Yeh Yu-Ling, Lin Yu-Sheng, Su Bei-Jia, Shen Wei-Chiang
Department of Plant Pathology and Microbiology, National Taiwan University, Room 216, Building Number 1, No. 1 Roosevelt Road, Sec. 4, 10617 Taipei, Taiwan.
Fungal Genet Biol. 2009 Jan;46(1):42-54. doi: 10.1016/j.fgb.2008.10.007. Epub 2008 Oct 25.
Blue light regulates diverse physiological and developmental processes in fungi. Our prior studies demonstrated that the evolutionally conserved Cwc1 and Cwc2 proteins mediate the blue light-inhibited sexual filamentation in Cryptococcus neoformans. To characterize the putative domains of the Cwc1 and Cwc2 proteins, we generated partially deleted versions of these genes under the GPD1 promoter and examined their effects. The results confirmed that LOV and PAS domains are essential for the function of the Cwc1 protein, and the PAS domain and zinc finger DNA-binding motif are also crucial for the Cwc2 protein. To further understand how light inhibits filamentous growth, a genome wide mutant screening was conducted to identify genes important for this process. Mutants which suppressed the light-dependent CWC1 overexpression phenotype and restored mating filamentation were identified. In the one with fully restored filamentation, the T-DNA was found to disrupt the expression of the CWC2 gene. Additionally, a mediator component, the SSN8 gene, known to involve in transcriptional regulation was also identified. Our results demonstrate that Cwc1 and Cwc2 are two central regulators of the C. neoformans photoresponses and the roles of other components identified in the screen are under investigation.
蓝光调节真菌中多种生理和发育过程。我们之前的研究表明，进化上保守的Cwc1和Cwc2蛋白介导新型隐球菌中蓝光抑制的有性丝状化。为了表征Cwc1和Cwc2蛋白的假定结构域，我们在GPD1启动子下生成了这些基因的部分缺失版本，并检测了它们的作用。结果证实，LOV和PAS结构域对Cwc1蛋白的功能至关重要，PAS结构域和锌指DNA结合基序对Cwc2蛋白也至关重要。为了进一步了解光如何抑制丝状生长，我们进行了全基因组突变体筛选，以鉴定对该过程重要的基因。鉴定出了抑制光依赖性CWC1过表达表型并恢复交配丝状化的突变体。在丝状化完全恢复的突变体中，发现T-DNA破坏了CWC2基因的表达。此外，还鉴定出了一个已知参与转录调控的中介体成分SSN8基因。我们的结果表明，Cwc1和Cwc2是新型隐球菌光反应的两个核心调节因子，筛选中鉴定出的其他成分的作用正在研究中。
