MISC

2004年6月25日

Extracellular proton sensing of the rat gustatory cyclic nucleotide-gated channel

Biochemical and Biophysical Research Communications
  • Makoto Sugita
  • ,
  • Hiroe Ohishi
  • ,
  • Yoshiko Iwasa
  • ,
  • Chikara Hirono
  • ,
  • Yoshiki Shiba

319
2
開始ページ
369
終了ページ
374
記述言語
英語
掲載種別
DOI
10.1016/j.bbrc.2004.05.009

Elevations of the intracellular levels of cyclic nucleotides appear to cause the cation influx through gustatory cyclic nucleotide-gated (CNGgust) channels expressed in taste cells. Although changes in the oral pH may directly regulate the activity of the CNGgust channel, the mechanism of pH-dependent control of the channel is not understood. In the present study, we combined the whole-cell patch-clamp recording and the site-directed mutagenesis to investigate the effect of extracellular pH on the ion permeation through CNGgust channels expressed in HEK293 cells. Extracellular acidification strongly inhibited ion permeation through open CNGgust channels. Mutation of Glu 289 remarkably attenuated the pH-dependence of the channel, suggesting that Glu289 in the pore-forming region is a major proton acceptor site. However, the mutant E289A-CNGgust channel possesses the other residual protonation/deprotonation site. The channel activity, tightly regulated by pHo and [cNMP]i, suggests the involvement of its pHo-dependent ion permeation in taste signal transduction events. © 2004 Elsevier Inc. All rights reserved.

リンク情報
DOI
https://doi.org/10.1016/j.bbrc.2004.05.009
CiNii Articles
http://ci.nii.ac.jp/naid/80016760117
PubMed
https://www.ncbi.nlm.nih.gov/pubmed/15178415

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