Light and temperature sensing are important features of many organisms. Light may provide energy but may also be used by non-photosynthetic organisms for orientation in the environment. Recent evidence suggests that plant and fungal phytochrome and plant phototropin serve dual functions as light and temperature sensors. Here we characterized the fungal LOV-domain blue-light receptor LreA of and show that it predominantly contains FAD as chromophore. Blue-light illumination induced ROS production followed by protein agglomeration . ROS may control LreA activity. LreA acts as a blue-light photoreceptor but also triggers temperature-shift-induced gene expression. Both responses required the conserved amino acid cysteine 421. We therefore propose that temperature mimics the photoresponse, which could be the ancient function of the chromoprotein. Temperature-dependent gene expression control with LreA was distinct from the response with phytochrome suggesting fine-tuned, photoreceptor-specific gene regulation.

中文翻译：

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真菌 Alternaria alternata 的 LOV 结构域蓝光受体 LreA 主要与 FAD 作为发色团结合，并充当光和温度传感器

光和温度传感是许多生物体的重要特征。光可以提供能量，但也可以被非光合生物体用来在环境中定向。最近的证据表明，植物和真菌光敏色素和植物向光素具有光和温度传感器的双重功能。在这里，我们对真菌 LOV 结构域蓝光受体 LreA 进行了表征，并表明它主要含有 FAD 作为发色团。蓝光照射诱导 ROS 产生，随后蛋白质聚集。 ROS 可能控制 LreA 活性。 LreA 充当蓝光感光器，但也会触发温度变化诱导的基因表达。两种反应都需要保守的氨基酸半胱氨酸 421。因此，我们认为温度模拟了光反应，这可能是色素蛋白的古老功能。 LreA 的温度依赖性基因表达控制与光敏色素的反应不同，表明微调的光感受器特异性基因调节。