GPI-Anchor Protein Disruption Alters Fungal Cell Wall and Growth Morphology
Researchers found that disrupting glycosylphosphatidylinositol (GPI)-anchored protein biosynthesis in the fungus Aspergillus oryzae changes cell wall composition and shifts growth from dense pellets to dispersed filaments. GPI-anchored proteins are key structural components of fungal cell walls that influence how cells aggregate and adhere to each other. This discovery could improve industrial fermentation efficiency by allowing better nutrient and oxygen transfer in fungal cultures used for protein production.
Using Aspergillus oryzae as a model system, researchers demonstrated that disrupting GPI-anchored protein biosynthesis—either by deleting the mcd4 gene or chemically inhibiting the Gwt1 enzyme with the antifungal drug manogepix (MGX)—induces hyper-branching and weakens the cell wall. Solid-state NMR analysis revealed that these perturbations reorganize key cell wall polysaccharides, including complete loss of cationic galactosamine, which normally promotes hyphal adhesion. Transcriptomic profiling showed downregulation of genes involved in cell fusion, mechanistically linking altered wall composition to reduced cell aggregation. The chemical inhibition approach notably caused a transition from pelleted to dispersed mycelial growth, a potentially valuable outcome for industrial fermentation where dense pellets limit nutrient transfer and oxygen uptake. The findings also revealed species-specific responses to MGX treatment in other industrially relevant fungi, suggesting that cell wall dependencies vary across fungal species.
What's missing
The study does not discuss potential toxicity or off-target effects of manogepix treatment in industrial fermentation contexts, nor does it address scalability of the morphology engineering approach to large-scale bioreactor conditions.
What different sources said
- bioRxivCenter
Perturbing glycosylphosphatidylinositol (GPI)-anchor biosynthesis alters cell wall architecture and modulates fungal morphology
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