Tracking the movement of discrete gating charges in a voltage-gated potassium channel
Positively charged amino acids respond to membrane potential changes to drive voltage sensor movement in voltage-gated ion channels, but determining the displacements of voltage sensor gating charges has proven difficult. We optically tracked the movement of the two most extracellular charged residu...
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eLife Sciences Publications Ltd
2021
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oai:doaj.org-article:653d41c01d7942449409f97e536ef6d32021-12-01T13:54:34ZTracking the movement of discrete gating charges in a voltage-gated potassium channel10.7554/eLife.581482050-084Xe58148https://doaj.org/article/653d41c01d7942449409f97e536ef6d32021-11-01T00:00:00Zhttps://elifesciences.org/articles/58148https://doaj.org/toc/2050-084XPositively charged amino acids respond to membrane potential changes to drive voltage sensor movement in voltage-gated ion channels, but determining the displacements of voltage sensor gating charges has proven difficult. We optically tracked the movement of the two most extracellular charged residues (R1 and R2) in the Shaker potassium channel voltage sensor using a fluorescent positively charged bimane derivative (qBBr) that is strongly quenched by tryptophan. By individually mutating residues to tryptophan within the putative pathway of gating charges, we observed that the charge motion during activation is a rotation and a tilted translation that differs between R1 and R2. Tryptophan-induced quenching of qBBr also indicates that a crucial residue of the hydrophobic plug is linked to the Cole–Moore shift through its interaction with R1. Finally, we show that this approach extends to additional voltage-sensing membrane proteins using the Ciona intestinalis voltage-sensitive phosphatase (CiVSP).Michael F PriestElizabeth EL LeeFrancisco BezanillaeLife Sciences Publications Ltdarticlevoltage sensorshakerfluorescence quenchingbimanesensor pathMedicineRScienceQBiology (General)QH301-705.5ENeLife, Vol 10 (2021) |
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voltage sensor shaker fluorescence quenching bimane sensor path Medicine R Science Q Biology (General) QH301-705.5 |
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voltage sensor shaker fluorescence quenching bimane sensor path Medicine R Science Q Biology (General) QH301-705.5 Michael F Priest Elizabeth EL Lee Francisco Bezanilla Tracking the movement of discrete gating charges in a voltage-gated potassium channel |
description |
Positively charged amino acids respond to membrane potential changes to drive voltage sensor movement in voltage-gated ion channels, but determining the displacements of voltage sensor gating charges has proven difficult. We optically tracked the movement of the two most extracellular charged residues (R1 and R2) in the Shaker potassium channel voltage sensor using a fluorescent positively charged bimane derivative (qBBr) that is strongly quenched by tryptophan. By individually mutating residues to tryptophan within the putative pathway of gating charges, we observed that the charge motion during activation is a rotation and a tilted translation that differs between R1 and R2. Tryptophan-induced quenching of qBBr also indicates that a crucial residue of the hydrophobic plug is linked to the Cole–Moore shift through its interaction with R1. Finally, we show that this approach extends to additional voltage-sensing membrane proteins using the Ciona intestinalis voltage-sensitive phosphatase (CiVSP). |
format |
article |
author |
Michael F Priest Elizabeth EL Lee Francisco Bezanilla |
author_facet |
Michael F Priest Elizabeth EL Lee Francisco Bezanilla |
author_sort |
Michael F Priest |
title |
Tracking the movement of discrete gating charges in a voltage-gated potassium channel |
title_short |
Tracking the movement of discrete gating charges in a voltage-gated potassium channel |
title_full |
Tracking the movement of discrete gating charges in a voltage-gated potassium channel |
title_fullStr |
Tracking the movement of discrete gating charges in a voltage-gated potassium channel |
title_full_unstemmed |
Tracking the movement of discrete gating charges in a voltage-gated potassium channel |
title_sort |
tracking the movement of discrete gating charges in a voltage-gated potassium channel |
publisher |
eLife Sciences Publications Ltd |
publishDate |
2021 |
url |
https://doaj.org/article/653d41c01d7942449409f97e536ef6d3 |
work_keys_str_mv |
AT michaelfpriest trackingthemovementofdiscretegatingchargesinavoltagegatedpotassiumchannel AT elizabethellee trackingthemovementofdiscretegatingchargesinavoltagegatedpotassiumchannel AT franciscobezanilla trackingthemovementofdiscretegatingchargesinavoltagegatedpotassiumchannel |
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