Functional reconstitution of a voltage-gated potassium channel in giant unilamellar vesicles

Sophie Aimon, John Manzi, Daniel Schmidt, Jose Antonio Poveda Larrosa, Patricia Bassereau, Gilman E S Toombes

Research output: Contribution to journalArticle

70 Scopus citations

Abstract

Voltage-gated ion channels are key players in cellular excitability. Recent studies suggest that their behavior can depend strongly on the membrane lipid composition and physical state. In vivo studies of membrane/channel and channel/channel interactions are challenging as membrane properties are actively regulated in living cells, and are difficult to control in experimental settings. We developed a method to reconstitute functional voltage-gated ion channels into cell-sized Giant Unilamellar Vesicles (GUVs) in which membrane composition, tension and geometry can be controlled. First, a voltage-gated potassium channel, KvAP, was purified, fluorescently labeled and reconstituted into small proteoliposomes. Small proteoliposomes were then converted into GUVs via electroformation. GUVs could be formed using different lipid compositions and buffers containing low (5 mM) or near-physiological (100 mM) salt concentrations. Protein incorporation into GUVs was characterized with quantitative confocal microscopy, and the protein density of GUVs was comparable to the small proteoliposomes from which they were formed. Furthermore, patch-clamp measurements confirmed that the reconstituted channels retained potassium selectivity and voltage-gated activation. GUVs containing functional voltage-gated ion channels will allow the study of channel activity, distribution and diffusion while controlling membrane state, and should prove a powerful tool for understanding how the membrane modulates cellular excitability.

Original languageEnglish (US)
Article numbere25529
JournalPloS one
Volume6
Issue number10
DOIs
StatePublished - Oct 6 2011

Fingerprint Dive into the research topics of 'Functional reconstitution of a voltage-gated potassium channel in giant unilamellar vesicles'. Together they form a unique fingerprint.

  • Cite this

    Aimon, S., Manzi, J., Schmidt, D., Larrosa, J. A. P., Bassereau, P., & Toombes, G. E. S. (2011). Functional reconstitution of a voltage-gated potassium channel in giant unilamellar vesicles. PloS one, 6(10), [e25529]. https://doi.org/10.1371/journal.pone.0025529