A Glycosylphosphatidylinositol-Anchored α-Amylase Encoded by Contributes to a Decrease in the Molecular Mass of Cell Wall α-1,3-Glucan in .

α-1,3-Glucan is one of the main polysaccharides in the cell wall of . We previously revealed that it plays a role in hyphal aggregation in liquid culture, and that its molecular mass (MM) in an -overexpressing () strain was larger than that in an -overexpressing () strain. The mechanism that regulates its MM is poorly understood. Although the gene , which encodes glycosylphosphatidylinositol (GPI)-anchored α-amylase (AmyD), is involved in the biosynthesis of α-1,3-glucan in . , how it regulates this biosynthesis remains unclear. Here we constructed strains with disrupted (Δ) or overexpressed () in the genetic background of the ABPU1 (wild-type), , or strain, and characterized the chemical structure of α-1,3-glucans in the cell wall of each strain, focusing on their MM. The MM of α-1,3-glucan from the strain was smaller than that in the parental strain. In addition, the MM of α-1,3-glucan from the Δ strain was greater than that in the strain. These results suggest that AmyD is involved in decreasing the MM of α-1,3-glucan. We also found that the C-terminal GPI-anchoring region is important for these functions.