Non-conducting function of the Kv2.1 channel enables it to recruit vesicles for release in neuroendocrine and nerve cells
| Autor: | Rachel Nachman, Jens Rettig, Uri Ashery, Ilana Lotan, Dodo Chikvashvili, Reut Friedrich, Lori Feinshreiber, Anton Sheinin, Ofer Yizhar, Dafna Singer-Lahat, Ulf Matti |
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| Rok vydání: | 2010 |
| Předmět: |
Neurons
Qa-SNARE Proteins Chromaffin Cells Secretory Vesicles Vesicle Kinetics Mutant Munc-18 Stimulation Cell Biology Biology Exocytosis Rats Cell biology Electrophysiology Shab Potassium Channels Animals Newborn Ganglia Spinal Facilitation Animals Syntaxin Calcium Signaling Rats Wistar Cells Cultured |
| Zdroj: | Journal of Cell Science. 123:1940-1947 |
| ISSN: | 1477-9137 0021-9533 |
| Popis: | Regulation of exocytosis by voltage-gated K+ channels has classically been viewed as inhibition mediated by K+ fluxes. We recently identified a new role for Kv2.1 in facilitating vesicle release from neuroendocrine cells, which is independent of K+ flux. Here, we show that Kv2.1-induced facilitation of release is not restricted to neuroendocrine cells, but also occurs in the somatic-vesicle release from dorsal-root-ganglion neurons and is mediated by direct association of Kv2.1 with syntaxin. We further show in adrenal chromaffin cells that facilitation induced by both wild-type and non-conducting mutant Kv2.1 channels in response to long stimulation persists during successive stimulation, and can be attributed to an increased number of exocytotic events and not to changes in single-spike kinetics. Moreover, rigorous analysis of the pools of released vesicles reveals that Kv2.1 enhances the rate of vesicle recruitment during stimulation with high Ca2+, without affecting the size of the readily releasable vesicle pool. These findings place a voltage-gated K+ channel among the syntaxin-binding proteins that directly regulate pre-fusion steps in exocytosis. |
| Databáze: | OpenAIRE |
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