Isolation of glucanase-containing particles from budding Saccharomyces cerevisiae

Area of Science:

• Cell Biology
• Biochemistry
• Mycology

Background:

• Yeast cell wall integrity is crucial for growth and division.
• Glucanases play a role in modifying the yeast cell wall, particularly during bud emergence.
• Intracellular glucanase activity is observed in exponentially growing yeast cells.

Purpose of the Study:

• To investigate the role of glucanases in yeast cell wall modification at new bud sites.
• To isolate and characterize subcellular particles involved in glucanase secretion.
• To determine the origin and composition of these particles.

Main Methods:

• Isolation of subcellular particles from budding yeast cells using differential and density gradient centrifugation.
• Analysis of particle composition, including glucanases, mannan, and protein.
• Comparison of isolated particles with in situ observed secretory vesicles.

Main Results:

• Specific intracellular glucanase-containing particles were isolated from budding yeast.
• These particles are enriched in exo- and endo-beta-1,3-glucanases, mannan, and protein.
• The isolated particles, primarily membrane-bounded, match the size of secretory vesicles and are absent in stationary phase cells.

Conclusions:

• The isolated particles are identified as vesicles derived from the endoplasmic reticulum.
• These vesicles are secreted locally into the cell wall of growing buds.
• The findings suggest these vesicles are involved in the secretion of glucanases for cell wall modification during yeast budding.