Optogenetic Control of Calcium Oscillation Waveform Defines NFAT as an Integrator of Calcium Load.
Optogenetic Control of Calcium Oscillation Waveform Defines NFAT as an Integrator of Calcium Load.
复制标题
DOI：
10.1016/j.cels.2016.03.010
复制
发表时间：
2016-04-27
期刊：
影响因子：
9.3
通讯作者：
Chow BY
中科院分区：
文献类型：
--
作者：
Hannanta-Anan P;Chow BY
已知钙依赖转录因子NFAT启动转录以响应钙信号的脉动负荷。然而，钙振荡频率、幅度和占空比对转录活性的相对贡献仍不清楚。在这里，我们设计了HeLa细胞，允许使用可编程LED阵列对细胞内钙浓度进行光遗传控制。这种方法允许我们产生恒定峰值幅度的钙振荡，其中频率在保持占空比恒定的情况下变化，反之亦然。使用这种设置和数学模型，我们发现NFAT转录活性更多地依赖于占空比，占空比的定义是振荡周期内整合的钙浓度的比例，而不仅仅是频率。这表明，NFAT主要作为累积负载的信号积分器，而不是频率选择性解码器。这种方法解决了钙编码的一个基本问题，并证明了光遗传学在分离更大信号行为的单个动态成分方面的价值。
It is known that the calcium-dependent transcription factor NFAT initiates transcription in response to pulsatile loads of calcium signal. However, the relative contributions of calcium oscillation frequency, amplitude, and duty cycle to transcriptional activity remain unclear. Here, we engineer HeLa cells to permit optogenetic control of intracellular calcium concentration using programmable LED arrays. This approach allows us to generate calcium oscillations of constant peak amplitude, in which frequency is varied while holding duty cycle constant, or vice versa. Using this setup and mathematical modeling, we show that NFAT transcriptional activity depends more on duty cycle, defined as the proportion of the integrated calcium concentration over the oscillation period, than on frequency alone. This demonstrates that NFAT acts primarily as a signal integrator of cumulative load rather than a frequency-selective decoder. This approach resolves a fundamental question in calcium encoding and demonstrates the value of optogenetics for isolating individual dynamical components of larger signaling behaviors.