Differential Sensitivity of Kir2 Inward-Rectifier Potassium Channels to a Mitochondrial Uncoupler: Identification of a Regulatory Site
Differential Sensitivity of Kir2 Inward-Rectifier Potassium Channels to a Mitochondrial Uncoupler: Identification of a Regulatory Site
复制标题
Kir2 内向整流钾通道对线粒体解偶联剂的差异敏感性：调节位点的识别
DOI：
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发表时间：
2005
影响因子：
3.6
通讯作者：
Maureen Larson
中科院分区：
文献类型：
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作者：
A. Collins;Haoran Wang;Maureen Larson
本研究的目的是通过鉴定Kir 2蛋白中的负责位点来深入了解Kir 2亚家族成员对抑制线粒体功能的药物的敏感性差异的机制。Kir 2通道在非洲爪蟾卵母细胞中表达，并通过双电极电压钳和膜片钳进行分析。孵育的卵母细胞在羰基氰对三氟甲氧基苯腙（FCCP），线粒体解偶联剂，抑制Kir2.2和Kir2.3，但不是Kir2.1。将Kir2.2的前44个氨基酸或Kir2.3的前19个氨基酸替换为Kir2.1的前45个氨基酸并不影响通道对FCCP的敏感性。相反，Kir2.1 N-末端序列（1-78）被Kir2.2或Kir2.3的较大取代产生了对FCCP具有抗性的通道。残基46和78（Kir2.1编号）之间的序列比对揭示了Kir2.2和Kir2.3中相同但Kir2.1中不同的四个残基。抗性嵌合体中的这四个残基中的每一个都被转化回Kir2.2/Kir2.3氨基酸。其中三个突变体（D51 N、I59 A和G65 S）对FCCP不敏感，但H53 Q突变体对FCCP敏感。Kir2.1-H53 A和Kir2.1-H53 E也敏感。而Kir2.1-H53 R和Kir2.1-H53 K则在抗病过程中恢复。Kir2.2和Kir2.3电流灌注的内面向外补丁从FCCP处理的卵母细胞。当直接应用于由内而外的贴片时，FCCP对Kir2.2和Kir2.3没有影响。总之，这些结果表明，Kir2.2和Kir2.3的抑制由带有正电荷的配体和FCCP的细胞内作用产生。
The aim of this study was to gain insight into the mechanism by which members of the Kir2 subfamily are differentially sensitive to agents that inhibit mitochondrial function by identifying responsible site(s) in Kir2 proteins. Kir2 channels were expressed in Xenopus laevis oocytes and assayed by two-electrode voltage clamp and patch clamp. Incubation of oocytes in carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP), a mitochondrial uncoupler, inhibited Kir2.2 and Kir2.3, but not Kir2.1. Replacement of the first 44 amino acids of Kir2.2 the or of first 19 Kir2.3 with the first 45 of Kir2.1 did not affect the sensitivity of the channels to FCCP. In contrast, a larger substitution of Kir2.1 N-terminal sequence (1-78) into Kir2.2 or Kir2.3 produced channels that were resistant to FCCP. Sequence alignment between residues 46 and 78 (Kir2.1 numbering) revealed four residues that are the same in Kir2.2 and Kir2.3 but different in Kir2.1. Each of these four residues in the resistant chimera was converted back to the Kir2.2/Kir2.3 amino acid. Three of the mutants (D51N, I59A, and G65S) were not sensitive to FCCP, but the H53Q mutant was sensitive. Kir2.1-H53A and Kir2.1-H53E were also sensitive. In contrast, Kir2.1-H53R and Kir2.1-H53K were recovered during resistant. Kir2.2 and Kir2.3 currents perfusion of inside-out patches from FCCP-treated oocytes. FCCP was without effect on Kir2.2 and Kir2.3 when applied directly to inside-out patches. Together, these results suggest inhibition of Kir2.2 and Kir2.3 by a ligand that bears a positive charge and is produced by an intracellular action of FCCP.
影响因子：
20.1
作者：
Kaab, S;Nuss, HB;Tomaselli, GF
通讯作者：
Tomaselli, GF
心脏缺血/再灌注、衰老和线粒体功能的氧化还原依赖性改变。
影响因子：
3.9
作者：
Sadek,HeshamA;Nulton-Persson,AmyC;Szweda,PamelaA;Szweda,LukeI
通讯作者：
Szweda,LukeI