Cloning and functional expression of the cDNA encoding a novel ATP-sensitive potassium channel subunit expressed in pancreatic beta-cells, brain, heart and skeletal muscle

被引：384

作者：

Sakura, H ^{[1
]}

Ammala, C ^{[1
]}

Smith, PA ^{[1
]}

Gribble, FM ^{[1
]}

Ashcroft, FM ^{[1
]}

机构：

[1] UNIV OXFORD,PHYSIOL LAB,OXFORD OX1 3PT,ENGLAND

来源：

FEBS LETTERS | 1995年 / 377卷 / 03期

基金：

英国惠康基金;

关键词：

ATP-sensitive K-channel; sulphonylurea receptor; pancreatic beta-cell; Kir6.2; cardiac muscle; skeletal muscle;

D O I：

10.1016/0014-5793(95)01369-5

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

A cDNA clone encoding an inwardly-rectifying potassium channel subunit (Kir6.2) was isolated from an insulinoma cDNA library, The mRNA. is strongly expressed in brain, skeletal muscle, cardiac muscle and in insulinoma cells, weakly expressed in lung and kidney and not detectable in spleen, liver or testis, Heterologous expression of Kir6.2 in HEK293 cells was only observed when the cDNA was cotransfected with that of the sulphonylurea receptor (SUR). Whole-cell Kir6.2/SUR currents were K+-selective, time-independent and showed, weak inward rectification. They were blocked by external barium (5 mM), tolbutamide (K-d = 4.5 mu M) or quinine (20 mu M) and by 5 mM intracellular ATP, The single-channel conductance was 73 pS, Single-channel activity was voltage-independent and mas blocked by 1 mM intracellular AIP or 0.5 mM tolbutamide, We conclude that the Kir6.2/SUR channel complex comprises the ATP-sensitive K-channel.

引用

页码：338 / 344

页数：7

共 16 条

[1] CLONING OF THE BETA-CELL HIGH-AFFINITY SULFONYLUREA RECEPTOR - A REGULATOR OF INSULIN-SECRETION [J].