Filament Negative Regulator Suppresses Glycogen Phosphorylase Encoded That Impacts the Cell Wall-Associated Features in .

We have previously identified (orf19.7021) whose protein product was associated with Cdc4. The gene is a putative glycogen phosphorylase because its homolog participates in glycogen catabolism, which involves the synthesis of β-glucan of the fungal cell wall. We made a strain whose expression is repressed, and is constitutively expressed. We established a null mutant strain and used it to conduct the in vitro virulence assays that detect cell wall function. The in vitro virulence assay is centered on biofilm formation in which analytic procedures are implemented to evaluate cell surface hydrophobicity; competence, either in stress resistance, germ tube formation, or fibronection association; and the XTT-based adhesion and biofilm formation. We showed that the constitutively expressed partially suppresses filamentation when the expression is repressed. The Gph1 protein is reduced in the presence of Cdc4 in comparison with the absence of Cdc4. Compared with the wild-type strain, the Δ/Δ mutant displayed a reduction in the capability to form germ tubes and the cell surface hydrophobicity but an increase in binding with fibronectin. Compared with the wild-type strain, the Δ/Δ mutant showed a rise in adhesion, the initial stage of biofilm formation, but displayed a similar capacity to form a mature biofilm. There was no major impact on the Δ/Δ mutant regarding the conditions of cell wall damaging and TOR pathway-associated nutrient depletion. We conclude that , adversely regulated by the filament suppressor , contributes to cell wall function in .