Unnatural amino acid photo-crosslinking of the IKs channel complex demonstrates a KCNE1:KCNQ1 stoichiometry of up to 4:4
Cardiac repolarization is determined in part by the slow delayed rectifier current (IKs), through the tetrameric voltage-gated ion channel, KCNQ1, and its β-subunit, KCNE1. The stoichiometry between α and β-subunits has been controversial with studies reporting either a strict 2 KCNE1:4 KCNQ1 or a v...
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| Format: | Article |
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eLife Sciences Publications Ltd
2016-01-01
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| Series: | eLife |
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| Online Access: | https://elifesciences.org/articles/11815 |
| _version_ | 1811180479661998080 |
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| author | Christopher I Murray Maartje Westhoff Jodene Eldstrom Emely Thompson Robert Emes David Fedida |
| author_facet | Christopher I Murray Maartje Westhoff Jodene Eldstrom Emely Thompson Robert Emes David Fedida |
| author_sort | Christopher I Murray |
| collection | DOAJ |
| description | Cardiac repolarization is determined in part by the slow delayed rectifier current (IKs), through the tetrameric voltage-gated ion channel, KCNQ1, and its β-subunit, KCNE1. The stoichiometry between α and β-subunits has been controversial with studies reporting either a strict 2 KCNE1:4 KCNQ1 or a variable ratio up to 4:4. We used IKs fusion proteins linking KCNE1 to one (EQ), two (EQQ) or four (EQQQQ) KCNQ1 subunits, to reproduce compulsory 4:4, 2:4 or 1:4 stoichiometries. Whole cell and single-channel recordings showed EQQ and EQQQQ to have increasingly hyperpolarized activation, reduced conductance, and shorter first latency of opening compared to EQ - all abolished by the addition of KCNE1. As well, using a UV-crosslinking unnatural amino acid in KCNE1, we found EQQQQ and EQQ crosslinking rates to be progressively slowed compared to KCNQ1, which demonstrates that no intrinsic mechanism limits the association of up to four β-subunits within the IKs complex. |
| first_indexed | 2024-04-11T09:03:48Z |
| format | Article |
| id | doaj.art-73646664f827455fb2c3f58e746d0331 |
| institution | Directory Open Access Journal |
| issn | 2050-084X |
| language | English |
| last_indexed | 2024-04-11T09:03:48Z |
| publishDate | 2016-01-01 |
| publisher | eLife Sciences Publications Ltd |
| record_format | Article |
| series | eLife |
| spelling | doaj.art-73646664f827455fb2c3f58e746d03312022-12-22T04:32:42ZengeLife Sciences Publications LtdeLife2050-084X2016-01-01510.7554/eLife.11815Unnatural amino acid photo-crosslinking of the IKs channel complex demonstrates a KCNE1:KCNQ1 stoichiometry of up to 4:4Christopher I Murray0Maartje Westhoff1Jodene Eldstrom2Emely Thompson3Robert Emes4David Fedida5Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, CanadaDepartment of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, CanadaDepartment of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, CanadaDepartment of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, CanadaDepartment of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, CanadaDepartment of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, CanadaCardiac repolarization is determined in part by the slow delayed rectifier current (IKs), through the tetrameric voltage-gated ion channel, KCNQ1, and its β-subunit, KCNE1. The stoichiometry between α and β-subunits has been controversial with studies reporting either a strict 2 KCNE1:4 KCNQ1 or a variable ratio up to 4:4. We used IKs fusion proteins linking KCNE1 to one (EQ), two (EQQ) or four (EQQQQ) KCNQ1 subunits, to reproduce compulsory 4:4, 2:4 or 1:4 stoichiometries. Whole cell and single-channel recordings showed EQQ and EQQQQ to have increasingly hyperpolarized activation, reduced conductance, and shorter first latency of opening compared to EQ - all abolished by the addition of KCNE1. As well, using a UV-crosslinking unnatural amino acid in KCNE1, we found EQQQQ and EQQ crosslinking rates to be progressively slowed compared to KCNQ1, which demonstrates that no intrinsic mechanism limits the association of up to four β-subunits within the IKs complex.https://elifesciences.org/articles/11815unnatrual amino acidKCNQ1KCNE1stoichiometrysingle channelphoto-crosslinking |
| spellingShingle | Christopher I Murray Maartje Westhoff Jodene Eldstrom Emely Thompson Robert Emes David Fedida Unnatural amino acid photo-crosslinking of the IKs channel complex demonstrates a KCNE1:KCNQ1 stoichiometry of up to 4:4 eLife unnatrual amino acid KCNQ1 KCNE1 stoichiometry single channel photo-crosslinking |
| title | Unnatural amino acid photo-crosslinking of the IKs channel complex demonstrates a KCNE1:KCNQ1 stoichiometry of up to 4:4 |
| title_full | Unnatural amino acid photo-crosslinking of the IKs channel complex demonstrates a KCNE1:KCNQ1 stoichiometry of up to 4:4 |
| title_fullStr | Unnatural amino acid photo-crosslinking of the IKs channel complex demonstrates a KCNE1:KCNQ1 stoichiometry of up to 4:4 |
| title_full_unstemmed | Unnatural amino acid photo-crosslinking of the IKs channel complex demonstrates a KCNE1:KCNQ1 stoichiometry of up to 4:4 |
| title_short | Unnatural amino acid photo-crosslinking of the IKs channel complex demonstrates a KCNE1:KCNQ1 stoichiometry of up to 4:4 |
| title_sort | unnatural amino acid photo crosslinking of the iks channel complex demonstrates a kcne1 kcnq1 stoichiometry of up to 4 4 |
| topic | unnatrual amino acid KCNQ1 KCNE1 stoichiometry single channel photo-crosslinking |
| url | https://elifesciences.org/articles/11815 |
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