Figure 7.

Sog2p is required for proper Ace2p localization, cell morphogenesis, and Cbk1p kinase activity. (A) Logarithmically growing sog2Δ (FLY1470) cells expressing Ace2-GFP were visualized by differential interference contrast microscopy (top) and fluorescence microscopy (bottom). Arrows point to Ace2-GFP in the nuclei of representative cells. (B) Top, immunoblot of Cbk1-Myc immunoprecipitated from mating pheromone-treated untagged cells (W303-1A), ace2Δ (FLY1268), mob2Δ (Y4035), and sog2Δ cells (FLY1492). The immunoblot was probed with anti-Myc antibody (9E10). Bottom, an autoradiograph of the corresponding histone H1 kinase assays. The relative kinase activity of immunoprecipitated Cbk1p from sog2Δ and mob2Δ cells was as low as immunoprecipitated kinase activity from untagged cells and was ∼10-fold less than from ace2Δ cells. Similar data was obtained from asynchronous cells (our unpublished data).