Karlsruhe Institute of Technology (KIT) - South Campus Institute for Applied Biosciences Dept. of Microbiology, Fritz-Haber-Weg 4, D-76131, Karlsruhe, Germany; Nanjing Agricultural University, Jiangsu Provincial Key Lab of Organic Solid Waste Utilization, College of Resources and Environmental Sciences, 210095, Nanjing, China.
Karlsruhe Institute of Technology (KIT) - South Campus Institute for Applied Biosciences Dept. of Microbiology, Fritz-Haber-Weg 4, D-76131, Karlsruhe, Germany.
Fungal Biol. 2020 May;124(5):447-457. doi: 10.1016/j.funbio.2019.12.009. Epub 2020 Jan 10.
A large proportion of fungal genomes are under the control of light. Most fungi employ complex light sensing systems, consisting of red-, blue-, and in some cases green-light photoreceptors. Here we studied the light response in Aspergillus nidulans. In a genetic screen, followed by whole-genome sequencing we identified a global regulator, which appears to be involved in chromatin structure modification. We therefore named the protein RlcA (regulator of light sensing and chromatin remodeling). The protein comprises a nuclear localization signal, a PHD (plant homeodomain) finger, a TFSII (found in the central region of the transcription elongation factor S-II), and a SPOC domain (Spen paralog and ortholog C-terminal domain). In the mutant, where light-controlled genes were constitutively active, the SPOC domain is missing. RlcA localized to the nucleus and interacted with the phytochrome FphA. The PHD-finger domain probably binds to trimethylated lysine 4 of histone H3, whereas the TFSII domain binds RNA polymerase II. The SPOC domain could mediate interaction with a global repressor protein. In the mutant, repressor recruitment would be hindered, whereas in the wild type repressor release would be induced after light stimulation. Our results add another layer of complexity to light sensing in filamentous fungi.
很大一部分真菌基因组受光的控制。大多数真菌采用复杂的光感系统，由红、蓝光，以及在某些情况下绿光光受体组成。在这里，我们研究了粗糙脉孢菌的光反应。在一个遗传筛选之后，我们通过全基因组测序鉴定了一个全局调控因子，它似乎参与了染色质结构修饰。因此，我们将该蛋白命名为 RlcA（光感应和染色质重塑的调节剂）。该蛋白包含一个核定位信号、一个 PHD（植物同源结构域）指、一个 TFSII（在转录延伸因子 S-II 的中心区域发现）和一个 SPOC 结构域（Spen 同源和异源 C 末端结构域）。在突变体中，光控基因持续激活，而 SPOC 结构域缺失。RlcA 定位于细胞核并与光敏色素 FphA 相互作用。PHD 指结构域可能与组蛋白 H3 的三甲基化赖氨酸 4 结合，而 TFSII 结构域与 RNA 聚合酶 II 结合。SPOC 结构域可能介导与全局抑制蛋白的相互作用。在突变体中，抑制蛋白的募集将受到阻碍，而在野生型中，光刺激后抑制蛋白的释放将被诱导。我们的结果为丝状真菌的光感应增加了另一层复杂性。
