FIGURE 4.

The effect of the Plc inhibitor (U73122) on the level of inositol phosphates in the wild type yeast cells released from α-factor block. Cells were labeled, synchronized in G₁ with α-factor, released into fresh medium containing 10 μm U73122, and harvested at the indicated times, and inositol phosphates were analyzed by HPLC as described under “Experimental Procedures.” Shown is the HPLC elution profile of inositol phosphates at time 0 (A) or 30 min after the release of the cells from α-factor block (B). Shown is the time course of changes in the level of InsP₃ (C), InsP₆ (D), InsP₇ (E), and InsP₈ (F) after the release of the cells from α-factor block. The results are means ± S.E. (error bars) for three different experiments. *, p < 0.05 (Student's t test) with respect to time 0.