Modulation of a cell surface glycoprotein in yeast: acid phosphatase.

Upon inorganic phosphate starvation the cell wall glycoprotein acid phosphatase of yeast Saccharomyces cerevisiae is derepressed. Purified acid phosphatase isolated from early log phase cells differs in reactivity and stability from acid phosphatase from late log phase cells indicating that the two enzymes are structurally different. This demonstrates that the yeast cell has not only the capacity to regulate the amount of acid phosphatase but also the ability to vary (modulate) the structure of the secreted enzyme. Modulation of acid phosphatase may be a mechanism which is involved in morphogenetic and behavioral differentiation of the yeast cell.