Research Institute of Agriculture and Life Sciences and Department of Agricultural Biotechnology, Seoul National University, 08826, Seoul, Republic of Korea.
Therapeutic & Biotechnology Division, Center for Eco-friendly New Materials, Korea Research Institute of Chemical Technology, Daejeon, 34114, Republic of Korea.
Sci Rep. 2020 Mar 17;10(1):4898. doi: 10.1038/s41598-020-61885-4.
The CCAAT sequence is a ubiquitous cis-element of eukaryotic promoters, and genes containing CCAAT sequences have been shown to be activated by the CCAAT-binding transcription factor complex in several eukaryotic model organisms. In general, CCAAT-binding transcription factors form heterodimers or heterotrimeric complexes that bind to CCAAT sequences within the promoters of target genes and regulate various cellular processes. To date, except Hap complex, CCAAT-binding complex has been rarely reported in fungi. In this study, we characterized two CCAAT-binding transcription factors (Fct1 and Fct2) in the plant pathogenic fungus Fusarium graminearum. Previously, FCT1 and FCT2 were shown to be related to DNA damage response among eight CCAAT-binding transcription factors in F. graminearum. We demonstrate that the nuclear CCAAT-binding complex of F. graminearum has important functions in various fungal developmental processes, not just DNA damage response but virulence and mycotoxin production. Moreover, the results of biochemical and genetic analyses revealed that Fct1 and Fct2 may form a complex and play distinct roles among the eight CCAAT-binding transcription factors encoded by F. graminearum. To the best of our knowledge, the results of this study represent a substantial advancement in our understanding of the molecular mechanisms underlying the functions of CCAAT-binding factors in eukaryotes.
CCAAT 序列是真核启动子的普遍顺式元件，含有 CCAAT 序列的基因已被证明在几种真核模式生物中被 CCAAT 结合转录因子复合物激活。一般来说，CCAAT 结合转录因子形成异二聚体或异三聚体复合物，与靶基因启动子内的 CCAAT 序列结合，调节各种细胞过程。迄今为止，除 Hap 复合物外，CCAAT 结合复合物在真菌中很少被报道。在这项研究中，我们对植物病原真菌禾谷镰刀菌中的两个 CCAAT 结合转录因子（Fct1 和 Fct2）进行了表征。先前的研究表明，在禾谷镰刀菌的八个 CCAAT 结合转录因子中，FCT1 和 FCT2 与 DNA 损伤反应有关。我们证明了禾谷镰刀菌核 CCAAT 结合复合物在各种真菌发育过程中具有重要功能，不仅与 DNA 损伤反应有关，还与毒性和产毒有关。此外，生化和遗传分析的结果表明，Fct1 和 Fct2 可能形成一个复合物，并在禾谷镰刀菌编码的八个 CCAAT 结合转录因子中发挥不同的作用。据我们所知，这项研究的结果代表了我们对真核生物 CCAAT 结合因子功能的分子机制的理解的重大进展。
