SPERMINE AND SPERMIDINE AS GATING MOLECULES FOR INWARD RECTIFIER K+ CHANNELS
SPERMINE AND SPERMIDINE AS GATING MOLECULES FOR INWARD RECTIFIER K+ CHANNELS
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DOI：
10.1126/science.7973666
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发表时间：
1994-11-11
期刊：
影响因子：
56.9
通讯作者：
BROWN, AM
中科院分区：
文献类型：
--
作者：
FICKER, E;TAGLIALATELA, M;BROWN, AM
向内整流K+通道通过突出的向内电流，而向外电流大部分被阻挡。向内整流是由于细胞内Mg2+和一个被称为本征门控的与Mg2+无关的过程阻断。斑块切除后门控的迅速丧失表明细胞质因子参与了门控。通过纳摩尔浓度的两种天然多胺，精胺和亚精胺，可以在切除的斑块中恢复“内在”门控。精胺和亚精胺可以作为内向整流K+通道的生理阻滞剂，而“本征”门控可能在很大程度上反映了这些阳离子的电压依赖性阻断。
Inward rectifier K+ channels pass prominent inward currents, while outward currents are largely blocked. The inward rectification is due to block by intracellular Mg2+ and a Mg2+-independent process described as intrinsic gating. The rapid loss of gating upon patch excision suggests that cytoplasmic factors participate in gating. ''intrinsic'' gating can be restored in excised patches by nanomolar concentrations of two naturally occurring polyamines, spermine and spermidine. Spermine and spermidine may function as physiological blockers of inward rectifier K+ channels and ''intrinsic'' gating may largely reflect voltage-dependent block by these cations.