Structural changes in the cytoplasmic pore of the Kir1.1 channel during pH<sub>i</sub>-gating probed by FRET
<p>Abstract</p> <p>Kir1.1 channels are important in maintaining K<sup>+ </sup>homeostasis in the kidney. Intracellular acidification reversibly closes the Kir1.1 channel and thus decreases K<sup>+ </sup>secretion. In this study, we used Foster resonance ener...
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| Format: | Article |
| Language: | English |
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BMC
2009-03-01
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| Series: | Journal of Biomedical Science |
| Online Access: | http://www.jbiomedsci.com/content/16/1/29 |
| _version_ | 1811311906275721216 |
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| author | Shieh Ru-Chi Lee Jay-Ron |
| author_facet | Shieh Ru-Chi Lee Jay-Ron |
| author_sort | Shieh Ru-Chi |
| collection | DOAJ |
| description | <p>Abstract</p> <p>Kir1.1 channels are important in maintaining K<sup>+ </sup>homeostasis in the kidney. Intracellular acidification reversibly closes the Kir1.1 channel and thus decreases K<sup>+ </sup>secretion. In this study, we used Foster resonance energy transfer (FRET) to determine whether the conformation of the cytoplasmic pore changes in response to intracellular pH (pH<sub>i</sub>)-gating in Kir1.1 channels fused with enhanced cyan fluorescent protein (ECFP) and enhanced yellow fluorescent protein (EYFP) (ECFP-Kir1.1-EYFP). Because the fluorescence intensities of ECFP and EYFP were affected at pH<sub>i </sub>< 7.4 where pH<sub>i</sub>-gating occurs in the ECFP-Kir1.1-EYFP construct, we examined the FRET efficiencies of an ECFP-S219R-EYFP mutant, which is completed closed at pH<sub>i </sub>7.4 and open at pH<sub>i </sub>10.0. FRET efficiency was increased from 25% to 40% when the pH<sub>i </sub>was decreased from 10.0 to 7.4. These results suggest that the conformation of the cytoplasmic pore in the Kir1.1 channel changes in response to pH<sub>i </sub>gating such that the N- and C-termini move apart from each other at pH<sub>i </sub>7.4, when the channel is open.</p> |
| first_indexed | 2024-04-13T10:27:03Z |
| format | Article |
| id | doaj.art-3bd5a2f5d3bd4586820c8884aeceafbe |
| institution | Directory Open Access Journal |
| issn | 1021-7770 1423-0127 |
| language | English |
| last_indexed | 2024-04-13T10:27:03Z |
| publishDate | 2009-03-01 |
| publisher | BMC |
| record_format | Article |
| series | Journal of Biomedical Science |
| spelling | doaj.art-3bd5a2f5d3bd4586820c8884aeceafbe2022-12-22T02:50:16ZengBMCJournal of Biomedical Science1021-77701423-01272009-03-011612910.1186/1423-0127-16-29Structural changes in the cytoplasmic pore of the Kir1.1 channel during pH<sub>i</sub>-gating probed by FRETShieh Ru-ChiLee Jay-Ron<p>Abstract</p> <p>Kir1.1 channels are important in maintaining K<sup>+ </sup>homeostasis in the kidney. Intracellular acidification reversibly closes the Kir1.1 channel and thus decreases K<sup>+ </sup>secretion. In this study, we used Foster resonance energy transfer (FRET) to determine whether the conformation of the cytoplasmic pore changes in response to intracellular pH (pH<sub>i</sub>)-gating in Kir1.1 channels fused with enhanced cyan fluorescent protein (ECFP) and enhanced yellow fluorescent protein (EYFP) (ECFP-Kir1.1-EYFP). Because the fluorescence intensities of ECFP and EYFP were affected at pH<sub>i </sub>< 7.4 where pH<sub>i</sub>-gating occurs in the ECFP-Kir1.1-EYFP construct, we examined the FRET efficiencies of an ECFP-S219R-EYFP mutant, which is completed closed at pH<sub>i </sub>7.4 and open at pH<sub>i </sub>10.0. FRET efficiency was increased from 25% to 40% when the pH<sub>i </sub>was decreased from 10.0 to 7.4. These results suggest that the conformation of the cytoplasmic pore in the Kir1.1 channel changes in response to pH<sub>i </sub>gating such that the N- and C-termini move apart from each other at pH<sub>i </sub>7.4, when the channel is open.</p>http://www.jbiomedsci.com/content/16/1/29 |
| spellingShingle | Shieh Ru-Chi Lee Jay-Ron Structural changes in the cytoplasmic pore of the Kir1.1 channel during pH<sub>i</sub>-gating probed by FRET Journal of Biomedical Science |
| title | Structural changes in the cytoplasmic pore of the Kir1.1 channel during pH<sub>i</sub>-gating probed by FRET |
| title_full | Structural changes in the cytoplasmic pore of the Kir1.1 channel during pH<sub>i</sub>-gating probed by FRET |
| title_fullStr | Structural changes in the cytoplasmic pore of the Kir1.1 channel during pH<sub>i</sub>-gating probed by FRET |
| title_full_unstemmed | Structural changes in the cytoplasmic pore of the Kir1.1 channel during pH<sub>i</sub>-gating probed by FRET |
| title_short | Structural changes in the cytoplasmic pore of the Kir1.1 channel during pH<sub>i</sub>-gating probed by FRET |
| title_sort | structural changes in the cytoplasmic pore of the kir1 1 channel during ph sub i sub gating probed by fret |
| url | http://www.jbiomedsci.com/content/16/1/29 |
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