He Qiyang, Cheng Ping, Yang Yuhong, Wang Lixing, Gardner Kevin H, Liu Yi
Department of Physiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.
Science. 2002 Aug 2;297(5582):840-3. doi: 10.1126/science.1072795. Epub 2002 Jul 4.
Blue light regulates many physiological processes in fungi, but their photoreceptors are not known. In Neurospora crassa, all light responses depend on the Per-Arnt-Sim (PAS) domain-containing transcription factor white collar-1 (wc-1). By removing the WC-1 light, oxygen, or voltage domain, a specialized PAS domain that binds flavin mononucleotide in plant phototropins, we show that light responses are abolished, including light entrainment of the circadian clock. However, the WC-1-mediated dark activation of frq remains normal in this mutant, and the circadian clock can be entrained by temperature. Furthermore, we demonstrate that the purified Neurospora WC-1-WC-2 protein complex is associated with stoichiometric amounts of the chromophore flavin-adenine dinucleotide. Together, these observations suggest that WC-1 is the blue-light photoreceptor for the circadian clock and other light responses in Neurospora.
蓝光调节真菌中的许多生理过程，但其光感受器尚不清楚。在粗糙脉孢菌中，所有光反应都依赖于含Per-Arnt-Sim（PAS）结构域的转录因子白领-1（wc-1）。通过去除WC-1的光、氧或电压结构域（一种在植物向光素中结合黄素单核苷酸的特殊PAS结构域），我们发现光反应被消除，包括昼夜节律钟的光诱导。然而，在该突变体中，WC-1介导的frq暗激活仍然正常，并且昼夜节律钟可以被温度诱导。此外，我们证明纯化的粗糙脉孢菌WC-1-WC-2蛋白复合物与化学计量的发色团黄素腺嘌呤二核苷酸相关。这些观察结果共同表明，WC-1是粗糙脉孢菌中昼夜节律钟和其他光反应的蓝光光感受器。
