Methods are described here to monitor changes in protein level and subcellular localization during the cell cycle progression in the budding yeastSaccharomyces cerevisiae. Cell synchronization is achieved by an α-factor-mediated block-and-release protocol. Cells are collected at different time points for the first two cell cycles upon release. Cellular DNA contents are analyzed by flow cytometry. Trichloroacetic acid protein precipitates are prepared for monitoring levels of cell cycle regulated proteins by Western blotting. The dynamic changes in protein subcellular localization patterns are examined by indirect immunofluorescence microscopy.
