Effect of oscillating and non-oscillating Ca2+ signal on gene expression in RBL-2H3 cells

Oscillations of Ca2+ signal are generated in all cell types, seen throughout the life of a cell, and are indispensable for diverse biological processes ranging from fertilization to cell death. Here we report that Ca2+ nanodomains near Ca2+ channels at the cell surface and not cytosolic Ca2+ oscillations are central to gene expression. Ca2+ nanodomains activate Ca2+-dependent transcription factors to the same extent as Ca2+ oscillations, at the same average cytosolic Ca2+, leading to equivalent activation of a range of intracellular pathways. Our results establish that the fundamental unit of excitation-transcription coupling is the Ca2+ channel nanodomain at the cell surface.钙（Ca2+）信号振荡广泛存在于所有细胞类型中，贯穿细胞整个生命周期，且对于从受精到细胞死亡的多种生物学过程均不可或缺。本研究发现，细胞表面钙（Ca2+）通道附近的钙（Ca2+）纳米域，而非胞质钙信号振荡，才是基因表达的核心调控因素。在相同的平均胞质钙浓度条件下，钙纳米域对钙（Ca2+）依赖性转录因子的激活程度与钙信号振荡相当，进而可同等激活一系列细胞内通路。本研究结果证实，兴奋-转录偶联（excitation-transcription coupling）的基本单元为细胞表面的钙通道纳米域。