Common in Fungal Extracellular Membrane (CFEM) domains are uniquely found in fungal extracellular membrane proteins which are important for pathogens. This study identified 13 StCFEM proteins in the genome of Setosphaeria turcica, the hemibiotrophic fungus that causes northern corn leaf blight. Sequence alignment and WebLogo analysis of their CFEM domains indicated that the amino acids were highly conserved and that, with the exception of StCFEM1, 2, 3, and 6, they contained eight cysteines. Phylogenic analysis suggested that these 13 proteins (StCFEM1–13) could be divided into 2 clades based on the presence of the trans-membrane domain. Six StCFEM proteins with a signal peptide and without a trans-membrane domain were considered as candidate effector proteins. The CFEM domain in the candidate effector proteins could form a helical-basket structure homologous to Csa2 in Candida albicans. Transcriptome analysis suggested that the 13 genes were expressed during fungal infection and a yeast secretion assay revealed that these candidate effectors were secreted proteins. It was also found that StCFEM3, 4, and 5 couldn't affect BAX/INF1-induced programmed cell death (PCD) in Nicotiana benthamiana and while StCFEM12 could suppress INF1-induced PCD, it showed no effect on BAX-induced PCD. This study found that there were 13 members of the S. turcica CFEM protein family and that StCFEM12 was a candidate effector. This study laid the foundation for illustrating the roles of CFEM proteins during the pathogenic processes of phytopathogens.

真菌细胞外膜 (CFEM) 结构域中的常见结构域在对病原体很重要的真菌细胞外膜蛋白中是独一无二的。这项研究在 Setosphaeria turcica的基因组中鉴定了 13 种 StCFEM 蛋白，这是一种导致北方玉米叶枯病的半生物营养真菌。CFEM 结构域的序列比对和 WebLogo 分析表明氨基酸高度保守，除 StCFEM1、2、3 和 6 外，它们包含八个半胱氨酸。系统发育分析表明，根据跨膜结构域的存在，这 13 种蛋白质 (StCFEM1-13) 可以分为 2 个进化枝。六个 StCFEM 蛋白，带有信号肽且不带反式-膜结构域被认为是候选效应蛋白。候选效应蛋白中的 CFEM 结构域可以形成与白色念珠菌中的Csa2 同源的螺旋篮结构。转录组分析表明，这 13 个基因在真菌感染期间表达，酵母分泌分析表明这些候选效应物是分泌蛋白。还发现 StCFEM3、4 和 5 不能影响本氏烟草中BAX/INF1 诱导的程序性细胞死亡 (PCD) ，虽然 StCFEM12 可以抑制 INF1 诱导的 PCD，但它对 BAX 诱导的 PCD 没有影响。本研究发现 S. turcica有 13 名成员CFEM 蛋白家族和 StCFEM12 是候选效应器。该研究为阐明 CFEM 蛋白在植物病原体致病过程中的作用奠定了基础。