{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,1]],"date-time":"2025-12-01T15:05:44Z","timestamp":1764601544831},"reference-count":50,"publisher":"Rockefeller University Press","issue":"6","content-domain":{"domain":["rupress.org"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[2005,12,1]]},"abstract":"<jats:p>Among all voltage-gated K+ channels from the model plant Arabidopsis thaliana, the weakly rectifying K+ channel (Kweak channel) AKT2 displays unique gating properties. AKT2 is exceptionally regulated by phosphorylation: when nonphosphorylated AKT2 behaves as an inward-rectifying potassium channel; phosphorylation of AKT2 abolishes inward rectification by shifting its activation threshold far positive (&amp;gt;200 mV) so that it closes only at voltages positive of +100 mV. In its phosphorylated form, AKT2 is thus locked in the open state in the entire physiological voltage range. To understand the molecular grounds of this unique gating behavior, we generated chimeras between AKT2 and the conventional inward-rectifying channel KAT1. The transfer of the pore from KAT1 to AKT2 altered the permeation properties of the channel. However, the gating properties were unaffected, suggesting that the pore region of AKT2 is not responsible for the unique Kweak gating. Instead, a lysine residue in S4, highly conserved among all Kweak channels but absent from other plant K+ channels, was pinpointed in a site-directed mutagenesis approach. Substitution of the lysine by serine or aspartate abolished the \u201copen-lock\u201d characteristic and converted AKT2 into an inward-rectifying channel. Interestingly, phosphoregulation of the mutant AKT2-K197S appeared to be similar to that of the Kin channel KAT1: as suggested by mimicking the phosphorylated and dephosphorylated states, phosphorylation induced a shift of the activation threshold of AKT2-K197S by about +50 mV. We conclude that the lysine residue K197 sensitizes AKT2 to phosphoregulation. The phosphorylation-induced reduction of the activation energy in AKT2 is \u223c6 kT larger than in the K197S mutant. It is discussed that this hypersensitive response of AKT2 to phosphorylation equips a cell with the versatility to establish a potassium gradient and to make efficient use of it.<\/jats:p>","DOI":"10.1085\/jgp.200509413","type":"journal-article","created":{"date-parts":[[2005,11,29]],"date-time":"2005-11-29T01:44:03Z","timestamp":1133228643000},"page":"605-617","update-policy":"http:\/\/dx.doi.org\/10.1085\/jgp.crossmarkpolicy","source":"Crossref","is-referenced-by-count":54,"title":["A Unique Voltage Sensor Sensitizes the Potassium Channel AKT2 to Phosphoregulation"],"prefix":"10.1085","volume":"126","author":[{"given":"Erwan","family":"Michard","sequence":"first","affiliation":[{"name":"1Universita\u0308t Potsdam, Institut fu\u0308r Biochemie und Biologie, Abteilung Molekularbiologie, D-14476 Potsdam-Golm, Germany"},{"name":"2Max-Planck Institute of Molecular Plant Physiology, Cooperate Research Group, D-14424 Potsdam-Golm, Germany"},{"name":"3Laboratoire de Biochimie et Physiologie Mole\u0301culaire des Plantes, UMR 5004, Agro-M\/CNRS\/INRA\/UM2, F-34000 Montpellier, France"}]},{"given":"Benoi\u0302t","family":"Lacombe","sequence":"additional","affiliation":[{"name":"3Laboratoire de Biochimie et Physiologie Mole\u0301culaire des Plantes, UMR 5004, Agro-M\/CNRS\/INRA\/UM2, F-34000 Montpellier, France"}]},{"given":"Fabien","family":"Pore\u0301e","sequence":"additional","affiliation":[{"name":"1Universita\u0308t