Engineered calmodulins reveal the unexpected eminence of Ca2+ channel inactivation in controlling heart excitation
Engineered calmodulins reveal the unexpected eminence of Ca2+ channel inactivation in controlling heart excitation
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DOI：
10.1073/pnas.262372999
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发表时间：
2002-12-24
影响因子：
11.1
通讯作者：
Yue, DT
中科院分区：
文献类型：
--
作者：
Alseikhan, BA;DeMaria, CD;Yue, DT
工程钙调素（CaMs），使Ca 2+不敏感的突变，在异源系统中作为显性负性的功能，并揭示了离子通道调节的Ca 2 +/CaM的机制。在天然哺乳动物细胞中使用这些钙调素现在成为揭示这种钙反馈生物学的一种策略。在这里，我们开发了携带工程钙调素的重组腺病毒，以促进其在成人心脏细胞中的表达，其中Ca 2+调节可能是必不可少的时刻到时刻控制心跳。工程钙调素不仅消除了天然钙通道的钙依赖性失活，但暴露了一个意想不到的巨大影响，消除这种反馈：前所未有的（4至5倍）延长动作电位。这一惊人的结果重塑了动作电位控制的基本范式，并说明了病毒传递的工程钙调素的承诺，以研究许多其他钙调素信号通路的生物学。
Engineered calmodulins (CaMs), rendered Ca2+-insensitive by mutations, function as dominant negatives in heterologous systems, and have revealed mechanisms of ion channel modulation by Ca2+/CaM. The use of these CaMs in native mammalian cells now emerges as a strategy to unmask the biology of such Ca2+ feedback. Here, we developed recombinant adenoviruses bearing engineered CaMs to facilitate their expression in adult heart cells, where Ca2+ regulation may be essential for moment-to-moment control of the heartbeat. Engineered CaMs not only eliminated the Ca2+-dependent inactivation of native calcium channels, but exposed an unexpectedly large impact of removing such feedback: the unprecedented (4- to 5-fold) prolongation of action potentials. This striking result recasts the basic paradigm for action-potential control and illustrates the promise of virally delivered engineered CaM to investigate the biology of numerous other CaM-signaling pathways.