Structural Biochemistry of a Fungal LOV Domain Photoreceptor Reveals an Evolutionarily Conserved Pathway Integrating Light and Oxidative Stress
Structural Biochemistry of a Fungal LOV Domain Photoreceptor Reveals an Evolutionarily Conserved Pathway Integrating Light and Oxidative Stress
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DOI：
10.1016/j.str.2014.10.020
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发表时间：
2015-01-06
期刊：
影响因子：
5.7
通讯作者：
Zoltowski, Brian D.
中科院分区：
文献类型：
--
作者：
Lokhandwala, Jameela;Hopkins, Hilary C.;Zoltowski, Brian D.
真菌 LOV 蛋白通过蓝光调节二聚体形成促进光适应。尽管这些蛋白质在密切相关的真菌中具有相当大的同源性，但信号传导存在偏差。在这里，我们报告了 ENVOY (ENV1) 的晶体结构，ENV1 是里氏木霉中粗糙脉孢菌 VVD 的同源物，里氏木霉是植物细胞壁降解的模式生物。结构研究与可逆竞争二聚化模型相矛盾。相反，进化压力促进了关键的半胱氨酸残基（Cys96）位置的两个残基转变，从而能够整合环境压力和光反应。 Cys96Thr 变体在体内以碳源依赖性方式消除了对光和氧化应激的适应性反应。系统发育分析验证了 Sordariomycetes 内不同顺序的 Cys 残基转移的进化相关性。通过这种方式，我们确定了一种广泛的氧化应激信号传导机制，该机制将代谢传感和蓝光反应结合起来，而之前在 LOV 蛋白中未发现这种机制。
Fungal LOV proteins facilitate photoadaptation via blue light regulation of dimer formation. Despite considerable homology of these proteins in closely related fungi, deviations in signaling exist. Here we report the crystal structure of ENVOY (ENV1), a homolog of N. crassa VVD in the fungus T. reesei, a model organism for plant cell wall degradation. Structural studies contradict a model of reversible competitive dimerization. Rather, evolutionary pressures have facilitated a two-residue shift in the position of a key Cys residue (Cys96) that enables the integration of environmental stress and light responses. A Cys96Thr variant abolishes adaptive responses to light and oxidative stress in a carbon source-dependent manner in vivo. Phylogenetic analysis verifies an evolutionary relevance of the Cys residue shift in different orders within Sordariomycetes. In this manner, we identified a widespread oxidative stress signaling mechanism that couples metabolic sensing and blue light responses not previously identified in LOV proteins.