Potsdam, Institut fu\u0308r Biochemie und Biologie, Abteilung Molekularbiologie, D-14476 Potsdam-Golm, Germany"},{"name":"2Max-Planck Institute of Molecular Plant Physiology, Cooperate Research Group, D-14424 Potsdam-Golm, Germany"}]},{"given":"Bernd","family":"Mueller-Roeber","sequence":"additional","affiliation":[{"name":"1Universita\u0308t Potsdam, Institut fu\u0308r Biochemie und Biologie, Abteilung Molekularbiologie, D-14476 Potsdam-Golm, Germany"},{"name":"2Max-Planck Institute of Molecular Plant Physiology, Cooperate Research Group, D-14424 Potsdam-Golm, Germany"}]},{"given":"Herve\u0301","family":"Sentenac","sequence":"additional","affiliation":[{"name":"3Laboratoire de Biochimie et Physiologie Mole\u0301culaire des Plantes, UMR 5004, Agro-M\/CNRS\/INRA\/UM2, F-34000 Montpellier, France"}]},{"given":"Jean-Baptiste","family":"Thibaud","sequence":"additional","affiliation":[{"name":"3Laboratoire de Biochimie et Physiologie Mole\u0301culaire des Plantes, UMR 5004, Agro-M\/CNRS\/INRA\/UM2, F-34000 Montpellier, France"}]},{"given":"Ingo","family":"Dreyer","sequence":"additional","affiliation":[{"name":"1Universita\u0308t Potsdam, Institut fu\u0308r Biochemie und Biologie, Abteilung Molekularbiologie, D-14476 Potsdam-Golm, Germany"},{"name":"2Max-Planck Institute of Molecular Plant Physiology, Cooperate Research Group, D-14424 Potsdam-Golm, Germany"},{"name":"3Laboratoire de Biochimie et Physiologie Mole\u0301culaire des Plantes, UMR 5004, Agro-M\/CNRS\/INRA\/UM2, F-34000 Montpellier, France"}]}],"member":"291","published-online":{"date-parts":[[2005,11,28]]},"reference":[{"key":"2023072618185004300_BIB1","doi-asserted-by":"crossref","first-page":"571","DOI":"10.1046\/j.1365-313X.2001.t01-1-01116.x","volume":"27","year":"2001","journal-title":"Plant J."},{"key":"2023072618185004300_BIB2"},{"key":"2023072618185004300_BIB3","doi-asserted-by":"crossref","first-page":"139","DOI":"10.1046\/j.1365-313X.2000.00844.x","volume":"24","year":"2000","journal-title":"Plant J."},{"key":"2023072618185004300_BIB4","doi-asserted-by":"crossref","first-page":"8123","DOI":"10.1073\/pnas.93.15.8123","volume":"93","year":"1996","journal-title":"Proc. Natl. Acad. Sci. USA."},{"key":"2023072618185004300_BIB5","doi-asserted-by":"crossref","first-page":"785","DOI":"10.1093\/pcp\/41.6.785","volume":"41","year":"2000","journal-title":"Plant Cell Physiol."},{"key":"2023072618185004300_BIB6","doi-asserted-by":"crossref","first-page":"555","DOI":"10.1152\/physrev.2000.80.2.555","volume":"80","year":"2000","journal-title":"Physiol. Rev."},{"key":"2023072618185004300_BIB7","doi-asserted-by":"crossref","first-page":"211","DOI":"10.1016\/S0065-3233(03)63009-3","volume":"63","year":"2003","journal-title":"Adv. Protein Chem."},{"key":"2023072618185004300_BIB8"},{"key":"2023072618185004300_BIB9","doi-asserted-by":"crossref","first-page":"17697","DOI":"10.1074\/jbc.270.30.17697","volume":"270","year":"1995","journal-title":"J. Biol. Chem."},{"key":"2023072618185004300_BIB10","doi-asserted-by":"crossref","first-page":"1093","DOI":"10.1104\/pp.109.3.1093","volume":"109","year":"1995","journal-title":"Plant Physiol."},{"key":"2023072618185004300_BIB11","doi-asserted-by":"crossref","first-page":"11277","DOI":"10.1073\/pnas.201250598","volume":"98","year":"2001","journal-title":"Proc. Natl. Acad. Sci. USA."},{"key":"2023072618185004300_BIB12","doi-asserted-by":"crossref","first-page":"1133","DOI":"10.1105\/tpc.000943","volume":"14","year":"2002","journal-title":"Plant Cell."