Practice question

Biosynthesis of cAMP from ATP is catalyzed by adenylyl cyclases encoded by acaA, acrA, and acgA genes expressed at distinct stages. ACA, a twelve-transmembrane protein, dominates early aggregation, activated downstream of cAR1, heterotrimeric G proteins, and cytosolic regulator CRAC. It generates both intracellular second messenger for protein kinase A and extracellular signal for relay. Phosphatases remove phosphate groups, while lyases and esterases perform unrelated cleavages. Later ACA activity declines, replaced by ACB during culmination and ACG during spore dormancy, each regulated by developmental promoters and environmental cues like osmolarity and ligand binding.