Figure 8.

cAMP stimulation of guanylyl cyclase activity in wild-type, rip3 null, aleA null, and rip3/aleA null strains. Cells were pulsed for 5 h with 30 nM cAMP and stimulated with cAMP, and measurements were taken for the quantitation of cGMP as described in MATERIALS AND METHODS. Unregulated activity of the enzyme was measured in the presence of 5 mM MnSO₄. Each strain was analyzed a minimum of three times in association with wild-type cells. The results of representative experiments are shown. The differences between rip3 and aleA null cells, wild-type cells and rip3/aleA null cells, and rip3 and aleA null strains are reproducible.