TWIK1, a unique background channel with variable ion selectivity

被引：77

作者：

Chatelain, Franck C. ^{[1
,2
]}

Bichet, Delphine ^{[1
,2
]}

Douguet, Dominique ^{[1
,2
]}

Feliciangeli, Sylvain ^{[1
,2
]}

Bendahhou, Said ^{[1
,3
]}

Reichold, Markus ^{[4
]}

Warth, Richard ^{[4
]}

Barhanin, Jacques ^{[1
,3
]}

Lesage, Florian ^{[1
,2
]}

机构：

[1] Univ Nice Sophia Antipolis, Labs Excellence Ion Channel Sci & Therapeut, F-06560 Valbonne, France

[2] Univ Nice Sophia Antipolis, CNRS, Inst Pharmacol Mol & Cellulaire, F-06560 Valbonne, France

[3] Univ Nice Sophia Antipolis, Lab PhysioMed Mol, CNRS, F-06108 Nice, France

[4] Univ Regensburg, Dept Physiol, D-93053 Regensburg, Germany

来源：

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA | 2012年 / 109卷 / 14期

关键词：

K+ CHANNEL; POTASSIUM CHANNELS; LEAK; CELLS; PH; LOCALIZATION; EXPRESSION; ROLES;

D O I：

10.1073/pnas.1201132109

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

TWIK1 belongs to the family of background K+ channels with two pore domains. In native and transfected cells, TWIK1 is detected mainly in recycling endosomes. In principal cells in the kidney, TWIK1 gene inactivation leads to the loss of a nonselective cationic conductance, an unexpected effect that was attributed to adaptive regulation of other channels. Here, we show that TWIK1 ion selectivity is modulated by extracellular pH. Although TWIK1 is K+ selective at neutral pH, it becomes permeable to Na+ at the acidic pH found in endosomes. Selectivity recovery is slow after restoration of a neutral pH. Such hysteresis makes plausible a role of TWIK1 as a background channel in which selectivity and resulting inhibitory or excitatory influences on cell excitability rely on its recycling rate between internal acidic stores and the plasma membrane. TWIK1(-/-) pancreatic beta cells are more polarized than control cells, confirming a depolarizing role of TWIK1 in kidney and pancreatic cells.

引用

页码：5499 / 5504

页数：6

共 29 条

[1] Structure, chromosome localization, and tissue distribution of the mouse twik K+ channel gene [J].