Vesicular ATPase Inserted into the Plasma Membrane of Motor Terminals by Exocytosis Alkalinizes Cytosolic pH and Facilitates Endocytosis
| Autor: | Zhongsheng Zhang, Gavriel David, Ellen F. Barrett, Khanh T. Nguyen |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
ATPase
Neuroscience(all) Presynaptic Terminals Action Potentials Mice Transgenic Biology Endocytosis Synaptic vesicle Article Exocytosis Cell membrane Mice chemistry.chemical_compound Cytosol medicine Animals General Neuroscience Vesicle Cell Membrane Bafilomycin Hydrogen-Ion Concentration Cell biology Proton-Translocating ATPases medicine.anatomical_structure chemistry biology.protein Synaptic Vesicles |
| Zdroj: | Neuron. 68(6):1097-1108 |
| ISSN: | 0896-6273 |
| DOI: | 10.1016/j.neuron.2010.11.035 |
| Popis: | Key components of vesicular neurotransmitter release, such as Ca(2+) influx and membrane recycling, are affected by cytosolic pH. We measured the pH-sensitive fluorescence of Yellow Fluorescent Protein transgenically expressed in mouse motor nerve terminals, and report that Ca(2+) influx elicited by action potential trains (12.5-100 Hz) evokes a biphasic pH change: a brief acidification (∼ 13 nM average peak increase in [H(+)]), followed by a prolonged alkalinization (∼ 30 nM peak decrease in [H(+)]) that outlasts the stimulation train. The alkalinization is selectively eliminated by blocking vesicular exocytosis with botulinum neurotoxins, and is prolonged by the endocytosis-inhibitor dynasore. Blocking H(+) pumping by vesicular H(+)-ATPase (with folimycin or bafilomycin) suppresses stimulation-induced alkalinization and reduces endocytotic uptake of FM1-43. These results suggest that H(+)-ATPase, known to transfer cytosolic H(+) into prefused vesicles, continues to extrude cytosolic H(+) after being exocytotically incorporated into the plasma membrane. The resulting cytosolic alkalinization may facilitate vesicular endocytosis. |
| Databáze: | OpenAIRE |
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