Cholesterol-induced suppression of Kir2 channels is mediated by decoupling at the inter-subunit interfaces
Summary: Cholesterol is a major regulator of multiple types of ion channels. Although there is increasing information about cholesterol binding sites, the molecular mechanisms through which cholesterol binding alters channel function are virtually unknown. In this study, we used a combination of Mar...
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| Format: | Article |
| Language: | English |
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Elsevier
2022-05-01
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| Series: | iScience |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2589004222006009 |
| _version_ | 1828822532784914432 |
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| author | Nicolas Barbera Sara T. Granados Carlos Guillermo Vanoye Tatiana V. Abramova Danielle Kulbak Sang Joon Ahn Alfred L. George, Jr. Belinda S. Akpa Irena Levitan |
| author_facet | Nicolas Barbera Sara T. Granados Carlos Guillermo Vanoye Tatiana V. Abramova Danielle Kulbak Sang Joon Ahn Alfred L. George, Jr. Belinda S. Akpa Irena Levitan |
| author_sort | Nicolas Barbera |
| collection | DOAJ |
| description | Summary: Cholesterol is a major regulator of multiple types of ion channels. Although there is increasing information about cholesterol binding sites, the molecular mechanisms through which cholesterol binding alters channel function are virtually unknown. In this study, we used a combination of Martini coarse-grained simulations, a network theory-based analysis, and electrophysiology to determine the effect of cholesterol on the dynamic structure of the Kir2.2 channel. We found that increasing membrane cholesterol reduced the likelihood of contact between specific regions of the cytoplasmic and transmembrane domains of the channel, most prominently at the subunit-subunit interfaces of the cytosolic domains. This decrease in contact was mediated by pairwise interactions of specific residues and correlated to the stoichiometry of cholesterol binding events. The predictions of the model were tested by site-directed mutagenesis of two identified residues—V265 and H222—and high throughput electrophysiology. |
| first_indexed | 2024-12-12T13:15:30Z |
| format | Article |
| id | doaj.art-418e7545d4254d19b60eb0bc326bea15 |
| institution | Directory Open Access Journal |
| issn | 2589-0042 |
| language | English |
| last_indexed | 2024-12-12T13:15:30Z |
| publishDate | 2022-05-01 |
| publisher | Elsevier |
| record_format | Article |
| series | iScience |
| spelling | doaj.art-418e7545d4254d19b60eb0bc326bea152022-12-22T00:23:25ZengElsevieriScience2589-00422022-05-01255104329Cholesterol-induced suppression of Kir2 channels is mediated by decoupling at the inter-subunit interfacesNicolas Barbera0Sara T. Granados1Carlos Guillermo Vanoye2Tatiana V. Abramova3Danielle Kulbak4Sang Joon Ahn5Alfred L. George, Jr.6Belinda S. Akpa7Irena Levitan8Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60611, USA; Corresponding authorDivision of Pulmonary and Critical Care Medicine, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60611, USADepartment of Pharmacology; Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USADepartment of Pharmacology; Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USADivision of Pulmonary and Critical Care Medicine, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60611, USADivision of Pulmonary and Critical Care Medicine, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60611, USADepartment of Pharmacology; Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USADivision of Biosciences, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA; Department of Chemical & Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996, USA; Molecular Biomedical Sciences, North Carolina State University, Raleigh, NC 27695, USA; Corresponding authorDivision of Pulmonary and Critical Care Medicine, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60611, USA; Corresponding authorSummary: Cholesterol is a major regulator of multiple types of ion channels. Although there is increasing information about cholesterol binding sites, the molecular mechanisms through which cholesterol binding alters channel function are virtually unknown. In this study, we used a combination of Martini coarse-grained simulations, a network theory-based analysis, and electrophysiology to determine the effect of cholesterol on the dynamic structure of the Kir2.2 channel. We found that increasing membrane cholesterol reduced the likelihood of contact between specific regions of the cytoplasmic and transmembrane domains of the channel, most prominently at the subunit-subunit interfaces of the cytosolic domains. This decrease in contact was mediated by pairwise interactions of specific residues and correlated to the stoichiometry of cholesterol binding events. The predictions of the model were tested by site-directed mutagenesis of two identified residues—V265 and H222—and high throughput electrophysiology.http://www.sciencedirect.com/science/article/pii/S2589004222006009Cellular physiologyMolecular biologyBiophysics |
| spellingShingle | Nicolas Barbera Sara T. Granados Carlos Guillermo Vanoye Tatiana V. Abramova Danielle Kulbak Sang Joon Ahn Alfred L. George, Jr. Belinda S. Akpa Irena Levitan Cholesterol-induced suppression of Kir2 channels is mediated by decoupling at the inter-subunit interfaces iScience Cellular physiology Molecular biology Biophysics |
| title | Cholesterol-induced suppression of Kir2 channels is mediated by decoupling at the inter-subunit interfaces |
| title_full | Cholesterol-induced suppression of Kir2 channels is mediated by decoupling at the inter-subunit interfaces |
| title_fullStr | Cholesterol-induced suppression of Kir2 channels is mediated by decoupling at the inter-subunit interfaces |
| title_full_unstemmed | Cholesterol-induced suppression of Kir2 channels is mediated by decoupling at the inter-subunit interfaces |
| title_short | Cholesterol-induced suppression of Kir2 channels is mediated by decoupling at the inter-subunit interfaces |
| title_sort | cholesterol induced suppression of kir2 channels is mediated by decoupling at the inter subunit interfaces |
| topic | Cellular physiology Molecular biology Biophysics |
| url | http://www.sciencedirect.com/science/article/pii/S2589004222006009 |
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