site in the externally facing "mouth." Toxin bound to the channel can be destabilized from its site by K+ entering the channel from the opposite, internal, solution. By analyzing point mutants of CTX expressed in E. coli, assayed with single Ca(2+)-activated K+(More)
Small conductance Ca2+-activated K+ channels (SK(Ca) channels) are a group of K+-selective ion channels activated by submicromolar concentrations of intracellular Ca2+ independent of membrane voltages. We expressed a cloned SK(Ca) channel, rSK2, in Xenopus oocytes and investigated the effects of intracellular divalent cations on the current-voltage (I-V)(More)
Developmental axon branching dramatically increases synaptic capacity and neuronal surface area. Netrin-1 promotes branching and synaptogenesis, but the mechanism by which Netrin-1 stimulates plasma membrane expansion is unknown. We demonstrate that SNARE-mediated exocytosis is a prerequisite for axon branching and identify the E3 ubiquitin ligase TRIM9 as(More)
Extracellular protons in the range of 10(-9) to 10(-5) M effectively suppressed Na+ current (K(1/2) = 10(-6.1)) through the bovine retinal guanosine 3',5'-cyclic mononucleotide-gated ion channel expressed in Xenopus oocytes. The reduction of channel current was mediated by a single glutamate residue (Glu363) within the pore-forming region of the channel,(More)
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