Anion and Cation Permeability of the Mouse TMEM16F Calcium-Activated Channel
TMEM16F is involved in several physiological processes, such as blood coagulation, bone development and virus infections. This protein acts both as a Ca<sup>2+</sup>-dependent phospholipid scramblase and a Ca<sup>2+</sup>-activated ion channel but several studies have reporte...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-08-01
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| Series: | International Journal of Molecular Sciences |
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| Online Access: | https://www.mdpi.com/1422-0067/22/16/8578 |
| _version_ | 1797523641942933504 |
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| author | Stefano Stabilini Anna Menini Simone Pifferi |
| author_facet | Stefano Stabilini Anna Menini Simone Pifferi |
| author_sort | Stefano Stabilini |
| collection | DOAJ |
| description | TMEM16F is involved in several physiological processes, such as blood coagulation, bone development and virus infections. This protein acts both as a Ca<sup>2+</sup>-dependent phospholipid scramblase and a Ca<sup>2+</sup>-activated ion channel but several studies have reported conflicting results about the ion selectivity of the TMEM16F-mediated current. Here, we have performed a detailed side-by-side comparison of the ion selectivity of TMEM16F using the whole-cell and inside-out excised patch configurations to directly compare the results. In inside-out configuration, Ca<sup>2+</sup>-dependent activation was fast and the TMEM16F-mediated current was activated in a few milliseconds, while in whole-cell recordings full activation required several minutes. We determined the relative permeability between Na<sup>+</sup> and Cl¯ (P<sub>Na</sub>/P<sub>Cl</sub>) using the dilution method in both configurations. The TMEM16F-mediated current was highly nonselective, but there were differences depending on the configuration of the recordings. In whole-cell recordings, P<sub>Na</sub>/P<sub>Cl</sub> was approximately 0.5, indicating a slight preference for Cl¯ permeation. In contrast, in inside-out experiments the TMEM16F channel showed a higher permeability for Na<sup>+</sup> with P<sub>Na</sub>/P<sub>Cl</sub> reaching 3.7. Our results demonstrate that the time dependence of Ca<sup>2+</sup> activation and the ion selectivity of TMEM16F depend on the recording configuration. |
| first_indexed | 2024-03-10T08:44:52Z |
| format | Article |
| id | doaj.art-7ca829c7a3d04915a6b09da7fbcacd84 |
| institution | Directory Open Access Journal |
| issn | 1661-6596 1422-0067 |
| language | English |
| last_indexed | 2024-03-10T08:44:52Z |
| publishDate | 2021-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | International Journal of Molecular Sciences |
| spelling | doaj.art-7ca829c7a3d04915a6b09da7fbcacd842023-11-22T07:57:16ZengMDPI AGInternational Journal of Molecular Sciences1661-65961422-00672021-08-012216857810.3390/ijms22168578Anion and Cation Permeability of the Mouse TMEM16F Calcium-Activated ChannelStefano Stabilini0Anna Menini1Simone Pifferi2Neurobiology Group, SISSA, International School for Advanced Studies, 34136 Trieste, ItalyNeurobiology Group, SISSA, International School for Advanced Studies, 34136 Trieste, ItalyNeurobiology Group, SISSA, International School for Advanced Studies, 34136 Trieste, ItalyTMEM16F is involved in several physiological processes, such as blood coagulation, bone development and virus infections. This protein acts both as a Ca<sup>2+</sup>-dependent phospholipid scramblase and a Ca<sup>2+</sup>-activated ion channel but several studies have reported conflicting results about the ion selectivity of the TMEM16F-mediated current. Here, we have performed a detailed side-by-side comparison of the ion selectivity of TMEM16F using the whole-cell and inside-out excised patch configurations to directly compare the results. In inside-out configuration, Ca<sup>2+</sup>-dependent activation was fast and the TMEM16F-mediated current was activated in a few milliseconds, while in whole-cell recordings full activation required several minutes. We determined the relative permeability between Na<sup>+</sup> and Cl¯ (P<sub>Na</sub>/P<sub>Cl</sub>) using the dilution method in both configurations. The TMEM16F-mediated current was highly nonselective, but there were differences depending on the configuration of the recordings. In whole-cell recordings, P<sub>Na</sub>/P<sub>Cl</sub> was approximately 0.5, indicating a slight preference for Cl¯ permeation. In contrast, in inside-out experiments the TMEM16F channel showed a higher permeability for Na<sup>+</sup> with P<sub>Na</sub>/P<sub>Cl</sub> reaching 3.7. Our results demonstrate that the time dependence of Ca<sup>2+</sup> activation and the ion selectivity of TMEM16F depend on the recording configuration.https://www.mdpi.com/1422-0067/22/16/8578ion channelelectrophysiologypermeability |
| spellingShingle | Stefano Stabilini Anna Menini Simone Pifferi Anion and Cation Permeability of the Mouse TMEM16F Calcium-Activated Channel International Journal of Molecular Sciences ion channel electrophysiology permeability |
| title | Anion and Cation Permeability of the Mouse TMEM16F Calcium-Activated Channel |
| title_full | Anion and Cation Permeability of the Mouse TMEM16F Calcium-Activated Channel |
| title_fullStr | Anion and Cation Permeability of the Mouse TMEM16F Calcium-Activated Channel |
| title_full_unstemmed | Anion and Cation Permeability of the Mouse TMEM16F Calcium-Activated Channel |
| title_short | Anion and Cation Permeability of the Mouse TMEM16F Calcium-Activated Channel |
| title_sort | anion and cation permeability of the mouse tmem16f calcium activated channel |
| topic | ion channel electrophysiology permeability |
| url | https://www.mdpi.com/1422-0067/22/16/8578 |
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