},{"key":"2023072618185004300_BIB13","doi-asserted-by":"crossref","first-page":"13859","DOI":"10.1074\/jbc.M313704200","volume":"279","year":"2004","journal-title":"J. Biol. Chem."},{"key":"2023072618185004300_BIB14","doi-asserted-by":"crossref","first-page":"334","DOI":"10.1007\/s00425-002-0895-1","volume":"216","year":"2002","journal-title":"Planta."},{"key":"2023072618185004300_BIB15","doi-asserted-by":"crossref","first-page":"121","DOI":"10.1007\/s004390100505","volume":"109","year":"2001","journal-title":"Hum. Genet."},{"key":"2023072618185004300_BIB16","doi-asserted-by":"crossref","first-page":"2143","DOI":"10.1016\/S0006-3495(97)78857-X","volume":"72","year":"1997","journal-title":"Biophys. J."},{"key":"2023072618185004300_BIB17","doi-asserted-by":"crossref","first-page":"370","DOI":"10.1016\/S0014-5793(98)00694-2","volume":"430","year":"1998","journal-title":"FEBS Lett."},{"key":"2023072618185004300_BIB18","first-page":"1073","volume":"50","year":"1999","journal-title":"J. Exp. Bot."},{"key":"2023072618185004300_BIB19","doi-asserted-by":"crossref","first-page":"233","DOI":"10.1016\/S0014-5793(01)02832-0","volume":"505","year":"2001","journal-title":"FEBS Lett."},{"key":"2023072618185004300_BIB20"},{"key":"2023072618185004300_BIB21","doi-asserted-by":"crossref","first-page":"1859","DOI":"10.1105\/tpc.003244","volume":"14","year":"2002","journal-title":"Plant Cell."},{"key":"2023072618185004300_BIB22","first-page":"107","volume":"24","year":"1995","journal-title":"Eur. Biophys. J."},{"key":"2023072618185004300_BIB23","doi-asserted-by":"crossref","first-page":"309","DOI":"10.1085\/jgp.105.3.309","volume":"105","year":"1995","journal-title":"J. Gen. Physiol."},{"key":"2023072618185004300_BIB24","doi-asserted-by":"crossref","first-page":"4806","DOI":"10.1073\/pnas.94.9.4806","volume":"94","year":"1997","journal-title":"Proc. Natl. Acad. Sci. USA."},{"key":"2023072618185004300_BIB25","first-page":"943","volume":"13","year":"2001","journal-title":"Plant Cell."},{"key":"2023072618185004300_BIB26","doi-asserted-by":"crossref","first-page":"483","DOI":"10.1085\/jgp.200409211","volume":"125","year":"2005","journal-title":"J. Gen. Physiol."},{"key":"2023072618185004300_BIB27","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1016\/0014-5793(95)01417-9","volume":"378","year":"1996","journal-title":"FEBS Lett."},{"key":"2023072618185004300_BIB28","first-page":"837","volume":"12","year":"2000","journal-title":"Plant Cell."},{"key":"2023072618185004300_BIB29","doi-asserted-by":"crossref","first-page":"395","DOI":"10.1016\/j.neuron.2005.06.019","volume":"47","year":"2005","journal-title":"Neuron."},{"key":"2023072618185004300_BIB30","doi-asserted-by":"crossref","first-page":"459","DOI":"10.1085\/jgp.200308818","volume":"122","year":"2003","journal-title":"J. Gen. Physiol."},{"key":"2023072618185004300_BIB31","doi-asserted-by":"crossref","first-page":"785","DOI":"10.1104\/pp.116.2.785","volume":"116","year":"1998","journal-title":"Plant Physiol."},{"key":"2023072618185004300_BIB32","doi-asserted-by":"crossref","first-page":"897","DOI":"10.1126\/science.1116269","volume":"309","year":"2005","journal-title":"Science."},{"key":"2023072618185004300_BIB33","doi-asserted-by":"crossref","first-page":"903","DOI":"10.1126\/science.1116270","volume":"309","year":"2005","journal-title":"Science."},{"key":"2023072618185004300_BIB34","doi-asserted-by":"crossref","first-page":"663","DOI":"10.1085\/jgp.20028696","volume":"120","year":"2002","journal-title":"J. Gen. Physiol."