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dc.contributor.authorHeitz, B.A.
dc.contributor.authorBränström, R.
dc.contributor.authorYang, W.
dc.contributor.authorHuang, Y.
dc.contributor.authorMoede, T.
dc.contributor.authorLeibiger, I.B.
dc.contributor.authorLeibiger, B.
dc.contributor.authorChen, L.Q.
dc.contributor.authorYu, J.
dc.contributor.authorYang, S.-N.
dc.contributor.authorLarsson, O.
dc.contributor.authorSaavedra, S.S.
dc.contributor.authorBerggren, P.-O.
dc.contributor.authorAspinwall, C.A.
dc.date.accessioned2021-12-13T23:26:20Z
dc.date.available2021-12-13T23:26:20Z
dc.date.issued2021
dc.identifier.citationHeitz, B. A., Bränström, R., Yang, W., Huang, Y., Moede, T., Leibiger, I. B., Leibiger, B., Chen, L. Q., Yu, J., Yang, S.-N., Larsson, O., Saavedra, S. S., Berggren, P.-O., & Aspinwall, C. A. (2021). Expression of truncated Kir6.2 promotes insertion of functionally inverted ATP-sensitive K+ channels. Scientific Reports.
dc.identifier.issn2045-2322
dc.identifier.doi10.1038/s41598-021-00988-y
dc.identifier.urihttp://hdl.handle.net/10150/662545
dc.description.abstractATP-sensitive K+ (KATP) channels couple cellular metabolism to electrical activity in many cell types. Wild-type KATP channels are comprised of four pore forming (Kir6.x) and four regulatory (sulfonylurea receptor, SURx) subunits that each contain RKR endoplasmic reticulum retention sequences that serve to properly translocate the channel to the plasma membrane. Truncated Kir6.x variants lacking RKR sequences facilitate plasma membrane expression of functional Kir6.x in the absence of SURx; however, the effects of channel truncation on plasma membrane orientation have not been explored. To investigate the role of truncation on plasma membrane orientation of ATP sensitive K+ channels, three truncated variants of Kir6.2 were used (Kir6.2ΔC26, 6xHis-Kir6.2ΔC26, and 6xHis-EGFP-Kir6.2ΔC26). Oocyte expression of Kir6.2ΔC26 shows the presence of a population of inverted inserted channels in the plasma membrane, which is not present when co-expressed with SUR1. Immunocytochemical staining of intact and permeabilized HEK293 cells revealed that the N-terminus of 6xHis-Kir6.2ΔC26 was accessible on both sides of the plasma membrane at roughly equivalent ratios, whereas the N-terminus of 6xHis-EGFP-Kir6.2Δ26 was only accessible on the intracellular face. In HEK293 cells, whole-cell electrophysiological recordings showed a ca. 50% reduction in K+ current upon addition of ATP to the extracellular solution for 6xHis-Kir6.2ΔC26, though sensitivity to extracellular ATP was not observed in 6xHis-EGFP-Kir6.2ΔC26. Importantly, the population of channels that is inverted exhibited similar function to properly inserted channels within the plasma membrane. Taken together, these data suggest that in the absence of SURx, inverted channels can be formed from truncated Kir6.x subunits that are functionally active which may provide a new model for testing pharmacological modulators of Kir6.x, but also indicates the need for added caution when using truncated Kir6.2 mutants. © 2021, The Author(s).
dc.language.isoen
dc.publisherNature Research
dc.rightsCopyright © The Author(s) 2021. This article is licensed under a Creative Commons Attribution 4.0 International License.
dc.rights.urihttps://creativecommons.org/licenses/by/4.0/
dc.titleExpression of truncated Kir6.2 promotes insertion of functionally inverted ATP-sensitive K+ channels
dc.typeArticle
dc.typetext
dc.contributor.departmentDepartment of Chemistry and Biochemistry, University of Arizona
dc.contributor.departmentBIO5 Institute and Department of Biomedical Engineering, University of Arizona
dc.identifier.journalScientific Reports
dc.description.noteOpen access journal
dc.description.collectioninformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.
dc.eprint.versionFinal published version
dc.source.journaltitleScientific Reports
refterms.dateFOA2021-12-13T23:26:20Z


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Copyright © The Author(s) 2021. This article is licensed under a Creative Commons Attribution 4.0 International License.
Except where otherwise noted, this item's license is described as Copyright © The Author(s) 2021. This article is licensed under a Creative Commons Attribution 4.0 International License.