Through the production of cAMP, activates cAMP-dependent protein kinases (PKAs), triggering terminal differential and the production of spores. ATP = 3',5'-cyclic AMP + diphosphate Binds 2 magnesium ions per subunit. Inhibited by high osmolarity. Inhibited by caffeine and 2',5'-dideoxyadenosine (DDA). Homodimer. Present at low levels in growing cells; accumulates to high levels throughout development (PubMed:10556070). Highly expressed during early culmination and in fruiting bodies, especially in the prestalk region. Cells cannot complete sporulation and have abnormally long, thin stalks, though able to aggregate and form normal slugs. Belongs to the adenylyl cyclase class-4/guanylyl cyclase family.