Abstract
The yeast Saccharomyces cerevisiae is utilized in various fields and understanding and modification of the cell wall structure are required in some scenes. The cell wall is composed of mannoproteins, β-1,3-glucan, β-1,6-glucan and chitin, and β-1,6-glucan plays a critical role for the cell wall architecture. Though some proteins were known to be involved in the biosynthesis of the polymer, the biosynthesis mechanism is still unknown. As a result of screening for proteins involved in the biosynthesis, we found that Big1p and Rot1p were greatly related to β-1,6-glucan synthesis. In big1 and rot1 deletion mutants, β-1,6-glucan levels decreased to 5 % of wild type. Here the features of mutants with a defect in β-1,6-glucan synthesis were analyzed using big1 and rot1 deletion mutants obtained from Saccharomyces Genome Deletion Consortium. In these mutants, the alkali-insoluble β-1,3-glucan and chitin levels in the cell wall increased, and the cell surface structure greatly changed in comparison with the wild type from the observation with an electron microscope. Those mutants showed abnormal morphology and cell aggregation. We have analyzed mannoproteins in the outer layer of the cell wall and those results will be discussed.
