State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 10010, China.
Science & Education, The Field Museum, Chicago, IL, 60605, USA.
Sci Rep. 2017 Nov 27;7(1):16333. doi: 10.1038/s41598-017-16716-4.
The multiprotein-bridging factor 1 (MBF1) gene family is well known in archaea, non-lichenized fungi, plants, and animals, and contains stress tolerance-related genes. Here, we identified four unique mbf1 genes in the lichenized fungi Endocarpon spp. A phylogenetic analysis based on protein sequences showed the translated MBF1 proteins of the newly isolated mbf1 genes formed a monophyletic clade different from other lichen-forming fungi and Ascomycota groups in general, which may reflect the evolution of the biological functions of MBF1s. In contrast to the lack of function reported in yeast, we determined that lysine in the deduced Endocarpon pusillum MBF1 protein (EpMBF1) had a specific function that was triggered by environmental stress. Further, the Endocarpon-specific C-terminus of EpMBF1 was found to participate in stress tolerance. Epmbf1 was induced by a number of abiotic stresses in E. pusillum and transgenic yeast, and its stress-resistant ability was stronger than that of the yeast mbf1. These findings highlight the evolution and function of EpMBF1 and provide new insights into the co-evolution hypothesis of MBF1 and TATA-box-binding proteins.
多蛋白桥接因子 1（MBF1）基因家族在古菌、非地衣真菌、植物和动物中广为人知，并且包含与应激耐受相关的基因。在这里，我们在地衣真菌内生盘菌属中鉴定出了四个独特的 mbf1 基因。基于蛋白质序列的系统发育分析表明，新分离的 mbf1 基因的翻译 MBF1 蛋白形成了一个单系分支，与其他地衣真菌和一般子囊菌门群体不同，这可能反映了 MBF1s 生物功能的进化。与酵母中报道的缺乏功能形成对比的是，我们确定了内盘菌属短小 MBF1 蛋白（EpMBF1）中的赖氨酸具有特定的功能，该功能是由环境应激触发的。此外，EpMBF1 的内盘菌属特异性 C 端参与了应激耐受。Epmbf1 在内生盘菌属短小酵母中被多种非生物胁迫诱导，其抗胁迫能力强于酵母 mbf1。这些发现突出了 EpMBF1 的进化和功能，并为 MBF1 和 TATA 结合蛋白的共同进化假说提供了新的见解。
