FgEnd1 is a putative component of the endocytic machinery and mediates ferrichrome uptake in F. graminearum

The function of endocytic pathway in filamentous fungi has remained elusive. Recently, we have identified that FgEnd1, which has a 27% amino acid homology and shares specific EH3 domain with ScEnd3 of Saccharomyces cerevisiae, is a putative member of the endocytic machinery in Fusarium graminearum. The failure of the scend3 mutant to uptake Lucifer yellow (LY) was recovered by introducing FgEnd1 into S. cerevisiae. The deletion of fgend1 in F. graminearum resulted in a 2-fold decrease in the rate of uptake of the endocytic marker FM4-64 when compared to wild-type cells. The rate of uptake was similar to that seen in latrunculin A (Lat-A)-treated cells. Furthermore, fgend1 deletion strain of F. graminearum showed lower ferrichrome (FC) uptake activity than wild-type F. graminearum, and the same rate as LatA-treated cells. Taken together, these results suggest that FgEnd1 is a putative member of the endocytic machinery, although it acts through a different mechanism from ScEnd3 or ScEnd4 of S. cerevisiae.