| Content Provider |
World Health Organization (WHO)-Global Index Medicus |
| Author |
Chang, Rui B. Nelson, Mark T. Wilson, Courtney E. Kinnamon, Sue C. Cooper, Alexander J. Mulhall, Eric M. Hill-eubanks, David C. Chick, Wallace S. Liman, Emily R. Ye, Wenlei Tu, Yu-hsiang Bushman, Jeremy D. |
| Description |
Author Affiliation: Ye W ( Section of Neurobiology, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089); Chang RB ( Section of Neurobiology, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089); Bushman JD ( Section of Neurobiology, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089); Tu YH ( Section of Neurobiology, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089); Mulhall EM ( Section of Neurobiology, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089); Wilson CE ( Department of Otolaryngology, University of Colorado Medical School, Aurora, CO 80045); Cooper AJ ( Section of Neurobiology, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089); Chick WS ( Department of Cell and Developmental Biology, University of Colorado Medical School, Aurora, CO 80045); Hill-Eubanks DC ( Department of Pharmacology, University of Vermont, Burlington, VT 05405); Nelson MT ( Department of Pharmacology, University of Vermont, Burlington, VT 05405); Kinnamon SC ( Department of Otolaryngology, University of Colorado Medical School, Aurora, CO 80045); Liman ER ( Section of Neurobiology, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089); |
| Abstract |
Sour taste is detected by a subset of taste cells on the tongue and palate epithelium that respond to acids with trains of action potentials. Entry of protons through a $Zn^{2+}-sensitive$ proton conductance that is specific to sour taste cells has been shown to be the initial event in sour taste transduction. Whether this conductance acts in concert with other channels sensitive to changes in intracellular pH, however, is not known. Here, we show that intracellular acidification generates excitatory responses in sour taste cells, which can be attributed to block of a resting $K^{+}$ current. We identify $K_{IR}2.1$ as the acid-sensitive $K^{+}$ channel in sour taste cells using pharmacological and RNA expression profiling and confirm its contribution to sour taste with tissue-specific knockout of the Kcnj2 gene. Surprisingly, acid sensitivity is not conferred on sour taste cells by the specific expression of $K_{ir}2.1,$ but by the relatively small magnitude of the current, which makes the cells exquisitely sensitive to changes in intracellular pH. Consistent with a role of the $K^{+}$ current in amplifying the sensory response, entry of protons through the $Zn^{2+}-sensitive$ conductance produces a transient block of the $K_{IR}2.1$ current. The identification in sour taste cells of an acid-sensitive $K^{+}$ channel suggests a mechanism for amplification of sour taste and may explain why weak acids that produce intracellular acidification, such as acetic acid, taste more sour than strong acids. |
| ISSN |
00278424 |
| e-ISSN |
10916490 |
| Journal |
Proceedings of the National Academy of Sciences of the United States of America |
| Issue Number |
2 |
| Volume Number |
113 |
| Language |
English |
| Publisher |
National Academy of Sciences |
| Publisher Date |
2016-01-01 |
| Publisher Place |
United States |
| Access Restriction |
Open |
| Subject Keyword |
Potassium Channels, Inwardly Rectifying Metabolism Protons Signal Transduction Taste Physiology Acids Pharmacology Action Potentials Drug Effects Animals Calcium Channels HEK293 Cells Hydrogen-Ion Concentration Integrases Intracellular Space Ion Channel Gating Mice, Knockout Models, Biological Organ Specificity Receptors, Cell Surface TRPM Cation Channels Taste Buds Cytology Zinc Research Support, N.I.H., Extramural Research Support, Non-U.S. Gov't Multidisciplinary |
| Content Type |
Text |
| Resource Type |
Article |
| Subject |
Multidisciplinary |
