Figure 5.

The amount of Cdr2 protein is constant during the cell cycle but decreases in nitrogen-starved cells. (A) Strain JK2312 (h⁻ cdr2HA6H cdc25–22) in which the genomic copy of cdr2⁺ encodes an HA epitope-tagged form of Cdr2 at the carboxyl terminus, was grown in EMM medium to midlog phase, and cells were synchronized as described in Figure 4. Samples were taken every 20 min after the shift to permissive temperature, and whole-cell extracts were prepared. Immunoblotting was performed with anti-HA antibodies for Cdr2–HA protein and with anti-PSTAIRE antibodies for Cdc2 protein (control). (B) Strain JK2310 (h⁻ cdr2HA6H) was grown to midlog phase in EMM2 and then resuspended in EMM2-N. Samples were taken at intervals after nitrogen starvation.