Figure 1.

Cell cycle-regulated RPA2 phosphorylation is absent in mec1-1. (A) Western blot analysis of RPA2 from exponentially growing wild-type cells. Crude extract was treated with the indicated combinations of λ protein phosphatase (PP′ase) and the phosphatase inhibitor sodium vanadate. (B) Western blot analysis of RPA2 from synchronized TWY397 (MEC1) and DLY285 (mec1-1) cells. Samples from the exponentially growing cultures prior to α factor treatment (exp) and from the G₁-arrested cultures directly prior to release (α) have been included. Equivalent volumes of original cell culture were analyzed. (C) Flow cytometry of synchronized cultures analyzed in B.