POTASSIUM CHANNEL ACTIVATION BY GLUTATHIONE-S-CONJUGATES IN ESCHERICHIA-COLI - PROTECTION AGAINST METHYLGLYOXAL IS MEDIATED BY CYTOPLASMIC ACIDIFICATION

被引：82

作者：

FERGUSON, GP ^{[1
]}

MCLAGGAN, D ^{[1
]}

BOOTH, IR ^{[1
]}

机构：

[1] UNIV ABERDEEN,MARISCHAL COLL,DEPT MOLEC & CELL BIOL,ABERDEEN AB9 1AS,SCOTLAND

来源：

MOLECULAR MICROBIOLOGY | 1995年 / 17卷 / 06期

关键词：

D O I：

10.1111/j.1365-2958.1995.mmi_17061025.x

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：

Escherichia coli possesses two glutathione-gated potassium channels, KefB and KefC, that are activated by glutathione-S-conjugates formed with methylglyoxal. We demonstrate that activation of the channels leads to cytoplasmic acidification and that this protects cells during electrophilic attack. Further, we demonstrate that mutants lacking the channels can be protected against the lethal effects of methylglyoxal by acidification of the cytoplasm with a weak acid. The degree of protection is determined by the absolute value of the pH(i) and the time at which acidification takes place. Alterations in the pH(i) do not accelerate the rate of detoxification of methylglyoxal. The mechanism by which methylglyoxal causes cell death and the implications for pH(i)-mediated resistance to methylglyoxal are discussed.

引用

页码：1025 / 1033

页数：9