FUNCTION OF A TRUNCATED DIHYDROPYRIDINE RECEPTOR AS BOTH VOLTAGE SENSOR AND CALCIUM-CHANNEL
FUNCTION OF A TRUNCATED DIHYDROPYRIDINE RECEPTOR AS BOTH VOLTAGE SENSOR AND CALCIUM-CHANNEL
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DOI：
10.1038/360169a0
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发表时间：
1992-11-12
期刊：
影响因子：
64.8
通讯作者：
TANABE, T
中科院分区：
文献类型：
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作者：
BEAM, KG;ADAMS, BA;TANABE, T
骨骼肌二氢吡啶（DHP）受体具有双重功能，作为兴奋-收缩偶联的电压传感器和L型钙通道1 -3。生化分析表明，骨骼肌中存在两种形式的DHP受体多肽，一种是作为次要物质存在的全长翻译产物，另一种是具有截短羧基末端的更丰富形式4 -6。基于这些和其他观察结果7，有人提出8，在骨骼肌中，只有全长DHP受体可以作为钙通道，而截短的形式只能作为兴奋-收缩耦合的电压传感器。为了解决这个问题，我们现在已经构建了一个互补的DNA（pC6 DELTA 1）编码的蛋白质对应于截短的DHP受体在骨骼肌。pC6 DELTA 1在发育不良的肌管中的表达完全恢复了兴奋-收缩偶联和钙电流，这与单一类别的DHP受体执行两种功能的想法一致。
THE skeletal muscle dihydropyridine (DHP) receptor serves dual functions, as a voltage sensor for excitation-contraction coupling and as an L-type calcium channel1-3. Biochemical analysis indicates the presence of two forms of the DHP receptor polypeptide in skeletal muscle, a full-length translation product present as a minor species and a much more abundant form that has a truncated carboxy-terminus4-6. On the basis of these and other observations7, it has been proposed8 that, in skeletal muscle, only the full-length DHP receptor can function as a calcium channel and that the truncated form can only function as a voltage sensor for excitation-contraction coupling. To resolve this issue, we have now constructed a complementary DNA (pC6DELTA1) encoding a protein corresponding to the truncated DHP receptor in skeletal muscle. Expression of pC6DELTA1 in dysgenic myotubes fully restores both excitation-contraction coupling and calcium current, consistent with the idea that a single class of DHP receptors performs both functions.