The βγ subunits of G proteins gate a K+ channel by pivoted bending of a transmembrane segment
The βγ subunits of G proteins gate a K+ channel by pivoted bending of a transmembrane segment
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DOI：
10.1016/s1097-2765(02)00659-7
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发表时间：
2002-09-01
期刊：
影响因子：
16
通讯作者：
Logothetis, DE
中科院分区：
文献类型：
--
作者：
Jin, TH;Peng, LY;Logothetis, DE
离子通道门控的分子机制尚不清楚。使用的方法，如脯氨酸扫描诱变和同源建模，我们本地化的门的K+通道控制的β γ亚基的G蛋白在孔衬束交叉的第二个跨膜（TM 2）螺旋。我们表明，由一个高度保守的甘氨酸残基在中间的TM2的灵活性是至关重要的通道门控。相反，在浇口下方引入的柔性会破坏浇口。我们建议，通道GPY相互作用产生的力是通过下面的螺旋束交叉到弯曲TM 2的甘氨酸，作为一个铰链和打开门的刚性区域转导。
The molecular mechanism of ion channel gating remains unclear. Using approaches such as proline scanning mutagenesis and homology modeling, we localize the gate of the K+ channels controlled by the betagamma subunits of G proteins at the pore-lining bundle crossing of the second transmembrane (TM2) helices. We show that the flexibility afforded by a highly conserved glycine residue in the middle of TM2 is crucial for channel gating. In contrast, flexibility introduced immediately below the gate disrupts gating. We propose that the force produced by channel-Gpy interactions is transduced through the rigid region below the helix bundle crossing to bend TM2 at the glycine that serves as a hinge and open the gate.