Fig. 2. srw1p is phosphorylated throughout the cell cycle. (A) Extracts were prepared from exponentially growing wild-type (wt) cells and srw1Δ cells, western blotted and probed with anti-srw1p antibody. The upper band is a non-specific cross-reacting protein. (B) cdc25-22 strain was blocked and released (B/R) as described in Figure 1. Samples were western blotted and probed with anti-srw1p and anti-cdc13p antibodies. An extract from G₁ arrested cdc10-129 cells was loaded as a control. (C) Extracts were prepared from exponentially growing wild-type cells (pre) and incubated with λ phosphatase in the absence (λPP) or presence (λPP + Inh) of phosphatase inhibitors.