Modulation of Kir4.1 and Kir4.1-Kir5.1 channels by extracellular cations

Rikke Søe; Mogens Andreasen; Dan Arne Klærke

doi:10.1016/j.bbamem.2009.07.002

Modulation of Kir4.1 and Kir4.1-Kir5.1 channels by extracellular cations

Rikke Søe, Mogens Andreasen, Dan Arne Klærke

2 Citationer (Scopus)

Abstract

This work demonstrates that extracellular Na(+) modulates the cloned inwardly rectifying K(+) channels Kir4.1 and Kir4.1-Kir5.1. Whole-cell patch clamp studies on astrocytes have previously indicated that inward potassium currents are regulated by external Na(+). We expressed Kir4.1 and Kir4.1-Kir5.1 in Xenopus oocytes to disclose if Kir4.1 and/or Kir4.1-Kir5.1 at the molecular level are responsible for the observed effect of [Na(+)](o) and to investigate the regulatory mechanism of external cations further. Our results showed that Na(+) has a biphasic modulatory effect on both Kir4.1 and Kir4.1-Kir5.1 currents. Depending on the Na(+)-concentration and applied voltage, the inward Kir4.1/Kir4.1-Kir5.1 currents are either enhanced or reduced by extracellular Na(+). The Na(+) activation was voltage-independent, whereas the Na(+)-induced reduction of the Kir4.1 and Kir4.1-Kir5.1 currents was both concentration-, time- and voltage-dependent. Our data indicate that the biphasic effect of extracellular Na(+)on the Kir4.1 and Kir4.1-Kir5.1 channels is caused by two separate mechanisms.

Originalsprog	Engelsk
Tidsskrift	Biochimica et Biophysica Acta - Biomembranes
Vol/bind	1788
Udgave nummer	9
Sider (fra-til)	1706-1713
Antal sider	8
ISSN	0005-2736
DOI	https://doi.org/10.1016/j.bbamem.2009.07.002
Status	Udgivet - 2009

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10.1016/j.bbamem.2009.07.002

Citationsformater

@article{4716c7c0a83211debc73000ea68e967b,

title = "Modulation of Kir4.1 and Kir4.1-Kir5.1 channels by extracellular cations",

abstract = "This work demonstrates that extracellular Na(+) modulates the cloned inwardly rectifying K(+) channels Kir4.1 and Kir4.1-Kir5.1. Whole-cell patch clamp studies on astrocytes have previously indicated that inward potassium currents are regulated by external Na(+). We expressed Kir4.1 and Kir4.1-Kir5.1 in Xenopus oocytes to disclose if Kir4.1 and/or Kir4.1-Kir5.1 at the molecular level are responsible for the observed effect of [Na(+)](o) and to investigate the regulatory mechanism of external cations further. Our results showed that Na(+) has a biphasic modulatory effect on both Kir4.1 and Kir4.1-Kir5.1 currents. Depending on the Na(+)-concentration and applied voltage, the inward Kir4.1/Kir4.1-Kir5.1 currents are either enhanced or reduced by extracellular Na(+). The Na(+) activation was voltage-independent, whereas the Na(+)-induced reduction of the Kir4.1 and Kir4.1-Kir5.1 currents was both concentration-, time- and voltage-dependent. Our data indicate that the biphasic effect of extracellular Na(+)on the Kir4.1 and Kir4.1-Kir5.1 channels is caused by two separate mechanisms.",

author = "Rikke S{\o}e and Mogens Andreasen and Kl{\ae}rke, {Dan Arne}",

year = "2009",

doi = "10.1016/j.bbamem.2009.07.002",

language = "English",

volume = "1788",

pages = "1706--1713",

journal = "Biochimica et Biophysica Acta - Biomembranes",

issn = "0005-2736",

publisher = "Elsevier",

number = "9",

}

TY - JOUR

T1 - Modulation of Kir4.1 and Kir4.1-Kir5.1 channels by extracellular cations

AU - Søe, Rikke

AU - Andreasen, Mogens

AU - Klærke, Dan Arne

PY - 2009

Y1 - 2009

N2 - This work demonstrates that extracellular Na(+) modulates the cloned inwardly rectifying K(+) channels Kir4.1 and Kir4.1-Kir5.1. Whole-cell patch clamp studies on astrocytes have previously indicated that inward potassium currents are regulated by external Na(+). We expressed Kir4.1 and Kir4.1-Kir5.1 in Xenopus oocytes to disclose if Kir4.1 and/or Kir4.1-Kir5.1 at the molecular level are responsible for the observed effect of [Na(+)](o) and to investigate the regulatory mechanism of external cations further. Our results showed that Na(+) has a biphasic modulatory effect on both Kir4.1 and Kir4.1-Kir5.1 currents. Depending on the Na(+)-concentration and applied voltage, the inward Kir4.1/Kir4.1-Kir5.1 currents are either enhanced or reduced by extracellular Na(+). The Na(+) activation was voltage-independent, whereas the Na(+)-induced reduction of the Kir4.1 and Kir4.1-Kir5.1 currents was both concentration-, time- and voltage-dependent. Our data indicate that the biphasic effect of extracellular Na(+)on the Kir4.1 and Kir4.1-Kir5.1 channels is caused by two separate mechanisms.

AB - This work demonstrates that extracellular Na(+) modulates the cloned inwardly rectifying K(+) channels Kir4.1 and Kir4.1-Kir5.1. Whole-cell patch clamp studies on astrocytes have previously indicated that inward potassium currents are regulated by external Na(+). We expressed Kir4.1 and Kir4.1-Kir5.1 in Xenopus oocytes to disclose if Kir4.1 and/or Kir4.1-Kir5.1 at the molecular level are responsible for the observed effect of [Na(+)](o) and to investigate the regulatory mechanism of external cations further. Our results showed that Na(+) has a biphasic modulatory effect on both Kir4.1 and Kir4.1-Kir5.1 currents. Depending on the Na(+)-concentration and applied voltage, the inward Kir4.1/Kir4.1-Kir5.1 currents are either enhanced or reduced by extracellular Na(+). The Na(+) activation was voltage-independent, whereas the Na(+)-induced reduction of the Kir4.1 and Kir4.1-Kir5.1 currents was both concentration-, time- and voltage-dependent. Our data indicate that the biphasic effect of extracellular Na(+)on the Kir4.1 and Kir4.1-Kir5.1 channels is caused by two separate mechanisms.

U2 - 10.1016/j.bbamem.2009.07.002

DO - 10.1016/j.bbamem.2009.07.002

M3 - Journal article

C2 - 19616510

SN - 0005-2736

VL - 1788

SP - 1706

EP - 1713

JO - Biochimica et Biophysica Acta - Biomembranes

JF - Biochimica et Biophysica Acta - Biomembranes

IS - 9

ER -

Modulation of Kir4.1 and Kir4.1-Kir5.1 channels by extracellular cations

Abstract

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