Six Gs-stimulated adenylyl cyclases have been cloned. Two additional forms have been identified as partial cDNAs. These adenylyl cyclases have distinct functional properties and are differentially regulated by protein kinases. The adenylyl cyclases have distinct patterns of distribution in peripheral tissues and various brain regions. The unique functional characteristics of the members of this effector family may allow each cell type and/or brain region to customize the signal-recognition and integrative properties of its cAMP-generation system by varying the ratios of the various adenylyl cyclases.