Couples activated G protein to adenylyl cyclase signal transduction from surface cAMP receptor. Pianissimo a cytosolic regulator and CRAC, are both essential for activation of the enzyme adenylyl cyclase. Pianissimo and CRAC do not function redundantly. Both proteins are integral components of the adenylyl cyclase activation pathway. Tightly developmentally regulated. dagA and piaA double mutants require both proteins for reconstitution and activation of adenylyl cyclase.