Visualization of subcellular thermoregulation in live cells using fluorescent coiled-coil proteins

在哺乳动物和鸟类中，调节体温以保持体温对生命至关重要。多种产热机制定位于不同的亚细胞细胞器被提出。然而，以往的研究未能在完整的细胞器中直接观察到产热。在这里，我们使用荧光热传感器tsGFP可视化了细胞内产热。特异性靶向tsGFPs可以可视化离散细胞器中的产热作用，特别是棕色脂肪细胞中的线粒体和肌管中的内质网。引人注目的是，在HeLa细胞中，靶向tsGFP揭示了线粒体产热的异质性，这与电化学梯度密切相关。因此，tsgfp直接证明了亚细胞热转导，并将作为评估体内产热的有力工具。

In mammals and birds, thermoregulation to conserve body temperature is vital to life. Multiple mechanisms of thermogeneration localized in different subcellular organelles have been proposed. However, previous studies have failed to observe thermogenesis directly in intact organelles. Here, we have visualized intracellular thermogenesis by using a fluorescent thermosensor, tsGFP. Specific targeting of tsGFPs enables visualization of thermogenesis in discrete organelles, notably mitochondria in brown adipocytes and the endoplasmic reticulum in myotubes. Strikingly, in HeLa cells, targeted tsGFP reveals heterogeneity in mitochondrial thermogenesis that is well correlated with the electrochemical gradient. Thus, tsGFPs directly demonstrate subcellular thermotransduction, and will serve as powerful tools to assess thermogenesis in vivo.