Movement of yeast 1,3-beta-glucan synthase is essential for uniform cell wall synthesis.

BACKGROUND: The cell wall has an important role in maintaining cell shape. In the budding yeast Saccharomyces cerevisiae, the major filamentous component of the cell wall responsible for its rigidity is 1,3-beta-glucan and is synthesized by 1,3-beta-glucan synthase (GS), localized on the plasma membrane.
RESULTS: Observations of green fluorescent protein (GFP)-conjugated Fks1p, a catalytic subunit of GS, revealed that it is co-localized with cortical actin patches and moves on the cell surface at the sites of cell wall remodelling. Mutants with impaired actin patch movement show immobility of Fks1p-GFP spots, indicating that actin patch motility is required for the movement of Fks1p. Cells with immobilized Fks1p exhibit defective cell wall structure and function. The cell wall thickness of the mutants becomes irregular, eventually leading to cell lysis.
CONCLUSION: We propose that GS movement is necessary for proper cell wall remodelling.