},{"key":"2023072618185004300_BIB35","doi-asserted-by":"crossref","first-page":"232","DOI":"10.1038\/350232a0","volume":"350","year":"1991","journal-title":"Nature."},{"key":"2023072618185004300_BIB36","doi-asserted-by":"crossref","first-page":"837","DOI":"10.1038\/nature01038","volume":"419","year":"2002","journal-title":"Nature."},{"key":"2023072618185004300_BIB37","doi-asserted-by":"crossref","first-page":"431","DOI":"10.1137\/0111030","volume":"11","year":"1963","journal-title":"J. Soc. Ind. Appl. Math."},{"key":"2023072618185004300_BIB38","doi-asserted-by":"crossref","first-page":"7581","DOI":"10.1073\/pnas.96.13.7581","volume":"96","year":"1999","journal-title":"Proc. Natl. Acad. Sci. USA."},{"key":"2023072618185004300_BIB39","doi-asserted-by":"publisher","DOI":"10.1111\/j.1365-313X"},{"key":"2023072618185004300_BIB40","doi-asserted-by":"crossref","first-page":"850","DOI":"10.1093\/pcp\/pcd003","volume":"41","year":"2000","journal-title":"Plant Cell Physiol."},{"key":"2023072618185004300_BIB41","doi-asserted-by":"crossref","first-page":"2409","DOI":"10.1002\/j.1460-2075.1995.tb07238.x","volume":"14","year":"1995","journal-title":"EMBO J."},{"key":"2023072618185004300_BIB42","doi-asserted-by":"crossref","first-page":"418","DOI":"10.1007\/s00239-002-2413-2","volume":"56","year":"2003","journal-title":"J. Mol. Evol."},{"key":"2023072618185004300_BIB43"},{"key":"2023072618185004300_BIB44","doi-asserted-by":"crossref","first-page":"905","DOI":"10.1038\/nrn1559","volume":"5","year":"2004","journal-title":"Nat. Rev. Neurosci."},{"key":"2023072618185004300_BIB45","doi-asserted-by":"crossref","first-page":"3089","DOI":"10.1016\/S0006-3495(99)77461-8","volume":"76","year":"1999","journal-title":"Biophys. J."},{"key":"2023072618185004300_BIB46","doi-asserted-by":"crossref","first-page":"18994","DOI":"10.1074\/jbc.M200410200","volume":"277","year":"2002","journal-title":"J. Biol. Chem."},{"key":"2023072618185004300_BIB47","doi-asserted-by":"crossref","first-page":"321","DOI":"10.1046\/j.1365-313X.1995.7020321.x","volume":"7","year":"1995","journal-title":"Plant J."},{"key":"2023072618185004300_BIB48","doi-asserted-by":"crossref","first-page":"575","DOI":"10.1146\/annurev.arplant.54.031902.134831","volume":"54","year":"2003","journal-title":"Annu. Rev. Plant Biol."},{"key":"2023072618185004300_BIB49","doi-asserted-by":"crossref","first-page":"35","DOI":"10.1038\/nature00978","volume":"419","year":"2002","journal-title":"Nature."},{"key":"2023072618185004300_BIB50","doi-asserted-by":"crossref","first-page":"679","DOI":"10.1085\/jgp.112.6.679","volume":"112","year":"1998","journal-title":"J. Gen. Physiol."}],"container-title":["The Journal of General Physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/rupress.org\/jgp\/article-pdf\/126\/6\/605\/1782311\/jgp1266605.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/rupress.org\/jgp\/article-pdf\/126\/6\/605\/1782311\/jgp1266605.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,7,26]],"date-time":"2023-07-26T20:43:40Z","timestamp":1690404220000},"score":1,"resource":{"primary":{"URL":"https:\/\/rupress.org\/jgp\/article\/126\/6\/605\/44055\/A-Unique-Voltage-Sensor-Sensitizes-the-Potassium"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2005,11,28]]},"references-count":50,"journal-issue":{"issue":"6","published-print":{"date-parts":[[2005,12,1]]}},"URL":"https:\/\/doi.org\/10.1085\/jgp.200509413","relation":{},"ISSN":["1540-7748","0022-1295"],"issn-type":[{"value":"1540-7748","type":"electronic"},{"value":"0022-1295","type":"print"}],"subject":[],"published":{"date-parts":[[2005,11,28]]}}}