Institute of Quantitative and Theoretical Biology, Heinrich Heine University, Düsseldorf, Germany.
Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg.
J R Soc Interface. 2018 May;15(142). doi: 10.1098/rsif.2017.0965.
Global warming exposes plants to severe heat stress, with consequent crop yield reduction. Organisms exposed to high temperature stresses typically protect themselves with a heat shock response (HSR), where accumulation of unfolded proteins initiates the synthesis of heat shock proteins through the heat shock transcription factor HSF1. While the molecular mechanisms are qualitatively well characterized, our quantitative understanding of the underlying dynamics is still very limited. Here, we study the dynamics of HSR in the photosynthetic model organism with a data-driven mathematical model of HSR. We based our dynamical model mostly on mass action kinetics, with a few nonlinear terms. The model was parametrized and validated by several independent datasets obtained from the literature. We demonstrate that HSR quantitatively and significantly differs if an increase in temperature of the same magnitude occurs abruptly, as often applied under laboratory conditions, or gradually, which would rather be expected under natural conditions. In contrast to rapid temperature increases, under gradual changes only negligible amounts of misfolded proteins accumulate, indicating that the HSR of efficiently avoids the accumulation of misfolded proteins under conditions most likely to prevail in nature. The mathematical model we developed is a flexible tool to simulate the HSR to different conditions and complements the current experimental approaches.
全球变暖使植物暴露在严重的热应激下，导致作物产量减少。通常，暴露在高温胁迫下的生物会通过热休克反应 (HSR) 来保护自己，其中未折叠蛋白质的积累会通过热休克转录因子 HSF1 启动热休克蛋白的合成。虽然分子机制在定性上得到了很好的描述，但我们对潜在动力学的定量理解仍然非常有限。在这里，我们使用热休克反应的基于数据的数学模型来研究光合作用模型生物中的 HSR 动力学。我们的动力学模型主要基于质量作用动力学，其中包含一些非线性项。该模型通过从文献中获得的几个独立数据集进行了参数化和验证。我们证明，如果相同幅度的温度升高是突然发生的，如在实验室条件下经常应用的那样，与逐渐发生的情况相比，HSR 会有很大的不同。与快速的温度升高相比，在逐渐变化的情况下，只有极少量的错误折叠蛋白质积累，这表明在自然条件下很可能占主导地位的条件下， 的 HSR 有效地避免了错误折叠蛋白质的积累。我们开发的数学模型是一种灵活的工具，可以模拟不同条件下的 HSR，并补充当前的实验方法。
